HYDRAULICALLY-REFUELABLE METAL-GAS DEPOLARIZED BATTERY SYSTEM

• US 3,847,671 A
• Filed: 04/13/1973
• Issued: 11/12/1974
• Est. Priority Date: 04/13/1973
• Status: Expired due to Term

• Current Assignee: Eltech Systems Corporation (Industrie De Nora S.p.A)
• Original Assignee: Angelo F. Leparulo, Charles Grun
• Inventors: Leparulo, Angelo F., Grun, Charles
• Primary Examiner(s): Douglas, Winston A.
• Assistant Examiner(s): Feeley, H. A.
• Application Number:
  US05/351,063
• Time in Patent Office: 578 Days
• Field of Search: 136/86A,86E,86R
• US Class Current: 429/404
• CPC Class Codes: H01M 8/225 Fuel cells in which the fuel is based on materials comprising particulate active material in the form of a suspension, a dispersion, a fluidised bed or a paste
• CPC Class Codes: Y02E 60/50 Fuel cells

Abstract

A metal-gas depolarized battery system is so constructed that both solid and liquid contents can be drained from the battery after discharge. The negative grid and the gas depolarized electrode in each cell define a compartment which can be refilled with a slurry of electrolyte and active metal powder, thereby recharging the battery in the time it takes to drain same and refill with said slurry. A system for collecting the discharge products of such a battery and reducing metal ion to metal which can then be slurried with electrolyte and returned to the cells of the battery is also described. The preferred system utilizes zinc, KOH and air and is especially suitable for propulsion of vehicles and the like.

Claims

1. A HYDRAULICALLY REFUELABLE BATTERY SYSTEM, EACH CELL IN THE BATTERY OF SAID SYSTEM COMPRISING BOTTOM AND SIDE WALLS, A NEGATIVE GRID, A POSITIVE GAS ELECTRODE OPPOSED TO SAID GRID, A SEPARATOR BETWEEN SAID GRID AND SAID POSITIVE GAS ELECTRODE SAID NEGATIVE GRID FORMING WITH SAID SEPARATOR AND SAID SIDE AND BOTTOM WALLS OF SAID CELL AN ANODE COMPARTMENT, FIRST PORT MEANS ABOVE EACH CELL FOR INTRODUCING ELECTROLYTE AND ACTIVE METAL POWDER AS A SLURRY IN ELECTROLYTE INTO EACH OF SAID COMPARTMENTS SECOND PORT MEANS PROXIMATE THE BOTTOM OF EACH CELL FOR REMOVING ELECTROLYTE AND SOLID DISCHARGE PRODUCTS FROM EACH CELL, FIRST MANIFOLD MEANS, FIRST BRANCH TUBES CONNECTING SJD FIRST MAINFOLD MEANS WITH EACH OF SAID FIRST PORT MEANS, SECOND MANIFOLD MEANS, SECOND BRANCH TUBES CONNECTING SAID SECOND MANIFOLD MEANS WITH EACH OF SAID SECOND PART MEANS, FIRST COUPLING MEANS FOR CONNECTING SAID FIRST MANIFOLD MEANS TO AN EXTERNAL STATIONARY SOURCE OF ELECTROLYTE AND ACTIVE METAL POWDER WHEREBY ELECTROLYTE AND ELECTROLYTE CARRYING SUSPENDED POWDER AS A SLURRY MAY BE TRANSFERRED THROUGH SAID FIRST MANIFOLD MEANS SAID FIRST BRANCH TUBES AND SAID FIRST PORT MEANS TO EACH OF SAID CELLS, SECOND COUPLING MEANS FOR CONNECTING SAID SECOND MANIFOLD MEANS TO AN EXTERNAL RECEIVER WHEREBY ANY CONTENTS OF SAID CELLS MAY BE TRANSFERRED AND FLUSHED THROUGH SAID SECOND PORT MEANS, SAID SECOND BRANCH TUBES AND SAID SECOND MANIFOLD MEANS TO AN EXTERNAL RECEIVER, DRAIN MEANS IN SAID SECOND MANIFOLD WHEREBY CONDUCTIVE ELECTROLYTE AND SUSPENDED METAL POWDER MAY BE DRAINED FROM SAID SECOND MANIFOLD FOR PREVENTING UNDESIRED ELECTRIC CURRENT THRERETHROUGH, FIRST VALVE MEANS IN EACH OF SAID SECOND BRANCH TUBES, SAID SECOND BRANCH TUBES AND SAID SECOND MANIFOLD HAVING THEREIN PORTIONS OF ELECTRICALLY INSULATIVE MATERIAL BETWEEN SAID FIRST VALVE MEANS FOR PREVENTING CONDUCTION OF ELECTRICITY THEREBETWEEN, CONDUIT MEANS IN SAID BATTERY FOR BRINGING DEPOLARIZING GAS TO THE POSITIVE GAS ELECTRODES OF ALL CELLS, SWITICHING MEANS FOR ELECTRICALLY DISCONNECT ING ALL CELLS FROM EACH OTHER DURING TRANSFER OF ELECTROLYTE AND SLURRY TO AND FROM SAID BATTERY, SAID CELLS BEING DIMENSIONED TO HOLD THE ENTIRE QUANTITY OF ACTIVE METAL POWDER TO BE USED BY SAID CELLS BETWEEN SUCCESSIVE COUPLINGS TO SAID EXTERNAL STATIONARY SOURCE OF ACTIVE METAL POWDER, THEREBY MAKING IT POSSIBLE TO REACTIVATE AN AT LEAST PARTLY DISCHARGED BATTERY BY EMPTYING SAME OF DISCHARGE PRODUCTS AND ELECTROLYTE AND REFILLING THE CELLS OF SAID BATTERY WITH A SLURRY OF ACTIVE METAL POWDER SUSPENDED IN ELECTROLYTE, WHICH GREATLY REDUCES THE TINE INVOLVED FOR REACTIVATING A BATTERY WHILE AVOIDING THE DANGER OF SHORTING BETWEEN OPPOSED ELECTRODE WHICH ARISES WHEN IT IS ATTEMPTED TO REDUCE METAL IONS TO METAL ELECTROCHEMICALLY IN A CELL USED FOR DISCHARGE.

