Duracell Inc.

The Gillette Company

Radek Fooksa

William L Bowden

Mark Capparella

Jonathan Boulton

C Robert Parent

An alkaline cell having an anode comprising zinc, a cathode comprising manganese dioxide and an electrolyte comprising polyvinylbenzyltrimethylammoniumhydroxide. The anode can comprise particulate zinc dispersed within an aqueous gel comprising crosslinked polyvinylbenzyltrimethylammoniumhydroxide polymer. Optionally, aqueous KOH can be added to the gel. The anode and cathode are desirably in the shape of a slab each having a pair of opposing parallel flat faces defining two opposing ends. The zinc particles dispersed in crosslinked polyvinylbenzytrimethylammoniumhydroxide polymer can be concentrated at one end of the anode slab with the opposing end being clear of zinc. The clear end of the anode preferably also comprising polyvinylbenzlytrimethylammoniumhydroxide functions as a separator between anode and cathode. The cathode slab comprises a mixture of particulate manganese dioxide, graphite, and linear polyvinylbenzyltrimethylammoniumhydroxide polymer. The polyvinylbenzyltrimethylammoniumhydroxide polymer functions to bind the manganese dioxide particles and also functions as electrolyte during cell discharge.

Alkaline cell with polymer electrolyte

Disclosed is a process for treating manganese dioxide containing ion-exchangeable cations by replacing the ion-exchangeable cations present in the manganese dioxide with lithium by a process comprising first replacing ion-exchangeable cations present in the manganese dioxide with hydrogen. This readily is accomplished by slurrying the manganese dioxide in an aqueous acid solution. The resulting acidic manganese dioxide then is neutralized with a basic solution of a lithium containing compound, such as lithium hydroxide. This neutralization step serves to accomplish replacement of the previously introduced hydrogen, by ion-exchange, with lithium. The manganese dioxide then is washed with water, dried, and heat-treated at an elevated temperature, in conventional manner, to convert the gamma manganese dioxide to a mixture of the gamma and beta forms, which then is used as the active cathodic component in an electrochemical cell.

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Needham, MA, United States of America

Radek Fooksa