A renaissance for alkaline fuel cells

The renaissance of alkaline-fuel-cells (AFC) technology, with new innovations and advancements, is discussed. AFC, which is build from inexpensive materials like carbon, plastics, and base metals, exhibits excellent electrochemical performance over a range of temperature and pressures. AFC's design is based on one of four cell/stack architectures and on the selection of appropriate electrode materials therein. The electrodes are extremely porous, with both hydrophobic and hydrophilic pores allowing the transport of gases and electrolytes. Raney-nickel (anode) and a silver catalyst called Silfon (cathode) have been used for more than 20 years in AFCs. AFCs yield savings because their catalysts need not be based on expensive nobel metals as a result of the lower corrosivity of the basic environment relative to the acidic zone. The catalyst and electrolyte represent a considerable cost advantage in comparison with proton exchange membrane fuel-cell.