RU2574165C2 - Systems of electric rechargeable metal-air batteries and methods - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: invention relates to the sphere of electrical engineering. Rechargeable metal-air cell of the battery includes metal (M) electrode (E) and air (A) electrode, as well as aqueous electrolyte separating M and A electrodes. In some embodiments M electrode contacts electrolyte directly without placement of a separator or porous membrane between A electrode and electrolyte. A unit of the battery cells comprises the first cell having the first ME, the first AE and electrolyte between them and the second cell having the second ME, the second AE and electrolyte between them At that the first ME of the first cell contacts the second AE of the second cell thus forming an air tunnel between them. The first ME may contact the second AE being pressed around the second AE thus forming centrode. Rechargeable metal-air cells of the battery may be electrically interconnected by centrodes connection. Subject matter of the invention includes also versions for energy storage.

EFFECT: attained stability of electric power in the mains and shift in power supply during periods of peak and non-peak loads.

23 cl, 23 dwg

Description

BACKGROUND OF THE INVENTION

[0001] With the combination of an aging electricity grid infrastructure and the integration of intermittent power generation due to large-scale renewable energy sources such as wind, solar energy and ocean waves, there is an increasing and critical need to develop efficient energy storage technologies to achieve sustainable power supply to the grid and to shift the supply of electricity during periods of peak and off-peak load. Utilities are looking for ways to facilitate the supply of clean energy to the grid, prevent power outages and regulate peak loads in a cost-effective way without adding additional generating capacity. Batteries are considered critical elements when expanding and introducing large-scale renewable energy sources, such as wind and solar power plants.

[0002] There are currently no battery systems that have achieved commercial success in this application, for several reasons. One reason is that the cost of existing battery systems is now too high. As a result, utilities mainly use gas turbines to cover peak loads if necessary. However, they are not so versatile or applicable compared to real energy storage devices such as batteries. The cyclic life of existing batteries is too small, which makes the real costs for the service life significantly higher compared to the initial cost. In addition, many batteries (such as sodium sulfur batteries) operate at elevated temperatures, contain hazardous chemicals, may contain flammable materials, or may be subject to uncontrolled reactions, such as those occurring in lithium-based batteries. In short, there is currently no commercial battery technology that offers oversized batteries with suitable performance and long life in terms of the number of charge-discharge cycles (cyclic resource) at a commercially acceptable cost and a useful life for utilities.

[0003] Thus, there is a need for improved battery systems. Additionally, there is a need for rechargeable battery configurations that will be commercially acceptable.

SUMMARY OF THE INVENTION

[0004] In order to overcome all these problems, in accordance with one aspect of the invention, a new design / chemistry of an electrically rechargeable metal-air system is provided. The design of the metal-air element includes a significant number of new and previously unexplored chemicals, materials, structural and design changes. These important changes and modifications will be described in more detail below. In some embodiments, the metal air element may be a zinc air element. An independent third-party test so far has determined that the proposed zinc-air cell can be charged and discharged more than 200 times without any evidence of deterioration of the air cathode, so a longer life is expected. Some (or all) of the modifications listed in this document can be combined to get the element working with a long cyclic resource, which can make this zinc-air system affordable and practical.

[0005] One aspect of the invention is directed to a rechargeable metal-air battery cell including a metal electrode; air electrode; an aqueous electrolyte between the metal electrode and the air electrode, the metal electrode being in direct contact with the electrolyte and no separator between the air electrode and the metal electrode is provided. In some further embodiments, no separator is provided between the air electrode and the electrolyte.

[0006] Another aspect of the invention is directed to a system of rechargeable metal-air battery cells, including a metal electrode; air electrode; and an aqueous electrolyte solution having a pH in the range of from about 3 to about 10, wherein the battery cell system is capable of at least 500 discharge and recharge cycles without physically degrading materials or substantially degrading the performance of the battery cell and system.

[0007] In accordance with another aspect of the invention, a battery cell assembly may be provided. The battery cell assembly may include a first cell including a metal electrode, an air electrode, and an electrolyte between them; and a second cell also having a metal electrode, an air electrode, and an electrolyte between them. These two elements are connected in such a way that the metal electrode of element No. 1 is in contact with the air electrode of element No. 2. This allows the formation of air space or a tunnel between the metal electrode of element No. 1 and the air electrode of element No. 2. In this configuration, the metal electrode and the air electrode are parallel to each other and are oriented horizontally. In some embodiments, the metal electrode and the air electrode can be aligned almost vertically.

[0008] An additional aspect of the present invention provides an energy storage system including: an electrolyte supply unit with a flow control part configured to distribute the electrolyte as necessary to an underlying metal-air battery element; and one or more elements of the metal-air battery, including at least one opening having an overflow section, the flow control part allowing the excess or excess electrolyte to be poured into each element if the electrolyte volumes increase significantly, or to fill individual elements with electrolyte, if the volumes of electrolyte in certain cells are reduced. In some embodiments, the flow control parts may be aligned vertically above the overflow site.

[0009] Another aspect of the invention may provide a method for storing energy. The method may include receiving electrolyte in an electrolyte supply tank; providing the possibility, if there is an overflow in the electrolyte supply tank, to drain a certain amount of electrolyte from the electrolyte supply tank into the underlying first element of the metal-air battery; and providing the possibility, if there is an overflow of the underlying element of the metal-air battery, to drain a certain amount of electrolyte from the underlying first element of the metal-air battery into the second element of the metal-air battery or collection tank. This cascade electrolyte transfusion effect ensures that the electrolyte levels in all cells are complete (to maintain good electrical contact) and approximately equal, and evens out the electrolyte volumes even when the electrolyte expands, contracts, or evaporates.

[0010] In accordance with other aspects of the invention, additional methods may be provided. The energy storage method may include providing one or more bipolar air electrodes with an air space between them (which may be referred to as “centrodes”), more specifically, with a metal electrode of the first element in contact with the air electrode of the second element, an air tunnel provided between the metal electrode and air electrode; and providing a first frame passing above said one or more centrodes and a second frame passing below said one or more centrodes, the first element including a space above the metal electrode and closed by the first frame for receiving electrolyte, and the second element includes a space under air electrolyte and closed by a second frame for receiving electrolyte. In some embodiments, a centrode may be provided, as described or illustrated elsewhere.

[0011] A utility-scale energy storage system provided in accordance with one aspect of the invention may include a plurality of vertically stacked metal-air elements including at least one frame, wherein one or more air tunnels are provided between the individual elements; an electrolyte flow control system configured to distribute electrolyte to one or more cells or stacks of cells; and an air flow assembly configured to provide air flow through said one or more air tunnels. In some embodiments, the electrolyte control system may be integrated into one or more frames.

[0012] Other objects and advantages of the invention will be further appreciated and understood when considered in conjunction with the following description and the attached drawings. Although the following description may contain specific details describing specific embodiments of the invention, this should not be construed as limiting the scope of the invention, but as giving an example of potential or preferred embodiments. For each aspect of the invention, multiple variations are possible in accordance with what is proposed herein, which are known to those of ordinary skill in the art. Within the scope of the invention, many changes and modifications can be made without departing from its essence.

Inclusion by reference

[0013] All publications, patents, and patent applications mentioned in this description are incorporated herein by reference to the same extent as if each individual publication, patent, or patent application were expressly and individually indicated to be incorporated by reference.

Brief Description of the Drawings

[0014] New features of the invention are set forth in detail in the attached claims. A better understanding of the features and advantages of this invention will be achieved by referring to the following detailed description, which sets forth explanatory embodiments in which the principles of the invention are used, and to the attached drawings, in which:

FIG. 1 shows rechargeable metal-air elements arranged in a horizontal orientation in accordance with an embodiment of the invention.

FIG. 2 shows an example of individual elements that can be stacked on top of each other.

FIG. 3 is an isometric sectional view of a unit cell in accordance with an embodiment of the invention.

FIG. 4A depicts a system for maintaining a substantially constant and uniform electrolyte level within a structure of horizontally located cells that may have a common electrolyte filling opening and a recirculation tank in accordance with an embodiment of the invention.

FIG. 4B shows an additional system for maintaining electrolyte levels within a plurality of cells, with side-by-side cells having common filling openings, and a separate reservoir or charging device for replacing spent electrolyte with a charged electrolyte (with metallic zinc or zinc suspension) in accordance with another embodiment implementation of the invention.

FIG. 5 depicts an example configuration of a stack (block) of battery.

FIG. 6 depicts an example of a centralized electrolyte control opening for an energy storage system that makes it possible to fill each cell and cascade to or pour into other cells in accordance with an embodiment of the invention.

FIG. 7 depicts an additional configuration view of a stack of batteries with metal electrode-air electrode connections vertically, as well as with horizontal redundancy to bypass a damaged element.

FIG. 8A shows an example of the use of a battery module in an insulated freight container and an HVAC machine with a separate stack of trays with an upper tank and a lower drain, which are part of an electrolyte recirculation system in accordance with an embodiment of the invention.

FIG. 8B shows separate cell trays at the bottom of the battery modules with tubes that are part of a recirculation system at the bottom of the container in accordance with an embodiment of the invention.

FIG. 8C shows a number of battery modules assembled in a battery system with recirculation tanks and inverters or other power control equipment.

FIG. 8D is a plan view of a battery system including a plurality of battery modules within a container.

FIG. 8E provides an example of an air flow assembly.

FIG. 8F provides an additional view of the airflow assembly.

FIG. 8G provides an alternative example of an air flow assembly.

FIG. 8H provides an example of a battery system inside a container.

FIG. 9A provides a bottom view of an element frame assembly or tray with electrical connections at the end of each row that are horizontally connected.

FIG. 9B is a view of an assembly of element frames or a tray and one or more centrodes.

FIG. 10 provides a top view of four elements in a horizontal assembly arranged to use a common fill and exit opening, which may be referred to as a “four”.

FIG. 11A is a plan view of an energy storage system with a common filling and overflow opening among elements in accordance with an embodiment of the invention.

FIG. 11B is a side view or sectional view of an energy storage system of FIG. 11A, located at an angle to remove or discharge gas using gravity, with an upstream water supply tank due to gravity.

FIG. 12 provides a three-electrode structure diagram for an electrically rechargeable metal-air element.

FIG. 13 depicts an example of cell voltage versus test time in accordance with an embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0038] Although preferred embodiments are shown and described herein, it will be apparent to those skilled in the art that such embodiments are provided by way of example only. Countless variations, changes, and replacements will come to mind for those skilled in the art without departing from the scope of the invention. It should be understood that in the practice of the invention, various alternatives to the embodiments described herein may be used.

[0039] The invention provides electrically rechargeable metal-air battery systems and methods. Various aspects of the invention described herein may be applied to any of the specific applications set forth below or to any other types of battery systems. The invention can be applied as an independent (autonomous) system or method, or as part of a network / utility system or system or method for storing renewable energy. It should be understood that various aspects of the invention can be understood individually, together or in combination with each other.

Metal air battery

[0040] Metal-air batteries potentially have very high energy density values at low cost. Metal-air battery systems use atmospheric oxygen as their cathode reagent, hence the word “air” in their name. Metal-air batteries are unique sources of energy in which one of the reagents - oxygen - is not stored inside the battery itself. Instead, gaseous oxygen, which makes up about 20 percent of the surrounding air, can be taken from an unlimited source of ambient air as needed and let into the cell where it is reduced by the catalytic surfaces inside the air electrode. Gaseous oxygen can be essentially an inexhaustible cathode reagent. Since gaseous oxygen should not be placed inside the element, the total weight, volume or size of the element can be relatively small, and the energy density values (capacitance values of the elements in ampere hours per given element weight) can be large. For example, the weight and volume values may be less than the weight values of battery cells of other designs, and energy densities may be higher than the energy densities of batteries of other designs. Another advantage is the small volume and weight, reduced due to air electrodes, which can lead to higher specific characteristics of the system (A · h / kg and A · h / l) in comparison with other electrochemical energy sources.

[0041] Metal-air battery systems can generate electricity by combining the oxidation reaction of a reactive metal electrode, which during the discharge of the cell can act as an anode, with an oxygen reduction reaction at a cathode containing suitable oxygen reduction catalysts. The generated free electrons from the zinc anode can move to the air electrode, acting as a cathode, through an external load.

[0042] However, a key disadvantage of metal-air type batteries may be that they were usually not electrically rechargeable for a large number of discharge and charge cycles. The discharge-charge cycle is defined here as one full electric discharge followed by a full electric charge. In some embodiments, a full electrical discharge can last about 6 hours, while a subsequent full charge can also last about 6 hours. This 12 hour full cycle of discharge and charge (with the possibility of a shorter charge and discharge to stabilize or regulate the operation of the network) can be typical and expected for a typical one full day of backup operation on the electric network. Electrical rechargeability may be necessary or highly desirable for any battery that they intend to use on the network. Traditional large-scale metal-air batteries either cannot completely recharge electrically, or they can only cycle in less than a few hundred discharge-charge cycles. Moreover, traditional large metal-air battery systems are not commercially available. In order to be practical for utility applications, an electrically rechargeable battery should preferably provide at least 3,500 to 10,000 high-performance discharge and charge cycles with good overall efficiency. This will correspond to approximately 10-30 years of service.

[0043] Inside a metal-air type battery, the conductive electrolyte connecting the metal electrode and the air electrode is usually a liquid solution (in some embodiments, water-based, aqueous) containing dissolved salts. Metal-air batteries can be considered to combine the desired properties of both fuel cells and batteries: metal (e.g. zinc) is fuel, reaction rates can be controlled by changing the air flow, and oxidized metal / electrolyte paste can be replaced with fresh metal or paste . A huge advantage of metal-air elements in terms of safety is the fact that they are inherently protected against short circuits. Since metal-air elements are limited by the amount of oxygen that they can continuously take and use from the surrounding air, they are ultimately limited by the amount of current that they can generate. When a short circuit occurs inside an element, unlike other chemical compositions of batteries, a metal-air element simply does not give unlimited current - the ability to give current has a maximum, an upper limit. This is an important safety consideration. Metal-air battery systems may include, but are not limited to, aluminum-air, magnesium-air, iron-air, lithium-air, sodium-air, titanium-air, beryllium-air, and zinc-air.

[0044] Zinc, in particular, has several advantages over other metals. However, any of the embodiments discussed elsewhere herein may also be applied to any type of metal-air battery system, which may or may not include zinc. Any references to zinc as an anode can also be used for any other metal, and vice versa. Any references to zinc-air batteries can also be used for any other metal-air batteries, and vice versa.

[0045] Zinc may be the preferred material since it is light in weight, non-toxic, inexpensive, readily available, and has high rates of electrochemical reactions for coating during an electrochemical charge. In this regard, zinc-air elements were used as primary (for emission) and rechargeable (reused) elements. Zinc-air cells can be charged either mechanically or electrically. In mechanically rechargeable (refuelable) cells, the spent zinc can be physically removed from the cell / battery and mechanically replaced with fresh zinc. Spent zinc can be separately recycled elsewhere back to zinc metal. Such mechanically rechargeable batteries may, in some embodiments, be used for the purpose of storing energy in the network.

[0046] In preferred embodiments, electrically rechargeable cells can be used. In more practical electrically rechargeable cells, electricity from an external source can be used to generate oxygen on the air electrode, while zinc metal can be electrochemically reprecipitated (deposited) back on the metal electrode to restore the original metal electrode. Both of these zinc-air systems typically use alkaline aqueous electrolytes based on the highly corrosive potassium hydroxide, KOH.

[0047] During the normal operation of the element during the discharge of the element, oxygen from the surrounding air can be reduced (receives electrons), while the reactive metal undergoes oxidation (loses electrons). In zinc-air cells containing an alkaline electrolyte, for example, the following simplified reactions can occur in a cell:

At the ^{anode: 2Zn + 4OH - → 2ZnO +} 2H ₂ O + 4e ^- E ₀ = 1.25 V

At the cathode: O ₂ + 2H ₂ O + 4e ^- → 4OH ^- E ₀ = 0.40 V

Total reaction: 2ZnO + O ₂ → ZnO E _(NRC) = 1.65 V

[0048] In some cases, the real reaction products at the anode are not just ZnO + H ₂ O, but rather Zn (OH) ₄ ^2- . The total reaction at the anode can therefore be written as follows:

2Zn + 8OH ^- → 2Zn (OH) ₄ ^2- + 4e ^-

[0049] The resulting zinc oxidation product, potassium zincate, may remain in solution.

[0050] Rechargeable zinc-air cells that use alkaline electrolytes can have a number of technical problems. The first problem is that when air enters the element, CO ₂ , carbon dioxide (usually present in ambient air) can also get inside and slowly react with an alkaline electrolyte to form various insoluble carbonates. These insoluble carbonates precipitate inside the pores of the air electrodes, as well as in the electrolyte. This formed precipitate reduces the electrolyte conductivity, and since the pores of the air electrode are blocked by insoluble material, the performance of the air electrode is significantly reduced. Although carbon dioxide absorption systems were used to remove CO ₂ from the incoming air, the added weight and complexity detract from the advantages of metal-air systems that use alkaline electrolyte.

