Alkaline electrochemical capacitor and electrode fabrication

The present invention relates generally to electrochemical energy storage devices and more specifically to alkaline electrochemical capacitors incorporating high surface area electrodes. A high power density alkaline electrochemical capacitor cell includes a pair of titanium nitride powder electrodes fabricated by subjecting titanium hydride powder to a controlled flow of ammonia vapor. A porous separating membrane for containing an electrolyte is attached to a first surface of the pair of powder electrodes. A conductive termination is attached to the second side of each of the powder electrodes. The electrodes have a high surface area and are electrochemically stable in strong alkaline electrolyte. The capacitor cell can be hermetically sealed and is capable of long-term cyclical operation over a wide range of operating temperatures (−55° C. to +100° C.) while providing high-density energy storage.