2. A hydraulically refuelable battery system as defined in claim 1 wherein said negative grid has essentially the form of a compartment.

3. A hydraulically refuelable battery system as defined in claim 1 wherein said negative grid has apertures which are sufficiently small to enable said grid to act as a filter for retention of solid particles in each of said cells.

4. A hydraulically refuelable battery system as defined in claim 1 wherein said separator covers the inner face of said positive gas electrode thereby preventing contact between metal powder in a cell and the corresponding positive gas electrode.

5. A hydraulically refuelable battery system as defined in claim 1 wherein said active metal is zinc and said battery includes means for introducing a depolarizing gas into said battery and means for bringing said gas into contact with the gas side of said positive gas electrodes.

6. A hydraulically refuelable battery system as defined in claim 1 wherein said active metal is selected from the group consisting of Li, Mg, Al, Zn, Cd and Fe, and said depolarizing gas is an oxygen-containing gas.

7. A hydraulically refuelable battery system as defined in claim 1 wherein said active metal is Zn and said oxidizing gas is air.

8. A hydraulically refuelable battery system as defined in claim 7 wherein said electrolyte is selected from the group consisting of aqueous NaOH and aqueous KOH.

9. A hydraulically refuelable battery system as defined in claim 8 wherein the concentration of said electrolyte lies between 10 and 50 percent.

10. A hydraulically refuelable battery system as defined in claim 8 wherein the concentration of said electrolyte lies between 31 and 40 percent.

11. A hydraulically refuelable battery system as defined in claim 1 wherein said negative grid is corrugated and apertured, each face of each cell consists essentially of a positive gas electrode having a separator engaging the interior surface thereof, and each negative grid serves to space apart the two separators in the corresponding cell and to hold a batch of said electrolyte and active metal powder in its convolutions.