[0051] In addition, since commonly used alkaline electrolytes suffer from their hygroscopicity (absorption of water from air) in humid environments, excess water can accumulate in these battery systems, causing the air electrode to flood with water. Since air (oxygen) cannot easily diffuse through water, less oxygen enters and is reduced at the air cathode. This can lead to a rapid loss of active properties by alkaline-based air cathodes.

[0052] Another problem with conventional alkaline-based zinc-air cells is that, although the ionic conductivity and energy characteristics of the cell improve with increasing OH ^- concentration, the solubility of the resulting zinc compounds also increases. This creates an element design dilemma. On the one hand, a higher pH is desirable for improved electrolyte conductivity and good cell capacity. The price for this is that a higher pH of the electrolyte can lead to greater solubility of the formed zinc exchange products, which leads to large changes in shape during the charge of the cell and, therefore, to a shorter service life. In other words, in a typical cell design, you can choose either a good cell capacity with a poor service life or a good service life with a poor cell capacity. The desired combination of both a good service life and a good cell capacity is currently not available in electrochemically rechargeable metal-air cells.

[0053] Another problem with typical alkaline electrolytes is that, during electrical charging, the deposited zinc tends to migrate and redistribute across the zinc electrode. After just a few charging cycles, zinc can precipitate with undesirable morphologies (for example, in the form of spongy, fleecy or fibrous / dendritic deposits). A dendritic deposit is a deposit that protrudes from a generally smooth surface of zinc. Unevenly deposited zinc particles can have greater electrical resistance and do not mechanically adhere well to each other. These zinc particles can easily break away from metal electrodes, forming isolated deposits of zinc. All of these factors contribute to reduced battery capacity and reduced power output in traditional zinc-air batteries after continuous discharge and charge cycles.

Battery electrolyte

[0054] In accordance with an aspect of the invention, a battery electrolyte can be selected that can improve the performance of a metal-air battery, such as a zinc-air battery. In some embodiments, the battery electrolyte may be a chloride-based aqueous electrolyte. In some embodiments, the battery electrolyte may have a pH of about 6. The electrolyte may have a pH of about 10 or less, or any other pH value mentioned here or less. In alternative embodiments, the electrolyte may have a pH in the ranges of 3-10, 4-9, 5-7, 5.5-6.5, or 5.75-6.25. In some embodiments, the electrolyte may have a pH of about 3, 4, 5, 5.25, 5.5, 5.75, 5.8, 5.9, 5.95, 6, 6.1, 6.2, 6 , 3, 6.5, 6.75, 7, 8, 9, or 10. In some embodiments, the electrolyte may be alkaline. The pH may be relatively pH neutral. In some embodiments, virtually no carbonates are formed due to the presence of CO ₂ in the air. The electrolyte may be non-dendritic with little or no CO ₂ uptake.

[0055] A battery provided in accordance with an embodiment of the invention may use a chloride-based aqueous electrolyte. Due to the low pH of the electrolyte, carbon dioxide is not absorbed from the air (or an extremely low level of carbon dioxide is absorbed), which means that insoluble carbonates are not formed either in the electrolyte or on the air electrode. In addition, since chloride-based aqueous electrolytes are generally accepted in galvanizing-related industries for the deposition of smooth and well-bonded zinc deposits, the efficiency of zinc deposition (during charging of the cell) should be significantly improved.

[0056] Preferred in accordance with an embodiment of the invention is a chloride-based electrolyte in a zinc air cell. The electrolyte may include a mixture of soluble chloride salts in an aqueous solution. Soluble chloride salts may have a cation suitable for preparing soluble chloride salts in an aqueous solution. Cations of suitable chloride salts may include zinc, ammonium, sodium, or any other cation that can produce soluble chloride salts in aqueous solution. The conductive electrolyte can be a mixture of soluble salts based on sulfates, nitrates, carbonates, hexafluorosilicates, tetrafluoroborates, methanesulfonates, permanganate, hexafluorophosphates, borates or phosphates, either separately or mixed together in an aqueous solution. If a mixture of chloride electrolytes is used, for example, this new zinc-air cell can be described as follows:

Zn / ZnCl ₂ , NH ₄ Cl, H ₂ O / O ₂ (Carbon)

Here, reading from left to right, zinc can be an anode. It can be separated from an electrolyte containing ZnCl ₂ and NH ₄ Cl and H ₂ O. The carbon-based air electrode is the place where O _{2 is} restored during the discharge and generated during the charge.

[0057] In some embodiments, KOH or other electrolytes can be used. Such a system may require the use or administration of the absorber (scrubber) CO _2, as an electrolyte based on potassium hydroxide absorbs CO _2. Any electrolyte known in the art can be used in combination with embodiments of the systems and methods described herein.

[0058] In some embodiments, oxygen evolution can be enhanced by charging the cell at low current densities. Such current densities can minimize or decrease the release of Cl ₂ . Examples of such current densities may include from about 1 mA / cm ² to about 100 mA / cm ² . Such current densities can be approximately lower, greater, or between any of the following current densities: approximately 1 mA / cm ² , 5 mA / cm ² , 10 mA / cm ² , 20 mA / cm ² , 30 mA / cm ² , 40 mA / cm ² , 50 mA / cm ² , 60 mA / cm ² , 70 mA / cm ² , 80 mA / cm ² , 90 mA / cm ² or 100 mA / cm ² . Oxygen evolution can also be enhanced by adjusting the pH of the electrolyte. Moreover, oxygen evolution can be enhanced by using an electrode or catalyst having a low oxygen evolution overvoltage.

[0059] In some embodiments, the metal electrode may be formed of zinc, may be deposited zinc, or may include zinc in any other form, such as an alloy. According to one embodiment of the invention, the electrolyte may include a mixture of about 15% zinc chloride (ZnCl ₂ ) and about 15% ammonium chloride (NH ₄ Cl ₂ ) in water in mass%. The electrolyte may alternatively include a mixture of about 15% zinc chloride and about 20% ammonium chloride in water in mass%. In some embodiments, the aqueous electrolyte may contain varying amounts of zinc chloride and ammonium chloride or other salts or chlorides, such as LiCl. For example, an electrolyte may contain about 10%, 12%, 13%, 14%, 14.5%, 15%, 15.5%, 16%, 17%, 18% or 20% zinc chloride or ammonium chloride. In some embodiments, approximately the same amount or similar amounts of zinc chloride and ammonium chloride may be provided. Other materials may be added to buffer electrolyte. They may include ammonium citrate or other compatible buffers, such as ammonium acetate, or ammonium hydroxide in 1-2 mass. % A porous carbon air electrode (cathode) containing catalysts based on Mn or Co can contribute to the oxygen reduction reaction.

[0060] During the discharge of an element, oxygen from the ambient air can enter the element through a porous air electrode and can undergo reduction at specially designated catalyst sites in or on the air electrode. The air electrode may be a carbon based electrode. At the same time, on a metal electrode (which may be zinc), zinc goes into solution in the form of soluble zinc ions. In the presence of a chloride-based electrolyte, zinc chloride may be partially soluble in an aqueous electrolyte. With continued discharge of the element and the creation of more zinc ions, the solubility limit of zinc chloride can be exceeded. This may cause precipitation of part of the zinc chloride. Methods for solving the problem of precipitation in accordance with an embodiment of the invention will be described in more detail below. In the process of charge of an element, an inverse electrochemical reaction occurs. Oxygen gas is generated on the air electrode, while zinc metal can be regenerated back on the zinc electrode (deposited on it).

[0061] Simplified discharge / charge processes in a chloride electrolyte, which can have a pH of about 6, can be described by the following reactions:

In the process of discharging an element

Cathode reaction: 2H ⁺ + ЅO ₂ + 2e ^- → H ₂ O

Reaction at the anode: Zn → Zn ²⁺ + 2e ^-

In the process of charging an element

Reaction at the cathode: H ₂ O + 2Cl ^- → 2HCl + ЅO ₂ + 2e ^-

Reaction at the anode: ZnCl ₂ ^{+ 2H + + 2e - → Zn} + 2HCl

Zinc compounds formed during the discharge of an element in an electrolyte based on ammonium chloride can be more accurately described as Zn (NH ₃ ) ₂ Cl ₂ .

[0062] At the air electrode, oxygen obtained from the ambient air may enter the cell through an air-permeable hydrophobic membrane. During charging of the cell, gaseous oxygen can be generated by electrolysis of water on an air electrode.

[0063] One of the effects of using aqueous chloride-based electrolytes in rechargeable zinc-air battery technologies is that an undesired side reaction with the release of chlorine may possibly occur during charging of the cell (at anode potentials):

(1) 2Cl ^- → Cl ₂ (g) + 2e ^- E ₀ = 1.36 V.

[0064] Chlorine generation may be an undesirable reaction in a given electrolyte system, as it may reduce the overall charge efficiency of the cell. For example, electrical energy can be used to generate chlorine instead of oxygen. Thus, it may be desirable for the battery system to be designed such that during charging of the cell, the anode potentials contribute to the evolution of oxygen and minimize the release of chlorine.

(2) 2H ₂ O → 4H ⁺ + O ₂ (g) + 4e ^- E ₀ = 1.23 V

[0065] Although the evolution of oxygen (reaction 2) with its lower oxidation potential is expected to occur predominantly because it is thermodynamically more advantageous than the evolution of chlorine (reaction 1), the evolution of chlorine is a much simpler chemical reaction and has a lower overvoltage . This means that in chloride environments, undesired chlorine evolution may actually become more likely than oxygen evolution.

[0066] The generated chlorine may dissolve in water to form hypochlorous acid, HClO. Hypochlorite ions can then decompose into chloride, several known oxidized chlorine compounds, or even free dissolved chlorine gas, depending on the conditions. Even though gaseous chlorine itself remains intact, this reaction may also be undesirable in our cell, since it reduces the overall charging efficiency.

[0067] There are a number of practical ways to minimize or reduce the unwanted release of chlorine (or hypochlorite) (or increase the efficiency of oxygen generation). Since oxygen evolution becomes more beneficial under conditions of low current density, one of the possibilities may be to reduce charge current densities to enhance oxygen evolution. In some embodiments, the desired charge current densities may be from about 10 mA / cm ² to about 200 mA / cm ² and may vary depending on the application up to the maximum charge or discharge current that the battery will withstand.

[0068] Another approach may be to control the pH of the electrolyte. At certain pH values, oxygen generation may become more beneficial than the evolution of chlorine. A higher pH favors the predominance of O ₂ over Cl ₂ . The pH of the electrolyte can be slightly increased and buffered by the addition of ammonium hydroxide, ammonium citrate. The release of chlorine becomes more advantageous at a pH of less than 2. While ammonium chloride acts as a pH buffer in this system, the addition of aqueous ammonium hydroxide will increase the pH of the electrolyte without negatively affecting the conductivity of the electrolyte or other working properties.

[0069] Another approach may be to use air electrodes or selected catalysts in the air electrode that have high chlorine evolution overvoltages and very low oxygen evolution overvoltages. Thus, in the process of charging an element, oxygen evolution becomes more advantageous. This can be achieved either by modifying the surfaces of the electrodes (which will be described in more detail below) or by adding materials such as MnO ₂ , which are well known as having low overvoltages of oxygen evolution. Similarly, the addition of various electrolyte salts has demonstrated a minimization of chlorine evolution. Examples of such salts or chemicals may include cobalt chloride, iridium oxide (IrO ₂ ), or soluble Mn salts. In addition, there are water-soluble additives, such as urea, which are known to react with chlorine (if formed) to produce non-toxic, easily vented gases.

[0070] However, it should be understood that the use of alkaline electrolyte can be used as part of the system disclosed herein if carbon dioxide is removed from the air. In this case, all the advantages of the element described here can still be realized.

Zinc-air element with a third electrode

[0071] An aspect of the invention may relate to a reversible or rechargeable battery, such as a zinc air cell, having a zinc electrode and a carbon based cathode for electrochemical reduction of gaseous oxygen. This type of cathode may also be known as an air cathode, since chemically reducing oxygen is usually obtained from ambient air.

[0072] In traditional limited electrically rechargeable metal-air cells, air electrodes are supposed to perform two opposite functions (hence the sometimes used name "bifunctional air electrode"). The first function is the reduction of oxygen (during the discharge of the element); the second function is the release of gaseous oxygen (in the process of charge of the element).

[0073] Since the bifunctional air electrode serves various purposes — reduction and oxidation — there are two main problems with these air electrodes. Firstly, there are only a few conductive materials that will not corrode quickly in aqueous electrolytes at such wide shifts of the applied electric potential. This makes the selection of the down conductor of the air electrode more difficult. Secondly, the generation of gaseous oxygen bubbles during the charge of the element can cause pressure and mechanical stresses in the porous carbon structure, which weakens this air electrode.

[0074] One possible approach is to not require the same porous air electrode to carry out both oxygen reduction and oxygen generation reactions. Instead, in some embodiments, a third or auxiliary electrode may be provided in place of the standard air electrode. The auxiliary electrode can exclusively charge the cell and the associated generation of oxygen. Thus, one air electrode can be designed solely to discharge the cell, while the second, auxiliary, air electrode is designed and used solely to charge the cell. This auxiliary electrode may either be located between the normally used air electrode and the metal electrode, or located on both sides of the metal electrode. Since the auxiliary electrode will usually be used only in the process of recharging the element and generating oxygen, it can be optimized for recharging (oxygen production), while the traditional air electrode will be optimized for discharge (oxygen reduction).

FIG. 12 depicts an example of this new electrode configuration. FIG. 12 provides a three-electrode circuit diagram of an electrically rechargeable zinc-air cell. Here, the traditional porous air electrode (SS) and solid zinc electrode (AA) are separated by a liquid electrolyte. Between the SS electrode and the AA electrode, a third auxiliary electrode (BB) can be located, which is used only in the process of charging the cell and is electrically isolated from the AA electrode. In some embodiments, the auxiliary electrode BB may be electrically isolated from the electrode AA either by an insulator or a gap.

[0076] The AA electrode may be a standard porous carbon air electrode or any other type of air electrode. The CC electrode may be a zinc metal electrode or any other metal electrode or anode, as described elsewhere herein. The third electrode (BB), which can be a metal sieve, foil, mesh or foam, or a pressed or sintered metal powder, is used only in the process of charging the cell.

[0077] During the discharge of the cell, the electrodes AA and CC are connected and electric currents are generated.

[0078] In the process of charging the cell, the electrodes BB and CC can be automatically connected using an electric switch, and electric currents from an external circuit can be supplied to these electrodes.

[0079] By using a structure with an auxiliary electrode, another (possibly cheaper and more efficient) charging electrode can be obtained. During the discharge of the cell, the electrodes CC and AA connected through an external circuit can produce electrical energy. Current can flow in the same direction as in traditional elements. Oxygen from ambient air can be electrochemically reduced by electrons generated at the zinc electrode.

[0080] Before charging the cell, this third electrode (BB) can be automatically electrically connected to the cell circuit, and electrode AA is disconnected from a metal electrode (CC), such as a zinc electrode. Now, in the process of charging, the electrodes BB and AA are electrically connected and used. Down conductors can be made having increased surface areas. These down conductors may be in the form of a mesh, porous plates, wires, sieves, foam, pressed or sintered powder, strips or other suitable open or large surface area structures. This may allow better contact with the electrolyte for the oxygen generation reaction. The porous nature of this electrode allows the electrolyte to pass through it, and also allows the generated oxygen gas to exit easily. Since gaseous O _{2 is} generated at this porous auxiliary electrode, carbon black will not become damaged.

[0081] This auxiliary, third electrode can also be designed containing special catalysts to enhance the release of O ₂ (catalysts with low overvoltage oxygen evolution). In addition, this third electrode can then be protected against reverse currents during the discharge process by using switching diodes, which allow the use of this electrode only in the process of charging the cell.

[0082] After the cell is fully charged, the third (charging) electrode may be disconnected from the cell circuit and a standard metal electrode and a conventional air electrode may be reconnected.

[0083] During the discharge, electrodes AA and CC can be connected.

[0084] During the charge, electrodes BB and CC can be connected.

[0085] Any switching or connecting / disconnecting mechanism known in the art can be used to provide the desired connections during the charge and discharge process. Such connections can be made in response to commands issued by the controller.

[0086] An air recharge electrode may be made:

1. Large compared to the air discharge electrode, to allow faster recharging at lower current densities;

2. Smaller than the air discharge electrode, so as to occupy less volume and not block the air electrode.

Metal hydrides as battery anode

[0087] In some embodiments of the invention, titanium hydride, TiH ₂ , may be a suitable metal electrode / anode material in a horizontal configuration battery.

