(1. 南开大学 新能源材料化学研究所, 天津 300071;
2. 南开大学-天津大学联合研究院, 天津 300071)
摘 要: 用固相扩散法合成了Mg2-xZrxNi (x=0, 0.2, 0.3, 0.4, 0.5, 0.6)系列合金。 XRD结构分析表明: 主相仍为Mg↓2Ni; Zr替代Mg使合金的微晶结构发生了改变, 趋于非晶化; 添加Zr的合金的容量比由扩散法合成的合金的容量有所提高; 合金中添加Zr, 提高了电极的放电容量, 增大了放电平台; 特别是Zr 对六方晶系Mg2Ni合金结构中Mg的部分取代大幅度提高了电极的循环寿命, 未经任何处理的 Mg1.4Zr0.6Ni合金电极经25个循环后, 放电容量仅衰减4.11%, 表明添加Zr对提高合金的循环寿命具有重要的作用。
关键字: 镁基储氢合金; 固相扩散法; 机械球磨; 电化学性能
Mg-based hydrogen storage
alloys with Zr
(1. Institute of New Energy Materials Chemistry,
Nankai University, Tianjin 300071, China;
2. The Union Institute of Nankai-Tianjin University,
Tianjin 300071, China)
Abstract:The Mg-based hydrogen storage alloys Mg2-xZrxNi(x=0, 0.2, 0.3, 0.4, 0.5, 0.6) were successful synthesized by means of a diffusion method (MD).The structure of these alloys was examined by X-ray diffraction. The results show that nanocrystallined and Mg2Ni phases exist in the alloys.With Zr adding in these alloys, the alloys show excellent electrochemical properties.The discharge capacity and cycle life of the alloys increase owing to Zr addition.The cycle life of Mg1.4Zr0.6Ni alloy only decays by 4.11% after 25 cycles.Consequently, the improvement of cycle life is described as the partial substitution of Zr for Mg in the alloy.
Key words: magnesium hydrogen alloys; diffusion method; ball mill; electrochemical performance