NONAQUEOUS ELECTROLYTE SECONDARY BATTERY

摘要

PROBLEM TO BE SOLVED: To provide a nonaqueous electrolyte secondary battery having an excellent capacity-keeping rate after high-temperature storage.SOLUTION: Disclosed is a nonaqueous electrolyte secondary battery which includes a rectangular outer package 12 in which a flat-shaped wound electrode body 4 having a positive electrode plate 1 and a negative electrode plate 2 and a nonaqueous electrolyte are housed. The nonaqueous electrolyte contains fluorosulfonic acid lithium. The rectangular outer package 12 has a pair of large area side walls 12a and a pair of small area side walls 12b. A value of the lamination number of the positive electrode plate 1 in the wound electrode body 4 arranged between the pair of large area side walls 12a with respect to the distance between the pair of large area side walls 12a is 5 layers per mm or more.