摘要 |
<P>PROBLEM TO BE SOLVED: To provide a secondary battery which allows the strength of a cap plate to be increased by making the thickness of the cap plate and a case region different from each other, the case region being susceptible to deformation by external forces. <P>SOLUTION: A secondary battery is disclosed as one example, which includes an electrode assembly including a first electrode plate, a second electrode plate and a separator interposed between the first and the second electrode plates; a first collector plate and a second collector plate which respectively are electrically connected to the first and the second electrode plates; a case which accommodates the electrode assembly and the first and the second collector plates; and a cap plate which covers the case so as to seal the electrode assembly, the case and the collector plates hermetically. The cap plate has reinforced step portions formed thereon, whereby the thickness of the cap plate in a central region and that in side regions are made different from each other. <P>COPYRIGHT: (C)2012,JPO&INPIT |