Separator of lithium-ion-battery preparation and method thereof

摘要

The present disclosure relates to a separator of a lithium-ion battery and a preparation method thereof, the separator comprises a substrate membrane and a coating provided on a surface of the substrate membrane, the coating comprises ceramic particles, an adhesive and a solid polymer wax which has a melting point of 85˜120° C., a molecular weight of 1,000˜25,000 and a particle size of 0.5˜10 μm. When the lithium-ion battery is heated due to overcharge and the like to make the interior temperature reach the melting point of the solid polymer wax, the solid polymer wax can be melt and enter among the ceramic particles and into the micropores of the substrate membrane by capillarity so as to function as electrical disconnection, which can effectively cut off the channel of the lithium ions and stop the overcharge, and ensure the safety performance of the lithium-ion battery under the situation of overcharge.

主权项

1. A separator of a lithium-ion battery, comprising:
a substrate membrane; and a coating provided on a surface of the substrate membrane, the coating comprising 10˜70 wt % of ceramic particles, 20˜80 wt % of a solid polymer wax and 5˜20 wt % of an adhesive, a melting point of the solid polymer wax being 85˜120° C., a relative molecular weight of the solid polymer wax being 1,000˜25,000, a particle size of the solid polymer wax being 0.5˜10 μm and the particle size of the solid polymer wax being larger than a pore size of the substrate membrane; wherein the coating further comprises 5˜15 wt % of a water-soluble polymer thickening agent.