工作温度对贮氢合金TiV_(2.1)Ni_(0.4)电化学性能的影响

INFLUENCE OF OPERATING TEMPERATURE ON ELECTROCHEMICAL PERFORMANCES OF TiV_(2.1)Ni_(0.4) HYDROGEN STORAGE ALLOY

系统研究了工作温度(T=25,35,45,55℃)对V基固溶体型贮氢合金TiV_(2.1)Ni_(0.4)电化学性能的影响。XRD及SEM分析表明,TiV_(2.1)Ni_(0.4)由体心立方(bcc)结构的V基固溶体主相和TiNi基第二相组成。电化学测试表明,当工作温度升高时,合金的活化性能得到改善,最大放电容量显著提高,循环稳定性明显降低。同时,ICP分析表明,高温下碱液中Ti和V元素的大量溶出,是导致合金循环容量衰退的主要原因。随着温度的增加,合金电极的交换电流密度I_o和极限电流密度I_L增大,电极表面的反应阻抗减小,合金高倍率放电性能得到改善。

Influence of operating temperature (T=25℃, 35℃, 45℃, 55℃) on the electrochemical performance of V-based solid solution type hydrogen storage alloy TiV_(2.1) Ni_(0.4) has been investigated systematically. XRD and SEM show that the alloy consists of a V-based solid solution main phase with bcc. structure and a TiNi-based secondary phase. Electrochemical measurements show that as the operating temperature rises, the activation process becomes faster, the maximum discharge capacity is noticeably improved, and t...