合金元素掺杂对TiV_(2.1)Ni_(0.4)合金相结构及电化学性能的影响

Effect of Elements Doping on the Phase Structure and Electrochemical Properties of TiV_(2.1)Ni_(0.4) Alloy

研究了合金元素掺杂对TiV2.1Ni0.4系列合金的相结构及电化学性能的影响。XRD分析表明,该合金由V基固溶体主相和以网状分布于主相晶界的Ti2Ni第二相和C15型Laves第三相组成。BEI、EDS和电化学测试表明,Zr、Cu合金元素进入第二相晶格而使合金的电化学容量略降,但提高了合金的循环性能;Cr元素由于大部分进入到主相晶格而使合金的电化学循环性能大幅度提高,经40次循环后容量保持率仍达88.4%,但最大放电容量有所降低。

The phase structure and electrochemical properties of TiV2.1Nio.4 alloys doped with different elements were investigated. XRD analyses indicate that these alloys consist of a V-based solid solution main phase, a network structure of TiENi secondary phase and C15 Laves third phase along grain boundaries of the main phase. BEI, EDS and electrochemical measurements show that Zr and Cu elements enter the crystal lattice of Ti2Ni secondary phase which depress a little the maximum capacity of the TiV2.1Ni0.4Zro 06Cu0.03 alloy electrode but improve the cycling stabilities. Element Cr enters the crystal lattice of V-based solid solution main phase which greatly enhance the cycling stabilities of the TiV2.1Ni0.4Zr0.06Cu0.03Cr0.10 alloy electrode. The capacity retention reaches 88.4% after 40 cycles. However, the maximum capacity of this alloy is reduced.