HK1166422A - A battery - Google Patents

Description

Battery with a battery cell

Technical Field

The present invention relates to the field of reusable batteries and in particular batteries activated by the addition of a liquid such as water.

Background

A problem with many conventional finished batteries, such as AA, AAA, D batteries, is that battery performance tends to decrease over time during storage. This is particularly problematic in emergency situations where a flashlight, radio or other potential life saving device needs to be powered by a battery that can be used properly.

Water-activated batteries have been employed to seek to address the above problems because they can be stored in an inactive state (i.e., when water or a water-based substance has not been added to the electrolyte powder mixture) for a relatively long period of time. Such batteries can then be activated by the addition of water or water-based substances when needed for use without significant loss of performance of the battery.

However, existing water activated batteries also exhibit certain disadvantages. For example, to add water to an electrolyte powder mixture within a cell to activate the cell, a pipette is typically required to inject the water under pressure into the cell housing through a small hole in the cell tip. This process can be tedious and cumbersome, especially for small children, and if the pipette is inadvertently lost, water cannot be injected into the small hole to properly activate the battery. Furthermore, due to the existing internal cell configuration, it is difficult to efficiently transport water into contact with most of the electrolyte powder within the cell, and this adversely affects the electrical performance of the cell.

Another problem associated with current water activated batteries is that the housing is often made of magnesium or other such materials that expand and deform over time during use. When the battery has deformed, it is not only difficult to remove from the electronic device, but it may also damage the electronic device as a result. Furthermore, current water activated batteries using magnesium anodes are susceptible to degradation and the useful life of the battery is relatively short due to strong reactions with water or water-based substances.

Disclosure of Invention

The present invention seeks to mitigate at least one of the problems discussed above in relation to the prior art.

The present invention may be embodied in a number of broad forms. Embodiments of the invention may comprise one or any combination of the different broad forms described herein.

In a first broad form, the present invention provides a battery comprising:

a metal tube having opposing first and second ends, and an inner peripheral surface defining a chamber in which a liquid activatable powder mixture is disposed;

a permeable separator plate for electrically isolating the powder mixture from the metal tube;

a conductive rod having a first end positioned adjacent to the first end of the metal tube and extending to a second end contacting the powder mixture; and

a channel extending between first and second opposite ends of the metal tube to allow a liquid to flow therethrough, wherein the liquid is capable of being conveyed from the channel through a permeable separator plate substantially along the length of the metal tube to contact the powder mixture so as to activate the powder mixture, whereby the activated powder mixture is adapted to create a potential difference between the conductive rod and the metal tube.

Preferably, the metal tube may include at least one of zinc, magnesium, aluminum, and combinations thereof. More preferably, the metal tube may comprise at least 99% zinc. It is also preferred that the metal tube be immersed in an indium solution to slow or mitigate corrosion.

Preferably, the first end of the metal tube may be substantially sealed by the first end cap and the second end of the metal tube may be releasably sealed by the second end cap. Preferably, the liquid may be adapted to be transported into the chamber via the second end of the metal tube when released from the second end of the metal tube. Typically, the first end cap may comprise a plastic material and the second end cap may comprise a metallic material, such as plated stainless steel, which may help slow or mitigate corrosion.

Preferably, the second end cap and the second end of the metal tube may comprise substantially similar diameters. Preferably, the second end cap may be adapted to directly threadingly engage the second end of the metal tube, or adapted to threadingly engage a housing surrounding the metal tube so as to allow the second end cap to releasably seal the second end of the metal tube. It is also preferred that the second end cap comprises a metallic material adapted to be in electrical communication with the metal tube when the second end of the metal tube is releasably sealed. Typically, the second end cap may also be in direct physical contact with the metal tube when releasably sealing the second end of the metal tube, which may serve as the negative electrode of the battery in use.

Advantageously, the liquid may be relatively easily and quickly transported into the cavity of the metal tube by pouring or otherwise scooping the liquid into the metal tube through the unsealed second end of the metal tube in order to activate the powder mixture. Preferably, the present invention is ideally submerged in purified water for a period of time. This convenient ability to open the second end of the metal tube to deliver liquid therein by removing the releasably sealable second end cap may also alleviate the additional cost and packaging space associated with certain prior art batteries that require the use of a pipette to eject liquid into the battery via a relatively small aperture in the battery housing. In this regard, the present invention may also be advantageous because it may be easier to determine whether the appropriate amount of water has been delivered into the metal tube to activate the cell by visual inspection. In contrast, for certain pre-existing water-activatable batteries, it is difficult to accurately determine whether the appropriate amount of water has been sprayed into the battery via the small hole using a pipette because the end cap of the battery is fixed and not designed to be manually removed by the user to perform a visual inspection. Some indication of the amount of water in the battery is only apparent if excess water has leaked out of a small hole in the battery housing, however, this process is both clumsy and inaccurate. Furthermore, the leakage of excess water from the aperture may not accurately indicate whether the proper amount of water has been delivered to contact the powder mixture within the battery to achieve proper functioning of the battery.

The use of a metal second end cap adapted to releasably seal the second end of the metal tube may also be advantageous in that the second end cap may be readily separated from the metal tube by a user for recycling and/or reuse, if desired. That is, because the metal second end cap can be easily separated from the metal tube of the cell, the need for relatively expensive recovery processes such as metal crushing, smelting, and magnetic separation typically required for a conventional cell that is integrally formed can be alleviated. Typically, the metal tube (which may be typically formed of a zinc material) may be relatively easily removed from the housing (which may be typically formed of a stainless steel material) so that the metal tube is recovered with relatively low energy requirements, while both the housing and the releasably sealable second end cap may be reused to produce a new battery.

Preferably, the first end of the collector bar may extend outside the first end of the metal tube via an aperture disposed in the first end cap. Preferably, the second end of the conductive rod may be substantially embedded within the powder mixture. Typically, the conductive bars may comprise at least one of brass, carbon, stainless steel materials, and combinations thereof.