[0088] Unlike other metal alloys of the AB-5 type for storing hydrogen, such as LaNi ₅ , Ti powder and its hydride can be cheaper and have higher energy densities. In addition, unlike other metal electrodes that dissolve, undergoing oxidation, TiH ₂ does not dissolve after its oxidation. TiH ₂ just becomes a solid, metallic Ti.

[0089] As an anode, during the discharge cycle of an element, TiH ₂ can release two protons and two electrons, forming a metallic Ti. During the charge process, two protons and two electrons can be returned to titanium (Ti) and TiH ₂ can again be formed. Discharge / charge reactions may be as follows:

Discharge: TiH ₂ => Ti + 2H ⁺ + 2e ^-

Charge: Ti + 2H ⁺ + 2e ^- => TiH ₂ .

[0090] Conventional metal hydrides deteriorate after numerous discharge / charge cycles due to induced stresses. This can lead to cracking and the formation of smaller metal powders and metal hydride. These smaller powders do not adhere well to each other, resulting in reduced electrical conductivity and poor cell performance. However, in conjunction with this proposed horizontal configuration of the cell, as provided hereinafter, where the metal electrodes are arranged horizontally, the action of gravity can help even finely dispersed Ti and TiH ₂ powder settle back onto the down conductor located below. Even if the metal electrodes are slightly inclined, the force of gravity should nevertheless cause the Ti and TiH ₂ powder to settle back onto the collector in a relatively even or uniform manner. TiH ₂ and Ti powders will remain in intimate contact, and this metal electrode can continue to undergo oxidation and reduction with good efficiency.

[0091] The Ti powder may also be modified by treatment using any of the various processing processes proposed herein to make Ti more electrically conductive.

[0092] Titanium hydride can operate as a standard battery or as a titanium hydride-air battery. Signs or discussion portions related to titanium hydride electrodes may also apply to zinc-air batteries or other metal-air batteries, and vice versa.

Horizontal configuration / element orientation

[0093] In accordance with another aspect of the invention, a metal-air battery system, such as a zinc-air battery system, may have a horizontal cell configuration. FIG. 1 depicts rechargeable zinc-air cells arranged in a horizontal orientation in accordance with an embodiment of the invention. The battery system may include a plastic frame 100a, 100b, an air electrode 102a, 102b, a metal electrode 104a, an electrolyte 106a, 106b, and an air flow tunnel 108a, 108b. In some embodiments, the air electrode 102a, 102b may include a hydrophobic membrane 110, carbon and catalyst 112, stretched titanium 114, and conductive carbon 116. The air electrode may function as a cathode during the discharge of the cell. The metal electrode functions as an anode during the discharge of the cell. In other words, the air electrode functions as a cathode during the discharge of the cell, and the metal electrode functions as the anode in the discharge of the cell. In the process of charging the cell, the porous carbon air electrode now functions as an anode, while the metal electrode now functions as a cathode. In some embodiments, a metal-air battery cell system may include a metal electrode, an air electrode, and an aqueous electrolyte solution. In some embodiments, the electrolyte may have a pH in the range of about 3 to 10.

[0094] In some examples, the plastic frame may be molded from noril, polypropylene (PP), polyphenylene oxide (PFD), polystyrene (PS), tightly packed polystyrene (PUPs), acrylonitrile butadiene styrene (ABS), polyethylene terephthalate (PET), polyester (PES), polyamides (PA), polyvinyl chloride (PVC), polyurethanes (PU), polycarbonate (PC), polyvinylidene chloride (PVDC), polyethylene (PE), polycarbonate / acrylonitrile butadiene styrene (PC / ABS) or from any other polymer or combinations thereof. In some embodiments, the plastic used to form the frame may be selected for its ability to withstand heat, i.e. up to the boiling point of the electrolyte. In some embodiments, the plastic used to form the frame may be injection molded. A plastic frame made of injection molded plastic, such as, but not limited to, noril, can be designed to hold both a solid zinc electrode (depicted at the bottom of the cell) and an air electrode. The zinc electrode at the bottom of the cell can be separated from the mesh down conductor of stretched metal titanium (embedded on the inside of the porous carbon air electrode) by a predetermined distance. This dividing space between the zinc electrode (metal electrode / anode) and the titanium wire collector (air electrode / cathode) fills the conductive aqueous solution of chloride electrolyte.

[0095] The frame 100a may surround the element. An air electrode 102a may be provided as the top layer of the cell. A metal electrode 104a may be provided as an intermediate part of the cell. An airflow tunnel 108b may be provided between the metal electrode 104a of the first element and the air electrode 102b of the second element. An electrolyte 106a may be provided within the cell. Electrolyte 106a may be contained in frame 100a and may be supported by a layer of metal electrode 104a. In alternative embodiments, the positions of the air electrode and the metal electrode may change, so that the metal electrode may be provided as the top layer, and the air electrode may be provided as the intermediate part.

[0096] In some embodiments, the air electrode may be a carbon oxygen cathode electrode or a polymer based oxygen electrode having an air-permeable hydrophobic catalytic membrane, a corrosion resistant metal collector, and oxygen evolution may be beneficial during electrical charging at anode potentials. Air electrodes may also include any materials known in the art.

[0097] In some embodiments, low-temperature gas-discharge plasma treatment can be applied to appreciably improve the adhesion of metals to various plastics. It has been shown that gas discharge plasma improves the adhesion of vapor deposited metals to various polymer surfaces. By treating the polymer surfaces with various gas-discharge plasmas before applying structural adhesives, a stronger, more durable joint can be formed. Examples of desired gas discharge plasmas may include O ₂ , mixtures of CF ₄ / O ₂ or N ₂ . Such processing is expected to improve the adhesion of the plastic frame to the metal electrode. In single-element or multi-element structures, there may be a number of locations within the stacks of elements where the plastic surface is adhesively bonded to the metal surface with structural adhesives. This longer sealing may result in longer component life.

[0098] There are a number of particular advantages in having a horizontal orientation of the electrodes. Firstly, the horizontal configuration can quickly and inexpensively assemble items from injection molded plastic containers or frames. Another advantage is that there is no need for a porous battery separator. On most batteries, separation membranes are often expensive, and piercing this membrane is also the main type of battery failure. By eliminating the need for a porous battery separator, cells can become more inexpensive and reliable in production and operation. In some embodiments, the electrolyte within a particular cell may directly contact a metal electrode of the same cell. In some embodiments, the electrolyte may or may not be in direct contact with the cell’s air electrode. There is no need to provide a separation layer between the electrolyte and the metal electrode. In some embodiments, a separation or separation layer may be absent between the electrolyte and the metal electrode and / or the air electrode. For example, a rechargeable metal-air battery cell may be provided that has a metal electrode, an air electrode and an aqueous electrolyte between the metal electrode and the air electrode, the air electrode being in direct contact with the electrolyte, and no separator is provided between the air electrode and the electrolyte.

[0099] The exclusion of the separation membrane is a key factor in reducing battery costs to acceptable levels and helping to extend the battery’s cycle life so that it becomes suitable for utility use. When the elements are oriented so that the metal electrode is in the lower part, the force of gravity prevents the electrode from the deposited metal in contact (and create a short circuit) with the air electrode located above. In some embodiments, the metal electrode may be an anode of zinc metal, and gravity may prevent deposited zinc from contacting an upstream air electrode. This contributes to the creation of an extremely reliable battery, since there is no malfunctioning membrane, and the cell is based on gravity as a guarantee of normal operation. A rechargeable metal-air battery system can be capable of a large number of discharge / recharge cycles without physically degrading materials or significantly degrading the performance of the battery cell system. In some embodiments, the system may be capable of about 100 or more, 200 or more, 300 or more, 350 or more, 400 or more, 450 or more, 500 or more, 700 or more, 1000 or more, 1500 or more, 2,000 or more, 3,000 or more, 5,000 or more, 10,000 or more, or 20,000 or more discharge / recharge cycles without significant degradation.

[00100] During the operation of the cell, the products of the discharge reaction may mainly be zinc chloride. When the solubility of zinc chloride exceeds its solubility limits (and since it is formed in chloride-based electrolytes, the presence of chloride ions will, due to the effect of the common ion, quickly exceed the solubility limits of zinc chloride), it precipitates. The horizontal configuration, together with the support of gravity, should help the precipitated particles of zinc chloride to settle back on the horizontally lower metallic zinc electrode. Since zinc chloride particles are deposited on / near the zinc electrode, zinc ions will undergo significantly less migration. This means that during the charge of the element, when zinc is deposited back onto the metal electrode, zinc losses to other places in the element can be less. This leads to significantly improved zinc cycling efficiencies and improved cell capacity. The exclusion of a membrane separator in rechargeable cells also means that the loss of internal resistance inside the cells can be minimized or reduced. This leads to higher working potentials and lower energy losses for heat generation.

[00101] The horizontal geometry may also allow a reproducible fixed distance to be established between the zinc electrode (anode) and the collector of the air electrode. This helps regulate electrolyte resistance more reproducibly. In some embodiments, the battery cell may have a frame that holds the metal electrode and the air electrode at a fixed distance from each other. A fixed distance may define a space in which liquid electrolyte may be contained. Secondly, with horizontal geometries, where each individual air-consuming electrode is facing up, numerous nodes of zinc-air elements can be stacked on top of each other. This will not only increase energy densities (since the cells can now be tightly packed with each other), but also allows you to construct a battery system with horizontal gas manifolds, where air can be pumped through the battery housings between the individual cells to circulate air / oxygen over each individual air electrode.

FIG. 2 shows an example of individual elements that can be stacked on top of each other. The cell may include a plastic frame 200a, 200b, an air electrode 202a, 202b, a metal electrode 204a, 204b, and an electrolyte 206a, 206b. The electrolyte may be contained in a plastic frame and may be supported by a metal electrode. In some embodiments, an air electrode may be provided above the electrolyte. The electrolyte may be located between the metal electrode and the air electrode. Between the elements, one or more air flow tunnels 208a, 208b may be provided. An air flow tunnel 208b may be provided between the metal electrode 204a and the air electrode 202b.

[00103] Thus, two separate elements can be separated from each other by a horizontal air passage or tunnel (not shown to scale). This horizontal configuration of the cell can allow air / oxygen to be pumped and circulated between the cells to separate air electrodes. The flow of air / oxygen to the air electrodes can also allow cells to maintain their oxygen supply even at higher current densities and additionally provide cooling of the cells. There is no need for continuous air circulation, and air flow can be adjusted using feedback mechanisms. In some embodiments, air may flow in the same direction in each of the air flow tunnels. Alternatively, air inside various air flow tunnels can flow in different directions.

[00104] In one example, a fan (which may include axial fans, centrifugal fans, cross-flow fans), a pump, or any other mechanism to create an air stream may be used. One or more actuators may be part of an air flow generating mechanism or may be in communication with an air flow generating mechanism. Examples of actuators may include, but are not limited to, motors, solenoids, linear actuators, pneumatic actuators, hydraulic actuators, electric actuators, piezoelectric actuators or magnets. Actuators can cause air to move depending on the signal received from the controller. Actuators may or may not have been connected to a power source. One or more sensors may be provided in the structure of the element. In some embodiments, the sensors may be temperature sensors, voltage sensors, current sensors, or pH sensors. These sensors can communicate with the controller. Based on the signals received from the sensors, the controller can send signals to the mechanisms for creating air flow, which can change and / or maintain the air flow between the elements.

[00105] As mentioned previously, there are a number of advantages to the horizontal geometry of metal-air elements.

A. Horizontal geometry may allow for fixed / adjustable electrolyte resistance, which may require less control of the cells.

B. Horizontal geometry can also provide ease of physical assembly and stacking of multiple elements.

C. A battery separator may not be necessary since gravity can separate materials with different densities.

D. The precipitated discharge product may be assisted by gravity, as mentioned earlier, deposited in the form of an even or practically even layer on a metal electrode.

E. The horizontal design can help cool the cells and can also provide increased oxygen delivery, which can make higher currents possible.

F. Gravity may also contribute to the flow of electrolyte, as will be described later.

G. Compression can hold elements in place.

[00106] The horizontal design of the battery should not be limited to a metal-air battery, such as a zinc-air battery. The horizontal battery design can also be used in other battery systems where a solid or poorly soluble discharge product is formed. These may include, but are not limited to, lead-acid ("flooded" and valve-regulated lead-acid (VRLA) batteries, nickel-cadmium (NiCd) batteries, nickel-metal hydride batteries, lithium-ion batteries, lithium -ionic polymer batteries or batteries with salt melts.

Centrode design for interconnecting elements

[00107] In accordance with an aspect of the invention, systems and methods can be provided for inexpensive, scalable connections between multiple elements.

[00108] Mutual connection of a number of individual metal-air elements with a series electrical connection while maintaining the horizontal geometric configuration of one or more elements (or each element) can be easily implemented using what can be called a "centrode". A “centrode” can be created by taking the air electrode of one element and squeezing it along two sides with a separate metal part, which can be electrically connected to the metal electrode or itself can be a metal electrode in the element located above it. The space between the metal electrode (now located above) and the air electrode (now located below) can be separated by a thin air channel 208a, 208b, which allows air to flow over these air electrodes. This is depicted in FIG. 2. The resulting centrode subassembly resembles a section of a hat when viewed along the air path 108a, 108b (front to back), as shown in FIG. 1. The metal electrode and the air electrode can be aligned (aligned) almost vertically and horizontally oriented.

FIG. 1 illustrates how a metal electrode 104a of a first element can be crimped around an air electrode 102b of a second element, thereby sequentially connecting the first and second elements. The metal electrode of the first element and the air electrode of the second element can be electrically connected in any other way. For example, either a metal electrode or an air electrode can be crimped onto each other, brazed to each other, welded to each other, crimped onto each other, fastened with conductive adhesive, brazed to each other with soft solder or otherwise fixed.

[00110] In some embodiments, the air electrode and the metal electrode may be separated by a fixed distance, the air electrode may be located above the metal electrode. The fixed distance may be the same in area of the air electrode and the metal electrode. Alternatively, the fixed distance may be variable over the area of the air electrode and the metal electrode. In some embodiments, the fixed distance may be in the range, which may include about 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 1 cm, 1.5 cm, 2 cm, 3 cm or more. The fixed distance between the air electrode and the metal electrode can determine the space in which the electrolyte can be contained or provided. The air electrode and the metal electrode may be part of the same metal-air element.

[00111] Any number of elements can be assembled, stacked and connected to achieve any desired total voltage. Each plastic frame can be a common part designed to fit the shape and sealing requirements of individual centrodes. Each centrode may have unique upper and lower parts molded in plastic. Molded in plastic parts may be the same from element to element, or may vary. Molded parts can help stack the elements and support the centrodes inside the elements. The automated process assembles the elements in a modular fashion, essentially placing multiple centrodes between two corresponding plastic element frames. This process can be repeated continuously.

FIG. 3 is an isometric sectional view of a single element in accordance with an embodiment of the invention. The element may have a frame 300, a metal electrode 302, and an air electrode 304. The element may have a desired shape or size. For example, the element may have a rectangular shape, a square shape, a circular shape, a triangular shape, a trapezoidal shape, a pentagonal shape, a hexagonal shape, or an octagonal shape. The frame can be made of appropriate shape in order to surround the element.

[00113] In some embodiments, the frame 300 may have a vertical portion 312. The frame may also have a horizontal shelf 306 that may protrude inside the element. The shelf may protrude from the vertical part anywhere along the vertical part. In some embodiments, the shelf may protrude below or near the bottom of the vertical part, above or near the top of the vertical part, or in the center or near the center of the vertical part. A vertical portion and / or horizontal shelf may be provided along the entire perimeter of the element, or may be provided along one, two, three, four or more sides of the element. In some embodiments, one or more parts of the element may or may not include part of the frame (for example, the vertical part and / or shelf of the frame). In some embodiments, the cross section of the shelf may be made rectangular, trapezoidal, square, some other quadrangular, triangular, or may have a different shape. In some embodiments, the top surface of the shelf may be tilted. In some embodiments, the top surface of the shelf may be tilted down toward the center of the element, or may be tilted down toward the perimeter of the element. Alternatively, the top surface may be flat with a horizontal orientation.

[00114] In some embodiments, the metal electrode 302 may be provided below the shelf 306. In some embodiments, the metal electrode may have a horizontal orientation. The metal electrode may contact the underside of the shelf. In some embodiments, the metal electrode may be shaped to contact one or more vertical sides 312 of the frame. Alternatively, the metal electrode may be shaped so that it is in close proximity to the vertical side, but not in contact with the vertical side. The metal electrode may be parallel or substantially parallel to the vertical side in this portion.

