CERAMIC AND GEL POLYMER MULTI-LAYER COMPOSITE LITHIUM BATTERY SEPARATOR AND PREPARATION METHOD THEREOF

摘要

Disclosed in the present invention is a preparation method for a ceramic and gel polymer multi-layer composite lithium battery separator, comprising the following steps: step 1: arranging aqueous PVDF slurry and aqueous ceramic slurry; step 2: combining a polypropylene membrane and a polyethylene membrane; thermally combining a layer of polypropylene membrane and a layer of polyethylene membrane at 50-100°C to obtain a PP/PE composite membrane; step 3: coating; using the PP/PE composite membrane obtained in step 2 as a base material, coating the aqueous slurry prepared in step 1 onto the PE side of the base material, first coating the aqueous ceramic slurry to form a ceramic layer and then coating the aqueous PVDF slurry to form a gel polymer layer, the coating speed being 5-100m/min; and drying in an oven at 30-100°C to obtain the final four-layered composite separator. Also disclosed in the present invention are the membranes prepared in turn by the method. The present invention has the advantages of the manufactured separator having high thermal safety and a strong ability to maintain electrolyte solution.