Preferably, the channel may extend the entire length of the metal tube. It is also preferred that the channel may extend in a substantially straight path between the first and second opposite ends of the metal tube. Typically, the channels may extend in a generally parallel path relative to the long axis of the metal tube. More preferably, the passage may include a groove formed in an inner peripheral surface of the metal pipe. Typically, a plurality of such grooves may be formed in the inner peripheral surface wall of the metal tube. In a preferred embodiment, at least six grooves may be formed in the inner peripheral surface. Typically, the plurality of grooves may be evenly spaced around the inner peripheral surface. The grooves may be etched from the inner peripheral surface of the metal tube using a suitable machine and known techniques. Alternatively, the metal tube may be die cast, wherein the groove is formed in the inner peripheral surface during the die casting process.

Alternatively, the channels may include a tortuous path that may allow for greater exposure to the permeable separator plate and/or surface area of the powder mixture along the length of the metal tube.

Advantageously, the inclusion of said channel, which in a preferred embodiment comprises at least one groove disposed in the inner peripheral surface of the metal tube, allows a more uniform and homogeneous transport of the liquid for contact over the entire surface area of the powder mixture in the metal tube via the permeable separating plate. This is because the liquid can flow through the channels substantially along the length of the metal tube.

In contrast, in some prior art water-activatable batteries, it is difficult to have water penetrate the powder mixture only through the top surface of the powder mixture. In addition, certain other prior art water activated batteries include a sponge located within a metal tube that does not tend to readily release absorbed water to contact the powder mixture immediately after it has been absorbed. As a result, the electrical performance of such prior art batteries tends to be less effective than the electrical performance of the present invention.

Preferably, the liquid may comprise water or any water-based liquid. More preferably, the liquid may include distilled or purified water. Typically, at least about 1.7 grams of water may be delivered into the metal tube of the cell to properly activate embodiments of the invention.

Preferably, the invention may comprise a casing surrounding the metal tube, which may be adapted to substantially reinforce the metal tube against deformation due to thermal effects and the like. In prior art batteries that do not use such a housing, the battery may be more susceptible to deformation due to heat, which makes it difficult to remove the battery from the battery compartment of the electronic device without causing further damage to the electronic device. Furthermore, certain prior art batteries tend not to allow for easy separation of the housing from the metal tube and therefore require shredding during recycling. Typically, the housing may comprise a thickness of between about 0.2 to 1mm and preferably a thickness of 0.5 mm.

Preferably, the second end cap is releasably engageable with the housing when the second end cap releasably seals the second end of the metal tube. It is also preferred that the second end cap is releasably engageable with the housing by means of a threaded engagement. It is also preferred that the second end cap is in electrical communication with the metal tube when the second end cap releasably engages the housing to releasably seal the second end of the metal tube. Alternatively, in certain embodiments, the second end cap may directly physically contact the second end of the metal tube when it is releasably engaged to the housing.

Typically, the housing may comprise a metal such as stainless steel. Advantageously, in embodiments where the second end cap releasably engages the housing, the second end cap may be in electrical communication with the metal tube via the housing.

Alternatively, it may be preferred in certain embodiments to have the housing comprise a plastic material. Advantageously, the plastic housing can reduce the weight of the battery as compared to using other materials such as metal. This may therefore reduce transportation costs when shipping a large number of embodiments of the present invention. The use of a plastic housing can further mitigate potential shorting of the cell in the event that a potentially loose powder mixture within the metal tube contacts the housing. Further, commercial indicia can be relatively easily and inexpensively imprinted and/or decorated (e.g., with color) on the plastic housing during manufacture using suitable machinery for marketing and/or aesthetic purposes, if desired. Typically, if a plastic housing is used, a portion of the plastic housing may be covered with a conductive material to provide electrical communication between the second end cap and the metal tube when the second end cap is releasably engaged to the plastic housing. Typically, the conductive material may cover the threaded portion of the plastic housing on the inner surface of the housing.

Preferably, the powder mixture may include metal oxide powders. Typically, the metal oxide may include at least one of activated carbon, manganese dioxide, iron oxide, and crystalline silver oxide.

Generally, the electrolyte powder mixture can include particles formed from a mixture of ammonium chloride particles, zinc chloride particles, manganese dioxide particles, acetylene carbon black particles, and zinc oxide particles. More generally, in a preferred embodiment, the powder mixture may include, by weight percent of the powder mixture, about 3% ammonium chloride particles, 16% zinc chloride particles, 68% manganese dioxide particles, 12.4% acetylene carbon black, and 0.6% zinc oxide particles.

Typically, the powder mixture may be ball milled using a rotary or planetary ball mill. Generally, the ball mill used to ball mill the powder mixture may include ceramic balls. Generally, the powder mixture particles may comprise diameters in the nanometer to micrometer range. More generally, the powder mixture may include particles having diameters generally in the nanometer to micrometer range. More typically, the powder mixture particles may comprise a diameter of approximately about 4.32 microns.

Preferably, the permeable separator plate may extend substantially along the length of the inner peripheral surface and lie flush with the inner peripheral surface, wherein it provides physical and electrical separation of the electrolyte powder mixture from the inner peripheral surface of the metal tube. Typically, the permeable separator sheet may comprise at least one of a permeable paper material, such as kraft paper, a permeable synthetic polymeric material, and a permeable natural polymeric material. Preferably, the permeable separator plate may comprise a thickness of approximately about 0.08 mm. It is also preferred that the permeable separator plate may comprise a double layer of 0.08mm permeable separator plate to assist in transporting liquid to contact the powder mixture.

Typically, the permeable separator plate may be preformed or folded to complement the contour of the inner peripheral surface of the metal tube. Preferably, a portion of the permeable separator plate arranged to be positioned adjacent to the second end of the metal tube may be adapted to fold over a top region of the powder mixture adjacent to the second end of the metal tube to mitigate leakage of the loose powder mixture outside the second end of the metal tube.

Preferably, a retaining member may be disposed in the chamber adjacent the second end of the metal tube, the retaining member abutting the folded portion of the permeable separator plate. Preferably, the retaining member may comprise at least one aperture to allow fluid communication therethrough from the unsealed second end of the metal tube to contact the folded portion of the permeable separator plate and thereafter contact the powder mixture. Typically, a plurality of apertures may be disposed in the retaining member, and in a preferred embodiment, four apertures may be provided.

