Particles of active electrode material are made by blending or mixing a mixture of activated carbon, optional conductive carbon, and binder. In selected implementations, the activated carbon particles have between about 70 and 98 percent microporous activated carbon particles and between about 2 and 30 percent mesaporous activated carbon particles by weight. Optionally, a small amount of conductive particles, such as conductive carbon particles may be used. In one implementation, the binder is inert. The electrode material may be attached to a current collector to obtain an electrode for use in various energy storage devices, including a double layer capacitor.