LITHIUMION SECONDARY BATTERY AND METHOD FOR PRODUCING NEGATIVE ELECTRODE THEREOF

摘要

Disclosed is an improved lithium ion secondary battery comprising a positive electrode, a negative electrode, a separator, a nonaqueous electrolyte solution, and a porous film formed on the surface of at least one of the electrodes. The porous film contains inorganic compound particles and a vinylidene polyfluoride. An 8 wt% N-methyl-2-pyrrolidone solution of the vinylidene polyfluoride at 250C has a viscosity of 600-2400 mPa.s, and the vinylidene polyfluoride content in the porous film is 1-10 parts by weight per 100 parts by weight of the inorganic compound particles.