Advantageously, the retaining means may help provide a safety mechanism in that if the second end of the metal tube is not sealed by the second end cap (e.g. due to a child inadvertently playing with the invention), the retaining means may help maintain the permeable separator plate securely folded over the top region of the powder mixture adjacent the second end. The powder mixture may then not have the potential to be swallowed or otherwise escape the metal tube by a child. Furthermore, the small hole in the retaining member may enable liquid to flow therethrough to contact the powder mixture also via the top of the powder mixture.

Preferably, the retaining means may comprise a three-dimensional arrangement adapted to engage an o-ring such that the o-ring may be maintained in a substantially fixed position within the metal tube of the cell to mitigate leakage of liquid from the metal tube of the cell in use. Typically, the three-dimensional configuration may include a notch, channel or groove for seating an o-ring. Typically, the three-dimensional configuration may be disposed along the periphery of the retaining member and typically on the side of the retaining member adapted to face outwardly of the second end of the metal tube. Typically, the o-ring may be about 0.5mm thick, whereby pressure of the second end cap releasably sealing the second end of the metal tube may cause the o-ring seated in the three-dimensional configuration of the retaining component to flatten and be forced tightly against the inner surface of the housing so as to mitigate leakage through the gap between the metal tube and the inner surface of the housing.

In a second broad form, the invention provides a battery comprising:

a metal tube having opposing first and second ends, and an inner peripheral surface, the first end substantially sealed by a first end cap and the second end releasably sealable by a second end cap, the inner peripheral surface defining a chamber in which a liquid activatable powder mixture is disposed;

a permeable separation plate disposed between the powder mixture and the inner peripheral surface for electrically isolating the powder mixture from the metal tube;

a conductive rod having a first end positioned outside a first end of the metal tube via a small hole disposed in a first end cap, the first end extending to a second end embedded in the powder mixture; and

a groove formed in an inner peripheral surface of the metal tube extending between the first and second opposing ends to allow a liquid to flow therethrough, wherein the liquid is capable of being conveyed from the groove via a permeable separator plate substantially along the length of the metal tube to contact the powder mixture so as to activate the powder mixture, whereby the activated powder mixture is adapted to create a potential difference between the conductive rod and the metal tube.

In a third broad form, the present invention provides a method of activating a battery, the battery comprising:

a metal tube having opposing first and second ends, and an inner peripheral surface defining a chamber in which a liquid activatable powder mixture is disposed;

a permeable separator plate for electrically isolating the powder mixture from the metal tube;

a conductive rod having a first end positioned adjacent to the first end of the metal tube and a second end embedded in the powder mixture; and is

Wherein the method comprises the steps of:

(i) delivering a liquid into the chamber; and

(ii) directing the liquid along a channel, wherein the liquid is capable of being conveyed from the channel via the permeable separation plate to contact the powder mixture substantially along the length of the metal tube so as to activate the powder mixture, whereby the activated powder mixture is adapted to create a potential difference between the conductive rod and the metal tube.

In a fourth broad form, the invention provides a package comprising a compartment for releasably sealing a battery therein.

Preferably, the battery may comprise a battery formed according to any one of the first and second broad forms of the invention.

Preferably, the capsule may be adapted to provide an air and/or liquid impermeable seal around the battery sealed therein. Preferably, the cells are releasably sealable within the compartment in a humidity controlled environment to mitigate moisture from being trapped within the compartment. Generally, the present invention may include a moisture-absorbing material, such as a desiccant, adapted to absorb at least some moisture from the compartment to mitigate premature activation of the cells therein.

Preferably, the package may comprise a plurality of package compartments arranged in a strip. Typically, the plurality of pods may be substantially identical in shape and size. Typically, the strip may form a rectangular shape.

Preferably, the present invention may include a dispenser having an opening, the dispenser being configured for incrementally dispensing the capsule from the opening. Typically, the dispenser may comprise a spool around which the strip may be wound.

Preferably, at least the first and second adjacent compartments are separable from each other via a tear line disposed in the encapsulation material between the first and second adjacent compartments.

Drawings

The invention will be more fully understood from the following detailed description of preferred but non-limiting embodiments of the invention, taken together with the accompanying drawings, in which:

fig. 1 shows an exploded perspective view of a water-activatable battery according to a first embodiment of the invention;

FIG. 2a shows a perspective view of a zinc cylindrical metal tube of the first embodiment;

FIG. 2b shows a perspective cross-sectional view of the zinc cylindrical metal tube of the first embodiment;

FIG. 2c shows a side cross-sectional view of the zinc cylindrical metal tube of the first embodiment, in which the grooves disposed in the inner peripheral surface of the metal tube can be seen;

FIG. 2d shows an end view of the zinc cylindrical metal tube of the first embodiment, in which evenly spaced grooves in the inner peripheral surface of the metal tube can be seen;

FIG. 3a shows a perspective view of a steel cylindrical shell surrounding and reinforcing a metal tube in a first embodiment;

FIG. 3b shows a perspective cut-away view of the steel cylindrical shell of the first embodiment;

FIG. 3c shows a perspective view of a steel cylindrical housing in which the threaded zones can be seen;

FIG. 4a shows a topological view of a second end cap of the first embodiment adapted to be releasably sealably attached to a steel cylindrical housing;

FIG. 4b shows a side cross-sectional view of the second endcap of the first embodiment;

FIG. 4c shows a side view of the second end cap of the first embodiment;

FIG. 4d shows a topological perspective view of the second end cap of the first embodiment;

FIG. 4e shows a bottom perspective view of the second endcap of the first embodiment;

FIG. 5a shows a bottom view of the retaining member of the first embodiment;

FIG. 5b shows a topology of the holding member of the first embodiment;

FIG. 5c shows a first topological perspective view of the retaining member of the first embodiment;

FIG. 5d shows a second topological perspective view of the retaining member of the first embodiment;

FIG. 6a shows a perspective view of the o-ring of the first embodiment adapted to engage in a three-dimensional seating configuration of a retaining member;

FIG. 6b shows a side view of the o-ring shown in FIG. 6 a;

FIG. 7a shows a side view of an assembly comprising a plastic first end cap, a steel contact, and a carbon rod adapted to contact the electrolyte powder mixture while the steel contact protrudes outside of an aperture in the first end cap;

FIG. 7b shows a first perspective view of an assembly including a plastic first end cap, a steel cap, and a carbon rod adapted to contact the electrolyte powder mixture while the steel contact protrudes outside of an aperture in the first end cap;

FIG. 7c shows a second perspective view of an assembly including a plastic first end contact, a steel contact, and a carbon rod adapted to contact the electrolyte powder mixture while the steel contact protrudes outside of an aperture in the first end cap;

FIG. 7d shows a topology of the first endcap;

FIG. 7e shows a bottom view of the first end cap; and

FIG. 8 shows a perspective view of a preformed permeable separator plate comprising a double layer of kraft paper used in accordance with the first embodiment; and

fig. 9 shows an exemplary tape package for a battery, such as a battery formed according to the first embodiment.

