Influence of LiH addition on electrochemical hydrogen storage performance of Ti45Zr38Ni17 quasicrystal

Abstract

Ti45Zr38Ni17 quasicrystal ribbons were prepared by arc-melting and subsequent melt spinning technique. Composite materials of Ti45Zr38Ni17 mixed with different amounts of LiH were fabricated via mechanical ball-milling method. The phase structures of the final composite materials consist of the icosahedral quasicrystal phase (I-phase), face-centered cubic phase with a Ti2Ni type crystal, C14 Laves phase and LiH phase. The electrochemical measurements showed that the maximum discharge capacities for the composites were higher than those for the Ti45Zr38Ni17 alloy and reached a maximum (91.5 mAh/g) for 10 wt.% additive content of LiH. Furthermore, the cycling stability and high-rate dischargeability (HRD) of the composite electrodes were improved obviously. The capacity retention of Ti45Zr38Ni17 + 10 wt.% LiH enhanced to 88.1%, and the HRD increased from 75.2% to 88.6%. The improvement of electrochemical properties for the composites may be due to the reversible reaction of LiH in alkaline conditions, which can enhance the electrochemical activity of the alloy during the charging and discharging reactions. The results indicated that LiH was an effective material in improving the hydrogen storage property of the Ti45Zr38Ni17 alloy.