摘要 |
A battery with an excellent discharge load characteristic and low temperature discharge characteristic is provided. The battery comprises a wound electrode where a strip-shaped positive electrode and a strip-shaped negative electrode are wound with a separator (23) therebetween which is impregnated with an electrolyte. The separator (23) includes a macroporous film (23a) having an average pore size of 0.15 mu m or less and an average ratio of a shortest internal diameter (Ds) to a longest internal diameter (DL) in a pore not less than 0.4 nor more than 1.0. This can prevent clogging of macropores (23b) and improve electrolyte permeability, ionic permeability, and electrolyte retention of the separator (23). Therefore, the excellent discharge load characteristic and low temperature discharge characteristic can be obtained. <IMAGE> |