Safety coating, preparation method thereof and composite current collector

The invention provides a safe coating and a preparation method thereof and a composite current collector, the safe coating is mainly prepared from a phosphate material, a conductive agent, a binder and a solvent, the phosphate material is a lithium iron manganese phosphate material doped with at least one metal selected from Cr, Mg, Ti, Al, Zn, W, Nb and Zr, and by controlling the addition ratio of the raw materials, the conductive agent can be added into the lithium iron manganese phosphate material to prepare the safe coating. The compactness of the safety coating and the current collector base material can be increased, and the stripping force of the active material layer and the safety coating can be effectively improved, so that the safety performance of the battery can be effectively improved, the influence on the energy density is small, and the service life of the battery is prolonged under the condition that a material system, pole piece performance and product performance are not changed. And long-t