元素Ti对贮氢合金ZrMn0．7V0．2CO0．1Ni1．2相结构和电化学性能的影响

研究了元素Ti对贮氢电极合金ZrMn0.7V0.2Co0.1Ni1.2的相结构、相组成以及电化学性能的影响。结果表明，对于合金Zr1-xTix(Mn0.7V0.2Co0.1Ni1.2)，其母体合金的主相为C15型Laves相，并含有少量的非Laves相Zr7M10；但随着掺Ti量的增加，合金中出现C14型Laves相，而且其含量逐渐增加；在x=0．1～0．2时，合金中还出现少量的TiNi相，而在x=0．4～0．5时，非Laves相Zr7M10和TiNi相全部消失，说明元素Ti大量的掺杂抑制了第二相的产生：而且随着Ti含量的增加，合金中的C15型和C14型Laves相的晶格常数逐渐减小。电化学测试结果发现，当含Ti量x=0．2时，合金有最大放电容量Cmax为354mAh／g，在放电电流为300mAh／g条件下，高倍率放电性能比母体合金提高了15％。

Effects of Substitution of Ti for ZrMn0.7V0.2Co0.1Ni1.2 Storage Hydrogen Alloys on Phase Structure and Electrochemical Properties

Phase structure and electrochemical properties of the storage hydrogen electrode alloys Zr1-xTix(Mn0.7V0.2 Co0.1Ni1.2)were investigated by XRD,SEM and EPMA, and electrochemical properties of the alloys were examined. The matrix alloys consisted of cubic C15 Laves phase and second phase (Zr7M10). With the increasing of Ti content, the lattice parameter of alloys decreased and C14 Laves phase appeared and increased. A little of TiNi phase appeared at x=0.1~0.2; however, Zr7M10 phase and TiNi phase decomposed at x=0.4~0.5, which demonstrated that high Ti content inhibited the appearance of second phase in the alloys. As a result, the storage hydrogen electrode alloy Zr0.8Ti0.2(Mn0.7V0.2Co0.1Ni1.2), the maximum discharge capacity of which is 354 mAh/g, possesses good rate capability. This contributes to change phase structure and phase composition, which plays a synergetic role in the charge-discharge process.