| 摘要 |
PROBLEM TO BE SOLVED: To provide a secondary battery in which there is no possibility of fracture and permeability of electrolyte is enhanced. SOLUTION: The secondary battery includes a wound body formed by winding a sheet-like positive electrode and a sheet-like negative electrode mutually. The positive electrode has a positive electrode collector and a positive electrode mixture layer formed thereon, and the negative electrode has a negative electrode collector and a negative electrode mixture layer formed thereon. In the secondary battery, a plurality of recesses independent from each other are formed on the surface of at least one of the positive electrode mixture layer and the negative electrode mixture layer, at least in the central part in the width direction for the winding direction. COPYRIGHT: (C)2013,JPO&INPIT |
