Nonaqueous-electrolyte secondary battery

摘要

A subject for the invention is to improve the cycle characteristics of a high-capacity secondary battery containing an active material packed at a high density. The invention relates to a nonaqueous-electrolyte secondary battery comprising a negative electrode and a positive electrode each capable of occluding/releasing lithium, a separator, and a nonaqueous electrolyte solution comprising a nonaqueous solvent and a lithium salt, characterized in that the separator comprises a porous film made of a thermoplastic resin containing an inorganic filler, and
the amount of water contained in the battery is 200-500 ppm in terms of water concentration in the electrolyte solution in the battery.