Nonaqueous electrolyte secondary battery

A nonaqueous electrolyte secondary battery, comprising:

• a case;
• a nonaqueous electrolytic solution provided in the case and comprising a nonaqueous solvent and a lithium salt dissolved in the nonaqueous solvent, the nonaqueous solvent comprising from 50 to 95% by volume of a sulfone-based compound represented by the following formula 1
• wherein R1 and R2 are each an alkyl group having 1 to 6 carbon atoms and satisfy R1≠R2;
• a positive electrode provided in the case and comprising a composite oxide represented by L1-xMn1.5-yNi0.5-zMy+zO4, wherein 0≦x≦1, 0≦y+z≦0.15, and M is at least one selected from the group consisting of Mg, Al, Ti, Fe, Co, Ni, Cu, Zn, Ga, Nb, Sn, Zr and Ta;
• and
• a negative electrode provided in the case and comprising a negative electrode active material being capable of absorbing and releasing lithium at 1 V or more based on a metallic lithium potential.