Lithium-containing diaphragm and preparation method thereof and lithium ion battery

The invention provides a lithium-containing diaphragm and a preparation method thereof and a lithium ion battery. The preparation method provided by the invention comprises the following steps: takinga protective gas as a carrier gas, loading heated lithium-containing powder, and spraying the lithium-containing powder onto the surface of a base membrane to obtain the lithium-containing diaphragm.According to the preparation method provided by the invention, the lithium-containing film is rapidly formed by spraying on the surface of the base film, and lithium loss in the battery charging anddischarging process can be supplemented. According to the invention, the thickness of the formed lithium film can be controlled, and regulation and control are carried out by adjusting the gas flow rate, the lithium powder content and the unwinding and winding speed of the diaphragm; and protective gas is used as carrier gas so as to ensure the requirement of the lithium-containing material for the environment, and good sea