CYCLE PERFORMANCE OF A HYDROGEN-ABSORBING LA0.8Y0.2NI4.8MN0.2 ALLOY

A long-term cycle test up to 30,000 cycles and two series of cycle tes ts under different cycle conditions were performed on a La0.8Y0.2Ni4.8 Mn0.2 alloy developed for a heat pump. The alloy kept 61% of its initi al hydrogen capacity after 30,000 cycles. A degradation model was chec ked with experimental results and showed good agreement. Influence of the temperature and pressure difference conditions on degradation of t he alloy was also investigated to estimate the degradation rate alloy under actual operating conditions in the heat pump and the alloy was c oncluded to have enough durability for practical use in application sy stems. Copyright (C) 1996 International Association for Hydrogen Energ y.