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WO1994009525A1 - Stockage d'energie electrochimique et processus d'alimentation d'energie a l'aide du couple fer-soufre - Google Patents

Stockage d'energie electrochimique et processus d'alimentation d'energie a l'aide du couple fer-soufre Download PDF

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Publication number
WO1994009525A1
WO1994009525A1 PCT/GB1993/002109 GB9302109W WO9409525A1 WO 1994009525 A1 WO1994009525 A1 WO 1994009525A1 GB 9302109 W GB9302109 W GB 9302109W WO 9409525 A1 WO9409525 A1 WO 9409525A1
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WIPO (PCT)
Prior art keywords
cell
electrode
chamber
electrolyte
ions
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Ceased
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PCT/GB1993/002109
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English (en)
Inventor
Ralph Zito
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National Power PLC
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National Power PLC
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Publication date
Application filed by National Power PLC filed Critical National Power PLC
Priority to JP6509759A priority Critical patent/JPH08502387A/ja
Priority to EP93922595A priority patent/EP0664931B1/fr
Priority to DE69310529T priority patent/DE69310529T2/de
Priority to AU51537/93A priority patent/AU672049B2/en
Publication of WO1994009525A1 publication Critical patent/WO1994009525A1/fr
Anticipated expiration legal-status Critical
Priority to GR970402028T priority patent/GR3024385T3/el
Ceased legal-status Critical Current

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H01M8/18—Regenerative fuel cells, e.g. redox flow batteries or secondary fuel cells
    • H01M8/184—Regeneration by electrochemical means
    • H01M8/188—Regeneration by electrochemical means by recharging of redox couples containing fluids; Redox flow type batteries
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
    • H01M8/04082—Arrangements for control of reactant parameters, e.g. pressure or concentration
    • H01M8/04186—Arrangements for control of reactant parameters, e.g. pressure or concentration of liquid-charged or electrolyte-charged reactants
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/30—Hydrogen technology
    • Y02E60/50—Fuel cells

