▎ 摘　　要

NOVELTY - Preparation of cesium lead halide (CsPbX3)/reduced graphene oxide (rGO)/polyimide composite film comprises prepolymerization stage by reacting 4,4'-diaminobiphenyl and 3,3',4,4'-biphenyl tetracarboxylic dianhydride under stirring condition for 6-12 hours at - 5-25 degrees C to obtain polyamic acid (PAA) solution, adding perovskite CsPbX3 powder in organic solvent, ultrasonically dispersing to obtain CsPbX3 solution, adding GO/organic solvent dispersion liquid in CsPbX3 solution, ultrasonically dispersing, adding into the polyamic acid solution, stirring for 5-20 hours at 0-25 degrees C, and obtaining CsPbX3/GO/PAA mixed solution, where the CsPbX3 is CsPbBr3, CsPbCl3 or CsPbI3; and thermal imidization stage by pouring the CsPbX3/GO/PAA mixed solution on a flat plate, drying for 6-12 hours at 40-60 degrees C, drying for 6-12 hours at 60-100 degrees C, and conducting imidization at 200-400 degrees C. USE - The method is for preparation of CsPbX3/rGO/polyimide composite film used for preparing a high temperature film capacitor (claimed). ADVANTAGE - The composite film has higher dielectric constant (122-230) and simple preparation, and keeps the excellent thermal and mechanical properties of polyimide. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for CsPbX3/rGO/polyimide composite film.