[00115] In some embodiments, the frame may have a lower part 314 provided on the lower part of the element. In some embodiments, the lower part may be a dent, groove, channel, slot, or hole, which may be provided at the bottom or near the bottom of the frame. The metal electrode can be made in such a way as to go inside the lower part. The portion of the metal electrode that extends into the bottom of the part may be parallel or substantially parallel to the surface of the metal electrode overlapping the cell (i.e., extending over the entire span of the cell). The part of the metal electrode that extends into the bottom of the part can be perpendicular or almost perpendicular to the part of the metal electrode in contact with the vertical side or in close proximity to the vertical side.

[00116] In some embodiments, the air electrode 304 may overlap an element (ie, extend over the entire span of such a cell). The air electrode may have a substantially flat configuration. In some embodiments, the air electrode may be in contact with the bottom member 314 of the cell. In some embodiments, the air electrode may extend into the bottom of the cell. In some embodiments, a portion of the metal electrode 302 may electrically contact an air electrode within the bottom of the cell. For example, a portion of the metal electrode may be crimped around the air electrode inside the lower part of the element. In preferred embodiments, a gap may be provided between the element covering part of the air electrode and the element covering part of the metal electrode. Air can be provided in this gap. In some embodiments, air may flow into this gap.

[00117] In some embodiments, an upper part may be provided on the upper part of the element. In some embodiments, the upper part may be a dent, groove, channel, target, or hole, which may be provided at the top or near the top of the frame. In some embodiments, the upper part may be a mirror image of the lower part. In some embodiments, the top piece can hold a metal electrode and / or an air electrode above the cell. In some embodiments, between the lower part of the first element and the upper part of the second element, electrical contact may be located between the metal electrode and the air electrode. In other embodiments, there is no need to provide a top piece. In addition, a plastic element (i.e., a plastic cell) may be molded (a) under pressure around a centrode or other electrical connections.

[00118] Other configurations of frame parts, metal electrodes, and air electrodes may be provided. For example, a metal electrode may be provided over the shelf. An air electrode may be provided over the cell. The positions of metal electrodes and air electrodes can be changed.

[00119] In some embodiments, the frame may include further molded parts, such as threshold 308. The frame may also include an inclined portion 310. In some embodiments, the threshold may hold electrolyte. In some embodiments, some electrolyte may be deflated by the inclined portion 310 into the cell. The electrolyte may be contained in the vertical portion 312 of the cell and may be supported by a portion of the metal electrode 302 that overlaps the cell. In some embodiments, the threshold may allow a portion of the electrolyte to flow through a portion of the frame threshold and leak out below the frame threshold portion. This can prevent or reduce electrolyte transfusion from the cell. In some embodiments, the electrolyte may be provided from within the cell, or may be provided from a source above the cell, or may be captured, held, or supplied to a paddle or expansion chamber, pushed upward or diagonally upward over the cell, so that gravity pushes the electrolyte back down when the element has a place.

[00120] An additional advantage of the horizontal configuration is that the cells can be designed so that electrolyte control becomes significantly easier. According to an embodiment of the invention, an electrolyte control system based on gravity may be provided. As the zinc-air batteries discharge, the useful capacity of the zinc-electrolyte system may increase. If no response is taken, pressure may increase as the electrolyte expands and liquid electrolyte can penetrate the underside of the air electrode. This can cause flooding of the air electrode, and a pressure drop due to the expanding electrolyte can cause damage to the fragile air electrode. In small, sealed batteries, additional space must be left for expansion of the electrolyte liquid. However, this additional volume can reduce the overall energy density and can create problems in a system where many cells are consistent and all cells must maintain the correct electrolyte level. This prevents the supply of new electrolyte to the system or the electrolyte testing.

[00121] In accordance with an aspect of the invention, this problem can be solved by four horizontally aligned adjacent elements, where all four elements are angled at one point. This four-element assembly can be called a “four”. At the point where all four elements converge, the elements may have a common filling or overflow or recirculation opening. Each element can be designed with access to a small opening. Each opening may have a small overflow threshold L, which may be slightly inclined above the lower surface of each air electrode.

[00122] FIG. 5 depicts an example of a four of four elements, and FIG. 4A shows a stack of cells in cross section within an electrolyte control system based on gravity. The gravity-based electrolyte control system may include a gas discharge channel A from the tank or tank B, which may be in fluid communication with another tank or other tank C. In some embodiments, valves may be provided on the tank either inlet or outlet openings D, E. In some embodiments, additional reservoirs or reservoirs F may be in fluid communication with the main reservoir or main reservoir C. Any distribution of reservoirs may be provided. Do tanks. They may or may not include filters that may trap unwanted particles. In some embodiments, the tanks may also provide the ability to provide any desired additives. Since the electrolyte can circulate inside the electrolyte control system, it can be replenished if necessary. In some embodiments, the electrolyte can be monitored during its circulation inside the system, and if necessary, modifications to the electrolyte can be made.

[00123] The fluid passage G may supply electrolyte to the battery system. The fluid return passage V may return electrolyte to the battery system. The fluid passage may include a tube, pipe, conduit, or any other assembly that can transport the fluid. The electrolyte may be supplied to the upper electrolyte tank H. One or more drains or an opening J may be provided. When the electrolyte overflows the K tank, it can drain down to the underlying cell and can be delayed by the overflow threshold L.

[00124] An overflow threshold L can guarantee a constant level of liquid electrolyte that is always in contact with all points of the surface of the lower side of the air electrode T. Electrolyte P can be provided inside the cell. During the discharge of the cell during expansion of the electrolyte, this threshold may allow the excess electrolyte to merge. All this can be realized without exerting any hydrostatic pressure on the air electrode. In other words, these unique openings can make it possible to expand the electrolyte and release gases while maintaining proper (and automatically adjustable) electrolyte levels. This balancing of the electrolyte level can also help to maintain uniform electrical characteristics. These openings (located in the common center of each “four” of four adjacent elements) can line up vertically with other openings below, creating a sequence of vertically oriented prefabricated nozzles that can distribute any overflowing electrolyte from all parts of the stacked elements inside a small drain pallet U at the bottom of the stack of items. These openings may include the prismatic part M, which can break the electrolyte into tiny drops of N.

[00125] Elements may include an air electrode T and a metal electrode R, which may be connected at one or more connection points S. An air tunnel O may be provided between the air electrode and the metal electrode. In some embodiments, the air electrode and the metal electrode may form centrode. Frame Q may be for an element, four, or groups of elements or fours. Frames can be stacked inside the battery system.

[00126] One or more valves or openings I may be provided inside the upper electrolyte tank H or the drain pan U. The opening may allow additives to be introduced into the electrolyte and / or to drain a certain amount of electrolyte. Another opening may provide the possibility of exhaust gases. In some embodiments, the openings may provide access for taking measurements. The openings may have other purposes.

[00127] In the process of charging the cell, while reducing the volume of electrolyte in each cell, these same filling openings can be used to add liquid electrolyte back to each cell of the "four". To fill the upper "four" in the process of charging the element can be run drain pump. The electrolyte overflowing this very top four enters the sewer and simply fills the horizontal “four” below it. Automatic filling of the fours with electrolyte can occur quickly until all fours in the vertical stack are refilled (or filled to the top) with electrolyte. These fill / overflow openings may be designed to serve a different function. A prismatic protrusion (M), located under each overflow threshold (4-L), can help break any liquid electrolyte into small droplets (N) before they drop to the four. This has the effect of interrupting any conductive circuit that might otherwise be created by a continuous flow of conductive fluid between the individual elements. An uninterrupted flow of conductive electrolyte could cause a serious electrical short circuit at high voltage, created by numerous cells stacked one on top of the other.

[00128] In vertically oriented elements that use traditional configurations such as plates and frames, fluid bridges between the elements can be a source of energy loss and other structural problems. The horizontal configuration provided in accordance with embodiments of the invention with the filling / overflow opening described can minimize or reduce these problems with an easily assembled, injection molded plastic part.

[00129] The ease of assembly, modularity, and scalability of this design are also immediately apparent compared to the difficulties associated with assembling traditional batteries (see FIG. 5).

FIG. 4B depicts an additional system for maintaining a constant electrolyte level within a plurality of stacked cells in accordance with another embodiment of the invention. The battery electrolyte control system with overflow by gravity may include two separate systems. The first system may include a transfusion station with an electrolyte recharge device. The second system may include a metal-air battery with overflow by gravity, such as a zinc-air battery with overflow by gravity.

[00131] According to an embodiment of the invention, an electrolyte charging device and a transfusion pump may be provided. The charging device can be electrically connected to a charging plug, which, in turn, can be connected to a power source, such as a mains / utility network. A rectifier may be provided to convert AC power from the power source to DC to charge the battery. A transfusion system with an electrolyte charging device can be used for existing gas stations (fuel), domestic and navy applications. It can be embedded in pre-existing structures. The transfusion pump may include one or more electrolyte-conducting parts A, B, which may be a tube, pipe, conduit or other fluid passage for transferring the aqueous electrolyte. The first electrolyte conductive part may be an electrolyte supply A. The second electrolyte conductive member may be an electrolyte outlet B. The electrolyte can pass from the electrolyte charging device and the transfusion pump in the electrolyte supply and can pass to the electrolyte charging device and the transfusion pump in the electrolyte drain. In some embodiments, a pump, valve, differential pressure, or some other mechanism may be used to cause the electrolyte to flow. In some embodiments, a valve, switch, or locking mechanism may be provided that can stop and / or start electrolyte flow.

[00132] A gravity-supported metal-air battery may include a recharged electrolyte supply pipe A, used electrolyte return pipe B, control valve C, electronic controller D, pump E, an electrolyte storage tank supply line F, a supply line G to the upper collectors, the upper valves H1, H2 for regulating the supply, the upper regulators I1, I2 for the electrolyte flow, the openings J-1, J-2, J-3, the storage tank K and the electrolyte return line L from the storage tank. In some embodiments, in a flow design assisted by gravity, gravity can push the electrolyte through the cells without the need for a pump to push the electrolyte through the cells. In an electrolyte transfusion-flow design by gravity, a spreading agent is not required.

[00133] The electrolyte supply pipe A may provide an electrolyte to a metal-air battery with flow by gravity. The control valve C can determine when the electrolyte should be supplied to the metal-air battery and how much electrolyte / at what flow rate the battery needs to be provided. The control valve can be controlled by an electronic controller D, which can issue commands to the control valve. These commands can determine how much electrolyte flow is allowed by the control valve. Commands can be issued by the controller automatically. The controller may or may not have an external processor that can issue commands to the controller. In some embodiments, the controller may have a user interface, or may communicate with an external device, which may have a user interface. In some embodiments, the user may be able to communicate with the user interface and may issue instructions to the controller, which may affect the commands issued to the control valve.

[00134] In some embodiments, the metal-air battery may have a pump E, which can facilitate the flow and circulation of the electrolyte. In some embodiments, a pump may be provided in the metal-air battery storage tank K. The electrolyte return line L from the storage tank can supply electrolyte from the storage tank K to the control valve C. The electrolyte return line from the storage tank can be connected to a pump. The pump may cause electrolyte to flow through the electrolyte return line to the control valve. The electronic controller may issue commands to the control valve, which may determine whether the electrolyte may return and / or the flow rate with which the electrolyte may return.

[00135] A supply line F to the storage tank may be provided. Electrolyte may pass from control valve C to storage tank K. A feed line G to the upper manifolds may be provided. Electrolyte can pass from the control valve to the upper collectors. In some embodiments, a single collector may be provided. In other embodiments, a plurality of upper collectors may be provided. The upper manifolds may or may not communicate with each other. In some embodiments, the electrolyte delivered through the supply line G may be controlled by one or more upper supply control valves H1, H2. In some embodiments, a control valve may be provided for each upper manifold. A control valve can regulate the flow of electrolyte into each upper collector. The electronic controller D may be in communication with the upper flow control valves. The electronic controller can issue commands to the upper flow control valves. In some embodiments, the commands issued by the electronic controller may be transmitted via a wired connection, or may be transmitted wirelessly.

[00136] In some embodiments, the upper electrolyte flow controllers I1, I2 can control the electrolyte flow from the upper collector to downstream cells. Flow controllers can break electrolyte into droplets. Flow controllers can control the flow rate of fluid transferred from the upper manifold to the underlying elements.

[00137] In some embodiments, the top collector and / or storage tank K may have openings J-1, J-2, J-3. In some embodiments, the openings may communicate with the electronic controller D. In some embodiments, the openings may provide access for one or more measurements. The measurement results can be transmitted to an electronic controller, which can issue commands to other parts of the electrolyte control system. For example, based on measurements, an electronic controller can adjust the electrolyte flow rate, adjust the electrolyte temperature, adjust the pH of the electrolyte, or adjust the composition of the electrolyte.

[00138] An electrical connection may be provided within the battery system. For example, one electrical connection may be provided on the (+) side of the battery, and another electrical connection may be provided on the (-) side of the battery and may be connected to a second charging plug. Charging plug 2 can be plugged into a wall outlet such as a power outlet / utility. An AC to DC rectifier may be provided that can convert alternating current from the mains / utility network to direct current to charge the batteries. An inverter may or may not be provided that can convert direct current from batteries to alternating current when the batteries are discharged.

[00139] In some embodiments, the voltage of the battery system can be monitored. In some embodiments, the voltage of the entire system can be controlled, or the voltage of each module can be separately controlled. When the voltage suddenly drops, this may indicate a problem with one or more elements. In some embodiments, the system may increase electrolyte consumption when the voltage drops.

[00140] In some embodiments, one or more characteristics of the battery and / or electrolyte can be monitored at one point. For example, you can measure the pH of the electrolyte, the temperature of the electrolyte, the composition of the electrolyte at one point, such as a storage tank. The invention may include a simplified monitoring system that can determine if the system needs adjustment without the need for expensive and complex sensor systems.

Additives to improve the quality of the zinc coating and the formation of insoluble zinc compounds

[00141] Losses on the internal resistance (BC) can be kept low by applying a good quality zinc coating during each recharge cycle. A key factor in the durability of this element is that it is not necessary to maintain any particular shape of the electrode. Unlike many chemical systems, such as lead acid, in which cycling does damage the electrode, a fresh zinc coating can be applied to this battery every time. The battery system may include additives that can improve the deposition of zinc on the metal electrode. With key additives such as polyethylene glycol of various molecular weights and / or thiourea, a fresh, smooth, highly conductive zinc coating can be applied during each recharge cycle of the cell. This zinc layer can then undergo oxidation to dissolved zinc ions during the next discharge of the element. Since no specific physical form is required during application and since gravity helps to keep deposited zinc in place, the probability of a metal electrode failure (quite common in other battery systems) can now be minimized or reduced as a cause of failure. This helps to achieve a very long cyclic battery life.

[00142] Another implementation option may include other additives that can cause the generated zinc ions (during oxidation on the metal electrode during discharge of the cell) to remain close to the metal electrode so that they are easily restored (without undue migration) during cell charge. Thus, it will be useful to have an electrolyte with water-soluble additives, which (when in contact with Zn ²⁺ ions formed on the metal electrode) can form insoluble zinc compounds that can precipitate on the bottom of horizontally oriented cells. Insoluble zinc compounds may remain near the zinc electrode and may be more readily recoverable during recharging. The battery system may include an additive that can control the desired precipitation. Such additives may include any of the following water soluble compounds. Examples of water-soluble compounds that form insoluble zinc compounds include: benzoates, carbonates, iodates and stearates.

[00143] In some embodiments, additives having any of the properties described herein may include urea, thiourea, polyethylene glycol, benzoates, carbonates, iodates, stearates, water soluble surfactant catalysts, or aloe vera, individually or in combination. In some embodiments, the addition of aloe vera extract can reduce zinc corrosion.

Soluble catalysts as an additive to electrolyte to improve oxygen production during recharging

[00144] In addition to the solid catalysts incorporated in the air electrode itself, other materials, such as water soluble manganese salts, may be added to improve the performance of the cell during the recharging process. Since oxygen is generated during the process of recharging the cell, it is also useful to allow air bubbles to escape easily. This can be done by adding surfactants that act as anti-foaming agents (such as Simethicone (simethicone) or Dowex) to break the generated bubbles. The battery system may include an additive that prevents foaming and enables the release of gas. Supplements may include one or more of the following: simethicone, Dowex, aloe vera, or other surfactants.

[00145] The air electrode can also be installed at a slight angle to the parallel to help the formed air bubbles leave the four through a common filling opening near the overflow threshold. In some embodiments, the stretched titanium may also be positioned with a slightly negative bulge or a gas discharge channel stamped along the perimeter so that it can be guaranteed that most of the surface area of the air electrode interacts with the electrolyte. Any air bubbles or gases can easily escape through common filling openings. These configurations will also solve flatness tolerance problems and mitigate level control problems.

