| 摘要 |
PROBLEM TO BE SOLVED: To provide a battery with excellent discharge load characteristics and excellent low temperature discharge characteristics. SOLUTION: This battery has a wound electrode body formed by winding a belt-shaped positive electrode and a belt-shaped negative electrode through a separator 23 in which an electrolyte is impregnated. The separator 23 contains a microporous film 23a in which average pore diameter is 0.15 μm or less and an average value of the ratio of the shortest diameter DS to the longest diameter DL of the pores is 0.4-1.0. Clogging of micropores 23b can be prevented, and electrolyte permeability, ion permeability, and electrolyte retainability of the separator 23 can be enhanced. Excellent discharge load characteristics and excellent low temperature discharge characteristics can be obtained. |
