LITHIUM BATTERY AND FORMATION METHOD THEREOF

A lithium-ion battery and a method of preparing the same are provided. The lithium-ion battery includes a cell and an electrolyte solution, and the cell includes a negative electrode sheet. The negative electrode sheet includes a negative electrode current collector, an active coating layer disposed on a surface of the current collector, and a protective coating layer disposed on a surface of the active coating layer. The protective coating layer is a solid-state electrolyte coating layer. The electrolyte solution contains a film-forming agent. The method includes the following steps. After the cell is placed in a casing and the electrolyte solution is injected, formation is performed on the lithium-ion battery. The formation includes: S1, performing charging to 3.4V to 3.75V with a constant current rate of 0.02C to 0.04C; and S2, performing charging to 3.75V to 4.25V with a constant current rate of 0.05C to 0.3C.