The characterization of an alkaline fuel cell that uses hydrogen storage alloys

The characterization of new type of alkaline fuel cell based on oxidation of chemical hydride has been studied. The chemical hydride can be used as a new fuel source in a fuel cell system. As a result, we have discovered that the electrochemical reaction rate is higher at a normal temperature compared with cells containing other hydrogen fuels where a hydrogen-releasing agent, NaBH4, is added to an aqueous alkaline solution of electrolyte as hydrogen fuel. That is, the fuel can be supplied very simply for the cell. If air is supplied to the oxygen cathode made of highly dispersed platinum particles supported in high-surface-area carbon paper, and the hydrogen releasing agent is fed to the alkaline solution of electrolyte at the side of metal hydride anode (ZrCr0.8Ni1.2 alloy), the cell can produce electric current continuously. Also it can be operated at a normal temperature and produce a large amount of energy due to its high energy density of 6,000 Ah/kg or more (for NaBH4 or KBH4). Therefore, the developed cell has higher electrochemical reaction rate and energy density than the conventional fuel cells using other hydrogen sources. (C) 2002 The Electrochemical Society.