Annealing effect on hydrogen storage property of Co-free La1.8Ti0.2MgNi8.7Al0.3 alloy

作者：Jiang, Weiqing^*; Qin, Changsheng; Zhu, Rongrong; Guo, Jin

来源：Journal of Alloys and Compounds, 2013, 565: 37-43.

DOI：10.1016/j.jallcom.2013.02.178

• La-Mg-Ni-based alloy
• Annealing treatment
• Hydrogen storage property
• Electrochemical characteristic

A series of Co-free La1.8Ti0.2MgNi8.7Al0.3 alloys are prepared by magnetic levitation melting followed by annealing treatment. The hydrogen storage properties of as-cast and annealed La1.8Ti0.2MgNi8.7Al0.3 alloys are investigated systematically. The results show that La(Ni, Al)(5) and LaMg2Ni9 are the main phases and a LaNi2 phase disappears at 900 degrees C. The enthalpies of the experimental alloys are close to -30.6 kJ/mol H-2 of LaNi5 compound. Comparing with as-cast alloy, annealed alloys exhibit larger hydrogen storage capacity, lower hydrogen absorption/desorption plateau pressure and longer cycle life. At 60% discharge capacity retention, the maximum charge-discharge cycles, 205 cycles (annealed 900 degrees C), are two times the minimum, 102 cycles (as-cast). The positive impact of annealing on the charge transfer rate at surface and the hydrogen diffusion rate in bulk enhances the high rate dischargeability. Annealed alloy (900 degrees C) shows good overall hydrogen storage properties.

• 出版日期2013-7-15
• 单位广西大学