US Patent 7835136 Electric double layer capacitance device

An electric double layer capacitance (EDLC) device is disclosed having an electrode containing an activated carbon cryogel with a tunable pore structure, the carbon cryogel having a surface area of at least 1500 m2/g as determined by nitrogen sorption at 77K and BET analysis, and the pore structure having a pore volume ranging from about 0.01 cc/g to about 0.25 cc/g for pores having a pore diameter of 0.6 to 1.0 nm.