Secondary battery having a terminal for surface mounting

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(CF3SO2)2;
• and
• a concentration of said LiN(CF3SO2)2 in said organic electrolyte is 0.9 to 1.3 mol/L.