PVDF (Polyvinylidene Fluoride) modified diaphragm, preparation method thereof and lithium ion battery

The invention provides a PVDF (Polyvinylidene Fluoride) modified diaphragm, a preparation method thereof and a lithium ion battery. The preparation method of the PVDF modified diaphragm comprises the following steps: dissolving rubber with polar groups by using an organic solvent to obtain a pretreated material, mixing the pretreated material with a thickening agent, enabling the high viscosity of the thickening agent to improve the storage performance of the material, sanding the mixed material and a dispersed PVDF slurry precursor, finally adding a binder, stirring to obtain modified PVDF slurry, and carrying out vacuum drying on the modified PVDF slurry to obtain the PVDF modified diaphragm. The PVDF modified diaphragm is obtained after coating and drying the surface of the base membrane, the problem of storage performance is solved by mixing the thickening agent and the rubber with polar groups, and the polar groups contained in the rubber can improve the acting force between PVDF molecules after being mi