硼添加对(Ti0.65Zr0.35)1.10(V0.5Mn0.3Cr0.4Ni0.8)Bx合金结构和电化学性能的影响

采用X射线衍射仪、扫描电镜和电化学测试设备，研究添加不同含量硼对(Ti0.65Zr0.35)1.10(V0.5Mn0.3Cr0.4Ni0.8)Bx (x=0，0.01，0.05，0.1，0.2)储氢合金组织结构和电化学性能的影响。结果表明，由于硼的添加，合金中出现了不易形成氢化物的棒状VB相，降低了合金的可逆放电容量，提高了合金的活化性能、循环稳定性和合金的倍率性能。分析表明，主要是由于棒状VB相增加了氢在合金中的扩散通道，增加了相界面，减小了合金在充放电过程中的晶格应力。合金电极的反应阻抗随着硼含量的增加而减小，合金的倍率性能和循环性能明显优化。

Effects of Boron Addition on Microstructures and Electrochemical Properties of (Ti0.65Zr0.35)1.10(V0.5Mn0.3Cr0.4Ni0.8)Bx Hydrogen Storage Alloys

Microstructures and electrochemical properties of the as-cast (Ti0.65Zr0.35)1.10(V0.5Mn0.3Cr0.4Ni0.8)Bx (x=0, 0.01, 0.05, 0.1, 0.2) alloys were analyzed by X-ray diffraction, scanning electron microscope, X-ray energy dispersive spectrum and electrochemical testing. The results show that VB phase appeared in the as-cast alloys when boron was added. Claviform VB phase is not an absorption phase. With the increase of boron addition, the activation property, the cycle stability and the high rate discharging performance are improved, and the reversible discharge capacity is decreased. Analyses show that the claviform VB phase increases the diffusion channels of hydrogen ion in the alloys. Furthermore, it increases the phase interface, and decreases the grain stress in the process of charging and discharging in alloy electrodes. Reaction resistance of the alloy electrode is decreased with boron addition increasing, and the rate property and cycle stability are optimized obviously.