Patent ID: 11909000

Abstract:
A lithium-ion secondary battery is provided, where an electrolyte solution of the lithium-ion secondary battery comprises a highly heat-stable salt (My+)x/yR1(SO2N−)xSO2R2, where the My+ is a metal ion, R1 and R2 are each independently a fluorine atom, an alkyl with 1-20 carbon atoms, a fluoroalkyl with 1-20 carbon atoms, or a fluoroalkoxy with 1-20 carton atoms, x is 1, 2, or 3, and y is 1, 2, or 3. A mass percent of the salt in the electrolyte solution is set as k2%; a temperature rise coefficient k1 of the positive electrode sheet satisfies 2.5≤k1≤32, where k1=Cw/Mc, Cw is a positive electrode material load per unit area (mg/cm2) on the surface of any side of the positive electrode current collector on which a positive electrode material layer is loaded, and Mc is a carbon content (%) of the positive electrode material layer; and the lithium-ion secondary battery satisfies 0.34≤k2/k1≤8.