Detailed Description

Preferred embodiments of the present invention will now be described with reference to the drawings. Exemplary embodiments described herein include water activatable batteries adapted for use in compliance with the shape, size and power output requirements of finished AA and AAA batteries. However, those skilled in the art will appreciate that embodiments of the present invention may include other types of batteries having different shapes and sizes and electrical outputs comparable to conventional AAA type batteries and the like.

Turning first to fig. 1, a first embodiment battery 1 is shown in an exploded perspective view. The battery 1 remains inactive until a liquid, such as water or any other suitable water-based liquid, is added thereto, and may have a much longer shelf life than conventional batteries intended for similar types of applications due to its initial inactive state, as such conventional batteries tend to deteriorate almost immediately after manufacture. When water is delivered into contact with the powder mixture 11 disposed inside the battery, the powder mixture 11 is activated and creates a potential difference between the electrically isolated positive and negative electrodes of the battery, which can then be used as a power source for flashlights, radios, and other electronic devices. The features and operation of this embodiment will be described in detail as follows.

The cell 1 comprises a cylindrical metal tube 2 having opposite first and second ends, as shown in fig. 1 and 2a to 2 c. The first end 2a of the metal tube is sealed by a disc-shaped first end cap 3, said first end cap 3 comprising ABS material 3b in which a small hole 3a is arranged. The second end 2b of the metal tube 2 may be releasably sealed by a second end cap 4, said second end cap 4 being adapted to threadedly engage complementary threads on the inner surface at the end of the housing 6 surrounding the metal tube 2. The first and second end caps 3, 4 are shaped to substantially complement the shape and size of the first and second ends 2a, 2b of the metal tube 2. The first and second end caps 3, 4 are shown in fig. 1, 4 a-4 e and 7 a-7 e of the drawings.

The second end cap 4 is formed from a metallic material, such as stainless steel, so that the metal tube 2 and the second end cap 4 are in electrical communication when screwed into a sealed position adjacent the second end 2b of the metal tube 2. In this embodiment, when the second end cap 4 is releasably sealing the second end 2b of the metal tube 2, the second end cap 4 is actually attached by threadedly engaging the steel housing 6 surrounding the metal tube 2. The steel housing 6 will be described in more detail below. When the second end cap 4 is screwed onto the steel casing 6, it is also in direct physical contact with the second end 2b of the metal tube 2 so as to enable electrical communication between the second end cap 4 and the metal tube 2, the second end cap 4 and the metal tube 2 together forming, in use, the negative electrode of the battery.

Referring now to fig. 2a to 2d, it can be seen that the metal tube 2 comprises an inner peripheral surface 2c, the inner peripheral surface 2c defining a chamber 2d for storing the powder mixture 11. Six evenly spaced grooves 2e are formed along the inner peripheral surface 2c of the metal tube 2, which extend in a substantially straight path between the first and second ends 2a, 2b of the metal tube 2. Grooves 2e are cut or etched from the inner peripheral surface so as to have a suitable size and dimension to allow water to freely flow therethrough from the second end 2b toward the first end 2a of the metal pipe 2. In some embodiments, it is possible to die cast the metal tube 2 with the grooves formed therein.

In an embodiment of the present invention, the electrolyte powder mixture 11 includes a metal oxide powder such as manganese dioxide, iron oxide, or crystalline silver oxide, which substantially fills the chamber 2d of the metal tube 2. In a preferred embodiment, the powder mixture 11 includes, by weight percent of the powder mixture 11, about 3% ammonium chloride particles, 16% zinc chloride particles, 68% manganese dioxide particles, 12.4% acetylene carbon black particles, and 0.6% zinc oxide particles.

The powder mixture is ball milled using a rotary or planetary ball mill and ceramic balls such as agate (light jade marrow). During the test, a laboratory ball mill with a capacity of 500ml and ceramic grinding balls with a weight of 110g and a diameter of 22.4mm or small balls with a weight of 190g and a diameter of 10.0mm were used. Furthermore, during the test, 150g of the powder mixture were ground in each case. It will be appreciated that ball milling of the powder mixture may be scaled up to commercial size as appropriate to accommodate much larger scale production.

The particles of the powder mixture produced by ball milling comprise diameters in the nanometer to micrometer range. In a preferred embodiment, the diameter of the powder mixture particles is about 4.32 microns.

In certain embodiments, the powder mixture 11 is deposited into the chamber 2d of the metal tube 2 by a machine after the permeable separating plate 9 has been positioned to line the inner peripheral surface 2c of the metal tube 2. Thereafter, the metal tube may be shaken to more evenly distribute the powder mixture 11 within the chamber 2 d. A plunger may then be used to compact the powder mixture 11. These steps may be repeated one or more times as necessary to help maximize the amount of powder mixture in the chamber 2d of the metal tube 2.

The powder mixture 11 is substantially physically and electrically isolated from the inner peripheral surface 2c of the metal tube 2 by the permeable separating plate 9. The permeable separator sheet comprises a double layer of 0.08mm kraft paper. A single piece of kraft paper may be doubled over for this purpose. The outer surface of the permeable separating plate 9 lies flush with the inner peripheral surface 2c of the metal pipe 2 while the inner surface contacts the powder mixture 11 in the metal pipe 2.

Although the permeable separator plate 9 is made of permeable paper, synthetic or natural polymeric materials may be used in alternative embodiments.

