Sealed rechargeable cells containing mercury-free zinc anodes, and a method of manufacture
AssigneeBattery Technologies Inc.
InventorsJosef Daniel-Ivad, R. James Book, Klaus Tomantschger
Life of this patent
Estimating the term…
Abstract
The zinc active powder for a mercury-free rechargeable electrochemical cell is coated with a surfactant, and separately with an aqueous solution of indium sulphate. Without any subsequent filtering, washing or drying, the powder is assembled into an electrochemical cell. The cell can include a hydrogen recombination catalyst in contact with the electrochemically active material of the cathode.
Claims45
A mercury-free rechargeable cell that performs at least twenty charge and discharge cycles comprising:
- a cathode;
- an electrolyte;
- an anode;
- and a separator between the anode and the cathode, wherein the anode comprises a zinc active powder that has been coated with a film of one of a surfactant and a solution of a surfactant;
- and a film of an aqueous, acidic solution of indium sulphate, to retard dendrite growth and hydrogen evolution during at least twenty charge and discharge cycles wherein each of the surfactant and the indium sulphate have been uniformly distributed as a film on the zinc active powder prior to assembly into the rechargeable cell, and wherein the coated zinc active powder is subsequently assembled into the electrochemical cell, without removal of zinc sulphate, and the surfactant, any solvent for the surfactant and the solution of the indium sulphate comprise a minor part the zinc active powder.
A mercury-free rechargeable cell that performs at least twenty charge and discharge cycles comprising:
- an anode;
- a cathode having an electrochemically active powder including an oxide of manganese;
- a separator including at least one semipermeable membrane layer;
- an electrolyte solution in the separator, the cathode and the anode, and filling pores thereof, wherein the anode comprises a zinc active powder, and for retarding both zinc dendrite growth and hydrogen evolution during at least twenty charge and discharge cycles, an indium additive and a nonionic surfactant of a molecular weight in the range of 300 to 1500 selected from the group consisting of compounds having polyoxypropylene chains and compounds with polyoxyethylene chains and of copolymers thereof.
A mercury-free rechargeable cell, that perform at least twenty charge and discharge cycles, the cell comprising:
- a cathode;
- an electrolyte;
- an anode including zinc as an electrochemically active material;
- and a coating, including a hydrogen recombination catalyst, provided on an external surface of the cathode.
A method of manufacturing a mercury-free zinc anode for use in a mercury-free rechargeable electrochemical cell that performs at least twenty charge and discharge cycles, the method comprising the steps of:
- (a) coating dry mercury free zinc active powder with one of a film of an organic surfactant and a film of a solution of an organic surfactant;
- (b) coating the mercury-free zinc active powder with a film of an aqueous, acidic solution of indium sulphate, the amounts of the surfactant and the indium sulphate solution being determined to leave the zinc free flowing;
- and
- (c) processing the coated zinc active powder into an anode, without removal of zinc sulphate.
A method of assembling an electrochemical cell, the method comprising the steps of:
- (a) coating dry mercury free zinc active powder with one of a film of an organic surfactant and a film of a solution of an organic surfactant;
- (b) coating the mercury free zinc active powder with a film of an acidic solution of indium sulphate, the amounts of the surfactant and the indium sulphate solution being determined to leave the zinc free flowing;
- (c) processing the coated zinc active powder into an anode without removal of zinc sulphate;
- (d) providing an external container defining the electrochemical cell;
- (e) providing a cathode in the container;
- (f) providing a separator between the cathode and the anode;
- (g) assembling the zinc active powder as part of the anode in the container;
- (h) providing an electrolyte for the cell in the container.
Dependencies are inferred from the claim text.