High capacitance cathode foil produced by abrasion process using titanium nitride powder

Abstract

A dry titanium nitride (TiN) powder abrasion method roughens the surface of a valve metal foil for use as a cathode in an electrolytic capacitor. This increases the surface area of the foil, thereby increasing the double-layer capacitance of the cathode, and also mechanically alloys TiN powder to the surface of the foil, thereby increasing the pseudo-capacitance of the cathode. In one embodiment, a piece of thin titanium foil is mounted on a hard metal backing and at least one surface of the foil is abraded with fine titanium nitride powder. In another embodiment, a continuous metal foil tape is fed into a bead blasting box and at least one surface of the metal foil tape is abraded with TiN powder delivered by a bead blasting nozzle located within the bead blasting box. Accordingly, a cathode having increased capacitance capability is provided to more closely match the capacitance of a poly-anode stack.

Dependencies are inferred from the claim text.