| abstract |
According to the present disclosure, there is provided a technique making it possible to improve suitably the performance of a nonaqueous electrolyte secondary cell in which a SEI film is formed on the surface of a negative electrode active material. The nonaqueous electrolyte secondary cell disclosed herein includes a positive electrode 10, a negative electrode 20, and a nonaqueous electrolytic solution, wherein a negative electrode SEI film 29 including at least a LiBOB skeleton and a fluorosulfonic acid skeleton is formed on the surface of a negative electrode active material 28, and a positive electrode SEI film 19 including at least a phosphoric acid skeleton is formed on the surface of a positive electrode active material 18. Where the component amount of the LiBOB skeleton in the negative electrode SEI film 29 is denoted by IB, the component amount of the fluorosulfonic acid skeleton in the negative electrode SEI film 29 is denoted by IS, and the component amount of the phosphoric acid skeleton in the positive electrode SEI film 19 is denoted by IP, a formula of 4≤IB/IS≤10 and a formula of 5 μmol/m2≤IP≤15 μmol/m2 are satisfied. |