To manufacture a battery which is good in battery efficiency and less hazardous in liquid leakage by using a polyfluoro vinylidene fine porous film in a separator of the lithium ion battery.
By a method including a wet film molding process, dissolving polyfluorovinylidene in a solvent flow extending this dope on a mold release material thereafter immersed in water containing dimethyl formamide and solidified, and a process swelling an obtained fine porous film thereafter impregnated with an electrolyte, a separator film is manufactured. Then, this separator is formed as an electrolyte layer, this layer is interposed by a positive/negative electrode, so as to constitute a battery. The flow extended dope is impregnated with a fiber reinforcing base material or it is buried, mechanical strength of the fine porous film is improved.
MATSUI SEIICHIRO
HIYOUGO TOYOAKI
KAMIBAYASHI KAICHIROU
MIURA AKIRA
MAEDA SHIZUO
WATANABE SHIRO