Definitions

  • the present invention relates generally to energy storage and power generation systems wherein compensating electrochemical reactions occur at opposite positive (hereinafter + ve ) and negative (hereinafter - ve ) electrodes and energy is stored in, and drawn from, an electrolyte in charge and discharge cycles.
  • the reactions in the class of such systems of interest for the purposes of this invention are substantially reversible such that driving current into such a system charges the system by storing energy in chemical reactants.
  • Chemical reactions take place on either side of an ion transport system (such as a membrane or multiple membranes and/or intermediate cell sections) with selective charge carriers being transported through the membrane. During power generation these chemical reactions reverse supplying current (power) to a load.
  • Some systems reconstitute or regenerate the reagents to restore the cell, as compared to driving current into the cell.
  • US-A-4485154 discloses an electrically rechargeable anionically active energy storage and power delivery system using a sulfide-polysulfide anolyte reaction and an iodide-polyiodide, chloride- chlorine or bromide-bromine catholyte reaction.
  • An object of this invention is to provide a redox process for energy storage and power delivery process where no solids are deposited on the electrodes and where the electrolytes can be electrically restored at least initially. 5. It is yet another object of the invention to provide a safe process with a sufficient power density depending upon the application needs.
  • Another object of this invention is to provide substantially full power even at low states of charge 0 of the system, i.e. the system power production stays constant over time maintaining substantially the same output until close to complete discharge.
  • the ions are provided from salts of these 0 reagents, preferably iron chloride in aqueous solution on the + ve side and potassium sulfide solution on the - ve side.
  • iron salts may also be used, such as the bromide or iodide.
  • K 2 S is preferred for use in the invention, 5 sodium sulfide, l- ⁇ S, will work almost as well, except that Na 2 S is much less soluble than K 2 S.
  • the process of the present invention is carried out in a single cell or in an array of cells, each of which has a + ve electrode and a - ve electrode, in which 0 circulating electrolyte flows are maintained.
  • An ion exchange membrane between the electrodes divides the cells into + ve and - ve chambers.
  • the electrolyte circulating through the - ve chamber during power delivery contains sulfide ions and the electrolyte 5 circulating through the + ve chamber during power delivery contains Fe 3+ ions.
  • a soluble, ionic salt selected from sodium, potassium, lithium and ammonium salts circulates through the + ve chamber of the cell during energy storage (charging) and acts as a charge carrier.
  • a double membrane is provided forming a buffer chamber between the membranes.
  • Eg. 2 The electrochemical reaction of Eg. 2 actually occurs in separate but dependent iron and sulfur reactions.
  • the iron reaction takes place on the + ve side of the membrane and the sulfur reaction on the - ve side.
  • the charge balance is provided by the transport of sodium, potassium, lithium or ammonium ions across the membrane.
  • the reagents involved in the process are as follows: In the discharged state: the + ve side contains FeCl 2 + KC1 + H 2 0, and the - ve side K 2 S 5 + H 2 0.
  • the stoichiometric ratio of FeCl 3 and K 2 S required to fully utilize these reagents is 4 moles FeCl3 to 2.5 moles K 2 S, according to the equation:
  • the primary charge carriers are potassium ions, K + , which are readily transported through the ion exchange membrane.
  • the Fe 3+ or Fe 2+ are poorly transported through the membrane despite the fact that it is a cation exchange membrane.
  • the sulfide ions, S 2 " are anions that are not transported through the cation exchange membrane. These transport properties are most important. Iron sulfide is insoluble in water. Hence, any transport of either sulfide across from the - ve side to the + ve side, or the transport of ferric or ferrous from the + ve side to the - ve side will result in unwanted precipitates which will clog the membrane.
  • the charge carrier comprises sodium, potassium, lithium or ammonium ions, going from the - ve side to the + ve side through the membrane during the discharge portion of a cycle.
  • the ferric ions in the + ve side are reduced to ferrous ions during discharge, and the S 2" ions in the - ve side are oxidized to sulfur (solubilized as polysulfide ion during discharge).
  • the total voltage for this process is 1.15 to 1.25 volts open circuit.
  • K + ions are transported across the membrane from the + ve to the - ve side to balance the charge and transform K 2 S 5 to K 2 S.
  • the sulfur which is present as a doubly charged polysulfide ion S 2" .S ⁇ , (where ⁇ may be as high as 4), is reduced initially to S 2" .S ⁇ _2, and eventually to S 2" .
  • the Fe 2+ is oxidized to Fe 3+ which goes into solution and is available to re-oxidize the S 2 " ions back to sulfur during discharge.
  • Flow of the electrolytes on both sides of the membrane(s) is/are provided, preferably a re- circulation rather than a once through flow in the majority of end uses.
  • the recirculation of the electrolytes provides a chemical replenishment of the electrolytes which operates in the present invention in addition to the electrical restoration of the + ve and - ve electrolytes.
  • These recirculating electrolytes are stored in independent containers where the quantity may be large enough for the specific requirements of a preferred embodiment.
