A lithium ion secondary battery at least includes a positive electrode, a negative electrode, and an electrolyte solution. The positive electrode at least includes a positive electrode active material and a binder. The positive electrode active material includes more than or equal to 0.08 mass % of a lithium carbonate and a remainder of a lithium complex oxide. The binder is at least one selected from a group consisting of polytetrafluoroethylene, polyethylene oxide, and carboxymethylcellulose. The electrolyte solution at least includes a solvent and a lithium salt. The solvent is at least one of N,N-dimethylformamide and dimethylacetamide. A concentration of the lithium salt in the electrolyte solution is more than or equal to 1.9 mol/l and less than or equal to 2.3 mol/l.