Urea as an additive to electrolyte to eliminate chlorine formation

[00146] The battery system may include an additive that prevents the release of chlorine and / or hypochlorite during the recharging process. Urea can be added to the battery’s aqueous electrolyte to control the generation of chlorine. Urea and chlorine can react with the formation of chlorides and “soft” gaseous products (for example, N ₂ , CO ₂ and H ₂ ). If some free chlorine forms in the electrolyte during charging of the cell, it can easily react with soluble urea to form additional chloride (which is already an electrolyte component). The gases generated by the reaction of chlorine with urea are not dangerous and can be safely removed. If urea is added to the electrolyte and is not replenished, then, as the cells charge (and if chlorine gas is generated), the urea may react with the chlorine formed, deplete and become unable to remove any chlorine gas generated during successive charging cycles.

[00147] In the cell design provided in accordance with an embodiment of the invention, electrolytes can be checked periodically and, if predetermined chlorine levels are exceeded, additional urea can be added if necessary. In some embodiments, electrolytes can be checked manually. In other embodiments, one or more sensors may be provided to automatically check chlorine levels and, if necessary, add additional urea to react with and remove chlorine. In some embodiments, urea may be added manually if necessary. In other embodiments, urea may be added automatically when chlorine levels are above a predetermined level. In some embodiments, a predetermined level may be in the range of 5% urea by weight, but it will usually be equal to several millionths of urea.

[00148] In some embodiments, the battery system may include an additive that can prevent hydrogen evolution during charging. The additive may include chloride salts with a high overvoltage of hydrogen evolution, such as tin chloride, lead chloride, mercury chloride, cadmium chloride or bismuth chloride.

Quick recharge with zinc / electrolyte suspension

[00149] With the horizontal design of the cell, a system can be provided where the cells can be quickly recharged (for example, for long-term mobile applications). Zinc chloride particles formed during the discharge process can be quickly removed from the elements by suctioning this suspension into a tank or flexible waste container. This used liquid electrolyte can be replaced with fresh zinc granules in suspension of the electrolyte, which can be pumped back into the horizontal cell. Solid electrolyte particles can settle on the bottom of the cell (metal electrode). This mechanical recharge (refill) is expected to take only a few minutes.

[00150] In some embodiments, as depicted in FIG. 4B, one or more horizontal elements may be located inside the housing or may form part of the battery housing. The housing can be connected to the tank. In some embodiments, the used liquid electrolyte may be returned to the reservoir. Liquid electrolyte can be returned through a tube, pipe, channel, return pipe or any other device for flow communication. In some embodiments, the reservoir may supply liquid electrolyte to the housing. The electrolyte can be supplied through a tube, pipe, channel, feed pipe or any other device for flow communication. In some embodiments, the same tank may receive used liquid electrolyte and provide fresh liquid electrolyte. Liquid electrolyte can circulate inside the system. In some embodiments, the reservoir may have one or more processing processes that can process the used liquid electrolyte before it is fed back into the housing. For example, fresh zinc granules may be added to the electrolyte. In other embodiments, various tanks may be used to receive used liquid electrolyte and provide fresh liquid electrolyte. Fresh electrolyte can enter the system, and used electrolyte can be removed from the system.

[00151] Particles of zinc chloride from the used element can be regenerated locally or at any local production facility (analogous to a refinery or tank farm) using well-known electrochemical technologies. Such a modification transforms this system from what is usually presented as a battery into something closer to a flow type element or a zinc-air fuel cell. However, all of the above advantages will also be available and a longer discharge cycle can be performed compared to a discharge cycle that would be available only with the amount of zinc that can be placed in each element without circulating external zinc. Another refueling method can be described as electrolyte transfusion, where the spent electrolyte can be replaced with fresh electrolyte for quick, traditional refueling, similar to traditional pumping stations.

Housing and assembly of the metal-air battery

[00152] As described previously, the metal-air battery system may include a battery case. This housing may have any number of configurations, which may contain one or more closed individual elements. In some embodiments, the element itself may form part of the housing. For example, the elements can be stacked so that the frames of the elements can form part of the housing. In some embodiments, the housing may be fluid tight. For example, the housing may be liquid tight and / or airtight. In some embodiments, the housing may include one or more purge mechanisms.

A. Plastic housing with a “four” of four combined elements and an electrolyte filling / outlet opening system

[00153] The layout and design of the plastic frame of the element can be optimized or improved to effectively use space, strength, formability and minimize or reduce losses in internal resistance due to reduced inter-element resistance.

[00154] The frame design of the cell in accordance with an embodiment of the invention can accommodate a common centralized electrolyte control system that can be shared between four separately framed, horizontally oriented cells. In other embodiments, a common centralized electrolyte control system can share any number of elements, including, but not limited to, one, two, three, four, five, six, seven, eight, nine, ten, eleven, twelve, thirteen, fourteen, fifteen, sixteen, seventeen, eighteen, nineteen, twenty or more elements. This design can make possible optimal “centralized” placement in space, physical stackability and electrical connectivity of the collector system.

FIG. 5 shows an example configuration of a stack of batteries of an energy storage system. The outer walls of the plastic frames 500a, 500b, 500c, 500d can form a wall of the housing 502. In some embodiments, four cells 504a, 504b, 504c, 504d can form a quadruple 504 with a common centralized electrolyte control system 506.

[00156] Any number of elements may be stacked on top of each other. For example, four elements 504c, 504e, 504f, 504g can be stacked on top of each other. In some embodiments, one or more, two or more, three or more, four or more, five or more, six or more, seven or more, eight or more, nine or more, ten or more, twelve or more, fifteen or more, twenty or more, thirty or more, or fifty or more elements may be stacked on top of each other. For each element, one or more air flow paths 508a, 508b, 508c, 508d may be provided. Many vertically stacked elements can be selected to achieve the desired voltage. If vertically stacked elements are connected in series, the number of vertically stacked elements may correspond to an increased voltage level. As described elsewhere herein, a centrode can be used to create a series connection between elements.

[00157] Any number of contiguous quads or stacks of quads may be provided. For example, the first four 504 may be adjacent to the second four 510. In the energy storage system, one or more rows of fours and / or one or more columns of fours may be provided. In some embodiments, the energy storage system may include an i × j quadruple array, where i, j are integers greater than or equal to 1, including, but not limited to, 1, 2, 3, 4, 5, 6, 7, 8 , 9, 10, 11, 12, 13, 14, 15 or more. In other embodiments, elements or quadruples may have step configurations (staggered), concentric configurations, or be positioned relative to each other in any way. Clearances between adjacent elements or quadruples may or may not be provided. Alternatively, adjacent elements and / or fours can be electrically connected to each other. In some embodiments, one or more elements, or one or more fours, may share a common frame with an adjacent element or adjacent four. In some embodiments, each element or each four may have its own frame, which may or may not be in contact with the frame of an adjacent element or adjacent four.

[00158] As discussed previously, any number of cells can share a common centralized electrolyte control system. Four quadrangular elements can share a common system of centralized electrolyte control, forming a four. In other examples, six triangular cells can share a common centralized electrolyte control system, or three hexagonal cells can share a common centralized electrolyte control system. Any combination of the shapes of the cells may be used, with the corners of one or more cells sharing a common centralized electrolyte control system. Any reference to fours can be applied to other numbers or configurations of cells that can share a common centralized electrolyte control system. Horizontal and / or vertical transverse conductive connections may be provided. Due to this, redundancy of the connection can be provided.

B. Unique collector system design and gravity-controlled runoff

FIG. 6 depicts an example of a centralized electrolyte control system for an energy storage system in accordance with an embodiment of the invention. A plurality of cells 600a, 600b, 600c may share a common electrolyte control system. The electrolyte control system may include a threshold 602a, 602b, 602c for each cell. The threshold may contribute to the content of liquid electrolyte inside the cell. The electrolyte control system may also include one or more inclined or vertical parts 604a, 604b, 604c. Inclined or vertical parts may direct the electrolyte to pass into cells. In some embodiments, the combination of a threshold and an inclined or vertical portion may delay the electrolyte provided from above relative to the cell. In some embodiments, one or more holding protrusions 606a, 606b, 606c may be provided. The centralized electrolyte control system may also include a prismatic protrusion 608a, 608b, 608c, which allows the irrigated electrolyte to drain into the underlying cells and / or into the underlying electrolyte collection tank.

[00160] In one example, the liquid electrolyte may be delayed by an overflow threshold 602a of the first cell 600a. The liquid electrolyte may pass down an inclined or vertical portion 604a and be contained within the cell. If the liquid electrolyte overflows the first cell, it can overflow through the overflow threshold and fall onto the prismatic protrusion 608a. It may flow along the prismatic protrusion and be held by a threshold 602d or the inclined or vertical portion 604d of the second element 600d below the first element. The electrolyte can be captured by the second element and contained in it. If the second cell is overflowed or overflowing, the flowing electrolyte may flow along the prismatic protrusion 608d of the second cell and be captured by the third cell 600e, or it may continue to flow down.

[00161] When initially filling the battery system with electrolyte, the cells at the top can be filled first, and then the electrolyte can be poured into the underlying cells or fours, which can then be poured into the underlying cells and fours, no matter how many layers of vertical cells are provided. As a result, all elements with a vertical stack configuration can be filled with electrolyte, and excess electrolyte can be detained by the bottom tray of the tank under the elements.

[00162] Any details of the electrolyte control system may be integrated into the cell frame or may be separate or separable from the cell frame. In some embodiments, the parts may be injection molded.

[00163] The electrolyte control system can continuously control liquid electrolyte levels in each four-cell “four” to ensure constant and uniform electrical contact with the bottom of each air electrode. Enough electrolyte must be provided in the cells so that the electrolytes can come into contact with the bottom (e.g., 610a) of the air electrode. In some embodiments, the bottom may be a metal electrode / anode. In other embodiments, sufficient electrolyte may or may not be provided in the cell to ensure that the electrolyte contacts the bottom portion 612a of the overhanging air electrode. The bottom of the air electrode may be a cathode during discharge.

FIG. 3 provides an additional view of an element having an electrolyte control system in a corner.

[00165] In preferred embodiments, the prismatic protrusion or threshold may be configured to rupture any potential bridge of the conductive fluid flowing between the elements. The prismatic protrusion can break the liquid electrolyte into small droplets. The prismatic protrusion can control the flow rate of any iridescent electrolyte.

[00166] An electrolyte control system may be useful in order to enable efficient electrolyte transfusion and control. Overflowing electrolyte can be delayed by the downstream cells or can flow down until it is held back by the downstream tank.

[00167] The electrolyte control system may also allow for safe removal of unwanted generated gases. In some embodiments, gases may be vented through paths formed by prismatic portions, either up or down.

[00168] Advantageously, the electrolyte control system can replenish the cells with liquid electrolyte using a system controlled by the gravity of the runoff. Cells can be replenished by overflowing from overhanging cells, or from an electrolyte source. For example, as shown in FIG. 4A, electrolyte may be supplied to the upper holding tank. The electrolyte may be supplied in any other way.

[00169] As provided in embodiments of the invention, transfusion facilitated by gravity and a common overflow opening for each cell can be generalized and used in any other energy storage devices where liquid electrolyte levels can change during discharge and charge. Such fluid control systems should not be limited to metal-air elements such as zinc-air elements. Other types of energy storage elements may use similar fluid control systems. The liquid electrolyte level can be automatically adjusted so that it only touches the bottom of each individual air electrode.

[00170] An additional modification of this design involves the manufacture of each element with a recessed cavity located on one side. It can function as a fluid reservoir where excess volumes of electrolyte can be stored safely if necessary. When the electrolyte volumes decrease, the excess liquid stored in this cavity can automatically drain due to gravity and be used to refill the cell, thereby ensuring that all parts of the side (bottom) of the air electrode facing the electrolyte remain in contact with the liquid electrolyte.

C. Compression design for reliability

FIG. 5 provides a view of a configuration of a stack of batteries. As described previously, in some embodiments, the outer surfaces of the element frames may form a housing. In some embodiments, all important sealing surfaces may be subject to a vertical compressive load for additional long-term sealing reliability. For example, a compressive load may be applied to a stack of elements that can distribute the compressive load across the frames. This makes the frames snuggle together and seal. A compressive load can be provided in a direction that corresponds to the compression of the stack of elements with each other. A compressive load may be provided in a direction perpendicular to the plane formed by the metal electrode or the air electrode of the element. In some embodiments, a compressive load may be provided in the vertical direction.

[00172] The centrode assemblies may be sandwiched between the respective plastic frames to form a series of individual sealed elements. As previously discussed, centrodes can be formed when the metal electrode of one element is electrically connected to the air electrode of another element. In one embodiment, this electrical connection may be formed when the metal electrode is crimped around the air electrode. This may make it possible to connect in series between the elements. In some embodiments, a compressive force may be applied between the elements. A compressive force may be applied to the connection between the metal electrode and the air electrode. The application of a force that brings the metal electrode and the air electrode together can improve the electrical connection between the metal electrode and the air electrode. In some embodiments, the contact point of the metal electrode and the air electrode may be sandwiched between the plastic frames, and a compressive load may provide a compressive force between the frames and the contacts. A fluid tight seal may be formed that may prevent the electrolyte from flowing from one cell to another through the contact of the frame with the centrode. This seal may be realized or supported by glue.

[00173] The outer walls and internal partitions (which can form the frames of the elements) can be structural elements designed to properly accommodate and seal the inner working space of each element and apply compressive loads at important junctions of the elements and on the sealing surfaces. This provides an easy-to-assemble, robust construction and advantageous structural system when individual elements are vertically stacked on top of each other. FIG. 1 and FIG. 2 depict how individual elements can be stacked vertically on top of each other. In some embodiments, the stack may be loaded with compressive force, which may be applied to the frames and / or joints between the metal electrodes and the air electrodes.

D. Subassembly of the metal electrode, air electrode

FIG. 1 shows a connection between a metal electrode and an air electrode. In some embodiments, with the stamping assembly method, the metal electrode is crimped around the air electrode to form a section in the shape of a hat for air to pass through it. In some embodiments, the metal electrode may be crimped around the air electrode so that part of the metal electrode contacts the edge on the first side of the air electrode and the edge on the second side of the air electrode. In some embodiments, the air electrode may be crimped around the metal electrode so that part of the air electrode contacts the edge on the first side of the metal electrode and the edge on the second side of the metal electrode. The metal electrode and the air electrode can be crimped together in any way so that they are bent or folded onto each other with different configurations. In some embodiments, they are crimped or otherwise fastened together so that they are in contact with each other without the need for any folds or creases. Other methods of forming an electrical connection may be used, as previously indicated.

[00175] The metal-air electrode assembly may use various materials that are crimped to form an electrically conductive connection along both sides of the air path. In some embodiments, examples of materials for the metal electrode may include zinc (such as powdered zinc amalgam) or mercury. Examples of materials for an air electrode may include carbon, teflon, or manganese.

[00176] A metal-air electrode assembly may be provided where the metal electrode provides a sealed floor for the electrolyte bath above it, while the air electrode forms a sealed cover for the electrolyte bath underneath. For example, as shown in FIG. 1, the metal electrode 104a may form a floor for the electrolyte bath 106a. Air electrolyte 102a may form a lid for the bath electrolyte. The metal electrode and / or air electrode may be sealed.

[00177] A centrode formed by a metal electrode and an air electrode may be of any size. One or more of the dimensions (e.g., length or width) may be about ј inch, Ѕ inch, 1 inch, 2 inch, 3 inch, 4 inch, 5 inch, 6 inch, 7 inch, 8 inch, 9 inch, 10 inch 11 inches, 12 inches or more.

E. Design of transverse conductive joints between elements

FIG. 7 depicts an additional configuration view of a stack of battery with metal electrode-air electrode connections. A configuration may be provided for the metal electrode - air electrode assembly, where adjacent crimped (flanged) edges or other protruding parts of the centrodes overlap or touch, creating a repeating, modular and horizontally and vertically electrically connected series configuration.

[00179] The first element may include frame parts 700a, 700c and may have a metal electrode 702a. The metal electrode may be crimped around the air electrode 704b of the underlying element. In some embodiments, the metal electrode of the adjacent member 702c may be crimped around the air electrode of the member 704d below it. In some embodiments, the electrical connection formed by the metal electrode 702a and the air electrode 704b may be electrically connected to the electrical connection formed by the metal electrode 704c and the air electrode 704d. For example, one of the metal electrodes 702c may be in contact with another metal electrode 702a. Alternatively, an electrical connection between adjacent elements may be formed by any combination of metal electrodes and / or air electrodes in contact with each other. In some embodiments, electrical connections between the upstream and downstream elements and adjacent elements (e.g., connections between 702c, 704d, 702a, 704b) can be provided between the frames (e.g., 700c, 700d).

