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US 5,804,327 AGranted
Thin walled electrochemical cell
AssigneeRayovac Corporation
InventorJohn Edward Oltman
Life of this patent
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Abstract
This invention pertains to alkaline electrochemical cells, typically to metal-air cells of the button-type. Non-reactive elements of cells of the invention are thinner than corresponding non-reactive elements of prior art cells. Such elements can be made thinner because of improved structures of such elements. The anode can is made from a metal strip structure having a higher steel content. The cathode can has a modified temper, which improves relative stiffness and rigidity while retaining sufficient ductility. By so reducing the thicknesses of non-reactive elements of the cell, and thus the volume occupied by such non-reactive elements, the fraction of the cell devoted to holding electrochemically reactive anode material therein is increased, with corresponding increase in the milliampere hour capacity of the cell.
Claims18
A metal-air electrochemical button cell, comprising:
- (a) an anode, including an anode can and anode material in said anode can, said anode can having a top wall, and a first circumferential side wall extending downwardly from said top wall to a first distal edge thereof, said first side wall having a first height generally corresponding to an overall second height of said anode can, said anode can having a first outer surface disposed outwardly on said top wall and outwardly on said first side wall, and thus outwardly on said electrochemical button cell, a second inner surface disposed inwardly on said top wall and inwardly on said first side wall, and thus inwardly on said electrochemical button cell, and an overall thickness between the first outer and the second inner surfaces of about 0.110 millimeter to about 0.145 millimeter, said anode can comprising a first layer comprising nickel, a second layer comprising copper, and a third layer comprising stainless steel between said first and second layers, said third layer comprising about 83 percent by volume to about 91 percent by volume of the overall thickness of at least one of said top wall and said first side wall of said anode can, the combination of said first and second layers comprising about 9 percent by volume to about 17 percent by volume of the overall thickness of the respective one of said top wall and said first side wall;
- (b) a cathode, including a cathode can, said cathode can having a bottom wall and a second circumferential side wall extending upwardly from said bottom wall and terminating at a second distal edge thereof, said second side wall having a third height generally corresponding to an overall fourth height of said cathode can, said cathode can comprising a substrate, said substrate, as taken at a location away from the second distal edge, comprising fourth and fifth layers comprising nickel, and a sixth layer comprising cold rolled steel between said fourth and fifth layers, said cathode further comprising an air cathode assembly in said cathode can,
- said anode, including said anode can and said anode material, being received inside said cathode can such that the entirety of said second side wall is disposed radially outwardly of said first side wall;
- (c) an aqueous alkaline electrolyte;
- (d) a space between said first and second side walls, extending over a substantial portion of the first height;
- and
- (e) seal material in the space between said first and second side walls,
- the combination of the second inner surface of said anode can and said cathode assembly at least in part defining a cavity in said electrochemical button cell, the second height of said first anode can side wall being significantly greater than one half the fourth height of said second side wall of said cathode can, said second side wall of said cathode can being crimped inwardly against said seal material, and by way of said seal material against an upper portion of said first side wall of said anode can such that said seal material provides a physical closure of said electrochemical button cell against leakage of contents out of said electrochemical button cell, and provides electrical insulation against passage of electrical current across the space.
5 more elements
A metal-air electrochemical button cell, comprising:
- (a) an anode, including an anode can and anode material in said anode can, said anode can having a top wall, and a first circumferential side wall extending downwardly from said top wall, said first side wall having a first height generally corresponding to an overall second height of said anode can, said anode can having a first outer surface disposed outwardly on said top wall and said first side wall, and thus outwardly on said electrochemical button cell, and a second inner surface disposed inwardly on said top wall and inwardly on said first side wall, and thus inwardly on said electrochemical button cell;
- (b) a cathode, including a cathode can, said cathode can having a bottom wall and a second circumferential side wall extending upwardly from said bottom wall and terminating at a distal edge thereof, said second side wall having a third height generally corresponding to an overall fourth height of said cathode can, said cathode can comprising a substrate, said substrate, as taken at a location away from said distal edge, comprising first and second layers comprising nickel, and a third layer comprising cold rolled steel between said first and second layers, said cathode further comprising an air cathode assembly in said cathode can, said cathode can having a third outer surface disposed outwardly on said bottom wall and outwardly on said second side wall, and thus outwardly on said electrochemical button cell, a fourth inner surface disposed inwardly on said bottom wall and inwardly on said second side wall, and thus inwardly on said electrochemical cell, and a thickness between the third outer surface and the fourth inner surface, at one of said bottom wall and said second side wall, of about 0.100 millimeter to about 0.140 millimeter,
- said anode, including said anode can and said anode material being received inside said cathode can such that said second side wall is disposed radially outwardly of said first side wall;
- (c) an aqueous alkaline electrolyte;
- (d) a space between said first and second side walls, extending over a substantial portion of the first height;
- and
- (e) seal material in the space between said first and second side walls,
- the second height of said anode can side wall being significantly greater than one half the fourth height of said second side wall of said cathode can, said second side wall of said cathode can being crimped inwardly against said seal material, and by way of said seal material against an upper portion of said anode can.
5 more elements
Dependencies are inferred from the claim text.