Conveniently, the permeable separator plate 9 enables liquid to pass therethrough and contact the powder mixture 11 by capillary action in use, without unduly retaining the liquid as in the case of sponge-like materials. As shown in fig. 8, the end portion 9a of the permeable separator plate 9 is folded against the area of the powder mixture 11 adjacent to the second end 2b of the metal tube 2 to help prevent any loose powder mixture 11 from leaking out of the second end 2b of the metal tube 2 when unsealed.

The battery 1 further comprises a current conducting rod 5, the current conducting rod 5 having a first end constituted by a steel contact 5a and a second end constituted by a carbon rod 5 b. The carbon rod 5b extends inside the metal tube 2 from the first end 2a of the metal tube 2 substantially toward the second end 2b of the metal tube 2, and is embedded in the powder mixture 11. A steel contact 5a coupled to a carbon rod 5b extends outside the first end 2a of the metal tube 2 via an aperture 3a in the first plastic end cap 3. The conductive rod 5 is electrically isolated from the metal tube 2 and the metal second end cap 4. When assembling the embodiment battery, the conductive rod 5 consisting of the steel contact 5a and the carbon rod 5b may be manipulated inside the metal tube 2 in a direction from the open second end 2b towards the first end 2a until the steel contact 5a protrudes outside the aperture 3a of the plastic first end cap 3. The apertures 3a are sized to prevent the conductive rods 5 from being able to pass entirely through the apertures 3 a.

The diameter of the small hole 3a in the first end cap 3 is designed to slip fit the diameter of the steel contact 5a in order to mitigate any loose powder mixture 11 adjacent the first end 2a of the metal tube 2 from escaping. An o-ring is disposed between the first end cap 3 and the first end 2a of the metal tube 2 for sealing purposes.

When the battery 1 is in operation, the collector bar 5 acts as the positive electrode of the battery 1 to which positive ions generated due to chemical reactions at the metal tube 2 will flow via the permeable separator plate 9 and the powder mixture 11.

To activate the cell 1, the second end cap 4 is unscrewed from the steel housing 6 to allow water to be delivered into the metal tube 2 to contact the powder mixture. For best electrical performance, the entire unsealed cell is preferably submerged in a cup of purified or distilled water for at least 5 minutes so that water can enter through the unsealed second end 2b of the metal tube, flow generally along the length of the groove 6e in the inner peripheral surface 2c of the metal tube 2, and then flow from the groove 6e through the permeable separator plate 9 to contact the powder mixture. This will help to allow water to flow more thoroughly through the grooves in the inner peripheral surface 2c of the metal tube 2. However, if the battery embodiment is not fully submerged in water, the powder mixture 11 may be activated by scooping or pouring at least about 1.7 grams of water into the unsealed second end 2b of the metal tube 2, followed by resealing the second end cap 4 to the second end 2b of the metal tube 2.

The water flows from the grooves 2e substantially along the entire length of the cell 1 and due to its capillary action passes through the permeable separator plate 9 and then contacts the powder mixture 11. In alternative embodiments, the grooves may include a curved path to further increase the amount of water that may have contact with the powder mixture 11. As will be appreciated, the surface area of the powder mixture 11 into which water can contact and penetrate is much greater than in the case of prior art water-activated cells, which require water to penetrate the powder mixture only at the top surface of the powder mixture 11.

Once the second end cap 4 has been screwed back onto the steel housing 6 to releasably seal the second end 2b of the metal tube 2, the battery 1 is activated and ready for powering the electronic device. In certain embodiments, it is contemplated that water may be injected under pressure into chamber 2d by using a pipette inserted into a relatively small opening in the sealed second end 2b of metal tube 2. However, this option is less preferred given that an additional pipette is required to spray water into the metal tube and a visual indication is lacking to help determine whether the battery 1 has been injected with the correct amount of water.

Once the water has contacted the powder mixture 11, the powder mixture 11 chemically reacts with the metal tube 2, thereby creating a potential difference between a positive electrode consisting of the conductive rod 5 and a negative electrode consisting of the combination of the second end cap 4 and the metal tube 2. While the permeable separator plate 9 disposed between the positive electrode (i.e., collector bar) and the negative electrode (i.e., metal tube and second end cap) of the cell 1 physically and electrically isolates the positive electrode and the negative electrode of the cell, it also allows positive ions formed in use as a result of chemical reactions to flow freely from the negative electrode metal tube 2 toward the positive electrode in order to continue to generate and maintain a potential difference. Thus, electrons formed at the negative electrode are able to flow from the negative electrode through the load device and back to the positive electrode of the battery 1.

In a preferred embodiment, the metal tube 2 is formed of at least 99% zinc, by weight percentage of the metal tube 2. The use of zinc material in metal tube 2 will result in a relatively low energy chemical reaction within cell 1 and this helps extend the operating life after cell activation, since the zinc material in metal tube 2 takes longer to corrode in use than conventional cells such as those using magnesium metal tubes. Additionally, the zinc metal tube 2 is immersed in indium to mitigate corrosion. In alternative embodiments, the metal tube 2 may be substantially formed of magnesium, aluminum, or any combination thereof. However, the use of magnesium to form metal tube 2 may cause relatively severe chemical reactions to occur within battery 1 after activation due to the relatively rapid depletion of magnesium metal tube 2, which tends to shorten the operating life of battery 1.

The use of the zinc metal tube 2 will also provide a relatively lower but more controlled and regular electrical output over a relatively longer lifetime after activation than the use of the magnesium metal tube 2, which will provide a relatively higher output power over a relatively shorter lifetime after activation. The use of magnesium metal tubes also produces an unconventional 2.1V initial voltage which may damage the product in the case of series use. Generally, if metal tube 2 is formed of magnesium, it is expected that the useful life of such embodiments may last about 2 to 3 weeks after activation, while the useful life of embodiments using zinc as metal tube 2 may last about 6 to 12 months after activation. It is contemplated that in a further alternative embodiment of the invention, a sacrificial anode may be included in the cell to slow corrosion of the metal tube material.