[00180] FIG. 7 depicts an example of how metal electrodes and air electrodes can make electrical connections by crimping and wrapping. However, any combination of contacts between metal electrodes and air electrodes wrapped around each other or in contact with each other can be used in accordance with various embodiments of the invention. The positions of the metal electrodes and air electrodes can be reversed in alternative embodiments of the invention, and any discussion regarding the positions of the metal electrodes can be applied to the positions of the air electrodes, and vice versa.

[00181] Overlapping or otherwise compatible crimped edges allow a series or parallel-parallel electrical connection to ensure reliability, simplicity and flexibility of the system. For example, one of the advantages of such a system can be that fewer wires and connection points are needed, since each row in the element frame can be electrically connected in series through overlapping crimped edges.

FIG. 9A provides a bottom view of an assembly of element frames with electrical connections. One or more of the cells 900a, 900b, 900c, 900d may form a four with a common electrolyte control system 902. The bottom of the cell may be formed of a metal electrode. One or more components 904a, 904b, 904c, 904d, 906a, 906b of the frame separating the elements may be provided. In some embodiments, electrical connections between the elements may be provided for adjacent elements. For example, electrical connections can be made between two or more elements within a row, for example, between a first element 900a and a second element 900b. An electrical connection may be provided adjacent to the frame 904a between the elements. Electrical connections can be made between two or more elements within the column, for example, between the first element 900a and the second element 900c. An electrical connection may be provided adjacent to the frame 906a between the elements. Electrical connections can be provided for any combination of adjacent elements in a row or column.

[00183] In some embodiments, electrical connections between adjacent elements are not provided. In some embodiments, electrical connections may be provided only between the overlying and underlying elements forming a stack.

FIG. 9B is a view of a frame assembly and one or more centrodes. Frame 880 may be for one or more single elements or quadruples, or a plurality of single elements or quadruples. One or more centrodes 882a, 882b may be formed from a metal electrode 884 and an air electrode 886. The centrode may be shaped to fit inside the frame. In some embodiments, the frame may lie on the centrodes so that the side of the frame forms the wall of the element, and the metal electrode of the centrode forms the floor of the element. Many adjacent centrodes, for example, 882a, 882b can be electrically connected to each other. For example, the centrode may have a point 888 where the metal electrode and the air electrode are in contact with each other. The contact point of the first element may be in contact with the contact point of the second element. In some embodiments, a centrode may be formed such that an air tunnel 890 is provided between the metal electrode and the air electrode.

[00185] The frame 880 may include an electrolyte distribution unit 892, which may be integral to the frame. The electrolyte distribution assembly may include an opening 894, which may allow the electrolyte to drain to the underlying cells. The electrolyte distribution assembly may include an overflow threshold 896 that can determine when the electrolyte will overflow into the hole. In some embodiments, the height of the overflow threshold may provide a margin in case the cells or the entire battery system are tilted. Even if the entire battery system is tilted, if the overflow threshold is high enough, enough electrolyte will remain inside the cells before the transfusion.

[00186] The frame may also include a shelf 898, which may protrude from the frame. The metal electrode 884 may be in contact with the shelf. In some embodiments, a fluid tight seal may be formed between the metal electrode and the shelf. The contact between the metal electrode and the air electrode 888 may contact the lower part of the frame 881. The lower part of the frame may lie over the contact point. The fluid impervious compound may or may not be formed. The lower portion 883 of the frame may lie over a contact point formed between adjacent centrodes.

F. Stackable configuration and modular assembly

FIG. 5 depicts a structure that uses one component of a plastic frame, which essentially encloses a plurality of centrodes between two common frames in a sandwich structure. This can advantageously provide a simplified design. For example, as shown, a frame may be provided that forms a mesh pattern that may span multiple elements. Mesh frames can be stacked on top of each other. In some embodiments, mesh frames may be formed from a single integral part. Alternatively, mesh frames can be formed from multiple parts that can be connected to each other. Multiple parts may or may not be detachable. Centrodes 512a, 512b may be provided between the frames 514a, 514b, 514c.

[00188] The frame design may include a water management system. A water management system may be provided in FIG. 4, which may depict water inlets, raised overflow openings, and prismatic drip edges as previously described. A water control system can be used to guarantee the desired electrolyte level within one or more cells.

[00189] When stacked, the construction of the plastic frame can form a sequence of vertical tubes or tubes that make it possible to overfill water, replenish the electrolyte by dripping and dropping gases. As previously discussed with reference to FIG. 4 and FIG. 6, an electrolyte control system may be provided. When the frames are stacked on top of each other, an electrolyte control system may be provided for stacks of cells.

[00190] The stackable configuration of the frame assemblies can be both modular and efficient. Plastic parts may conform to the conjugation form of the metal electrode below and the air electrode above the element below it, which may allow a modular configuration with fewer parts. FIG. 1 and FIG. 2 provide an example of a stack of elements with parts within a framework that can be molded to fit the connection of the metal electrode and the air electrode. Depending on the shape of the connection between the metal electrode and the air electrode, the frames may be shaped to match the shape of the connection. In some embodiments, one or more ribs, grooves, channels, protrusions, or holes may be provided on the plastic frame to complement the corresponding metal-to-air electrode connection shape. In some embodiments, the complementary shape may hold the frame from horizontal displacement in one or more directions. Any details can be integrated with the element or be separable from the element. In some embodiments, the frame parts may be molded under pressure.

G. Modular installation and configurations for application

[00191] Configurations with multiple batteries can be achieved by scaling the frame design up or down. For example, a frame design may include a single element frame, a four element frame, or multiple fours in a single frame. The frame design for each grouping (for example, a single element, quadruples of elements, multiple quadruples) can be formed from a single integral part. Alternatively, the frame design may include many parts.

[00192] In some embodiments, a plurality of frames may also be provided adjacent to each other. For example, multiple singleton frames, four-element frames, or multi-quadruple frames may be provided adjacent to each other. Frames provided adjacent to each other may or may not be connected to each other using a connector. In some embodiments, a force may be provided to hold the frames adjacent to each other.

[00193] Frames can be stacked until any desired height is reached, depending on power and storage (storage) requirements. Any number of frames can be stacked on top of each other. For example, one or more, two or more, three or more, four or more, five or more, six or more, seven or more, eight or more, nine or more, ten or more, twelve or more, fifteen or more, twenty or more, thirty or more, sixty or more, ninety or more, 120 or more, or 150 or more frames may be stacked on top of each other. In some embodiments, each frame may be about ⅛ inch, ј inch, Ѕ inch, дюйма inch, 1 inch, 1.25 inch, 1.5 inch, 2 inch, 2.5 inch, 3 inch, 4 inch, 5 inch 6 inches, 8 inches, 10 inches or 12 inches tall. In some embodiments, the overall stack height of the frames may be of the order of about 1 or more inches, 3 or more inches, six or more inches, 1 or more feet, 2 or more feet, 3 or more feet, 5 or more feet, 10 or more feet, or 20 or more feet.

[00194] Stacks of individual frames can be oriented in different directions to optimize air circulation. For example, air tunnels may be provided within the elements. In some embodiments, air tunnels may be provided between the elements. For example, a continuous air tunnel may be formed between adjacent elements. Air tunnels may be provided for columns of elements and / or for rows of elements. In some embodiments, the air tunnels may be parallel to each other. In other embodiments, one or more air tunnels may be perpendicular to each other. In some embodiments, the air tunnels may be formed in a straight line, or in other embodiments, the air tunnels may have bends or curves. In some implementations, when the elements can be slightly inclined, the air tunnels can be oriented almost horizontally, but have a slight rise and fall to match the inclination of the elements. Air can flow in the same direction in the case of parallel air tunnels or can flow in opposite directions. In some embodiments, the air tunnel may be limited to one level. In other embodiments, aisles may be provided that may allow for an air tunnel at many levels of stacks. Any combination of these configurations can be applied.

[00195] A stack or series of stacks can be applied in various configurations and installed in various cases. For example, stack heights may vary. Similarly, the number of elements provided at each level of the stack may vary. In some embodiments, the sizes or shapes of the individual elements may be the same, while in other embodiments, the sizes or shapes of the individual elements may vary. The dimensions of the case may vary depending on the size of the stacks. For example, an entire energy storage system may have one or more sizes (eg, height, width, length) of the order of inches, feet, tens of feet, or hundreds of feet. Each size can be within the same order of magnitude, or it can be within varying orders of magnitude.

[00196] A stack or series of stacks can be configured as a fuel cell system by replacing or replenishing an electrolyte and packaging said auxiliary systems. For example, a zinc-air fuel cell system may include the addition of zinc metal and the removal of zinc oxide. As indicated previously, zinc granules can be added to the electrolyte. Zinc oxide or zinc chloride can be removed to a waste tank.

H. Use in an insulated freight container and HVAC machine

FIG. 8A shows an example application in an insulated freight container and an HVAC machine for a battery pack in accordance with an embodiment of the invention. A plurality of modules 800a, 800b, 800c may be provided within the housing 802. Each module may have an upper tray 804, one or more stacks of elements (which may include one or more levels / layers of single elements, fours of elements, and / or any number of elements) 806 , and a lower tray or pallet 808. See also FIG. 8H, and each stack of cells could have a collector through which electrolyte can be sent to or interrupted on a given stack or section of the stack. Similarly, electrical connections to specific stacks can be separated and disconnected.

[00198] In one example, 16 modules 800a, 800b, 800c of 960 element quadruples may be provided. Two rows can be provided, each of which has eight modules. In various embodiments of the invention, any number of modules may be provided, including but not limited to one or more, two or more, three or more, four or more, five or more, six or more, seven or more, eight or more , nine or more, ten or more, twelve or more, fifteen or more, twenty or more, thirty or more, fifty or more, or one hundred or more modules. In some embodiments, the modules may be arranged in one or more rows and / or in one or more columns. In some embodiments, the modules may be arranged in an array. Housing 802 may be configured to accommodate modules. In some embodiments, the hull may be about 40, 45, 50, or 52 feet long.

[00199] The module may be of any size. In some embodiments, the module may be approximately 50 inches by 44 inches. In one example, a module may comprise 80 or 120 or more stacks of 15 or more or less than four elements. However, the module can be formed from any number of levels / layers in stacks, including, but not limited to, 1 or more layers, 2 or more layers, 3 or more layers, 5 or more layers, 10 or more layers, 20 or more layers, 30 or more layers, 40 or more layers, 50 or more layers, 60 or more layers, 70 or more layers, 80 or more layers, 90 or more layers, 100 or more layers, 120 or more layers, 150 or more layers, or 200 or more layers. Each stack layer can include any number of single elements or four elements. For example, each level / layer of the stack may include 1 or more, 2 or more, 3 or more, 4 or more, 5 or more, 6 or more, 7 or more, 8 or more, 9 or more, 10 or more, 12 or more, 14 or more, 16 or more, 20 or more, 25 or more, 30 or more, 36 or more, 40 or more, 50 or more, or 60 or more single elements or four elements per level / layer .

[00200] In some embodiments, the module may include an upper tray 804. The upper tray may be configured to receive electrolyte. In some embodiments, the top tray may be configured to distribute electrolyte into one or more cells. The upper tray may be in fluid communication with cell electrolyte control systems. In some embodiments, the top tray may be in fluid communication with one or more elements. The upper tray may include one or more protrusions. One or more protrusions may provide structural support for the lid above the tray. The upper tray may include one or more channels or grooves. In some embodiments, the upper tray may include one or more openings or passages that allow fluid communication with the underlying layers.

[00201] The module may also include a bottom tray or tray 808. In some embodiments, the bottom tray or tray may collect electrolyte that can spill from stacks above it. The bottom tray or tray may contain collected electrolyte or may transfer it elsewhere.

[00202] The modular design can be designed to fit various freight containers of the standard ISO (International Organization for Standardization, ISO) in an optimal way. In some embodiments, the housing may be a MOS freight container. The hull may be approximately 20 feet (6.1 m), 40 feet (12.2 m), 45 feet (13.7 m), 48 feet (14.6 m) and 53 feet (16.2 m) long. The MOS container may also have a width of about 8 feet. In some embodiments, the container may have a height of about 9 feet 6 inches (2.9 m) or 4 feet 3 inches (1.3 m), or 8 feet 6 inches (2.6 m). The modular design can also be made suitable for other containers of various standards, such as containers for air transportation. The modular design can provide flexibility to the energy storage system so that it can fit into existing containers or structure.

[00203] The modular design can take advantage of existing refrigeration and air conditioning equipment connected to insulated containers as a complete heating, ventilation and air conditioning (HVAC) solution.

[00204] Conventional cooling can be implemented by properly positioning cooling fans outside an enclosed space.

[00205] In some embodiments, a battery system may include one or more battery modules, one or more electrolyte control systems, and one or more air cooling units. In some embodiments, the battery module may include an upper tray, a lower tray, and one or more stacks of cells. In some embodiments, the stack of elements may include one or more layers or levels of elements. In some embodiments, one or more levels or layers of elements may include a single element, four elements, many elements, or many four elements. For example, a layer can be made of an array of m × n elements or an array of m × n fours, where m and / or n can be selected from any integers greater than or equal to 1, including, but not limited to, 1, 2, 3 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25 or more. Each module may include one or more parts of an electrolyte control system. In some embodiments, each four may share a common one or more parts of an electrolyte control system.

[00206] In some embodiments, the module may be a 50 kW / 300 kW · h module. In other embodiments, the module may have any other power / energy metrics. For example, a module may provide 10 kW or more, 20 kW or more, 30 kW or more, 50 kW or more, 70 kW or more, 100 kW or more, 200 kW or more, 300 kW or more, 500 kW or more, 750 kW or more, 1 MW or more, 2 MW or more, 3 MW or more, 5 MW or more, 10 MW or more, 20 MW or more, 50 MW or more, 100 MW or more, 200 MW or more, 500 MW or more, or 1000 MW or more. The module can also provide 50 kWh or more, 100 kWh or more, 200 kWh or more, 250 kWh or more, 300 kWh or more, 350 kWh or more, 400 kWh or more, 500 kWh or more, 700 kWh or more, 1 MWh or more, 1.5 MWh or more, 2 MWh or more, 3 MWh or more, 5 MW h or more, 10 MWh or more, 20 MWh or more, 50 MWh or more, 100 MWh or more, 200 MWh or more, 500 MWh or more, 1000 MWh or more, 2000 MWh or more, or 5000 MWh or more.

FIG. 8B depicts the lower parts of battery modules in accordance with an embodiment of the invention. The lower parts may include one or more stacks 820, which may include one or more layers / levels of 836 elements. The battery module may include a base 824 of the battery pack under the layers of cells. The base of the block may support the block underneath the lower reservoir 822. The lower reservoir may be configured to contain electrolyte that can drain from the stacks. The base of the unit may be configured to prevent contact of the electrolyte with the bottom of the stacks, such as an air electrode at the bottom of the stack. In other embodiments, the base of the block may allow the electrolyte to contact the bottom of the stack, but may provide support to hold the base of the block overhanging parts of the lower reservoir.

[00208] In some embodiments, a lower electrolyte storage tank, which can be thermoformed, can receive an iridescent electrolyte and promote electrolyte circulation within the battery system. For example, the lower reservoir may direct electrolyte to the verification reservoir and then to the upper reservoir, which can distribute the electrolyte into one or more stacks. The lower reservoir may be fluidly connected to one or more fluid distribution parts 826, which may include tubes, channels, or any other fluid distribution passages known in the art.

[00209] The stack 820 inside the battery module may include one or more layers or levels 836. The level or layer may include a frame 830. The frame may be injection molded or otherwise formed. In some embodiments, a separate frame formed as a single unit may be provided for each layer or level. In other embodiments, multiple frames or detachable portions of the frames may be provided for each layer or level. In some embodiments, the frame may include part of an electrolyte control system 832. An electrolyte control system may be formed integrally within the frame. When the layers of the frames are stacked vertically, parts of the electrolyte control system can become vertically aligned and allow the electrolyte to be distributed to cells 834 within the layers.

[00210] The element 834 may be formed by a surrounded frame 830 and supported by an electrode 828. In preferred embodiments, the electrode surface forming the bottom of the element may be a metal electrode. The electrolyte can flow into the cell and supported by the electrode, as well as held by the frame. Any electrolyte overflow can drain into the electrolyte control system 832 and can be distributed to the underlying cell, or it can drain down to the lower reservoir 822.

FIG. 8C shows a plurality of battery modules in a battery system. In some embodiments, the battery system may include a housing, which may include a bottom 840 or a base, or one or more walls 842 or shells. As indicated previously, in some embodiments, the housing may be a standard container, such as a shipping container.

