| abstract |
An object of the present invention is to provide 1 Vvs. In non-aqueous electrolyte secondary battery using a negative electrode active material capable of inserting / extracting lithium ions at a potential of Li / Li + or higher, non-aqueous with suppressed self-discharge by suppressing increase in internal resistance at high temperature An electrolyte secondary battery is provided. In a non-aqueous electrolyte secondary battery comprising a positive electrode active material, a negative electrode active material, and a non-aqueous electrolyte, compound X is present on the surface of the negative electrode active material, and the negative electrode active material is 1 V vs. Li / Li + is a compound capable of inserting / extracting lithium ions at a potential of not less than Li / Li + , and the compound X includes manganese oxide other than manganese dioxide, manganese phosphate, manganese fluoride, cobalt oxide, cobalt phosphate, fluorine It is at least one selected from the group consisting of cobalt halides. [Selection figure] None |