▎ 摘　　要

NOVELTY - A lithium-ion battery separator producing method involves mixing a graphene nanosheet with organic solvent to obtain graphene nanodispersion, heating high-density polyethylene in dibutyl phthalate and preparing high-density polyethylene particles. Polymer, high-density polyethylene particles, graphene nanodispersion, pore-forming agent and organic solvent are heated and stirred to obtain polymer particles. The polymer particles are mixed with graphene. A casting liquid is precipitated to obtain polymer precipitate. The polymer precipitate is mixed with graphene and non-solvent. USE - Method for producing lithium-ion battery separator. ADVANTAGE - The method enables producing lithium-ion battery separator with thickness of 10-100 mu m and breakdown voltage of 4.6 V or more, providing suitability for preparing different battery materials, increasing porosity and ionic electric conductivity by 30% and 50%, and lifting puncture strength to 46%. DETAILED DESCRIPTION - A lithium-ion battery separator producing method involves mixing a graphene nanosheet with organic solvent to obtain 0.1 g/l graphene nanodispersion, where the organic solvent is N-dimethylacetamide, dibutyl phthalate, N-methylpyrrolidone or N-dimethylformamide, heating high-density polyethylene in dibutyl phthalate at 100-220 degrees C for 10-60 minutes and preparing high-density polyethylene particles with particle diameter of 600 nm by emulsion polymerization method. 8-25 mass% polymer, 0.01-4 mass% high-density polyethylene particles, 0.00001-0.01 mass% graphene nanodispersion, 0.05-5 mass% pore-forming agent and 65.99-91.94 mass% organic solvent are heated and stirred to obtain polymer particles, where the polymer is polyvinylidene fluoride or poly(vinylidene fluoride-co-hexafluoropropylene). The polymer particles are mixed with graphene to obtain casting liquid. The casting liquid is precipitated to obtain polymer precipitate. The polymer precipitate is mixed with graphene and non-solvent, where the non-solvent is water, ethyl alcohol, propanol or ethanediol.