[00212] The battery system may include an electrolyte control system. In some embodiments, the electrolyte control system may include one or more reservoirs 844a, 844b, which can facilitate circulation of the electrolyte within the system or the storage or supply of water to ensure a constant electrolyte mixture when evaporation occurs. These tanks can either help filter the electrolyte inside the system, or help provide additives to the electrolyte inside the system. In some embodiments, one or more pumps, valves, or differential pressures, such as a positive pressure source or negative pressure source, may be used in the electrolyte system, thereby promoting electrolyte circulation. In some embodiments, the reservoir may have system entry and / or exit. The inlet and / or outlet may be used to remove waste or filtered material, provide additives, vent gases or excessive fluid, or provide fresh fluid to the system. In some embodiments, one or more electrolyte-conducting parts 846 may be provided within the battery system. The electrolyte-conducting part may be a tube, channel, or any other assembly capable of transporting fluid from the reservoir to the upper reservoirs of the stacks directly or through a collector. Electrolyte-conducting parts may transfer electrolyte from reservoir 844a, 844b to one or more modules 850. In some embodiments, the electrolyte may be transferred to an upper tray or module reservoir. In some embodiments, electrolyte-conducting parts may be used to transfer electrolyte from the module to reservoir 844a, 844b. The electrolyte-conducting part may transfer electrolyte from the bottom tray or module reservoir to the reservoir 844a, 844b.

[00213] The battery system may include an air flow assembly. An air flow assembly can cause air to circulate inside the battery system. In some embodiments, an air flow assembly may cause air to flow inside the modules. In some embodiments, an air flow assembly may cause air to pass into the air tunnels between the elements. In some embodiments, one or more air tunnels may be provided between each layer of the stack. In some embodiments, the air flow tunnels may be oriented horizontally. In some embodiments, the air flow tunnels may be oriented almost horizontally and / or may have a slight slope (for example, from 1 to 5 degrees). The air flow assembly may include a fan, a pump, a differential pressure such as a positive pressure source or negative pressure source, or any other assembly that can cause air to move. In some embodiments, an air flow assembly may cause air to flow inside the tunnels of one or more modules. In some embodiments, air may pass between tunnels of various modules. Elements can be configured so that air tunnels can be formed continuously between adjacent elements and / or adjacent modules. In other embodiments, gaps may occur in the tunnel between the elements and / or between the modules.

[00214] In some embodiments, the battery system may also include one or more inverter units 848. The inverter unit can convert direct current electricity to alternating current.

[00215] FIG. 8D is a plan view of a battery system including a plurality of battery modules. As described previously, a housing may be provided for the battery system. The housing may include a bottom 860 and / or a shell or door 862, which may have walls or a ceiling. One or more reservoirs 864 or electrolyte-conducting parts 866, such as a pipe, may be provided. An electrolyte-conducting part may fluidically connect the reservoir to one or more modules 870. In some embodiments, each module may be directly flow-connected to the reservoir via an electrolyte-conducting part. In some other embodiments, one or more of the modules may not be directly connected to the reservoir through other modules. In some embodiments, the electrolyte-conducting part may be connected to one or more modules at the top of the module. The electrolyte-conducting part may be configured to supply electrolyte to the upper tray of one or more modules.

[00216] Any number of modules 870 may be provided within the battery system. For example, one, two, three, four, five, six, seven, eight, nine, ten, eleven, twelve, thirteen, fourteen, fifteen, sixteen, seventeen, eighteen, nineteen, twenty, twenty one can be provided within a battery system , twenty two, twenty three, twenty four, twenty five, twenty six, twenty seven, twenty eight, twenty nine, thirty or more modules. In some embodiments, the battery system may be a 1 MW 6-hour energy storage container. In other embodiments, the battery system may be a system with a capacity of 100 kW, 200 kW, 300 kW, 500 kW, 700 kW, 1 MW, 2 MW, 3 MW, 5 MW, 7 MW, 10 MW, 15 MW, 20 MW, 30 MW or more. In some embodiments, the battery system may be a system with a storage duration of 1 hour, 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, 11 hours, 12 hours, 13 hours , 14 hours, 15 hours or more.

[00217] In some embodiments, for a standard module, one or more of the following characteristics may be applicable: the system may have parameters such as 500 kW - 2 MW, 2-12 MW · h, and it is assumed that the system will have a low cost. Such parameters are given only as an example and do not limit the invention.

[00218] The modules may be of any configuration within the battery system. For example, one or more rows and / or columns of modules may be provided. In some embodiments, an array of modules may be provided. For example, two rows of 12 modules each may be provided.

[00219] In some embodiments, the electrolyte-conducting part may be a pipe that can extend over each module. In some embodiments, the pipe may be in fluid communication with each module on top of the module. The pipe can carry electrolyte into the top tray of each module. In some embodiments, the pipe may extend in the form of a straight pipe above the first row of modules, then it may bend and turn and pass in the form of a straight pipe above the second row of modules. Alternatively, the pipe may have any other curved or zigzag configuration.

[00220] In some embodiments, a battery system may also include one or more inverter units 868. The inverter unit can convert direct current electricity to alternating current.

FIG. 8E depicts an example battery system including an air flow assembly. The battery assembly may have a container with a front end and a rear end. In some embodiments, the container may be thermally insulated and / or electrically insulated. In some embodiments, the container may be a standard container, such as described previously, or a refrigerated container. In some embodiments, the container may be approximately 40 feet in length.

[00222] One or more modules may be contained within a container. In some embodiments, up to 36 modules may be provided within the container. Modules can be laid out in a container so that two rows of modules are provided, each row having 12 modules. Thus, a battery system can have a structure in which 12 models are deep and 2 modules are wide. In some embodiments, 1800 quadruples of elements may be provided for each module. A module can have 120 elements in height (for example, having 120 layers or levels) and can have 15 four elements for each layer or level. In some embodiments, a battery system may have a total of approximately 50,000 quartet cells.

FIG. 8E provides an example of an air flow assembly. An air flow assembly may be provided inside the container. The bottom of container A may include t-beams (T-profiles), gutters, channels, protrusions, ribs, or other shapes. In some refrigerated containers, a lower air flow manifold B may be provided or a t-shaped floor profile may be used. In some embodiments, air in the lower manifold may extend laterally. In some embodiments, air may pass to a central passage C of the airflow assembly. In some embodiments, air may rise in a central passage. One or more air tunnels D may be provided for one or more modules. The air tunnel may have a horizontal orientation. Air tunnels may be provided as part of the element centrodes. Air can flow from the central passage into one or more air tunnels that channel the air to the side between the elements.

[00224] From the air tunnel D, air can pass laterally into the peripheral passage E. One or more peripheral passages can be provided. In some embodiments, two peripheral passages E, F may be provided. Air may rise along the peripheral passages. A peripheral passage may be provided between the module K and the wall I of the container. In some embodiments with a fan (s) or air circulation or blowing system, an upper air manifold H with a skin G of the upper air manifold may be provided. The upper air manifold may receive air from peripheral passages. In some embodiments, a blocking device J may be provided to prevent air from rising from the central passage directly into the upper air manifold. It can cause some air to pass through the air tunnels. In alternative embodiments, a certain amount of air may rise from the central passage to the upper manifold. In some embodiments, air may extend longitudinally along the upper air manifold. For example, air may pass from the side of the container with the accessory area to the other end of the container.

FIG. 8F provides an additional view of the airflow assembly. An air flow assembly may be provided inside the container. The bottom of container A may include t-beams, gutters, channels, protrusions, ribs, or other shapes. Air may pass along spaces provided at the bottom between the surface details of the bottom. A lower air passage or tunnel B may be provided. In some embodiments, air may pass in the lower passage and may extend laterally. In some embodiments, air may pass to a central passage C of the airflow assembly. In some embodiments, air may rise in a central passage. One or more air tunnels D may be provided for one or more modules. The air tunnel may have a horizontal orientation. Air tunnels may be provided as part of the element centrodes. Air can flow from the central passage into one or more air tunnels that channel the air to the side between the elements.

[00226] From the air tunnel D, air can flow sideways into the peripheral passage E. One or more peripheral passages can be provided. In some embodiments, two peripheral passages may be provided. Air may rise along peripheral passages. A peripheral passage may be provided between the module and the wall I of the container. In some embodiments, the upper air manifold J may be provided with a skin for the upper air manifold. The upper air manifold may receive air from peripheral passages. In some embodiments, a blocking device H may be provided to prevent air from rising from the central passage directly into the upper air manifold. It can cause some air to pass through the air tunnels. In alternative embodiments, a certain amount of air may rise from the central passage to the upper manifold. In some embodiments, air may extend longitudinally along the upper air manifold. For example, air may pass from the side of the container with the accessory area to the other end of the container.

[00227] An upper electrolyte supply tank G may be provided as part of the module. A lower electrolyte receiving tank T may also be provided as part of the module. In some embodiments, container I may lie on surface K.

[00228] In some embodiments, the supplied air may be air supplied through the bottom and bottom of the manifold. The supplied air can then rise through the central passage and pass through the air tunnels. The exhaust air can pass directly through the peripheral passages and flow through the upper manifold. In alternative embodiments of the invention, air may flow in other directions (for example, may be supplied from the upper manifold and may pass through air tunnels in opposite directions).

[00229] FIG. 8G depicts an alternative example of a configuration of air flows. In some embodiments, the air may extend longitudinally along the container and should not split sideways. Air may or may not circulate back longitudinally along the container.

[00230] In some embodiments, the modules may be placed on the bottom of the container. In some embodiments, the bottom of the container may have t-shaped floor beams. In some embodiments, the bottom may have one or more grooves, channels, grooves, protrusions, or ribs that can support the modules while providing space under the modules. In some embodiments, air may pass inside the space under the modules. This may help when adjusting the temperature.

[00231] In some embodiments, an auxiliary equipment placement area is provided within the container and adjacent to the modules. For example, modules may be located inside the container to provide a 6 by 7 foot area for auxiliary equipment. In some embodiments, a user may be able to access an area of auxiliary equipment. The user may be able to enter the container into the area of the auxiliary equipment. In some embodiments, the accessory placement area may be located at the rear end of the container.

[00232] In some embodiments, an air distribution chamber (plenum) may be provided within the container. The air distribution chamber may protrude from the container wall at the front end. The air distribution chamber may be bent and may meet the module about halfway up. In some embodiments, air may be provided in one part of the air distribution chamber, and air intake may be provided in another part of the air distribution chamber. For example, air may be provided from the lower side of the air distribution chamber, and air intake may be provided at the upper part of the air distribution chamber, or vice versa. In some embodiments, the air supply may include cold, treated air. The air supply can occur in the first horizontal direction through the modules provided on the supply side of the air distribution chamber. For example, if an air supply is provided from the bottom of the air distribution chamber, air can flow horizontally through the lower half of the modules in the first direction. Air may pass through one or more module air tunnels.

[00233] When air enters the accessory area at the other end of the container, air can move to another part of the modules. For example, air can rise to the top of the modules and pass in a second direction back to the top of the air distribution chamber. In some embodiments, the second direction may be horizontal and / or may be opposite to the first direction. Air may reach the return air intake at the top of the air distribution chamber. An air distribution chamber may be provided at the front end of the container. Alternatively, the air does not have to be circulated back and can be taken in by the intake on the side of the container access area. The side of the container accessory area may or may not provide a second air supply, which may flow back to the first air supply. A transfer unit may also be provided at the front end of the container. The transfer unit may receive an air intake and may cool it, may change and / or maintain the temperature of the air, may filter the air and / or may change or maintain the composition of the air.

Installation Balance Configurations

A. Circulation and electrolyte treatment systems

[00234] As described previously and shown in FIG. 4A, an electrolyte circulation and processing system consisting of several components may be provided. In some embodiments, a separate plant balancing (electrolyte / air and water control system) may be provided. An electrolyte circulation and processing system may include one or more of the following:

[00235] A device for deionizing and filtering the feed water before it enters the system.

[00236] A chemical reservoir for introducing and mixing various salts and other chemicals with deionized water. This may form at least a portion of the electrolyte.

[00237] A reservoir or series of reservoirs that measure and process battery electrolyte.

[00238] A pump or series of pumps that distributes electrolyte throughout an entire battery system.

[00239] Various sensors that measure and monitor total volume, density, temperature, electrolyte pH levels, and other system operation parameters.

[00240] Supply and return lines that distribute liquid electrolyte to and from the battery.

[00241] Various sensors and valves for regulating the flow of liquid electrolyte and regulating electrical connections from the control unit.

[00242] FIG. 8H provides an example of a battery system inside a container. One or more reservoirs (e.g., treatment / containment reservoir, electrolyte reservoir) may be provided and may be connected to one or more modules via flow connectors and valves. For example, the electrolyte can be provided through a collector, and then individually separated into separate flow-through connectors that move the electrolyte to each of the modules within the system. For example, each upper module reservoir inside the system can be in fluid communication with the collector and can receive fluid from it. In some embodiments, one or more user interfaces may be provided.

[00243] In some embodiments, an airtight partition between the modules and the rest of the container may be provided. For example, a service or placement area for auxiliary equipment may be provided, which may be accessed by an operator or other user. For example, a service passage may be provided where an operator or other user may enter. In some embodiments, the service or placement area of auxiliary equipment may include tanks, a user interface, or electronic controls. In one example, an airtight partition may separate the service or placement area of auxiliary equipment from the modules.

B. Circulation and air conditioning systems

FIG. 8A shows an example application in an insulated freight container and an HVAC machine according to an embodiment of the invention. An energy storage system may include a circulation and air conditioning system consisting of several components. FIG. 8E provides an example of an air circulation system.

[00245] A sequence of air distribution flow chambers may be provided to control and evenly distribute the air flow between the elements. Forced air cooling can be more efficient than convection, especially when combined with good internal heat sinks and an enclosed space design in the style of an air distribution chamber. Heated air can be removed from enclosed spaces with fans or blowers, which can also draw cooler air into enclosed spaces through vents. Depending on cooling requirements, small or large volumes of air can move through an enclosed space.

[00246] In some embodiments, one or more temperature sensors may be provided. Based on the temperature detected by the temperature sensor, the operation parameters of the fans or blowers can be varied and / or maintained to control air flow. A fan system may be provided that pushes air through the battery.

[00247] The system may include a fresh air recharge and filtration system for introducing oxygen, while filtering out unwanted contaminants. In some embodiments, it may be desirable to have a higher oxygen content than ambient air.

[00248] An HVAC system may be provided that measures and controls the temperature of the air inside the battery case.

[00249] The system may also include a humidity control system that humidifies or dehydrates the air inside the battery case. One or more humidity sensors may be provided. A humidity control system can change and / or maintain air humidity based on measurements from humidity sensors.

[00250] In some embodiments, a series of sensors may be provided that communicate with various other systems.

C. Electrical connectivity and control

[00251] An electrical system may be provided that facilitates the flow of electricity within the battery and distributes electricity between the battery and the electrical network or other power source. In some embodiments, the electrical system may determine whether to provide power flow between the battery and the electrical network or another source or consumer of electricity. The electrical system may determine the direction and / or magnitude of the power flow between the battery and the source or consumer of electricity.

D. Measurement and regulation systems

[00252] A centralized measurement system may be composed of various sensors that are associated with a computerized control system. In some embodiments, a computerized control system may include one or more processors or memory devices. A computerized control system can collect measurement results from various sensors. A computerized control system may perform one or more calculations based on these measurement results. Any algorithm, calculation, or other steps can be implemented using tangible computer-readable (computer-readable) media, which may include code, logic, instructions for performing such steps. Such computer-readable media may be stored in a storage device. One or more processors may access and perform steps in such a storage device.

[00253] A computerized control system may be associated with various other mechanical systems. In some embodiments, a computerized control system may instruct one or more mechanical systems to perform an action. For example, a computerized control system may instruct the pump to pump a larger volume of electrolyte into the upper tray. A computerized control system may command one or more valves that may affect the distribution of electrolyte between multiple modules. In another example, a computerized system may cause a fan to blow at a lower speed. In some embodiments, a computerized control system may issue one or more commands based on measurements received from one or more sensors. Any commands can be provided by the controller via a wired or wireless connection.

[00254] A computerized control system may be connected to telephone and / or cellular communication networks. In some embodiments, a computerized control system may include a processing device, such as a computer. Any discussion of a processing device or any special type of processing device may include, but is not limited to, a personal computer, a server computer, or a laptop computer; personal digital assistants (PCs), such as a Palm-based device or a Windows-based device; Phones, such as cell phones or handheld location phones (such as GPS); a roaming device, such as a roaming device connected to a network; a wireless device, such as a wireless email device or other device capable of communicating wirelessly with a computer network; or any other type of network device that can communicate over the network and carry out electronic transactions. In some embodiments, a computerized control system may include multiple devices. In some cases, a computerized control system may include a client-server architecture. In some embodiments, the processing devices may be specifically programmed to perform one or more steps or calculations, or to execute any algorithm. The computerized control system can exchange information over any network, including but not limited to cellular networks, other telephone networks, local area networks (LANs), or a wide area network (such as the Internet). Any transmission of information may be provided through a wired connection and / or wireless connection.

