Patent attributes
Provided is a non-aqueous electrolyte secondary battery that can achieve both battery characteristics during normal usage and resistance to overcharging at high levels. In this non-aqueous electrolyte secondary battery, an electrode body, which includes a positive electrode and a negative electrode, and a non-aqueous electrolyte are housed in a battery case. The battery case is provided with a current interrupt mechanism that activates when the pressure inside the case increases. The non-aqueous electrolyte contains cyclohexylbenzene and 4,4′-difluorobiphenyl as gas generating agents that decompose and generate gas when the battery reaches an overcharged state. In addition, when the overall quantity of the non-aqueous electrolyte is taken to be 100 mass %, a ratio of the content (mass %) of the 4,4′-difluorobiphenyl (W2) relative to the content (mass %) of the cyclohexylbenzene (W1) (W2/W1) is 0.025 to 0.25.
