The Gillette Company

Keith Buckle

David L Pappas

Daniel W Gibbons

Sean A Sargeant

Leo White

Charles R Ferraro

Thomas Takahura

Karthik Ramaswami

Mark Andrews

Jay Lucas

A method of forming a nickel layer on a metal substrate forming the terminal contact area of the cathode casing for a zinc-air cell. A cathode casing in desired shape and size for a zinc-air cell is formed of a substrate metal such as cold rolled steel or stainless steel. A nickel layer is plated onto the cathode casing substrate metal over the terminal contact area and is subsequently heat treated resulting in reduction in the surface hardness. The method of heat treatment involves heating the substrate metal with nickel plated thereon in an inert atmosphere at temperatures preferably between about 860&#xb0; F. and 135&#xb0; F. The method reduces the nickel surface hardness to a level below 8 GPa. This improves the electrical contact with the hearing aid or other device being powered.

Method of forming a nickel layer on the cathode casing for a zinc-air cell

A zinc/air cell having thin walled cup shaped anode casing and cathode casing. The cell may be a button cell having an anode comprising zinc and a cathode, which may be catalytic, comprising manganese dioxide. The anode and cathode casings have small wall thicknesses, preferably between 2 and 5 mil (0.0508 and 0.127 mm), desirably between about 2 and 3 mil (0.0508 and 0.0762 mm). There is an insulating seal ring covering at least a portion of the anode casing side walls. During cell assembly the cathode casing side wall is pushed over at least a portion of the anode casing side wall with insulating sealing disk therebetween. A tight interference fit is achieved with the outside diameter of the anode casing plus insulating seal thereon being preferably between about 2 and 4.5 mil (0.0508 and 0.114 mm) greater than the inside diameter of the cathode casing. This reduces the tendency of the casing side walls to spring back after crimping.

Zinc/air cell

An assembly process for manufacture of zinc/air cells, typically zinc/air button cells. The cells have a cup shaped anode casing and cup shaped cathode casing, each having an open and closed end. The process comprises an assembly step wherein the two casings are pushed together, followed by a crimping step wherein the cell is punched through a die thereby crimping the cathode casing edge over the anode casing side wall with insulator seal therebetween. In each step, particularly in the crimping step, an anode punch having an annular protruding surface impacts the corner edge of the closed end of the anode casing while another punch is applied with an opposing force to the cathode casing. The process has particular utility for anode and cathode casings of small wall thickness, preferably between 2 and 5 mil (0.0508 and 0.127 mm).

Zinc/air cell assembly

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.

A process is described for forming a can from extremely thin side wall material. The process includes the steps of reverse forming a portion of the can, and during the reverse forming process including a tapered side wall portion. Battery cans formed during the process are also described.

Thin-wall anode can

A casing for cylindrical electrochemical cells, for example, alkaline cells or lithium cells. The casing is characterized by having a non-uniform wall thickness. The casing comprises a cylindrical body surface, an open end and an integrally formed closed bottom. A portion of the casing body forms the peripheral edge of the casing at the open end thereof. The casing body surface has a wall thickness which is less than the wall thickness of the casing bottom. The casing has a peripheral edge which has a wall thickness which is greater than the wall thickness of the body surface. The peripheral edge wall thickness is desirably about the same or greater than the wall thickness of the casing bottom. The casing is formed by subjecting a sheet of metal to a series of discrete punching steps. A partially formed cup is punched through a die cavity in each step thereby progressively drawing the cup to a progressively reduced diameter and increased length. This is accomplished desirably without changing any portion of the cup's wall thickness. The cup is subjected to a finishing step wherein the wall thickness of the body surface is reduced without altering the wall thickness of the bottom. The wall thickness of the peripheral edge remains the same or is increased in the finishing step.

Growing community of inventors

Bellingham, MA, United States of America

Keith Buckle