DEGRADATION OF LANI5 BY THERMOBARIC CYCLING IN HYDROGEN AND HYDROGEN NITROGEN MIXTURE

The dynamics of LaNi5 degradation by thermobaric cycling up to 7000 cycles in hydrogen and hydrogen-nitrogen mixture has been studied. The quantitative X-ray analysis and the study of desorption isotherms of the samples subjected to cycling have been carried out. It has been shown that the dynamics of change of the hydrogen capacity is identical in the cases of technical hydrogen, pure hydrogen and hydrogen-nitrogen mixtures at an absorption temperature of less than 40°C and at decomposition temperatures of 100°C and 150°C. It has been shown that one can distinguish the irreversible loss of hydrogen capacity conditioned by the hydrogenolysis reaction and the restorable loss conditioned by the formation of LaNi5H4 phase in a kinetically immobilized form. © 1990.