Current collector for polymer electrochemical cells and eclectrochemical generators thereof

Abstract

A current collector for an electrochemical cell. The current collector comprises a polymer support film having a surface. The current collector also comprises a conductive metallic layer on at least a portion of the surface of the polymer support film, the conductive metallic layer having a first thickness. The current collector further comprises a protective metallic layer on the conductive metallic layer. The protective metallic layer has a second thickness less than the first thickness and is adapted to protect the conductive metallic layer against corrosion. Also provided are a method of manufacturing such a current collector and an electrochemical generator comprising such a current collector.

Description

CROSS-REFERENCE TO RELATED APPLICATION [0001] The present application is a continuation of U.S. patent application Ser. No. 10 / 329,364 filed on Dec. 27, 2002, which is hereby incorporated by reference herein.FIELD OF THE INVENTION [0002] The present invention relates to polymer electrolyte batteries and, more particularly, to current collectors for use in polymer electrolyte batteries. BACKGROUND [0003] Rechargeable batteries manufactured from laminates of solid polymer electrolytes and sheet-like electrodes display many advantages over conventional liquid electrolyte batteries. These advantages include: lower overall battery weight; higher power density; higher specific energy; and longer service life. In addition, they are more environmentally friendly since the danger of spilling toxic liquid into the environment is eliminated. [0004] Solid polymer battery components generally include: positive electrodes (commonly referred to as cathodes); negative electrodes (commonly referred ...

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Benefits of technology

[0008] In accordance with a first broad aspect, the invention seeks to provide a current collector for an electrochemical cell. The current collector comprises a polymer support film having a surface. The current collector also comprises a conductive metallic layer on at least a portion of the surface of the polymer support film, the conductive metallic layer having a first thickness. The current collector further comprises a protective metallic layer on the conductive metallic layer. The protective metallic layer has a second thickness less than the first thickness and is adapted to protect the conductive metallic layer against corrosion.

[0009] In accordance with a second broad aspect, the invention seeks to provide an electrochemical generator comprising at least one thin-film electrochemical cell. Each one of the at least one thin-film electrochemical cell comprises at least one thin-film solid electrolyte disposed between a film constituting an anode and a film constituting a cathode, and a current collector associated with one of the anode and the cathode. The current collector comprises a polymer support film having a surface. The current collector also comprises a conductive metallic layer on at least a portion of the surface of the polymer support film, the conductive metallic layer having a first thickness. The current collector also comprises a protective metallic layer on the conductive metallic layer. The protective metallic layer has a second thickness less than the first thickness and is adapted to protect the conductive metallic layer against corrosion.

[0013] coating a protective metallic layer onto the conductive metallic layer, the protective metallic layer having a second thickness less than the first thickness and being adapted to protect the conductive metallic layer against corrosion.

Problems solved by technology

Current collectors have a tendency to corrode or form an insulating film, which impairs the passage of electrons between the collector and the active material of the electrode, thereby increasing the internal resistance of the electrochemical cell and reducing power density and cycle life of such rechargeable batteries.

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