Patent ID: 6998194

Claim:
A nonaqueous electrolyte secondary battery, comprising: a case; an electrode group comprising a positive electrode, and a negative electrode which is provided in the case; and a nonaqueous electrolyte which is provided in the case and comprises a nonaqueous solvent, wherein the nonaqueous solvent comprises ethylene carbonate (EC), propylene carbonate (PC), γ-butyrolactone (GBL), vinylene carbonate (VC) and a fifth component that comprises vinyl ethylene carbonate and/or phenyl ethylene carbonate and the nonaqueous solvent satisfies the following relationships (5) to (9): 15≦x≦50 (5) 30≦y≦75 (6) 0<z≦25 (7) 0<w≦5 (8) 0<q≦5 (9) where, x is the ratio (volume %) of ethylene carbonate to the total volume of the nonaqueous solvent, y is the ratio (volume %) of propylene carbonate to the total volume of the nonaqueous solvent, z is the ratio (volume %) of γ-butyrolactone to the total volume of the nonaqueous solvent, w is the ratio (volume %) of vinylene carbonate to the total volume of the nonaqueous solvent, and q is the ratio (volume %) of the fifth component to the total volume of the nonaqueous solvent.