▎ 摘　　要

NOVELTY - An asymmetric separator comprises a conductive layer comprising a polar polymer (A) and a conductive material, and a porous layer, and a dense layer comprising polar polymer (B). The material of the polar polymer (A) and the polar polymer (B) are the same or different. When the separator is working, the conductive layer faces the positive side and the dense layer faces the negative side of the battery. USE - Asymmetric separator for lithium-ion battery (claimed). ADVANTAGE - The separator includes a conductive layer having excellent thermal stability and conductance, is tightly bound to porous layer and does not fall off, reduces charge transfer impedance of lithium-ion battery and improves cycle stability of the battery. The separator further includes a porous layer that absorbs electrolyte and a dense layer having a flat surface and which induces lithium to nucleate and homogenize and inhibits the growth of lithium dendrite. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for preparation of the separator, which involves mixing the polar polymer (A), conductive material, and a solvent comprising one of dimethylsulfoxide, N,N-dimethylformamide and N,N-dimethylacetamide, coating on a substrate, obtaining conductive layer having a thickness of 100-500 mu m, mixing polar polymer (B) and the solvent, coating over the conductive layer, soaking in a coagulation bath comprising one or more of deionized water, ethanol, isopropanol, ethyl acetate, methanol, and n-hexane, placing in deionized water, and drying.