Jing Lin,Fei Liang,Yaoming Wu,Wanqiang Liu,Limin Wang
We prepared Ti 1.4 V 0.6 Ni ribbons by arc-melting and subsequent melt-spinning techniques. Ti 1.4 V 0.6 Ni + x Mg ( x = 1, 1.5, 2, 2.5 and 3, wt.%) composite alloys were obtained by the mechanical ball-milling method. The structures and hydrogen storage properties of alloys were investigated. Ti 1.4 V 0.6 Ni + x Mg composite alloys contained icosahedral quasicrystalline phase, Ti 2 Ni-type phase, β-Ti solid-solution phase and metallic Mg. The electrochemical and gaseous hydrogen storage properties of alloys were improved with Mg addition. Ti 1.4 V 0.6 Ni + 2 Mg alloy showed maximum electrochemical discharge capacity of 282.5 mAh g −1 as well as copacetic high-rate discharge ability of 82.3% at the discharge current density of 240 mA g −1 compared with that of 30 mA g −1 , and the cycling life achieved above 200 mAh g −1 after 50 consecutive cycles of charging and discharging. The hydrogen absorption/desorption properties of Ti 1.4 V 0.6 Ni + x Mg ( x = 1, 2 and 3, wt.%) alloys were better than Ti 1.4 V 0.6 Ni. Ti 1.4 V 0.6 Ni + 3 Mg alloy also exhibited a favorable hydrogen absorption capacity of 1.53 wt.%. The improvement in the hydrogen storage characteristics caused by adding Mg may be ascribed to better hydrogen diffusion and anti-corrosion ability.
Jing Lin,Zhanyi Cao,Lianshan Sun,Fei Liang,Limin Wang
Ti 1.4 V 0.6 Ni + x LiAlH 4 ( x = 0.5, 1, 1.5, 2, 2.5, wt.%) composites were prepared by ball-milling, and the effects of LiAlH 4 content on structure and electrochemical properties of the composites were investigated systematically. The addition of LiAlH 4 to the Ti 1.4 V 0.6 Ni alloy significantly affected the morphology and size of the composite particles . The electrochemical cycling stability and rate dischargeability of the composite electrodes benefitted from adding some LiAlH 4 ( x = 1), which however deteriorated when the LiAlH 4 content increased further. The positive effect of LiAlH 4 on the electrochemical performance of the studied alloy was caused by suppression of the dissolution of active components of the Ti 1.4 V 0.6 Ni hydrogen storage alloy.