  • the circulation also allows the electrolytes to be filtered, or otherwise reconstituted on a routine basis without taking the system off-line.
  • the electrolyte in the + ve side As the electrolyte in the + ve side is circulated, ferric ions in solution are absorbed at a surface of the + ve electrode and/or in a porous surface layer thereof and replenished at such sites as discharge reduces the ferric to ferrous ions.
  • the surface of the + ve electrode is preferably coated with an active ingredient, preferably an activated carbon, which augments the iron reaction kinetics. This combination provides iron promptly for the discharge requirements, and thus provides full power until substantially fully discharged. During this discharge the output voltage of the cell is nearly constant, with little polarization loss.
  • the - ve side has a similar electrode which absorbs the S 2 " solution for subsequent discharge and enhances performance similar to that described at the + ve electrode.
  • Mid electrodes also defined as intermediate or bipolar electrodes combine the above such that a + ve electrode is provided on one surface, and a - ve electrode on another surface formed on the same substrate.
  • FIGS. IA and IB are schematic views of the basic components of two cell types (A and B) used according to a preferred embodiment of the invention.
  • FIG. IC is diagram of a cell array using the FIG. IB type B cells
  • FIG. ID shows an encapsulation of an array of cells
  • FIG. IE shows a reclamation technique
  • FIG. 2A is a block diagram of a full system using one or both types of the cells of FIG. IA and FIG. IB;
  • FIG. 2B shows a pH compensation cell on both sides
  • FIG. 2C shows an alternative pH compensation cell in the + ve side utilizing a membrane
  • FIG. 3 is a graph of certain cells during discharge.
  • FIGS. 4 and 5 are graphs of the charge/discharge characteristics of certain cells.
  • FIG. IA shows a Type A cell 10 with a + ve electrode 12 and a - ve electrode 14.
  • a cation membrane 16 is formed from a heterogeneous structure made by Sybron Chemical Co. called IONAC MC3470.
  • the membrane 16 acts to separate the + ve and - ve sides of the cell 10 and is selected to minimize migration of iron from the + ve side to the - ve side and to minimize migration of S 2" ions from the - ve to the + ve side.
  • An aqueous solution 22 of FeCl3, FeCl 2 and NaCl is provided in a chamber 22C formed between + ve electrode 12 and the membrane 16, and an aqueous solution 24 of NaS ⁇ is provided in a chamber 24C formed between the - ve electrode 14 and the membrane 16.
  • a solution of ferric chloride of up to 4.0 molar concentration exists in the chamber 22C of the cell, and a solution of Na 2 S at 2.5 molar concentration, exists in chamber 24C of the cell.
  • each of chambers 22C, 24C has a volume of about 200 cc.
  • the cation membrane 16 allows the passage of charge via the transport of Na* ions.
  • IA illustrates a cell which though rechargeable initially cannot be electrically recharged indefinitely.
  • the solutions should periodically be reconstituted externally to the cell and replaced.
  • the charge carriers are the sodium ions (Na + ) which transfer charge through the membrane 16.
  • the Na + ions are moving from the - ve side to the + ve side through the membrane.
  • the ferric ions in the + ve side are being reduced to ferrous ions, and the S 2" ions in the - ve side are being oxidized to sulfur (which is solubilized by the sodium sulfide).
  • the - ve ions are trying to move into the - ve side, but little Cl " is lost since the membrane is a cation exchange membrane.
  • the cation exchange membrane has to satisfy certain conditions with respect to conductivity and selectivity. It must freely transport Na* but exhibit a low diffusion rate for Fe cations.
  • the Type B cell is electrically rechargeable.
  • This embodiment has, in addition to the two chambers of the type A cell, an additional middle chamber 23C separated from the other two chambers enclosing the electrodes by two cation exchange membranes 16A and 16B.
  • the center chamber has an NaCl or NaOH solution 23 circulating through it which does not change composition (an "idler" electrolyte).
  • Using the three chamber rechargeable cell illustrated in FIG. IB means that any precipitation will occur in the middle chamber, and can be removed without interfering with the main electrolyte flow circuits.
  • This method is a totally self contained process (within the energy system) and does not require the introduction of any additional chemical reagents.
  • the liquid 23 is circulated to the idler tank chamber 25, it is passed through an ancillary electrochemical cell 27 specifically designed for reclamation.
  • the - ve electrode 29 of this cell is porous carbon which will collect the iron sulfide precipitates as a filter in the stream of the liquid 23.
  • the + ve electrode 30 is a lightly surfaced carbon composite substrate.
  • liquid 23 in the middle chamber 23C is an NaCl or KCl solution
  • electrolysis will generate iron within the porous carbon - ve electrode and HS at the + ve electrode.
  • the H 2 S is vented from cell 27 as a gas along line 31 back into the - ve electrolyte of the power cell where it reacts with NaOH or KOH to form Na 2 S or K 2 S, respectively, for reuse as the energy storing reagents in the electrolyte.
  • the reaction within the reclamation cell is as follows:
  • the plated iron, Fe ⁇ is later removed by the direct action of Fe 3t ions in the positive side of the power cell by hydraulically switching the reclamation cell into the + ve electrolyte line.
  • the reaction with the reclamation cell is:
  • the cell When providing power, the cell is discharging. In both type A and type B cells similar reactions occur at the two electrodes.
  • ferric ions are reduced to ferrous ions, Fe + to Fe 2+ , and an electron is acquired from the external circuit.
