Structures and properties of La-Mg-Ni system hydrogen storage alloys
(Research Institute of Rare Metal, Guangzhou Research Institute of Non-ferrous Metals, Guangzhou 510651, China)
Abstract: The double-roller rapid quenching technology was successfully used to prepare La-Mg-Ni system hydrogen storage alloys. The effects of magnesium content and heat-treatment process on the alloys properties were studied. When the alloy with 1.09%(mass fraction) Mg is heat treated at 900 ℃ for 4 h , its discharge capacity is more than 380 mA∙h/g at 0.2C, and the cyclic life is beyond 500 counts at 2C. By XRD and PCI analyzing, the results show that the alloys are composed of LaNi5 and LaNi3 phase. The hydrogen absorption/desorption pressure of the alloy increases, so does the slope of plateau, and the plateau becomes broad first and narrow again as Mg content increases. This method is simple to be suitable for production on a large scale.
Key words: La-Mg-Ni; hydrogen storage alloy; structures; properties; double-roller rapid quenching