Patent ID: 7622226

Claim:
A secondary battery having a terminal for surface mounting comprising a power generating element and a battery case for housing said power generating element, wherein: said power generating element comprises a positive electrode, a negative electrode, a separator interposed between said positive electrode and said negative electrode, and an organic electrolyte; said battery case comprises a positive electrode can electrically connected with said positive electrode, a negative electrode can electrically connected with said negative electrode, and a gasket interposed between said positive electrode can and said negative electrode can; said organic electrolyte comprises an organic solvent and a solute dissolved therein; said organic solvent comprises sulfolane and 1,2-dimethoxyethane; amounts of said sulfolane and said 1,2-dimethoxyethane are 80 to 95 volume % and 5 to 20 volume %, respectively, with respect to the total amount of said sulfolane and said 1,2-dimethoxyethane; said solute comprises LiN(CF 3 SO 2 ) 2 ; and a concentration of said LiN(CF 3 SO 2 ) 2 in said organic electrolyte is 0.9 to 1.3 mol/L.