Journal of Materials Science, Vol.56, No.13, 8159-8171, 2021
Superior electrochemical characteristics of A(2)B(7)-type hydrogen storage alloy at ultralow temperature with the addition of alane
In an attempt to enhance the low-temperature dischargeability of A(2)B(7)-type hydrogen storage alloy, the addition of alane (AlH3) by convenient ball milling method was investigated based on La-Y-Ni superlattice alloy containing Y2Ni7-type phase and YNi3-type phase primarily. The maximum discharge capacity of the composite with doping 1 wt.% AlH3 increased by 364.2% reaching 208.9 mAh g(-1) at 233 K compared with the pristine sample. The initial high-rate discharge capacity of doping 1 wt.% AlH3 sample reached 151.7 mAh g(-1) at 4000 mA g(-1) current density. The improvement could be ascribed to strengthening of hydrogen diffusion channel and acceleration of H-kinetics at low temperatures derived from formation of new porous structure and modification of lattice defects by dissolution of aluminum on the surface. It has made a powerfully contribution to a pace of commercialization of A(2)B(7)-type superlattice hydrogen storage alloy applying in high altitude or latitude regions.