Battery diaphragm capable of inhibiting growth of sodium dendrites as well as preparation method and application of battery diaphragm

The invention relates to the technical field of diaphragms for sodium ion batteries, in particular to a battery diaphragm capable of inhibiting growth of sodium dendrites as well as a preparation method and application of the battery diaphragm, and the battery diaphragm comprises a base membrane, a ceramic coating coated on the surface of the base membrane and a polymer coating coated on the surface of the ceramic coating; wherein the base film is one of PE (polyethylene), PP (polypropylene), PET (polyethylene terephthalate), PI (polyimide) and cellulose base films; the ceramic coating comprises a ceramic material and a solvent I; the polymer coating comprises a binder and a solvent II, and the binder comprises one or more of sodium carboxymethyl cellulose, PAA (Polyacrylic Acid), PMMA (Polymethyl Methacrylate) and PVDF (Polyvinylidene Fluoride). By adopting the technical scheme, the mechanical strength of the diaphragm and the interface stability of the aluminum foil can be effectively improved, the growth o