Abstract: Carbon/carbon composite materials for use in electrochemical cells are prepared by carbonizing a resin material used to bind a layer of carbon containing material to convert the resin to residual carbon. In one embodiment of the invention, the carbon containing material is a mixture of activated carbon fibers and activated carbon powder. In another embodiment, an activated carbon fabric is used instead of the discrete carbon fibers. Substantial improvements in mechanical properties, resistivity and surface area are achieved in the present invention. The composite materials may be used in the fabrication of electrodes and bipolar electrical devices such as capacitors.