冷却速率对TiV2.1Ni0.4Zr0.06Cu0.03Cr0.1合金相结构及电化学性能的影响

Effect of Quenching Rates on the Phase Structure and Electrochemical Properties of TiV_(2.1)Ni_(0.4)Zr_(0.06)Cu_(0.03)Cr_(0.1) Alloys

研究了冷却速率对TiV2.1Ni0.4Zr0.06Cu0.03Cr0.1合金的相结构及电化学性能的影响。XRD、EBI、EDS分析表明,合金主要由V基固溶体主相和以网状分布于主相晶界的Ti2Ni基第二相组成。电化学测试表明,冷却速率较快时合金的最大放电容量、交换电流密度、极限电流密度和循环稳定性都得到提高。而高倍率性能下降是由于在较大的电流密度下快冷样品中第二相催化相在碱液中的溶解析出速率较快造成的。

The phase structures and electrochemical properties of TiV2.1Ni0.4Zr0.06Cu0.03Cr0.1 alloys at different quenching rates were investigated. XRD, EBI and EDS analyses indicate that the alloys mainly consist of a V-based solid solution main phase and a network structure of Ti2Ni secondary phase along grain boundaries of the main phase. Electrochemical measurements show that the maximum discharge capacity, the exchange current density, limiting current density and the cycling stability are all increased by higher quenching rate. The high-rate dischargeablity (HRD) is decreased because of the quick dissolution of the secondary catalytic phase in alkali solution at higher discharge current density.