Fabrication and Rate Performance of a Microfiber Cathode in a Mg–H[sub 2]O[sub 2] Flowing Electrolyte Semi-Fuel Cell

Three-dimensional electrodes based on an array of carbon microfibers were prepared by a process called direct-charging electrostatic flocking. The cathodes comprised carbon fibers in diameter and long that protruded from a titanium foil support like blades of grass. The fiber density was 125,000 fibers per of geometric area. The fibers were coated with an alloy of Pd and Ir to catalyze hydrogen peroxide reduction. The electrochemical performance of catalyst-coated carbon microfiber arrays (CMAs) was investigated in a flowing electrolyte semi-fuel cell. In these studies, CMA-based cathodes showed higher voltages at high current densities, better power densities, and equivalent utilization compared to planar cathodes with the same loading of catalyst.