  • sulfide ions are oxidized to molecular sulfur which is solubilized by the sodium sulfide.
  • the electrons produced at the - ve electrode form the current through a load.
  • the chemical reaction at the + ve electrode produces 0.7 to 0.75 volts (open circuit) and the chemical reaction at the - ve electrode produces 0.45 volts (open circuit).
  • the combined reaction produces 1.15 to 1.20 volts per cell (open circuit).
  • FIG. IC shows a cell array 20 of multiple cells connected in electrical series and fluid parallel. End electrodes 12E (+ ve ) and 14E (- ve ) and multiple mid-electrodes 13 (each one having a + ve electrode portion 12A and - ve electrode portion 14A) are spaced out from each other by membranes 16 and screen or mesh spacers 22D, 24D in all the cell chambers 22C, 24C,
  • end electrodes 12E (+ ve ) and 14E (- ve ) have internal conductors 12F and 14F (typically copper screens) encapsulated therein and leading to external terminals 12G, 14G which are connected to external loads (e.g. to a motor M via a control circuit CONT, the motor driving a vehicle) or to power sources (e.g. a utility power grid when used as a load levelling device).
  • loads e.g. to a motor M via a control circuit CONT, the motor driving a vehicle
  • power sources e.g. a utility power grid when used as a load levelling device.
  • FIG. ID shows the manner of encapsulating a cell array such as that of FIG. IC.
  • a cell array 20 (such as shown in FIG. IC) is held between clamping blocks CB and dipped at one edge into a shallow container having a bath of liquid epoxy resin (not shown) therein. The epoxy resin hardens to form a wall of the battery.
  • Flow conduits such as manifold 22M with feed tubes 22N for the FeCl 3 /NaCl solution feed are provided (a similar arrangement (not shown) being provided for the sodium sulfide solution feed). These flow conduits are simultaneously encapsulated with the electrode and membrane edges.
  • the cell array is rotated 90 degrees and the process repeated three times to form four long walls.
  • Manifolds and tubes for electrolyte withdrawal are provided at the top face. Additional encapsulation can be provided at the backs of end electrodes 12E, 14E.
  • An alternative approach to encapsulation is to use a dissolvable or low melting point solid to fill the cell chambers 22C, 24C, and the manifolds and tubes of essentially all cells of battery 20.
  • the battery is then dipped in its entirety into a deep epoxy resin bath. After the epoxy resin hardens, the battery is subjected to water or other solvent fed through its circulatory path to dissolve the solid, or is heated to melt the solid.
  • Another effective encapsulation approach is a plate and frame structure (not shown) which has enough short-term sealing integrity to permit a single pouring of encasing polymer (epoxy). The polymer provides the long-term sealing along all edges of the electrodes and membranes.
  • FIG. 2A shows a free flow system, a power generation/storage system utilizing one or more of the cells or cell array formats 20.
  • Each cell 20 receives electrolyte through pumps 26 and 28 for the FeCl 3 /NaCl and NaS 5 solutions (22 and 24, respectively) .
  • the electrolytes 22 and 24 are stored in containers 32 and 34 large enough for the needs of a particular job.
  • the tanks 32, ' 34 can be replaced with freshly charged electrolyte by substituting tanks containing fresh electrolyte and/or refilling them from charged supply sources via lines 32R, 34R with corresponding lines (not shown) provided for draining spent (discharged) reagent.
  • End electrodes differ from the mid electrodes because they must have a metallic conductor embedded within the structure running across the electrode area. This is required because the resistivity of the substrate material from which they are formed is too high to allow adequate electrical conduction to an external electrical connector.
  • a 25cm by 25cm square (10 inch by 10 inch square) of substrate material of 0.25 cm (0.10 inch) thickness will have a resistance of about 10 ohms where a corresponding cell has an internal resistance of about 0.01 ohms.
  • a sheet of copper of 0.025 cm (0.010 inch) thickness with approximately the same area embedded into the electrode will reduce the effective resistance to about 100 micro ohms.
  • the end electrodes are unipolar, whereas the mid-electrodes are bipolar.
  • the conductor sheet is a thin screen structure embedded along the length of the end electrodes which make mechanically good contact along the current path.
  • the process of making the bipolar mid-electrodes is as follows. Substrates are formed of graphite flakes mixed with a plastic binder or other suitable binder, generally in a 1:1 weight ratio of such components. The mixture is freed from moisture by heating and/or desiccation methods, formed as sheets and hot pressed at temperatures and pressures appropriate to the materials used.
  • the substrates are coated on both the - ve and + ve surfaces with activated carbon particles by placing a sprinkling of such particles on mold plate surfaces and hot pressing the substrates to complete sealing of all voids in the substrate and to embed the particles in its surfaces.
  • Suitable types of activated carbon for use in surfacing the electrodes are G212 of North America Carbon Co., UU of Barnebey-Cheney Co., GAC of Calgon Carbon Co. , or PCB of Calgon Carbon Co.
  • the press mold and its contents are cooled under pressure by using a water cooled heat exchanger to safeguard against bowing or warping and also to ensure a compact, non-porous structure.
  • End electrodes are prepared by making substrates by mixing graphite flakes and a plastic binder together, in the same general manner as described for the process of making bipolar mid-electrodes.
