Porous Polyimide Membrane, Battery Separator, Battery, and Method

摘要

A porous polyimide membrane is provided. The volume of pores with a diameter of between about 50 and about 300 nm is more than about 40%, preferably more than 75% of the total pore volume in the membrane. A method for preparing a porous polyimide membrane comprises: preparing a porous polyamide acid membrane; stretching the porous polyamide acid membrane to form a stretched membrane; and imidizing the stretched membrane to form a porous polyimide membrane. The volume of the pores with a diameter of about 50-300 nm is more than about 40%, preferably more than 75% of the total pore volume in the porous polyimide membrane.