SEPARATOR COMPRISING DENSITY-CONTROLLED COATING LAYER, AND BATTERY USING THE SEPARATOR

摘要

PURPOSE: A membrane is provided to have an excellent short circuit prevention effect of an electrode with thin thickness by including a high density coating layer with a strong adhesiveness, and to be able to provide a high capacity battery with an improved stability and lifetime. CONSTITUTION: A membrane includes a polyolefin base film and an organic and inorganic mixture coating layer on one side or both sides of the base film. The coating layer includes polyvinylidene fluoride homopolymer organic binder with the weight average molecular weight of 1,000,000 g/mol or more, and inorganic particles with an average particle diameter of 1-700 nm. The density of the coating layer is 1.2-2 g/m^3. The coating layer further includes polyvinylidene fluoride-hexafluoropropylene copolymer organic binder with the weight average molecular weight of 700,000 g/mol or less.