The present application discloses a lithium ion secondary battery including a positive electrode sheet, a negative electrode sheet, a separator, and an electrolyte, wherein the positive electrode sheet includes a positive electrode current collector and a positive electrode film sheet disposed on at least one surface of the positive electrode current collector, and the On the positive electrode film sheet, the first positive electrode active material represented by the _{formula Li 1+x} Ni _a Co _b Me _1-ab O _2-y A _{y and the formula Li 1 + z} Mn _c N _{2 - c} O _{4 - d} B _d The second positive electrode active material is contained, the positive electrode sheet has an electrical resistivity r of 3500 Ω*m or less, and the electrolyte solution contains a fluorine-containing lithium salt additive. The lithium ion secondary battery provided in the present application has high safety performance, high temperature storage performance, and cycle performance at the same time.