
The present invention is characterized in that a nonaqueous electrolyte contains a sultone compound having unsaturated bonds, and the present invention thereby aims at suppressing the swelling of a nonaqueous electrolyte secondary battery, as represented by a lithium secondary battery, after being allowed to stand at a high temperature and at obtaining an excellent high temperature standing performance. Furthermore, by making the nonaqueous electrolyte contain, in addition to the sultone compoun...











