Lithium ion battery diaphragm, preparation method thereof, lithium ion battery and vehicle

The invention discloses a lithium ion battery diaphragm and a preparation method thereof, a lithium ion battery and a vehicle, the lithium ion battery diaphragm comprises a base membrane and an aramid nanofiber coating arranged on at least one side of the base membrane, and the aramid nanofiber coating comprises a metal organic framework. The surface affinity of the lithium ion battery diaphragm is improved, the lyophilic property of the diaphragm is improved, the aramid nanofiber coating is flat and uniform, the porosity of the coating is improved through the porous metal organic framework, excessive stacking of nanofibers is avoided, and the contact impedance of the lithium ion battery is effectively reduced. 本发明公开了一种锂离子电池隔膜及其制备方法、锂离子电池和车辆，锂离子电池隔膜包括基膜和设置在所述基膜至少一侧的芳纶纳米纤维涂层，所述芳纶纳米纤维涂层中包括金属有机骨架。本发明改善了锂离子电池隔膜的表面亲和性，提高隔膜的亲液性，芳纶纳米纤维涂覆涂层平整均匀，多孔的金属有机骨架提高了涂层的孔隙率，避免纳米纤维过度堆叠，有效降低了锂离子电池的接触阻抗。