Patent ID: 11450880

Abstract:
Provided is a nonaqueous electrolyte secondary battery, in which the capacity retention rate after high temperature storage is high, the gas amount after high temperature storage is suppressed, the resistance after high temperature storage is low, the amount of metal dissolution from a positive electrode is small, and the amount of heat generation at a high temperature is small. A nonaqueous electrolyte secondary battery including a positive electrode with a positive electrode active material capable of absorbing and releasing a metal ion; a negative electrode with a negative electrode active material capable of absorbing and releasing a metal ion; and a nonaqueous electrolyte solution; wherein the positive electrode active material includes a lithium transition metal compound, and the positive electrode active material includes at least Ni, Mn and Co, wherein the molar ratio of Mn/(Ni+Mn+Co) is larger than 0 and not larger than 0.32, the molar ratio of Ni/(Ni+Mn+Co) is 0.45 or more, the plate density of the positive electrode is 3.0 g/cm3 or more; and the nonaqueous electrolyte solution includes a monofluorophosphate and/or a difluorophosphate.