Patent ID: 7616428
Filing Date: 2009-11-10
Classification: H01G,Y02E,Y02T

Abstract:
1. A separator for an electric double layer capacitor, wherein the separator consists only of an ultrafine fibrous aggregate prepared by an electrostatic spinning process and heat-treated at 160° C. or higher, a thickness of the entire separator is 25 μm or less, an average fiber diameter of ultrafine fibers constituting said ultrafine fibrous aggregate is 1 μm or less, a maximum pore size of said ultrafine fibrous aggregate is not more than 3 times a mean flow pore size, an apparent density of said ultrafine fibrous aggregate is 0.1 to less than 0.27 g/cm 3 , and a mass per unit area of the separator is 1 to less than 5 g/m 2 .