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采用XRD、SEM-EDS等方法对Ti0.4Zr0.1V1.1Mn0.5Ni0.4Crx(x=0,0.1,0.2,0.3)储氢合金的微观结构及电化学性能进行了表征。XRD分析结果表明Ti0.4Zr0.1V1.1Mn0.5Ni0.4Crx(x=0,0.1,0.2,0.3)储氢合金由BCC结构的V基固溶体主相和少量的C14Laves第二相组成。SEM-EDS分析结果表明,V基固溶体主相为树枝晶结构,C14Laves相呈网格状沿着主相晶界析出。电化学测试结果表明,Ti0.4Zr0.1V1.1Mn0.5Ni0.4Crx(x=0,0.1,0.2,0.3)氢化物电极在303K下,随Cr含量的增加,最大放电容量分别为574.6mAh/g、418.8mAh/g、368.8mAh/g和322.9mAh/g。当x=0.3时,合金电极在333K下的最大放电容量达到了824.1mAh/g。Cr的添加显著提高了合金电极的高倍率放电性能和循环寿命,40次充放电循环后Ti0.4Zr0.1V1.1Mn0.5Ni0.4Cr0.3合金电极的容量保持率为62.3%。
The microstructure and electrochemical properties of Ti0.4Zr0.1V1.1Mn0.5Ni0.4Crx (x = 0,0.1,0.2,0.3) hydrogen storage alloys were characterized by XRD and SEM-EDS. XRD analysis results show that the Ti0.4Zr0.1V1.1Mn0.5Ni0.4Crx (x = 0,0.1,0.2,0.3) hydrogen storage alloy consists of the VCC solid solution main phase of BCC structure and a small amount of C14Laves second phase. SEM-EDS analysis showed that the main phase of the V-based solid solution was a dendritic structure, and the C14Laves phase was precipitated along the grain boundary of the main phase. The results of electrochemical tests showed that the maximum discharge capacity of Ti0.4Zr0.1V1.1Mn0.5Ni0.4Crx (x = 0,0.1,0.2,0.3) hydride electrode at 303K with the increase of Cr content was 574.6mAh / g , 418.8 mAh / g, 368.8 mAh / g and 322.9 mAh / g. When x = 0.3, the maximum discharge capacity of alloy electrode at 333K reached 824.1mAh / g. The addition of Cr significantly enhanced the high-rate discharge performance and cycle life of the alloy electrode. The capacity retention rate of Ti0.4Zr0.1V1.1Mn0.5Ni0.4Cr0.3 alloy electrode was 62.3% after 40 charge-discharge cycles.