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研究了V基固溶体型贮氢合金(TiV211Ni013和TiV211Ni015)与Cu粉进行复合球磨处理对其相结构及电化学性能的影响。X射线衍射和扫描电镜分析表明,铸态合金均由体心立方(bcc)结构的V基固溶体主相和bcc结构的TiNi基第二相组成;当与Cu粉复合球磨处理后,合金均变成由V基固溶体主相和体心四方(bct)结构的CuNi2Ti第二相组成,且合金颗粒的表面状态发生改变。电化学测试表明,球磨处理后合金电极的最大放电容量增加了25～39mA·h/g,100次循环容量保持率大幅提高,循环稳定性得到显著改善。结果表明,Cu粉复合球磨处理是通过同时改变V基合金的第二相成分和晶体结构以及合金颗粒的表面状态来改善合金的电极性能,这与其他传统球磨方式仅通过改变合金的表面状态来改善电极性能的作用机制有所不同。
The effect of complex ball milling on the phase structure and electrochemical performance of V-based solid solution hydrogen storage alloys (TiV211Ni013 and TiV211Ni015) and Cu powder was studied. X-ray diffraction and scanning electron microscopy analysis showed that the as-cast alloys were composed of the V-based solid solution bulk phase of the bcc structure and the TiNi-based second phase of the bcc structure. When the alloy was ball-milled with Cu powder, Into a V-based solid solution main phase and the body center bct structure of CuNi2Ti second phase composition, and the surface state of the alloy particles change. Electrochemical tests showed that the maximum discharge capacity of the alloy electrode increased by 25-39 mA · h / g after ball milling, and the capacity retention rate increased significantly after 100 cycles, and the cycle stability was significantly improved. The results show that the Cu powder composite ball milling can improve the electrode properties of the alloy by changing the second phase composition and crystal structure of the V-based alloy and the surface state of the alloy particles at the same time. This is in contrast with other conventional ball milling methods only by changing the surface state of the alloy The mechanism of action to improve electrode performance is different.