[00255] In some embodiments, a user may interact with a computerized control system. The user can be remote (i.e., be at a distance) from the computerized control system and can exchange information with the computerized control system over the network. Alternatively, the user can be locally connected to the user interface of a computerized control system.

E. Installation and placement configurations

[00256] Typically, modular batteries and their systems are not limited in size, volume or scale. Conventional industrial cabinets, containers, buildings and other structures can be configured to accommodate the battery and its systems.

[00257] The battery and its auxiliary systems can be designed for mobile and stationary configurations. For example, a battery and its auxiliary systems may be provided in buildings, shipping containers, ships and cars, for example.

Fuel Cell Configuration

[00258] In accordance with some embodiments of the invention, the energy storage system described elsewhere here may be used in a fuel cell configuration. In a configuration with fuel cells, each cell can be equipped with inlet and outlet valves for supply and discharge for transfer or transfusion of electrolyte. In some embodiments, a battery electrolyte displacement system may be used with flow by gravity. For example, a supply inlet may be provided above the element, and a discharge outlet may be provided below the element. In other embodiments, groups of elements (such as quadruples or layers) may be provided with an inlet for supply and an outlet for outlet.

[00259] A fuel cell configuration may include mechanisms that remove depleted electrolyte and add fresh electrolyte through a remote and suitable transfer or transfusion opening.

Market adaptation and adaptation scenarios

[00260] An energy storage system, which may include the implementation options discussed here elsewhere, can be advantageously used with clean energy generators. Examples of clean energy generators may include wind farms, solar power plants or tidal power plants. An energy storage system can also be used with conventional energy generators, such as fossil fuel fired steam generators or nuclear generators. In some embodiments, an energy storage system may store (accumulate) energy from a generator. In other embodiments, it may be possible to supplement or shift the energy generated by the generator.

[00261] An energy storage system may be used in energy distribution. For example, it can be used with regional utility companies for public utilities, local utility companies for utility utilities (electric utilities), remote storage, or mobile storage.

[00262] The energy storage system may also have applications in energy storage, energy management, and backup power. For example, energy storage can be used for government and military applications, commercial and industrial applications, public and departmental applications, residential and private applications (fuel cell or battery). In some embodiments, excess energy may be stored in the energy storage system and then used if necessary. An energy storage system can be energy-intensive to be located in suburban substations or in urban basements.

[00263] Transport applications may be provided for an energy storage system. For example, an energy storage system can be used to power a locomotive and train. An energy storage system can also be used for freight transport (land or water). An energy storage system can also be used for mass transportation by public transport and business. For example, an energy storage system may be provided as a fuel cell or battery on public transport vehicles or other mass transportation vehicles. Similarly, an energy storage system can be used in the automotive industry and can be provided as a fuel cell or battery for a motor vehicle (automobile). Preferably, the vehicle energy storage system may be rechargeable.

The design of the elements in the form of a flattened four-sided pyramid compensates for the change in the volume of electrolytes

[00264] In rechargeable zinc-air cells, electrolyte volumes usually do not remain constant. During the discharge of an element, as zinc metal (with a relatively high density) is converted to lower density zinc compounds, the volumes of electrolyte may increase. During the charge of the cell, a reverse reaction occurs, and the volume of electrolyte may decrease. Electrolyte volumes may also decrease due to evaporation of water.

[00265] These changes in electrolyte volumes can adversely affect cell performance. If the electrolyte volumes become too small, there may be insufficient conductive electrolyte between the metal electrode and the air electrode. This can cause an increase in the resistance of the element, which, in turn, can adversely affect the performance of the element. Similarly, if electrolyte volumes increase too much, excess electrolyte may be forced to enter the pores of the air electrode. The electrolyte penetrating into and flooding the pores of the air electrode does not allow gaseous oxygen to easily diffuse (and electrochemically recover) inside the pores. In addition, the increased volume of electrolyte exerts pressure on the air electrode and can lead to mechanical damage to the electrode. This leads to poor performance of the element.

[00266] The regulation of these constantly changing volumes of electrolyte in a working full battery pack can be implemented by the presence of a feedback mechanism that can automatically compensate for changes in electrolyte volumes. When cells need additional electrolyte (for example, during cell charging, when electrolyte levels decrease), the electrolyte may be allowed to slowly drain from the reservoir into individual cells. During the discharge of cells, as the electrolyte volume increases, excess electrolyte inside the cells can be diverted through the overflow opening into the storage tank.

[00267] The previously described embodiments may include a four-element, horizontal structure, which includes a filling opening and an output opening located at the junction where all four horizontally located elements meet. This hollow fill / outlet opening may allow electrolyte to flow in and out of the individual cells as needed. Since a number of these four-element assemblies are stacked on top of each other, the fill / output opening of the upper four-element assembly can be located exactly above the lower four-element assembly. Thus, a certain number of four-element assemblies stacked in a vertical stack can share a common filling / output opening, which is connected to a common tank.

[00268] Another horizontal four-element structure may be provided in accordance with another embodiment of the invention. The horizontal design may include assembling a four-element assembly in such a way that each element in this assembly has a slight bias (was tilted) upward (only on one side) to the filling / output opening. This can physically compensate for the evolution of gas, allowing the gas to move more freely toward the outlet.

[00269] FIG. 10 depicts a top view (looking down) of four elements (Element 1, Element 2, Element 3, Element 4) in a horizontal node. Elements can be arranged so that they share a common opening of filling and output (denoted by O). The angle of each individual element is slightly inclined upward to O. Thus, the angle of each individual element located farthest from O can be inclined downward.

[00270] Another way to visualize this design would be to represent four separate elements arranged in a four-sided pyramid (the top of the pyramid would be the point where all four elements meet), but instead of sharply tilting upwards as in a regular pyramid, this the pyramid would be flattened until the tilt angles were only 1-5 degrees relative to the horizontal. The tilt angle of each individual element in a four-element assembly can have any value, including, but not limited to, 0.25 degrees or less, 0.5 degrees or less, 0.75 degrees or less, 1 degree or less, 2 degrees or less , 3 degrees or less, 4 degrees or less, 5 degrees or less, 6 degrees or less, 7 degrees or less, or 10 degrees or less. Preferably, each element may be inclined at the same angle, while in other embodiments, individual elements may be inclined at different angles. This flattened, four-sided pyramid design is designed to facilitate electrolyte control and gas evolution during discharge / charge cycles.

[00271] This is shown in side view in FIG. 11B. Here, each of the elements 1150a, 1150b, 1150c in the stack assembly may be slightly inclined upward relative to the horizontal, closer to the filling opening. In some embodiments, a slope of about 1.5 degrees may be provided. The upper water tank 1152 may have one or more drain pipes 1154. Drain tubes can allow an adjustable amount of electrolyte to drain from the upper water tank to the downstream cells. In some embodiments, tap tubes with an internal diameter of ѕ inch may be provided.

[00272] The design may include one or more spacers 1156 inside the manifold 1158. This manifold may provide a clearance between the upper water reservoir and the underlying elements. In some embodiments, the spacer may help maintain a clearance between the upper water tank and the individual elements. In some embodiments, the spacer may provide support between the elements and the upper water reservoir.

[00273] One or more flow control parts 1166 may control the flow rate of electrolyte from the upper water reservoir to the underlying cells. In some embodiments, the flow control part may protrude or may be vertically aligned. The flow control part may break the electrolyte into small droplets. In some embodiments, the flow control part may prevent an electrical bridge from forming between the electrolyte in the upper water reservoir and the electrolyte in any separate underlying cell. A drop from the flow control part may be “caught” by the underlying element. In some embodiments, the underlying elements may have an opening with an overflow area. Details of the flow control can be vertically aligned over the overflow site. The openings of vertically aligned elements can also be vertically aligned. In some embodiments, a drop may fall into the cell electrolyte bath 1160. The electrolyte from the upper cell can drain into the underlying cell. In some embodiments, each cell can have its own cell flow control part 1164, which can also control the flow of electrolyte entering the underlying cells. The cell flow control part can break the electrolyte into droplets and prevent the formation of an electrical bridge between the electrolyte in this cell and the electrolyte in the underlying cell. In some embodiments, the flow control parts may be in substantially vertical alignment with the flow control parts located above and / or below the elements. As an alternative, they can have a stepwise or some other combination (alignment). Between the elements, one or more ducts 1162 may be provided.

[00274] As previously discussed, the individual cells can be tilted so that the electrolyte-receiving portion of the cell can be tilted up. The electrolyte may flow from the electrolyte-receiving portion of the cell to the other end of the cell.

[00275] The slightly inclined orientation of the elements has a number of notable advantages when the elements are stacked. The first advantage is that the constant and reproducible resistance of the element between the metal electrode and the air electrode is still maintained. This helps keep electrolyte resistance under tight control.

[00276] A second advantage is the control of gas bubble formation. During the charge cycles of the element, as water is restored, gaseous oxygen bubbles are necessarily generated. This inclined electrode design can allow these generated gas bubbles to move easily towards the top of the electrode — close to the angle of the electrode, where they can then be safely retracted. The fact that gas bubbles move easily to one side eliminates the potential problem of increasing electrolyte resistance due to trapped gas bubbles in the electrolyte. The tilted structure can be positioned at a slight angle to allow gas to escape and facilitate the flow of suspended solids in the flow-through configuration of the battery.

[00277] A third advantage is that during charge cycles (when electrolyte is added from the reservoir to each individual cell), the tilted design of the cell allows the added electrolyte to easily enter and fill each individual cell.

[00278] The angle of each element should not be large. It is clear that if the tilt angles of the individual cells were too steep, the added electrolyte would drain to the bottom of the cell and flood the bottom of the air electrodes.

[00279] The preferred angle of inclination may be in the range of only 1-5 degrees relative to the horizontal. It can be small enough so that the electrolyte will practically not collect at the bottom of each element, but any generated gas bubbles are diverted and rise to the top opening of the assembly and can easily exit.

[00280] FIG. 11A depicts an example of a top view of an energy storage system in accordance with an embodiment of the invention. In some embodiments, the energy storage system may function as a flow element. As an alternative, it does not have to function as a flow element. The upper water tank may have a bottom 1100. A drain pipe 1102 may be provided to allow the electrolyte to drain into one or more lower cells. In some embodiments, one or more flow control parts 1104 may be provided to control the flow rate of the electrolyte passing into the underlying cells. In some embodiments, the flow control part may break the electrolyte into droplets. In some embodiments, a flow control part may be provided for each underlying element. For example, if four horizontally oriented cells (forming a four) share a common electrolyte control system, then four flow control details may be provided. Each detail of the flow control can be projected above its corresponding element. Any number of flow control parts may be provided, which may or may not correspond to the number of underlying elements in the layer immediately below. For example, one, two, three, four, five, six, seven, eight, nine, ten or more flow control parts may be provided.

[00281] The four elements may also have a central portion that can be tilted down in the direction of the element. Any electrolyte that can drain to the central part can flow down into the underlying cell. In some embodiments, the central portion may be injection molded.

[00282] One or more features, characteristics, components, materials or steps known in the art may be included in the invention, and vice versa. See, for example, US patent No. 4168349, US patent No. 4463067, US patent No. 5126218, US patent No. 7582385, US patent No. 7314685, US patent No. 5716726, US patent No. 4842963, US patent No. 4038458, US patent No. 5242763, patent US No. 5306579, US patent No. 6235418, US patent publication No. 2006/0141340, US patent publication No. 2008/0096061, PCT publication No. WO 2007/144357, which are incorporated herein by reference in full.

[00283] Example

[00284] In one example, a test item could be provided. FIG. 13 depicts an example of a cell voltage versus test time in accordance with an embodiment of the invention. A test time of 350,000 seconds was provided to demonstrate that the system was working.

[00285] The stable voltage range was the result of an early test element. In the early version of the element, there was no physical deterioration (degradation). For example, as shown in FIG. 13, the voltage remained relatively stable for 350,000 seconds. For the most part, the voltage cyclically fluctuated between 0.9 and 2.1 volts.

[00286] It should be understood from the foregoing that, although specific implementations have been illustrated and described, various modifications can be made and anticipated in them. It is also not intended that the invention be limited by the specific examples given in the description. Although the invention has been described with reference to the above description, descriptions and illustrations of preferred embodiments are not to be construed in a limiting sense. Moreover, it should be understood that all aspects of the invention are not limited to the specific images, configurations, or relative proportions given herein, which depend on a wide variety of conditions and variable parameters. Various modifications in the form and details of embodiments of the invention will be apparent to those skilled in the art. Therefore, it is intended that the invention should also cover any such modifications, changes, and equivalents.

Claims (23)

1. Battery cell assembly comprising:
a first element having a first metal electrode, a first air electrode and an electrolyte between them; and
a second element having a second metal electrode, a second air electrode and an electrolyte between them,
wherein the first metal electrode of the first element is in contact with the second air electrode of the second element so that an air tunnel is formed between the first metal electrode and the second air electrode, and the first metal electrode and the second air electrode are aligned vertically and horizontally oriented. 2. The battery cell assembly according to claim 1, wherein the first metal electrode is in contact with the second air electrode, being crimped around the second air electrode, thereby forming a centrode. 3. The battery cell assembly according to claim 2, wherein the centrode provides a serial connection between the first cell and the second cell. 4. The battery cell assembly according to claim 1, wherein the first cell, the second cell and one or more cells are stacked vertically and oriented horizontally. 5. The battery cell assembly according to claim 1, wherein gas flows horizontally inside the air tunnel. 6. The battery cell assembly according to claim 3, further
containing:
a third element having a third metal electrode, a third air electrode and an electrolyte between them; and
a fourth cell having a fourth metal electrode, a fourth air electrode and an electrolyte between them;
wherein the third metal electrode of the third element is crimped around the fourth air electrode of the fourth element so that an air tunnel is formed between the third metal electrode and the fourth air electrode, thereby forming a second centrode, and
wherein the second centrode is in electrical contact with the centrode, providing a connection between the first and second elements. 7. An energy storage system comprising:
an electrolyte supply unit with a flow control part configured to distribute liquid electrolyte to an underlying metal-air battery cell; and
a plurality of metal-air battery cells containing at least one filling or discharge opening having an overflow section,
wherein the flow control part is aligned vertically above the overflow area, wherein the metal-air battery cells are vertically aligned and stacked on top of each other, and the metal-air battery cells are configured to undergo one or more electrode reactions, further comprising at least one from: chlorine, hypochlorite
or chloride. 8. A rechargeable metal-air battery cell comprising:
metal electrode;
air electrode; and
an aqueous electrolyte between the metal electrode and the air electrode,
wherein the metal electrode is in direct contact with the electrolyte, and no separator is provided between the air electrode and said metal electrode. 9. The battery cell according to claim 8, further comprising a frame supporting the metal electrode and the air electrode at a fixed distance from each other. 10. The battery cell according to claim 8, wherein a fixed distance between the metal electrode and the air electrode determines the space in which the aqueous electrolyte is contained. 11. The battery cell according to claim 8, wherein the metal electrode is a zinc-based anode. 12. The battery cell according to claim 8, wherein the air electrode is a carbon based oxygen cathode or a polymer based oxygen electrode having a breathable hydrophobic membrane; corrosion resistant metal down conductor; and at the same time, during oxygen charging at anode potentials, oxygen evolution prevails. 13. The battery cell according to claim 8, wherein the frame is formed of plastic. 14. The battery cell according to claim 8, wherein the air electrode is provided above the metal electrode. 15. The battery cell according to claim 8, wherein the frame includes a shelf that protrudes into the cell and contacts a metal electrode. 16. The battery cell according to claim 8, further comprising an auxiliary electrode between the air electrode and the metal electrode or on both sides of the metal electrode, configured to charge the cell and the associated generation of oxygen. 17. The battery cell according to claim 8, wherein the air electrode contains manganese. 18. The battery cell according to claim 8, wherein the air electrode comprises at least one of: manganese dioxide or a soluble manganese salt. 19. The battery cell according to claim 8, wherein the air electrode comprises at least one of cobalt or iridium. 20. The battery cell according to claim 8, wherein the air electrode comprises at least one of: cobalt chloride or iridium oxide. 21. The battery cell according to claim 8, wherein the battery cell is configured to undergo one or more electrode reactions, further including at least one of: urea or ammonia. 22. The battery cell according to claim 8, wherein the battery cell is configured to undergo one or more electrode reactions, further including at least one of: chlorine, hypochlorite or chloride. 23. A method of storing energy, including:
providing one or more centrodes having a metal electrode of the first element in contact with the air electrode of the second element, while providing an air tunnel between the metal electrode and the air electrode; and
providing a first frame extending above said one or more centrodes and a second frame extending below said one or more centrodes, wherein the first cell includes a space above the metal electrode and is surrounded by a first frame for receiving electrolyte, and the second cell includes a space under the air electrode and is surrounded by a second frame for receiving electrolyte.

Images