Patent ID: 7829226

Claim:
A non-aqueous secondary battery comprising: a positive electrode; a negative electrode; a separator; and non-aqueous electrolytic solution, wherein the positive electrode comprises a layered structure lithium-containing compound oxide containing manganese as an active material, the non-aqueous electrolytic solution contains at least one additive selected from the group consisting of: a sulfonic acid anhydride expressed by the general formula (1); a sulfonate ester derivative expressed by the general formula (2); a cyclic sulfate derivative expressed by the general formula (3); and a cyclic sulfonate ester derivative expressed by the general formula (4), and a vinylene carbonate or a derivative of the vinylene carbonate: wherein each of R 1 and R 2 in the general formula (1) represents independently an organic residue having 1-10 of carbon atoms, each of R 3 and R 4 in the general formula (2) represents independently an organic residue having 1-10 of carbon atoms, R 5 in the general formula (3) represents independently hydrogen or an alkyl group having 1-4 of carbon atoms, which can have a fluorinated substituent, n is 0 or 1, and R 6 in the general formula (4) represents independently hydrogen or an alkyl group having 1-4 of carbon atoms, which can have a fluorinated substituent, m is 0, 1 or 2, wherein a potential of the positive electrode is 4.35V or higher versus a Li reference electrode, in a state in which the battery is charged up to a designed electric capacity; wherein the layered structure lithium-containing compound oxide comprises a compound expressed by the formula of (i) Li x Ni 1/3 Mn 1/3 Co 1/3 O 2 wherein 0<x≦1.1 or (ii) Li x Ni 5/12 Mn 5/12 Co 1/6 O 2 wherein 0<x≦1.1.