Composite carbon electrodes for use in, for example, Capacitive Deionization (CDI) of a fluid stream or, for example, an electric double layer capacitor (EDLC) are described. Methods of making the composite carbon electrodes are also described. The composite carbon electrode comprises an electrically conductive porous matrix comprising carbon; and an electric double layer capacitor, comprising an activated carbonized material, dispersed throughout the pore volume of the electrically conductive porous matrix.