When the potential difference across the cell 1 drops to an unusable level, water may be refilled into the cell 1 as described above to reactivate the powder mixture 11 and again create a usable potential difference across the positive and negative electrodes of the cell 1.

As mentioned above, the steel shell 6 surrounds the metal tube 2 as a reinforcement of the metal tube 2 to resist deformation due to heat and other stresses typically generated during use. In this embodiment, the steel housing 6 is adapted to slide over the metal tube 2 as a sliding fit over the outer sleeve. As shown in fig. 9, the housing 6 is folded over the first end 2a of the metal tube 2 and over the peripheral edge of the first end cap 3 in order to prevent the metal tube and the first end cap from being ejected out of said end of the housing 6. The opposite end of the housing 6 on which the thread 6a is located is not folded over the second end 2b of the metal tube 2 so as not to prevent the metal tube 2 from being ejected from said end of the housing 6 during separation for recycling purposes as described further below.

In the case where the housing 6 is a metallic material, it will be in electrical communication with the metal tube 2 because the inner peripheral surface of the housing surrounds and closely abuts the outer peripheral surface of the metal tube 2 so as to facilitate electrical communication therebetween.

The housing 6 comprises internal threads 6a as shown in fig. 3c to releasably engage a complementary thread arrangement 4a disposed on the second end cap 4 as shown in fig. 4 b-4 e. The second end cap 4 includes a cruciform indentation 4d disposed on its outwardly facing surface to enable screwdriver heads, coins and fingernails to screw the second end cap 4 to the steel shell 6 or unscrew the second end cap 4 from the steel shell 6. The second end cap 4 further comprises a ridge 4b arranged around the peripheral edge which can be grasped by the fingers of a user to unscrew the second end cap 4 from the housing 6.

In certain embodiments, a plastic housing 6 may be used. The plastic housing may be preformed and/or molded to fit tightly around the metal tube 2. If a plastic housing 6 is used, it will be necessary to ensure that the second end cap 4 is screwed firmly inside the plastic housing 6 and contacts the second end 2b of the metal tube 2 so that it is electrically connected and the second end cap 4 and metal tube 2 act as a negative electrode in use. In certain embodiments, the threaded portion 6a of the plastic housing 6 is covered with an electrically conductive material to help provide electrical communication between the second end cap 4 and the metal tube 2. Advantageously, the outer surface of the plastic housing 6 may be relatively easily embossed and/or decorated with trademarks and/or other commercial indicia. Also, the plastic housing may be desirable due to its relatively light weight, which saves cost during shipping of the disassembled plastic housing to a factory for reuse in manufacturing new batteries.

In the case of the metal housing 6, the second end cap 4 provides electrical communication between the second end cap 4 and the metal tube 2 without the second end cap 4 having to directly contact the metal tube 2. The second end cap 4 should still be screwed firmly to releasably engage the housing 6 so that pressure is exerted on the o-ring 10 as shown in fig. 6a and 6b to help hold it in a substantially stable position whereby it mitigates liquid leakage in the gap between the zinc metal tube 2 and the inner surface of the housing 6.

In an alternative embodiment, second end cap 4 may be releasably engaged directly to second end 2b of metal tube 2 by threaded engagement or any other suitable attachment means without the use of a housing.

Turning to fig. 5 a-5 d, a plastic circular holding member 8 is shown that is adapted to rest on a folded portion 9a of a permeable separator plate 9, the folded portion 9a closing off a top portion of the electrolyte powder mixture 11 adjacent the second end 2b of the metal tube 2. The holding member 8 comprises a cylindrical cross-section with a diameter similar to the diameter of the second end 2b of the metal tube 2 such that it fits tightly inside the second end 2b of the metal tube 2.

The holding part 8 also comprises four segment-shaped apertures 8a, which pass completely through from one side to the other. Advantageously, the retaining member 8 not only helps to hold the folded portion 9a of the permeable separation plate 9 in place to prevent the loose powder mixture 11 from escaping via the second end 2b of the metal tube 2, but it also allows water to flow therethrough via the folded portion 9a of the permeable separation plate 9 to contact the powder mixture 11. When water is delivered into the unsealed second end 2b of the metal tube 2, not only will the water flow along the length of the metal tube 2 via the grooves 2e in the inner peripheral surface 2c of the metal tube 2, but also some of the water may flow through the small holes 8a in the holding member 8 and contact the powder mixture 11 via the top of the powder mixture 11 covered by the folded portion 9a of the permeable separating plate 9. It should be noted that in certain alternative embodiments, the water may first pass through the small hole 8a of the holding member 8, after which the water flows into and along the groove 2e in the inner peripheral surface of the metal pipe 2.

Also as mentioned above, the retaining member 8 includes a three-dimensional configuration 8b adapted to engage another o-ring 10. As such, the three-dimensional configuration includes a recess extending around the periphery of the retention member 8 on the outward facing side of the retention member 8. The o-ring 10 is about 0.5mm thick, whereby the pressure of the second end cap 4 releasably sealing the second end 2b of the metal tube 2 causes the o-ring 10 seated in the three-dimensional configuration 8b of the holding member 8 to flatten and be forced tightly against the inner surface of the housing 6, so as to mitigate leakage through the gap between the metal tube 2 and the inner surface of the housing 6.

It will be appreciated that during operation of the cell 1, corrosion of the metal tube 2 tends to cause a build-up of waste material at the metal tube 2 which may at least partially block the flow of liquid through the channel 2e over time. In this regard, the ability of the retaining member 8 to allow water to pass therethrough and contact the top surface of the powder mixture 11 is advantageous.

Embodiments of the present invention are assembled in a humidity controlled environment (commonly referred to as a "dry chamber") to mitigate the risk of moisture activating the powder mixture 11 and thereby disrupting battery operation.

In addition to the actual battery embodiments being assembled in a humidity controlled environment, the battery embodiments are also packaged in a humidity controlled environment to mitigate the risk of excess moisture being trapped within the package.

In a preferred embodiment as depicted in fig. 9, the package 12 includes a plurality of substantially identical compartments 12a, which form a strip. Each of the compartments 12a provides a liquid and air impermeable seal around the battery 1 formed in accordance with the first embodiment. The chamber 12a is formed from an environmentally transparent plastics material. The compartment 12a may be formed, for example, by heat sealing a plastics material around the battery 1 using a suitable machine.

