Ti1.8(VFe)CrNi0.2+xwt%LaNi5(x=0,5,10,20)复合合金的相结构对电化学性能的影响

Influence of Phase Structure on electrochemical Properties of Ti1.8(VFe)CrNi0.2+xwt%LaNi5(x=0,5,10,20) composite Alloy

摘要:

采用XRD、SEM+EDS和电化学性能测试仪对复合合金Ti1.8(VFe)CrNi0.2+xwt%LaNi5(x=0,5,10,20)的相结构及其在323K下电化学性能进行表征。结果表明，随LaNi5的添加，合金由胞状晶的BCC结构的Ti-V-Cr基相和体心四方结构的Cr-Ni-Ti-Fe为主相逐渐转变为树枝晶的Ti-V-Cr-Fe-Ni为主相的BCC单结构。电化学性能显示，随x的变化，复合合金的活化及放电容量等呈规律性变化。x=5时，合金的活化和放电容量明显改善，需9次活化且达到最大值360mAh/g，这是因为棒状晶的形成和第二相Cr-Ni-Ti-Fe相与Ti-V-Cr基主相独特的协同作用。

Abstract:

XRD, SEM+EDS and electrochemical tester at 323K were adopted to measure phase structure and electrochemical properties of Ti1.8(VFe)CrNi0.2+x.wt%LaNi5 hydrogen storage composite. It has showed that main phase, which is BCC structure with alloy’s cellular crystal and Cr-Ni-Ti-Fe with BCT structure, transformed into Ti-V-Cr-Fe-Ni which is main phase of BCC structure with dentrite crystal. Electrochemical properties show that activity and discharge capacity and so on is changed regularly. When x is 5, activity and discharge capacity of the composite alloy is the best of all, which is active by 9 cycle time and the discharge capacity reach 360mAh/g. It can be certain that the formation of rod-like crystal and synergistic reaction between the second phase Cr-Ni-Ti-Fe phase and the main phase of BCC structure plays the most important role in ipproving the alloy’s electrochemical properties.