▎ 摘　　要

NOVELTY - Sodium ion battery separator comprises three-layer structure comprising first base film: sodium electroporous diaphragm base film; and second layer of insulating and thermally stable ceramic coating comprises 10-95 wt.% ceramic coating material, and 5-90wt.% polymer binder. The third layer active material layer comprises 60-90 wt.% anode/cathode active material, 5-30 wt.% polymer binder, and 5-10 wt.% conductive agent. USE - The sodium ion battery diaphragm is useful in battery preparation field, preferably for preparing sodium ion batteries, preferably lithium ion batteries. ADVANTAGE - The sodium ion battery diaphragm has larger pore radius, and can well form uniform sodium ion channel, at the same time, the soakage capability of the electrolyte is greatly improved, it can be quickly soaked by electrolyte, the performance of the sodium ion ion battery is further improved, and the application of the insulating thermostable ceramic coating and active material layer greatly improves the problem that the common commercial diappragm is not compatible with the sodium ions battery, and improves the safety of the battery, improves the mechanical performance, thermal stability and the capacity of the batteries. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for preparing sodium ion battery diaphragm. DESCRIPTION OF DRAWING(S) - The drawing shows an EIS impedance spectrum of the NVP coating diaphragm and commercial diaphragm cell.