ZrCr2合金对TiV1.1Mn0.9Ni0.5电极合金结构和电化学性能的影响

Effect of ZrCr2 Alloy on Structure and Electrochemical Characteristics of TiV1.1Mn0.9Ni0.5 Electrode Alloy

摘要:

用两步熔炼法制备TiV1.1Mn0.9Ni0.5-ZrCr2复合电极合金。XRD、EDS、ICP及EIS等分析结果表明：复合合金具有与母体合金相同的双相结构，但是两相的特征参数以及复合合金电极的热力学特性均发生了一系列变化；组分合金在复合过程中产生明显的协同效应；复合合金电极的最大放电容量达到457.2 mAh/g；循环稳定性、荷电保持率和高倍率放电等动力学性能均得到显著改善；1000 mA/g放电电流密度时，复合合金电极的高倍率放电性能是由电极/电解质界面上的电化学反应和合金体内氢的扩散混合控制

Abstract:

TiV1.1Mn0.9Ni0.5-ZrCr2 composite electrode alloy was prepared by two-step re-melting. Results of XRD, EDS, ICP and EIS analyses show that the composite alloy is of two-phase structure which is the same as that of the matrix alloy, whereas the characteristic parameters of the two phases in the composite alloy and the thermodynamic characteristics of the alloy electrode change a lot. Synergetic effect appears distinctly during the composite process of the compositive alloys. The maximum discharge capacity of the composite alloy electrode reaches to 457.2 mAh/g. The dynamic characteristics such as the cyclic durability, the charge retention and high-rate discharging are notably improved. The high-rate dischargeability is controlled by both the charge-transfer reaction of hydrogen at the electrode/electrolyte interface and the hydrogen diffusion in the bulk of the alloy at discharge current density of 1000 mA/g