Patent ID: 6573001
Filing Date: 2003-06-03
Classification: H01M,Y02E,Y02P,Y10T

Abstract:
A sealed battery, comprising:an external casing that is made of an aluminum alloy, the external casing with an opening and a rim around the opening, a thickness of the external casing at the rim being no greater than a thickness of the external casing at parts of the external casing other than the rim of the external casing; and a closure cap that is made of the aluminum alloy, the closure cap being a plate with a rib along an outer edge of the plate, wherein the closure cap is disposed so that the rib comes into contact with the rim, and the external casing and the closure cap are welded together by radiation of an energy beam, wherein the closure cap satisfies equations T2&gE;(T1/10+40) &mgr;m and 50 (&mgr;m)&lE;T3&lE;1, a thickness of the plate being set as T1 (&mgr;m), a height of the rib being set as T2 (&mgr;m), and a thickness of the rib being set as T3 (&mgr;m), and as a result, heat stress at a time of welding the aluminum alloy is reduced when the closure cap and the external casing are welded together.