12. A hydraulically refuelable battery system as defined in claim 1 wherein each cell comprises two finely apertured, vertical opposed negative grids, said grids being closely spaced apart and defining a conduit, two separators each defining a compartment with one of said grids, two gas-depolarized positive electrodes each engaging the outer surface of one of said separators, side-wall and bottom means around the peripheries of said grids, separators and positive gas electrodes, fourth port means and fourth branch tubes at the bottom of each of said conduits, said fourth branch tubes connecting each of said fourth port means with said second manifold means, third valve means in each of said fourth branch tubes, and electrically insulating sections in said fourth branch tubes and said second manifold means between said Third valve means.

13. A hydraulically refuelable battery system as defined in claim 1 wherein said active metal is zinc, said electrolyte is KOH and said depolarizing gas is selected from the group consisting of air, oxygen-enriched air and oxygen.

14. A hydraulically refuelable battery system as defined in claim 1, wherein said bottom wall of each cell is finely apertured so that electrolyte free of metal powder may pass therethrough and further comprising a chamber below each apertured bottom wall, third port means proximate the bottom of each chamber, third manifold means, third branch tubes connecting each of said third port means to said third manifold means, second valve means in each of said third branch tubes, said third branch tubes and said third manifold means having therein portions of electrically insulative material between said third valve means for preventing conduction of electricity therebetween, coupling means in said third manifold means for coupling same to an external receiver for electrolyte, and drain means for emptying said third manifold of conductive electrolyte and metal powder, whereby electrolyte from said battery may be removed while supplying a slurry of electrolyte and metal powder to the cells of said battery.

15. A method of operating hydraulically refuelable metal-gas depolarized battery system, wherein the bottom of each cell is apertured and each cell has below said apertured bottom a lower chamber having third port means proximate the bottom thereof and said battery has third manifold means, third branch tubes connecting said third manifold means with each of said lower chambers for drainage of fluid therefrom, second valve means in each of said third branch tubes, second branch tubes proximate the bottom of each cell, said second branch tubes and said third manifold means having therein portions of electrically insulating materials for preventing conduction of electricity therethrough, second manifold means joined to all of said second branch tubes, coupling means for joining said third manifold means to an external receiver and means for draining said third manifold means of electrolyte, comprising the steps of disconnecting said cells electrically from each other by switch means prior to refueling, connecting said battery to a stationary charging system including an external receiver, introducing a slurry of electrolyte and active metal powder through a first manifold and first branch tubes into each cell until a desired level of metal powder is reached, preventing return of electrolyte from said cells to said external receiver, introducing electrolyte into said cells until a desired level of electrolyte is reached, disconnecting said battery from said stationary charging system, reconnecting said cells electrically, discharging said battery to a desired extent, reconnecting said battery to said stationary charging system, flushing out waste products and residual solids from said cells by passing electrolyte through said first, second and third manifolds, and producing active metal powder in said stationary charging system from said waste products.

16. A method of operating a hydraulically refuelable metal-gas depolarized battery system as defined in claim 15 wherein said active metal is a member selected from the group consisting of Li, Mg, Al, Zn, Cd and Fe.

17. A method of operating a hydraulically refuelable metal-gas depolarized battery system as defined in claim 15 wherein said battery is depolarized by a gas selected from the group consisting of air, oxygen-enriched air, H2O2, O2, Cl2 and Br2 vapor.

18. A method of operating a hydraulically refuelable metal-gas depolarized battery system as defined in claim 15 wherein said active metal is Zn, said electrolyte is KOH and said depolarizing gas is air, oxygen-enriched air or oxygen.

19. A method of operating a hydraulically refuelable metal-gas depolarized battery system as defined in claim 15, further compriSing the steps of flushing with fresh electrolyte residual solids from said cells after discharge when said battery is connected to said charging system, draining electrolyte from each of said cells during said transfer of slurry to same until the quantity of active metal in each of said cells reaches a predetermined value, terminating said drainage of electrolyte and filling each cell with electrolyte to a level at least as high as that of the active metal within said cell.

20. A method of operating a hydraulically refuelable metal-gas depolarized battery system as defined in claim 15, wherein each of said cells has two compartments, each compartment being bounded at the inner surface thereof by an apertured collector plate, said plates, cell side-walls and bottom walls forming a conduit connectable to said stationary charging system and further comprising the step of forcing electrolyte into said conduits and through said apertured plates for the purpose of removing any solid deposit in the apertures and on the surfaces of said plates facing said compartments.