US Patent Application 20100028779 - Porous Polyimide Membrane, Battery Separator, Battery, and Method
InventorsAssigneeUS Classes429/231.95, The alkali metal is lithium521/56, Particle which is expandible, process of preparing an expandible particle, or process of expanding a particle to form a cellular product521/183Nitrogen containing reactantAttorney, Agent or FirmForeign Documents
International ClassesH01M 4/58C08J 9/16 C08G 73/10 Abstract textA 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. |
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