| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a secondary battery which is superior on reliability while securing sufficient capacity. <P>SOLUTION: The secondary battery has a multilayer structure of a positive electrode, a separator 23, and a negative electrode, and a winding body having a flat cross-section including a pair of opposite flat sections and a pair of opposite curved sections are stored in an outer package can. Air permeability of the separator 23 at the curved section is higher than that of the separator 23 at the flat section continued to the curved section. The separator 23 has a base material 231 made of a porous resin, and polymer compound layers 232A, 232B arranged on both sides of the base material 231. The polymer compound layers 232A, 232B are formed so as to make thickness on a part 23R corresponding to the curved section larger than that on a part 23S corresponding to the flat section. <P>COPYRIGHT: (C)2010,JPO&INPIT |