Each of the compartments 12a of the package 12 may be separated from one another by tearing along the tear line 12 b.

Advantageously, embodiments of the present invention have been engineered to conform to the physical parameters of standard AA, AAA type batteries, etc. suitable for use in flashlights, radios, mobile phones, etc., while providing output capabilities suitable for powering such devices. By way of example, it has been found that the AA-type cell embodiments of the present invention involving the use of zinc metal tubes are capable of producing an electrical output of 4500 to 5000mA short circuit (maximum amps) at 1.7V, and achieving an mAh of about 600 to 700 at a 25mA constant drain current, which is comparable to the electrical output of conventional AA-type cells used in similar applications.

Tests have been conducted with respect to embodiments of the present invention using different electrolyte powder mixture components to evaluate their effect on electrical performance.

A first powder component comprising about 60% manganese oxide, 3% ammonium chloride, 16% zinc chloride, 0.6% zinc oxide and 20% acetylene black by weight of the powder mixture was used in the examples tested. With a relatively low amount of manganese oxide and a relatively high amount of acetylene black in the electrolyte powder mixture, an initial voltage of 1.62V and a maximum or short circuit amperage of 1.75A produced an electrical output of 250mAh (based on a constant current drain of 200mA with a 0.9V cutoff). An initial voltage of 1.61V and a maximum or short circuit amperage of 2.05A produced an electrical output of 254mAh (based on a constant current drain of 200mA with 0.9V cutoff).

A second powder component comprising about 71% manganese oxide, 3% ammonium chloride, 16% zinc chloride, 0.6% zinc oxide and 9.2% acetylene black by weight percent of the powder mixture was used in the examples tested. With a slightly higher amount of manganese oxide and a slightly lower amount of acetylene black in the electrolyte powder mixture, an initial voltage of 1.65V and a maximum or short circuit amperage of 1.62A produced an electrical output of 280mAh (based on a constant current drain of 200mA with a 0.9V cutoff). An initial voltage of 1.64V and a maximum or short circuit amperage of 1.53A produced an electrical output of 279mAh (based on a constant current drain of 200mA with 0.9V off).

A third powder component comprising, in weight percent of the powder mixture, about 68% manganese oxide, 3% ammonium chloride, 16% zinc chloride, 0.6% zinc oxide, and 12.4% acetylene black was used in the examples tested. An initial voltage of 1.75V and a maximum or short circuit amperage of 3.78A produced an electrical output of 368mAh (based on a constant current drain of 200mA with 0.9V cutoff). An initial voltage of 1.75V and a maximum or short circuit amperage of 3.3A produced an electrical output of 375mAh (based on a constant current drain of 200mA with 0.9V cutoff). This powder component was considered to provide the best electrical properties in the examples of the invention tested.

Advantageously, liquid activated batteries according to embodiments of the invention provide a relatively longer shelf life than conventional batteries, provided that they become effective only after the addition of a liquid to the powder mixture therein. In contrast, conventional batteries tend to deteriorate immediately after manufacture and may not be usable after a relatively short storage duration. While the embodiments of the invention described herein are particularly well suited and intended for use during emergency situations due to long shelf life, the actual output performance of such battery embodiments may be comparable or better than the power output expected of certain conventional batteries.

Advantageously also, the mechanical design of embodiments of the present invention helps provide ease of reusability and recyclability of the component parts. For example, after unscrewing the second end cap 4 from the steel housing 6, the retaining member and o-ring can be easily removed from the metal tube 2, and then the electrically conductive rod 5 and the first end cap 3 can subsequently be passed out of the housing 6 via the second end 2b of the metal tube 2, after which the permeable separation plate 9 is removed. The metal tube 2 will also be easily separable from the steel outer shell 6 via the end of the steel outer tube 6 that is not folded over the second end 2b of the metal tube. The separation of the component parts may be performed manually, by using an automated machine, or a combination thereof.

Thereafter, the housing, second end cap 4 and conductive rod may be collected and returned to the factory for reuse in manufacturing new batteries without incurring time, cost and energy in recycling such portions. Further cost savings can be obtained by collecting these reusable component parts in relatively cost-effective manufacturing rights and shipping them to the factory in bulk.

In embodiments using plastic housings, the relatively light weight of plastic compared to metal can further reduce the cost of shipping the housing back to the factory for reuse, especially if shipped over relatively long distances. It is also understood that the plastic housing can be easier to reuse or recycle because there is typically no welding or fusing involved with the zinc metal tube, which facilitates relatively easy separation from the zinc metal tube 2 before shipping back to the factory for reuse.

The zinc metal tube, the permeable separator plate, and the plastic first end cap can be recycled in a relatively convenient and energy efficient manner as compared to the recycling of conventional batteries. That is, conventional batteries must first be crushed and then smelted, with various materials being recovered at different temperatures. Since the zinc metal tube 2 can be easily separated from the housing 6, pulverization is not required. Also, because the melting temperature of the zinc metal tube tends to be lower than that of the metal tube of a conventional battery, less energy is consumed during the recovery of the zinc tube.

In addition to the advantages outlined above, embodiments of the present invention have also been tested and found to meet the requirements of directive 2002/95/EC (ROHS) for limiting the use of hazardous substances in electrical and electronic equipment. Accordingly, it is believed that the battery embodiments provide an environmentally friendly alternative to prior art batteries due to the high percentage of component parts that can be recycled/reused following ROHS directives.

In addition, embodiments of the present invention have been tested and found to meet the requirements of directive 2006/66/EC and EN 71, section 4(1), clause, in relation to the mercury content of the cell. It has been found that the examples do not contain mercury levels exceeding the specified limits and are therefore considered safe for human use.

It will be appreciated by persons skilled in the art that the invention described herein is susceptible to variations and modifications other than those specifically described without departing from the scope of the invention. All such variations and modifications as would be readily apparent to one skilled in the art are deemed to be within the spirit and scope of the invention as broadly described herein. It is to be understood that the invention includes all such variations and modifications. The invention also includes all of the steps and features referred to or indicated in the specification, individually or collectively, and any and all combinations of any two or more of said steps or features.

