Phase forming law and electrochemical properties of A2B7-type La–Y–Ni-based hydrogen storage alloys with different La/Y ratios

The effects of different proportions La and Y elements in the A-side on structure properties A2B7-type La–Y–Ni hydrogen storage alloys were investigated. (La,Y)2Ni7 with La/Y ratios prepared by sintering Y2Ni4 precursor AB5-type precursors at 1298 K for 5 h subsequently annealed 20 1248 K. All only contain Ce2Ni7 (2H-type) Gd2Co7 (3R-type) phases mass ratios. As ratio decreases, cell volume two declines corresponding plateau pressure gradually increases. proportion alloy increases, capacity increases from 1.309 wt% (La/Y = 1/1) to 1.713 1/5) high-rate discharge (HRD1500) ability electrodes 62.7% 88.6% 1/5). diffusion rate bulk is controlling step hydriding/dehydriding kinetics. element can effectively inhibit hydrogen-induced amorphous (HIA) alloys, but poor stability alkaline KOH aqueous solution leads a decrease electrochemical cyclic increasing content.