Zinc electrode for alkaline storage battery

• US 5,382,482 A
• Filed: 07/29/1993
• Issued: 01/17/1995
• Est. Priority Date: 08/07/1992
• Status: Expired due to Fees

• Current Assignee: Nippon Mitsubshi Oil Corporation
• Original Assignee: Nippon Oil Corporation (ENEOS Holdings, Inc.)
• Inventors: Kuroda, Nobuyuki, Suga, Masanobu, Akita, Seiichi
• Primary Examiner(s): Skapars, Anthony
• Application Number:
  US08/099,174
• Time in Patent Office: 537 Days
• Field of Search: 429/229-231, 429/216, 429/247, 429/248, 429/249, 429/137, 429/212, 429/206
• US Class Current: 429/206
• CPC Class Codes: H01M 4/244 Zinc electrodes
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

According to the present invention there is provided a negative zinc electrode for an alkaline storage battery, comprising an electrode using zinc as an active material and a polymer layer which is substantially in direct contact with the electrode, the polymer layer containing at least a polymer having a crosslinked structure. There is also provided an alkaline storage battery using such negative zinc electrode and in which the occurrence of dendrites and shape change is suppressed.

Claims

1. A negative zinc electrode for an alkaline storage battery, comprising an electrode using zinc as an active material and a polymer layer formed on said electrode, said polymer layer containing at least a polymer having a crosslinked structure, wherein said polymer is selected from the group consisting of a polymer A having an ion conductivity of 10^-3 to 10¹ S/cm in an alkali electrolyte, a crosslinked polymer obtained by crosslinking the polymer A, a polymer A'"'"' obtained by introducing a group B into a portion of a main chain of the polymer A, said group B being able to improve gas permeability, a polymer C having an oxygen permeability constant of larger than 1×

10^-10 cm³ (STP) cm^-1 s^-1 cmHg^-1, a crosslinked polymer obtained by crosslinking the polymer C, and a polymer C'"'"' obtained by introducing a group D into a portion of a main chain of the polymer C, said group D being able to improve ion conductivity.

2. A negative zinc electrode as set forth in claim 1, wherein the polymer A is polyvinyl alcohol, polyacrylonitrile, carboxymethyl cellulose, polyacrylic acid, polyacrylate, polymethacrylic acid, polymethacrylate, polyvinyl pyrrolidone, polyparabanic acid, polyoxazoline, polyethylene oxide, or sodium polystyrenesulfonate.

3. A negative zinc electrode as set forth in claim 1, wherein the group B capable of improving gas permeability is --SiR₃, --OSi)_n OR'"'"', --CH₂ CH(CH₃)₂, where R and R'"'"' are each a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

4. A negative zinc electrode as set forth in claim 1, wherein the polymer C is polyorganosiloxane, polyvinyltriorganosiloxane, polyalkylsulfone, or poly(4-methylpentene-1), having a molecular weight of about 1,000 to about 2,000,000.

5. A negative zinc electrode as set forth in claim 1, wherein the group D capable of improving ion conductivity is --COOH, --CN, --CONH₂ or --N⁺ R₃ where R is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

6. A negative zinc electrode as set forth in claim 1, wherein the crosslinked structure is present substantially uniformly along the surface of the polymer layer and vicinity thereof.

7. A negative zinc electrode as set forth in claim 1, wherein the polymer layer has been obtained by forming on the electrode a coating of the polymer A, polymer A'"'"', polymer C or polymer C'"'"' and thereafter allowing a crosslinking reaction to take place.

8. A negative zinc electrode as set forth in claim 1, wherein the polymer layer further contains another polymer.

9. An alkaline storage battery comprising the zinc electrode described in claim 1, a separator, a positive electrode and an electrolyte.