A method of forming a composite comprising the steps of providing a porous carbon structure comprising a surface and pores and infiltrating the structure with a coating comprising MnO.sub.2 without completely filling or obstructing a majority of the pores. A method of storing charge comprising the steps of providing a capacitor comprising an anode, a cathode, and an electrolyte, wherein the anode, the cathode, or both comprise a composite comprising a porous carbon structure comprising a surface and pores and a coating on the surface comprising MnO.sub.2 wherein the coating does not completely fill or obstruct a majority of the pores and a current collector in electrical contact with the composite, and charging the capacitor.