  • One surface of this substrate is then surfaced with activated carbon or silicon dioxide particles, or a mixture of silicon dioxide / activated carbon particles, depending on whether a - ve electrode or a + ve electrode is being formed. This is effected by placing a sprinkling of the required particles (activated carbon or silicon dioxide) on the electrode surface and hot pressing to embed the particles in the surface thereof. After each pressing step the press mold and its contents are cooled, for example using a water-cooled heat exchanger to safeguard against bowing or warping.
  • the preferred cation exchange membrane for use in the present invention is a heterogeneous structure made by Sybron Chemical Co. called IONAC MC3470 or NAFION made by Du Pont de Nemours.
  • IONAC is a cation exchange membrane containing sulfonated resins as the functional materials bonded together with Kynar. The material is bonded to a fibrous support sheet of glass cloth or polymer fiber. The specifications for this membrane are: 0.040cm (0.016 inches) thick, 96% permselectivity and 5 ohms/square cm in 1 N NaCl.
  • the surfaces of the electrodes are coated with a porous activated carbon which acts to absorb the iron solutions in the + ve side and to absorb the S2 " solution in the - ve side.
  • the large surface areas enhance the availability of the iron and sulfur during discharge. This enhancement provides better performance by maintaining the output voltage and power even when the cell is near complete discharge. Polarization losses are low.
  • FIG. 2B shows a pH control system in which pH control of both the + ve side and the - ve side of the cell 10 is effected. It will be understood that pH control will be required in some circumstances in one side of the cell 10 only, and this is within the scope of the invention.
  • a pH control cell 50 is positioned in the flow path of the electrolyte 22 from the + ve chamber 22C of cell 10.
  • a DC current is passed from the + ve electrode 52 to the - ve electrode 54 of the cell 50 at a voltage greater than 1.6 volts (in order to overcome the open circuit voltage of the pH control cell).
  • the + ve electrode 52 has an activated carbon surface 56 which absorbs the electrolyte solution 22 and catalyses the formation of HC1 and HC10.
  • iron is produced which is dissolved by the ferric ions in the electrolyte 22 to form ferrous ions.
  • a pH control cell 80 is positioned in the flow path of the electrolyte 24 from the - ve chamber 24C of the cell 10.
  • the - ve side of cell 80 has a "starved" cathode 86.
  • a DC current is passed from the + ve electrode 82 to the - ve electrode 86, electrolyzing water to produce H 2 gas at the cathode 86, with the OH * ions also produced raising the pH of the electrolyte solution and thus compensating for the migration of OH " ions from the - ve side to the + ve side of cell 10.
  • the cathode 86 of cell 80 is "starved" to maximize the OH ' ion production and to minimize the production of sodium sulfide.
  • the starving of the cathode 86 is accomplished by surfacing the cathode with a thick porous layer 88 which reduces the availability of the sodium polysulfides at the - ve electrode surface, thus promoting the electrolysis of water.
  • a preferred porous surfacing for the cathode 86 is an unwoven polypropylene cloth, such as Webril cloth made by the Kendall Co.
  • the H 2 gas may be vented from the tank 34 by means of a vent 85.
  • the pH control cell 80 may, if desired, employ a membrane in order to divide the cell into a + ve chamber and a - ve chamber.
  • the H 2 gas product may be vented directly from the - ve chamber of the cell .
  • FIG. 2C shows a more complicated pH control cell 60 designed with two fluid chambers 72, 74 separated by a cation exchange membrane 58.
  • This cation exchange membrane 58 permits only H + ions to transfer from the + ve to the - ve side of the pH control cell 60.
  • the cell 60 has a - ve electrode 76 and a + ve electrode 68.
  • the electrode + ve 68 is starved of Cl" ions by limiting the flow 66 of the electrolyte 22 to the anode surface by placing a diffusion limiting layer of a porous non- conductive material 67, such as fluorocarbon particles or silicon dioxide particles, on the anode surface.
  • a DC current is passed through the cell from the + ve electrode 68 to the - ve electrode 76.
  • the electrolysis of water occurs forming oxygen gas at the electrode 68 and hydrogen ions in solution which are transported across the membrane 58 into the chamber 74 through which electrolyte stream 64 flows.
  • H + ions lower the pH of the electrolyte 22.
  • Some chlorine is also produced at the + ve electrode, but it reacts with the ferrous ions in solution.
  • the oxygen gas is vented into the main flow path 70 of the electrolyte to the chamber 22C of cell 10.
  • Examples 1 and 2 are comparative Examples carried out in cells in which no ionic salt is included in the electrolyte circulating in the + ve chamber during energy storage. In these comparative Examples the cells were conducted as primary devices, i.e. discharge only modes.
  • Two substrates were prepared by mixing graphite flakes (#4012 graphite flakes of Asbury Carbon Co. ) with a polyvinylidene fluoride, PVDF, binder (Penwalt's #461) in a 1:1 weight ratio. The mixture was heated to remove moisture, formed into sheets and hot pressed at a temperature of 177°C (350°F) and a pressure of 1723 kPa (250 psi) for 10 minutes, and then cooled at the same pressure between water cooled platens.
  • graphite flakes #4012 graphite flakes of Asbury Carbon Co.
  • PVDF polyvinylidene fluoride
  • binder Penwalt's #461
  • a stack was then formed, from bottom to top, of an aluminum base plate, Teflon sheet, substrate, a copper screen (0.025 cm. thick), the other substrate, a Teflon sheet, high temperature rubber sheet, and finally another aluminum base plate.
