Non-aqueous electrolyte secondary battery and battery pack

摘要

A non-aqueous electrolyte secondary battery of an embodiment includes an exterior member, a negative electrode containing a titanium-containing oxide housed in the exterior member, a positive electrode housed in the exterior member, a separator housed in the exterior member and arranged between the positive electrode and the negative electrode, and a non-aqueous electrolyte solution housed in the exterior member. At least one type or more chain carbonates are contained in a solvent of the non-aqueous electrolyte solution. A self-diffusion coefficient of the chain carbonate in -20°C is from 1.4 × 10 -10 to 2.0 × 10 -10 m 2 /sec.