A method of forming a composite involving the steps of providing a porous carbon electrode structure having a surface and pores wherein the pores have an average diameter that ranges from about 2 nm to about 1 μm, depositing a coating comprising FeOx via self-limiting electroless deposition without completely filling or obstructing a majority of the pores, wherein the coating comprising FeOx covers most to all of the interior and exterior surfaces of the prefabricated porous carbon electrode structure and can be deposited in a homogenous form and wherein it can be used directly as an electrode without requiring additional conductive additives or binders to be processed into a device-suitable electrode.