Preparation method of ceramic-modified lithium-ion battery diaphragm

The invention relates to a preparation method of a ceramic-modified lithium-ion battery diaphragm. The preparation method is characterized by particularly comprising the following steps: (A) coating a polymer porous diaphragm with slurry; (B) treating ceramic particles by adopting an active material; (C) uniformly distributing ceramic obtained in the step (B) on the porous polymer diaphragm coated with the slurry in the step (A); and (D) carrying out hot pressing on the diaphragm obtained in the step (C) to obtain a product. The preparation method disclosed by the invention fundamentally solves the problem that ceramic components are non-uniformly dispersed in the preparation process of liquid ceramic slurry, by using the method, a surface active agent is prevented from being adopted for promoting the uniform dispersion of the ceramics, the cost is saved, the dimensional stability and the mechanical property of the diaphragm can be greatly enhanced, and the method can be applied to a lithium-ion battery, a fu