Substrate for use in wet capacitors

Abstract

A porous substrate for use in a wide variety of applications, such as wet capacitors, is provided. The substrate is formed by subjecting a metal substrate to a voltage while in solution to initiate anodic formation of an oxide film. Contrary to conventional anodization processes, however, the newly created oxide quickly breaks down to once again expose the metal surface to the electrolytic solution. This may be accomplished in a variety of ways, such as by raising the voltage of the solution above a critical level known as the 'breakdown voltage', employing a corrosive acid in the solution that dissolves the oxide, etc. Regardless of the mechanism employed, the nearly simultaneous process of oxide growth/breakdown results in the formation of a structure having pores arranged at substantially regular intervals. The resulting structure is highly porous and can exhibit excellent adhesion to electrochemically-active materials and stability in aqueous electrolytes.