  • the assembly was then pressed at 1034 kPa (150 psi) at 177°C (350°F) for 10 minutes, and then cooled at the same pressure between water-cooled platens.
  • the substrate to be surfaced had its edges covered with tape and was then placed on an aluminum base plate covered with a Teflon sheet, and a mixture of 80% graphite and 20% Kynar sprinkled over the surface. The surface of the substrate was then sprinkled with a layer of activated carbon particles (G212 of North American Carbon Co., or UU of Barnebey- Cheney Co. ).
  • a high temperature rubber sheet was placed on top of the surfaced substrate, followed by a Teflon sheet and an aluminum base plate.
  • the structure was then pressed at 517 kPa (75 psi) at 177°C (350°F) for 10 minutes, and then cooled at the same pressure between water-cooled platens.
  • the tape was then removed from the edges of the surfaced side and a rubber "picture" frame placed on top of the cleared border.
  • the electrode was then placed with the surfaced side uppermost onto an aluminum base plate covered with a Teflon sheet and the top surface of the structure covered with a Teflon sheet and an aluminum base plate.
  • the edges of the assembly were pressed at 2413 kPa (350 psi) at 177°C (350°F) for 210 minutes,and then cooled at the same pressure between water-cooled platens. This step sealed the substrate sheets along the edges in order to ensure that the copper screen was totally encapsulated to prevent corrosion by the electrolyte.
  • a sealed single cell was made by placing a + ve electrode and a - ve electrode together with an IONAC MC3470 membrane therebetween.
  • the four edges of the cell were cast with an epoxy resin to encapsulate the cell and ports formed to allow the electrolytes to be supplied to and to be removed from the cell.
  • the construction of the cell ensures that the copper screens and the wires attached, which make electrical contacts to the cell, do not contact the electrolyte.
  • the above described cell was used, with UU carbon surfaced electrodes, spaced apart 0.50 inch, with the space between the electrode surface and membrane on each side being filled with G-212 porous carbon.
  • the active area of the cell was 129 sq. cm (20 sq. in.)
  • the electrolytes were:
  • Electrolyte replacement was accomplished by draining the cell compartments and refilling the compartments with fresh solutions three times in order to flush out the "spent" reagents within the surface pores of the porous G-212 carbon.
  • a cell was constructed in the manner as described in Example 1 except that the electrode-to-electrode spacing was 1.00 cm (0.40 inch). Even though the cell had static electrolytes (non-circulating) the solutions were stirred or agitated periodically to ensure adequate mixing and physical availability of ionic species at the electrode surfaces.
  • the active area of the cell was 129 sq. cm. (20 sq. in.) with excess cell volume to accommodate additional electrolyte.
  • the electrolytes were:
  • the capacity was limited, in these examples by the amount of FeCl 3 in solution in the positive side.
  • Figure 3 is the discharge curve which is typical of the shape of the discharge curve for non-circulating electrolytes with adequate agitation or stirring.
  • the cell resistance rose from its 0.2 ohms to over 100 ohms, and current diminished to less than 10 ma.
  • Cell resistance continued to rise as long as the "charging" power supply was connected to the terminals.
  • the cell resistance decreased to its normal 0.2 ohm value, and discharging proceeded as usual. There were no observable remaining effects within the membrane as a result of the attempts to recharge electrically.
  • a cell was assembled to characterize a rechargeable version of the above couple.
  • the cell had static electrolytes (non-circulating) and three compartments.
  • the + ve compartment contained the oxidizing agent, FeCl 3 , and NaCl in aqueous solution and the + ve electrode.
  • the - ve compartment contained the reducing agent, NaS, in aqueous solution and the - ve electrode.
  • a middle compartment was an isolation chamber or buffer compartment. It contained a 2 molar solution of NaCl.
  • Each of the three compartments was separated by a cation membrane.
  • the physical parameters of the cell were as follows:
  • Electrolytes were: Positive side .... 200 cc of 3 molar solution of FeCl 3 and 1.5 molar solution of NaCl Negative side .... 200 cc of 2 molar solution of Na 2 S
  • EXAMPLE 4 A cell was constructed in the manner as described in Example 1 with a UU carbon surfaced - ve electrode and a GAC carbon surfaced + ve electrode. The electrodes were separated by a Nafion 117 membrane, the electrode spacing being 0.50cm. The active area of the cell was 155cm 2 .
  • the electrolytes were:
  • a cell was constructed in the manner as described in Example 4 with the compartments separated by Nafion 117 membranes.
  • the electrolytes circulating in the + ve and - ve compartments were as described in Example 4.
  • the middle chamber was a buffer chamber or isolation chamber through which 350cc of a 2 molar solution of NaCl was circulated.
  • the spacings between the cell components were 0.25cm from - ve electrode to membrane. 0.62cm between the two membranes, and 0.25cm from + ve electrode to membrane.
  • the active area of the cell was 155cm 2 .
  • the cell resistance was 106 milliohms. Both electrolytes were in the charged state initially. The cell was discharged and charged over three cycles at 3 amps. The results are given in Figure 5. It can be seen from these results that the charging potentials indicate a very large increase in resistance. The resistance of the cell is, however, lower than that of the single membrane cell used in Example 4.