The reference to any prior art in this specification is not, and should not be taken as, an acknowledgment or any form of suggestion that prior art forms part of the common general knowledge.

Claims (37)

1. A battery, comprising:

a metal tube having opposing first and second ends, and an inner peripheral surface defining a chamber in which a liquid activatable powder mixture is disposed;

a permeable separator plate for electrically isolating the powder mixture from the metal tube;

a conductive rod having a first end positioned adjacent to the first end of the metal tube and extending to a second end contacting the powder mixture; and

a channel extending between first and second opposite ends of the metal tube to allow a liquid to flow therethrough, wherein the liquid is conveyable from the channel along the length of the metal tube via the permeable separation plate to contact the powder mixture so as to activate the powder mixture, whereby the activated powder mixture is adapted to create a potential difference between the conductive rod and the metal tube.

2. The battery of claim 1, wherein the metal tube comprises at least one of zinc, magnesium, aluminum, and combinations thereof.

3. The battery of claim 2, wherein the metal tube comprises at least 99% zinc by weight of the metal tube.

4. The cell defined in claim 3, wherein the metal tube is immersed in indium.

5. The battery of any of claims 1-4, wherein the first end of the metal tube is sealed by a first end cap comprising a plastic material.

6. The cell defined in any one of claims 1 to 5, wherein the second end of the metal tube is releasably sealable by a second end cap, the second end of the metal tube being adapted to allow the liquid to be transported therethrough into the chamber when unsealed.

7. The cell defined in claim 6, wherein the second end cap and the second end of the metal tube comprise similar diameters.

8. The battery of any one of claims 6 or 7, wherein the second end cap comprises a metallic material adapted to be in electrical communication with the metal tube when the second end of the metal tube is releasably sealed.

9. The cell defined in any one of claims 1-8, wherein the first end of the collector bar extends outside the first end of the metal tube via an aperture disposed in the first end cap.

10. The battery of any of claims 1-9, wherein the second end of the conductive rod is embedded within the powder mixture.

11. The battery of any of claims 1-10, wherein the conductive bars comprise at least one of brass, carbon, and stainless steel.

12. The cell defined in any one of claims 1-11, wherein the channel extends the entire length of the metal tube.

13. The battery of any of claims 1-12, wherein the channel extends in a straight path between the first and second opposing ends of the metal tube.

14. The cell defined in claim 13, wherein the channels extend in a path parallel to the long axis of the metal tube.

15. The battery of any one of claims 1-12, wherein the channel comprises a tortuous path.

16. The battery of any of claims 1-15, wherein the channel comprises a groove formed in the inner peripheral surface of the metal tube.

17. The battery of claim 16, comprising at least six grooves formed in the inner peripheral surface of the metal tube.

18. The battery of claim 17, wherein the at least six grooves are evenly spaced around the inner peripheral surface.

19. The cell defined in any one of claims 1-18, wherein the liquid comprises water or any water-based liquid.

20. The cell defined in any one of claims 1-19, comprising a casing surrounding the metal tube, the casing being adapted to reinforce the metal tube against deformation.

21. The battery of claim 20, wherein the housing comprises at least one of a metal and a plastic material.

22. The battery of claim 21, wherein the metallic material comprises stainless steel.

23. The battery of any one of claims 20-22, wherein the housing comprises a thickness of between 0.2-1 mm.

24. The battery of claims 20 to 23, wherein the second end cap is adapted to threadingly matingly engage the housing to releasably seal the second end of the metal tube, whereby the second end cap is in electrical communication with the metal tube.

25. The battery of any one of claims 1-24, wherein the powder mixture comprises a metal oxide powder.

26. The battery of claim 25, wherein the metal oxide powder comprises at least one of activated carbon, manganese dioxide, iron oxide, and crystalline silver oxide.

27. The cell defined in claim 25 or claim 26, wherein powder mixture particles comprise 3% ammonium chloride particles, 16% zinc chloride particles, 68% manganese dioxide particles, 12.4% acetylene carbon black and 0.6% zinc oxide particles by weight of the powder mixture particles.

28. The battery of any one of claims 1-27, wherein the powder mixture comprises particles having a diameter of 4.32 microns.

29. The battery of any of claims 1-28, wherein the permeable separator sheet comprises at least one of a permeable paper material, a permeable synthetic polymeric material, and a permeable natural polymeric material.

30. The cell defined in any one of claims 1-29, comprising a double-layer sheet of kraft paper 0.08mm thick.

31. The battery of any one of claims 1-30, wherein the permeable separator plate lies flush with the inner peripheral surface of the metal tube.

32. The cell defined in any one of claims 1-31, wherein a portion of the permeable separator plate is folded over the powder mixture adjacent the second end of the metal tube.

33. The cell defined in claim 32, comprising a retaining member disposed in the chamber adjacent the second end of the metal tube, the retaining member abutting the folded portion of the permeable separator plate.

34. The cell defined in claim 33, wherein the retention component comprises at least one aperture to allow fluid communication from the second end of the metal tube therethrough to contact the folded portion of the permeable separator plate.

35. The cell of any one of claims 33 or 34 wherein the retaining member comprises a three-dimensional configuration adapted to engage an o-ring such that the o-ring can be maintained in a fixed position adjacent to the sealed second end cap so as to mitigate liquid leakage from the metal tube.

36. The battery of any of claims 1-35, comprising a shape and size of at least one of an AA-type and AAA-type battery.

37. A method of activating a battery, the battery comprising:

a metal tube having opposing first and second ends, and an inner peripheral surface defining a chamber in which a liquid activatable powder mixture is disposed;

a permeable separator plate for electrically isolating the powder mixture from the metal tube;

a conductive rod having a first end positioned adjacent to the first end of the metal tube and a second end embedded in the powder mixture; and is

Wherein the method of activating the battery comprises the steps of:

(i) delivering a liquid into the chamber; and

(ii) directing the liquid along a channel, wherein the liquid is capable of being conveyed from the channel along the length of the metal tube via the permeable separator plate to contact the powder mixture so as to activate the powder mixture, whereby the activated powder mixture is adapted to create a potential difference between the conductive rod and the metal tube.