A battery case (1) has a cutting groove (10) formed on its elongated side surface (1a). Between a groove bottom surface of the cutting groove (10) and an inner surface of the battery case (1) is provided a thin-walled easily-rupturable portion (12) designe...

An electrochemical cell having plate electrodes (16) housed inside mating "clam shell" casing components (12,14). Also, the present casing design allows for indentation structures (30,32) in the casing components by virtue of them being stamped metal parts...