【摘要】 系统研究了TiV2.1Nix(x=0.2,0.3,0.4,0.5,0.6)贮氢合金的相结构及电化学性能。XRD及SEM分析表明:合金均由体心立方(bcc)结构的V基固溶体主相和TiNi基第二相组成;随着Ni含量x的增加,合金中V基固溶体主相的相含量和晶胞参数逐渐减小,TiNi基第二相含量逐渐增多,且当x≥0.4时,TiNi基第二相组织沿主相晶界形成明显的三维网络状结构。电化学测试表明:随着x的增加,合金的高倍率放电性能及循环稳定性均得到显著改善;但当x从0.4增加到0.6时,合金的活化性能变差,最大放电容量降低。在研究的合金中,TiV2.1Ni0.4表现出较好的综合性能。更多还原

【Abstract】 The phase structures and electrochemical properties of TiV2.1Nix (x=0.2, 0.3, 0.4, 0.5, 0.6) hydrogen storage alloys have been investigated systematically. XRD and SEM show that all the alloys consist of a V-based solid solution main phase with b.c.c. structure and a TiNi-based secondary phase. The abundance and lattice parameters of main phase decrease with the increase of nickel content, while the abundance of TiNi-based secondary phase increases at the same time. The TiNi-based secondary phase forms a visible three-dimensional network along the grain boundaries of V-based solid solution main phase as x increases beyond 0.4. Electrochemical measurements show that the high-rate-dischargeability and cycling stability are noticeably improved as x increases. However, when x≥0.4, the activation behavior and the maximum discharge capacity decline with the increase of nickel content. Among the studied alloys, the TiV2.1Ni0.4 has the best overall electrochemical performance.更多还原