Co替代Ni对钛钒基储氢电极合金循环稳定性的影响

Effects of Substitution of Co for Ni on Cycling Stability of Ti-V-Based Electrode Alloys

研究了储氢电极合金Ti0．8Zr0．2V2．7Mn0．5Cr0．6Ni1．25-xCoxFe0．2（x=0．00～0．20）的循环稳定性，并探讨了该系列合金电极的本征／非本征衰退机理．研究结果表明，随着Co含量的增加，合金电极的循环稳定性呈现先提高后下降的趋势．电解液化学成分分析结果显示，随着Co含量的增加，合金中的有效吸氢元素（V与Ti）在电解液中的溶出数量呈现先减少后增加的趋势．此外，随Co含量的增加，在充放电循环过程中合金颗粒的粉化得到抑制，合金电极交换电流密度的下降趋势也逐渐减小．

The effects of substitution of Co for Ni on the cycling stability of Ti0.8Zr0.2V2.TMn0.5- Cr0.6Ni1.25-xCoxFe0.2（x=0.00 - 0.20） hydrogen storage alloys were investigated, and its intrinsic/extrinsic degradation mechanism was analyzed. The results show that the cycling stability of this type of alloy strengthens firstly and then weakens with increasing x from 0.00 to 0.20. Furthermore, the dissolution amount of the hydrogen absorbing elements （Ti and V） in KOH solution decreases firstly and then increases with increasing Co content after the same charge/discharge cycles, and the pulverization of the alloy particles and the deterioration of the electrode surface are suppressed with increasing x value.