Claims
- 1. A coherent electrode for use in electrochemical devices having an aqueous electrolyte, said electrode comprising particulate manganese dioxide and particulate electrically conductive material both of which are substantially dispersed in a binder, said binder comprising colloidal electrically conductive material having a surface area as defined by the B.E.T. method using N.sub.2 absorption at 78.degree.K. of less than about 100 m.sup.2 /g, and an electrolyte-wettable polymer, thereby forming a polymeric binder.
- 2. The electrode of claim 1 wherein said polymer is selected from the group consisting of acrylonitrile-butadiene-styrene polymer, epoxy resin, polymerized lower alkyl ester of acrylic or methacrylic acid, melamine-formaldehyde resin, urea-formaldehyde resin, chlorinated polyether, polycarbonate, phenol-formaldehyde resin, polysulfone, polystyrene, styrene-acrylonitrile copolymer, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl alcohol, and styrene-butadiene copolymer.
- 3. The electrode of claim 1 wherein the polymer is an epoxy resin, a polymerized lower alkyl ester of acrylic or methacrylic acid, polysulfone, or polystyrene.
- 4. The electrode of claim 1 wherein the colloidal electrically conductive material is graphite, heat treated carbon, or a powdered metal, and wherein the particulate electrically conductive material is graphite, or heat treated carbon.
- 5. The electrode of claim 4 wherein the colloidal electrically conductive material is graphite.
- 6. The electrode of claim 1 wherein said electrode contains at least 1 weight per cent of said colloidal electrically conductive material, at least 5 weight per cent of said particulate electrically conductive material, at least 1 weight per cent of said polymeric binder, and at least 70 weight per cent of manganese dioxide, the percentages being based on weight of electrode.
- 7. The electrode of claim 1 wherein said electrode is a flat electrode having a thickness of from about 10 to about 50 mils.
- 8. An electrochemical device having an anode, a cathode, and an aqueous electrolyte in contact with said anode and cathode, wherein, in the charged condition, said cathode is the electrode of claim 1.
- 9. The electrochemical device of claim 8 wherein the anode is zinc, cadmium, lead, aluminum, or magnesium.
- 10. The electrochemical device of claim 8 wherein the anode is zinc or cadmium, and the electrolyte is aqueous alkali.
- 11. The electrochemical device of claim 8 wherein the anode is lead and the electrolyte is aqueous acid.
- 12. The electrochemical device of claim 8 wherein the anode is magnesium and the electrolyte is aqueous magnesium bromide.
- 13. Process for producing a coherent electrode comprising the steps:
- a. preparing a first mixture of an electrolyte-wettable polymeric binder and a colloidal electrically conductive material so as to form a conductive binder mixture;
- b. mixing particulate manganese dioxide, particulate electrically conductive material and the conductive binder mixture of step a) to form a mixture of said materials; and
- c. forming said mixture of the four materials into a coherent electrode wherein the particulate manganese dioxide and particulate electrically conductive material are dispersed in the conductive binder composed of the colloidal electrically conductive material and the electrolyte-wettable polymeric binder.
- 14. The process of claim 13 wherein in step (b) the forming of said mixture into a coherent electrode includes contacting said mixture with a current collector.
- 15. The process of claim 13 wherein the polymeric binder is selected from the group consisting of acrylonitrile-butadiene-styrene polymer, epoxy resin, polymerized lower alkyl ester of acrylic or methacrylic acid, melamine-formaldehyde resin, urea-formaldehyde resin, chlorinated polyether, polycarbonate, phenol-formaldehyde resin, polysulfone, polystyrene, styrene-acrylonitrile copolymer, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl alcohol, and styrene-butadiene copolymer.
- 16. The process of claim 13 wherein the colloidal electrically conductive material is graphite, heat treated carbon, or a powdered metal, wherein the particulate electrically conductive material is heat-treated carbon or graphite, and wherein the polymeric binder is employed as a solution or a dispersion in a volatile liquid.
- 17. The process of claim 16 wherein said colloidal electrically conductive material is graphite.
- 18. The process of claim 17 wherein the colloidal graphite is employed as a dispersion in said volatile liquid.
- 19. The process of claim 13 wherein step (b) includes subjecting said mixture of the four materials to pressure.
- 20. The process of claim 16 wherein step (b) includes subjecting said mixture of the materials to pressure, said volatilizing said volatile liquid to form pores in said coherent electrode.
Parent Case Info
This is a continuation-in-part of application Ser. No. 212,908 filed Dec. 28, 1971 now abandoned.
US Referenced Citations (9)
Non-Patent Literature Citations (2)
Entry |
Mellor, Comprehensive Treatise on Inorganic & Theoretical Chem., Vol. 5, 1924 p. 753. |
Glaister, Compounding for Electrical Conductivity, Technical Report RG-128, Cabot Corp., 10/11/68 pp. 4-7, 18 & 19. |
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
212908 |
Dec 1971 |
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