HYDROGEN-ABSORBING ALLOY, METHOD FOR ABSORPTION/ DESORPTION OF HYDROGEN USING THE ALLOY, AND HYDROGEN FUEL CELL USING THE METHOD

摘要

PROBLEM TO BE SOLVED: To increase the amount of absorbed/desorbed hydrogen in a hydrogen- absorbing alloy having double plateau or slope plateau. SOLUTION: A repetition of hydrogen pressurization and decompression is properly applied to a body-centered cubic structure type hydrogen-absorbing alloy showing double plateau characteristics or slope plateau characteristics in the relation between hydrogen storage capacity and hydrogen pressure to carry out the absorption/desorption of hydrogen. In the above method for absorbing/desorbing hydrogen, the temperature (T2) of the hydrogen-absorbing alloy is regulated, at least temporarily in the course of hydrogen desorption, to a temperature (T2T1) higher than the temperature (T1) of the hydrogen- absorbing alloy in the course of hydrogen absorption. By this method, absorbed hydrogen in a low-pressure plateau region or a slope plateau lower region, which has so far been unusable as available hydrogen, can be desorbed and used.