Patent ID: 8133617

Claim:
A method of using a non-aqueous electrolyte battery comprising a non-aqueous electrolyte containing an electrolytic salt and a non-aqueous solvent, a positive electrode and a negative electrode having a negative active material that intercalates/deintercalates lithium ions at a potential not lower than 1.2 V relative to the potential of lithium, the method comprising: performing an initial charge/discharge of the non-aqueous electrolyte battery by lowering the potential of the negative electrode to an initial region that is not higher than 0.3 V relative to the potential of lithium at least once before operating the non-aqueous electrolyte battery so as to form a film coat having a carbonate structure and a thickness of not less than 10 nm on a surface of said negative electrode; and operating the non-aqueous electrolyte battery in an operating region of the potential of the negative electrode that is higher than 0.8 V relative to the potential of lithium.