| 摘要 |
PROBLEM TO BE SOLVED: To provide a non-aqueous secondary battery that has a large capacity of 30 Wh or more and a volumetric energy density of 180 Wh/l or more and that is excellent in cold temperature characteristics and rate characteristics and further, that has excellent heat radiation characteristics as well as high safety. SOLUTION: This is a flat type non-aqueous secondary battery comprising a positive electrode, a negative electrode and a non-aqueous electrolyte which is obtained by dissolving lithium salt in non-aqueous solvent. In it, (1) the non- aqueous solvent is a mixture of solvent containing at least ethylene carbonate and ethyl-methyl carbonate, (2) the combined volume of ethylene carbonate and ethyl-methyl carbonate is 60% or more of the total volume of solvent, (3) ethyl-methyl carbonate/ethylene carbonate (volume ratio) is 1 or more, (4) the energy capacity of the battery is 30 Wh or more, and (5) the volumetric energy density of the battery is 180 Wh/l or more. |
