The invention discloses a preparation process of a
lithium battery diaphragm. The preparation process comprises the following steps of: 1, preparing a membrane
casting solution; 2, carrying out electrostatic
spinning on the membrane
casting solution to obtain a prefabricated
fiber membrane; 3, performing baking at high temperature; and 4,
coating the upper surface and the lower surface of the
fiber membrane with a
ceramic material. According to the invention,
polyimide is modified, a soft
chain segment can be introduced into a
polyimide molecular chain, the flexibility of the
polyimide molecular chain is improved, the flexibility of the
fiber membrane is improved, also
polyethylene glycol is combined with a
membrane matrix in a chemical bonding mode, the
binding force is high, the solventresistance and the high
temperature resistance of
polyethylene glycol are improved, and the diaphragm has efficient and lasting
ionic conductivity; besides, the surface of the polyimide fiber membraneis coated with the
ceramic material, so that the
pore diameter of the diaphragm can be effectively reduced, the average
pore diameter of the diaphragm is about 0.1microm, the
pore diameter distribution is uniform, and the use performance of the
lithium battery diaphragm is improved.