An electric double layer capacitor comprises first and second electrodes, each comprising respective first and second carbon materials having distinct pore size distributions. A pore volume ratio of the first carbon material is greater than a pore volume ratio of the second carbon material. The pore volume ratio R is defined as R=V1/V, where V1 is a total volume of pores having a pore size of less than 1 nm, and V is a total volume of pores having a pore size greater than 1 nm.