Gas-tight, sealed alkaline secondary cell

US5122426A · kind A · utility

Assignee

• Varta Batterie Aktiengesellschaft · DE

Inventors

• Gerhard Simon · Mühltal, DE
• Klaus Kleinsorgen · Kelkheim, DE
• Uwe Kohler · Kelkheim, DE

Key dates

• Filing date: Aug 17, 1990
• Grant date: Jun 16, 1992
• Expiry date: Aug 17, 2010

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02P70/50
• WIPO field: Electrical machinery, apparatus, energy
• WIPO sector: Electrical engineering

Abstract

An auxiliary electrode for improving the consumption of oxygen in a gas-tight, sealed alkaline secondary cell is comprised of a synthetic nonwoven fabric and a film rolled onto the fabric. The film is a PTFE-bound activated carbon, and the side of the nonwoven fabric receiving the film is first impregnated with an aqueous cellulose ether mixture to develop a three layer structure including a highly porous, hydrophobic layer made of the nonwoven material, left in its original state and facing the electrolyte or a gas supply, a hydrophilic impregnated layer, and a catalytically active hydrophobic consumption layer electrically connected with the cell's negative electrode and constituting the preferred location for oxygen reduction, at the resulting hydrophobic/hydrophilic transition layer. The auxiliary electrode is located outside of the ionic path between electrodes of opposite polarity, but in electron-conducting contact with the negative electrode, excluding the auxiliary electrode from unwanted interaction with the NO.sub.2 /NH.sub.3 --auto-discharge path.