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  • Compounds Of Iron (AREA)

Abstract

Un procédé électrochimique de stockage d'énergie et de production d'énergie se compose d'une seule pile ou d'un groupement de piles unitaires (10), chaque pile comprenant une électrode +ve (12) et une électrode -ve (14), une membrane divisant chaque pile en chambres +?ve et -ve¿ (22C et 24C) destinées à des solutions de posilyte et d'anolyte (22, 24) que l'on fait recirculer par des pompes séparées (26, 28) et des réservoirs de stockage (32, 34), et que l'on renvoie vers les chambres. On utilise un couple fer-soufre, la réaction globale étant: 2Fe?3+ + S2- = 2Fe2+¿ + S(Eq.8), les ions de Fe3+ étant pris comme chlorure, bromure ou iodure, et le sulfure étant pris comme sels de sodium, de lithium ou d'ammonium. La chambre +ve contient un sel ionique soluble qui agit comme un porteur de charge lors du stockage d'énergie, et qui est de préférence du chlorure de sodium ou de potassium. Des éléments sont prévus pour compenser le pH dans le système, et d'autres éléments forment une troisième chambre (23C). On peut ainsi recharger électriquement le système de manière plus efficace.
PCT/GB1993/002109 1992-10-14 1993-10-13 Stockage d'energie electrochimique et processus d'alimentation d'energie a l'aide du couple fer-soufre Ceased WO1994009525A1 (fr)

Priority Applications (5)

Application Number Priority Date Filing Date Title
JP6509759A JPH08502387A (ja) 1992-10-14 1993-10-13 鉄−硫黄カップルを利用したエネルギー貯蔵および電力配給用電気化学的装置
EP93922595A EP0664931B1 (fr) 1992-10-14 1993-10-13 Stockage d'energie electrochimique et processus d'alimentation d'energie a l'aide du couple fer-soufre
DE69310529T DE69310529T2 (de) 1992-10-14 1993-10-13 Elektrochemische energiespeicherung und stromversorgungsverfahren unter verwendung eines eisen-schwefel-paares
AU51537/93A AU672049B2 (en) 1992-10-14 1993-10-13 Electrochemical energy storage and power delivery process utilizing iron-sulfur couple
GR970402028T GR3024385T3 (en) 1992-10-14 1997-08-07 Electrochemical energy storage and power delivery process utilizing iron-sulfur couple.

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
US96112392A 1992-10-14 1992-10-14
US96111292A 1992-10-14 1992-10-14
US07/961,112 1992-10-14
US07/961,123 1992-12-16

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WO1994009525A1 true WO1994009525A1 (fr) 1994-04-28

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EP (1) EP0664931B1 (fr)
JP (1) JPH08502387A (fr)
AT (1) ATE152860T1 (fr)
AU (1) AU672049B2 (fr)
DE (1) DE69310529T2 (fr)
DK (1) DK0664931T3 (fr)
ES (1) ES2104179T3 (fr)
GR (1) GR3024385T3 (fr)
WO (1) WO1994009525A1 (fr)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1996034422A1 (fr) * 1995-04-26 1996-10-31 Zao 'avtouaz' Convertisseur electrochimique d'energie
WO1999057775A1 (fr) * 1998-05-07 1999-11-11 National Power Plc Electrodes a base de carbone
WO2001003221A1 (fr) * 1999-07-02 2001-01-11 Regenesys Technologies Limited Systeme de reequilibrage d'electrolytes
KR100666260B1 (ko) * 1999-07-02 2007-01-09 리제네시스 테크놀로지스 리미티드 전해질 재평형 시스템
US11056698B2 (en) 2018-08-02 2021-07-06 Raytheon Technologies Corporation Redox flow battery with electrolyte balancing and compatibility enabling features
US11271226B1 (en) 2020-12-11 2022-03-08 Raytheon Technologies Corporation Redox flow battery with improved efficiency
CN118412509A (zh) * 2024-05-27 2024-07-30 安徽恒焺储能科技有限公司 一种酸碱两性铁-硫杂化液流电池及其制备方法

