The Gillette Company

Daniel W Gibbons

Leo White

Peter R Moses

Alexander Boris Shelekhin

Keith Buckle

David L Pappas

Guang Wei

Michael J Kolb

Rokeya Huq

Ilya Nizker

Michael Brovarski

Karthik Ramaswami

An alkaline battery can include a housing, a cathode within the housing, an anode, a separator between the anode and the cathode, and an alkaline electrolyte contacting the anode and the cathode. The cathode defines an anode cavity and the anode is deposited within the anode cavity. The cathode has a top surface adjacent to the anode cavity. The battery can include a protective layer deposited on the top surface of the cathode and/or a gel plug deposited over the anode. The protective layer can include a PVA layer coated over the top surface of the cathode.

Alkaline battery having a protective layer

A method of applying liquid adhesive to surfaces of components of an electrochemical cell employing a needle valve applicator. The liquid adhesive is applied by dispensing it through a tubular tip connected to a pneumatically actuated needle valve applicator. The method is effective in applying adhesive to narrow width or difficult to reach surfaces of cell components in a precise, consistent and reproducible manner. In a specific application the adhesive can be applied to the narrow recessed step surrounding the terminal portion of the cathode casing of a zinc/air button cell. In such application the cathode casing may typically be rotated at speeds of between about 50 and 1000 revolutions per minute as adhesive is applied thereto from the applicator. The adhesive provides a tight seal between the cathode casing and cathode assembly, thereby preventing leakage of electrolyte from the cell.

Method of applying adhesive to electrochemical cell components

A zinc/air button cell comprising a cathode casing and an anode casing wherein the anode casing is inserted into the cathode casing. The anode casing is formed of multiclad metal layers, for example nickel/stainless steel/copper. A protective metal is plated onto the exposed peripheral edge of the anode casing. The protective metal is desirably selected from copper, tin, indium, silver, brass, bronze or gold. The application of the protective metal covers the multiclad metals exposed along the peripheral edge surface. The protective metal is also desirably plated onto the portion of the outside surface of the anode casing abutting the insulating material placed between the anode and cathode casing. Application of the protective metal to the anode casing peripheral edge eliminates the potential gradients caused by exposure of the different metals comprising the multiclad material. This reduces the chance of electrolyte leakage which can be promoted by secondary reactions occurring along the anode casing peripheral edge.

Zinc/air cell

A spray method of applying liquid adhesive to surfaces of components of an electrochemical cell. The adhesive is applied by spraying through a nozzle, preferably activated by a piezoelectric transducer. The nozzle can be an elongated resilient tube terminating in an outlet opening. The adhesive is preferably sprayed in a pulsed stream of droplets. The liquid adhesive is desirably dispensed in fine droplets at a rate of between about 500 and 5000 droplets per second. The method is effective in applying adhesive to narrow width or difficult to reach surfaces of cell components in a precise, consistent and reproducible manner. In a specific application the adhesive can be applied to the narrow recessed step surrounding the terminal portion of the cathode casing of a zinc/air button cell. In such application the adhesive provides a tight seal between the cathode casing and cathode assembly, thereby preventing leakage of electrolyte from the cell.

A process for heat treating the metal sheeting forming the anode casing of a zinc/air depolarized cell before anode material comprising zinc is inserted into the anode casing. The anode casing has a layer of copper on its inside surface. The process comprises heat treating the metal sheeting forming the anode casing by passing a gas at a temperature between about 200&deg; C. and 700&deg; C., preferably between about 300&deg; C. and 600&deg; C. in contact therewith to form a heat treated sheeting and then cooling said heat treated sheeting to ambient temperature. The anode casing is stored away from atmospheric air until anode active material is inserted therein during cell assembly. The heat treating process significantly reduces gassing during cell discharge and storage. The cell's capacity and performance is improved when the cell's anode comprises particulate zinc (or zinc alloy) plated with indium, preferably between about 200 and 600 ppm indium. The need to add mercury to the anode material is reduced and can be eliminated.

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Southbury, CT, United States of America

Daniel W Gibbons