Patent ID: 7914704
Filing Date: 2011-03-29
Classification: H01G,Y02E

Abstract:
1. An electric double layer capacitor, comprising an electrode and an electrolyte for the electric double layer capacitor, wherein an electrode layer comprising the following copolymer (A) and an active material for the electrode is bonded to a current collector: a copolymer (A) comprising: monomer units derived from at least one compound (a) represented by the following general formula (1): wherein R 1 represents a hydrogen atom or a methyl group, and R 2 represents an alkyl group or a cycloalkyl group, the glass transition temperature obtained by homopolymerizing the compound (a) being less than 0° C., and monomer units derived from at least one compound (b) selected from acrylic acid alkyl esters, methacrylic acid alkyl esters, aromatic vinyl compounds, and acrylonitrile, the glass transition temperature obtained by homopolymerizing the compound (b) being 0° C. or higher; wherein the total content of the monomer units derived from the compound (a) and those derived from the compound (b) is 90% or more by weight per 100% by weight of the whole copolymer (A); and wherein the amount of the monomer units derived from the compound (a) in the copolymer (A) is 50 to 95% by weight per 100% by weight of the whole copolymer (A), and the amount of the monomer units derived from the compound (b) in the copolymer (A) is 5 to 50% by weight per 100% by weight of the whole copolymer (A), and the glass transition temperature of the copolymer (A) is 10° C. or lower, wherein the electrolyte includes tetraethylammonium tetrafluoroborate, triethylmonomethylammonium tetrafluoroborate, or tetraethylammonium hexafluorophosphate.