LITHIUM ION SECONDARY BATTERY

摘要

The present invention provides a lithium ion secondary battery which has improved safety without significantly reducing the battery capacity. A lithium ion secondary battery of the present invention comprises: a positive electrode (11); a negative electrode (31); a separator (21) that is sandwiched between the positive electrode and the negative electrode; and a nonaqueous electrolyte solution that is obtained by dissolving a lithium salt into a nonaqueous solvent. This lithium ion secondary battery also comprises an inorganic layer (22) on the positive electrode side of the separator (21), said inorganic layer (22) containing a polyanionic compound. The inorganic layer (22) is bonded with the separator (21), and is in electric contact with the positive electrode (11).