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5496659A (en) * 1992-10-14 1996-03-05 National Power Plc Electrochemical apparatus for energy storage and/or power delivery comprising multi-compartment cells
GB201015859D0 (en) * 2010-09-21 2010-10-27 Imp Innovations Ltd Regenerative fuel cells
US10347925B2 (en) * 2016-04-29 2019-07-09 Lockheed Martin Energy, Llc Three-chamber electrochemical balancing cells for simultaneous modification of state of charge and acidity within a flow battery

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3920474A (en) * 1972-05-25 1975-11-18 Gen Engineering Lab Inc Method of operating a fuel cell using sulfide fuel
US4069371A (en) * 1976-05-10 1978-01-17 Gel, Inc. Energy conversion
JPS58176880A (ja) * 1982-04-12 1983-10-17 Agency Of Ind Science & Technol レドツクス・フロ−型電池の運転制御方法
US4485154A (en) * 1981-09-08 1984-11-27 Institute Of Gas Technology Electrically rechargeable anionically active reduction-oxidation electrical storage-supply system

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS62194372A (ja) * 1986-02-19 1987-08-26 藤井　正視 電柱
JPS62287086A (ja) * 1986-06-04 1987-12-12 Fujita Corp 鉄筋コンクリ−ト構造物における鉄筋の防蝕方法
JPH01222075A (ja) * 1988-02-29 1989-09-05 Tokyo Gas Co Ltd 電気防食遠隔集中管理機構

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3920474A (en) * 1972-05-25 1975-11-18 Gen Engineering Lab Inc Method of operating a fuel cell using sulfide fuel
US4069371A (en) * 1976-05-10 1978-01-17 Gel, Inc. Energy conversion
US4485154A (en) * 1981-09-08 1984-11-27 Institute Of Gas Technology Electrically rechargeable anionically active reduction-oxidation electrical storage-supply system
JPS58176880A (ja) * 1982-04-12 1983-10-17 Agency Of Ind Science & Technol レドツクス・フロ−型電池の運転制御方法

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
PATENT ABSTRACTS OF JAPAN vol. 8, no. 13 (E - 222)<1450> 20 January 1984 (1984-01-20) *

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1996034422A1 (fr) * 1995-04-26 1996-10-31 Zao 'avtouaz' Convertisseur electrochimique d'energie
WO1999057775A1 (fr) * 1998-05-07 1999-11-11 National Power Plc Electrodes a base de carbone
WO2001003221A1 (fr) * 1999-07-02 2001-01-11 Regenesys Technologies Limited Systeme de reequilibrage d'electrolytes
KR100666260B1 (ko) * 1999-07-02 2007-01-09 리제네시스 테크놀로지스 리미티드 전해질 재평형 시스템
US11056698B2 (en) 2018-08-02 2021-07-06 Raytheon Technologies Corporation Redox flow battery with electrolyte balancing and compatibility enabling features
US11637298B2 (en) 2018-08-02 2023-04-25 Raytheon Technologies Corporation Redox flow battery with electrolyte balancing and compatibility enabling features
US11271226B1 (en) 2020-12-11 2022-03-08 Raytheon Technologies Corporation Redox flow battery with improved efficiency
CN118412509A (zh) * 2024-05-27 2024-07-30 安徽恒焺储能科技有限公司 一种酸碱两性铁-硫杂化液流电池及其制备方法

Also Published As

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ATE152860T1 (de) 1997-05-15
JPH08502387A (ja) 1996-03-12
DE69310529D1 (de) 1997-06-12
DE69310529T2 (de) 1997-11-06
DK0664931T3 (da) 1997-12-08
AU672049B2 (en) 1996-09-19
ES2104179T3 (es) 1997-10-01
GR3024385T3 (en) 1997-11-28
EP0664931B1 (fr) 1997-05-07
EP0664931A1 (fr) 1995-08-02
AU5153793A (en) 1994-05-09

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