ZrMn_(0.9-x)V_xNi_(1.1)(x=0.1～0.8) Laves相贮氢合金的电化学性能

ELECTROCHEMICAL PERFORMANCES OF ZrMn 0. 9-x V x Ni 1. 1 ( x= 0.1～0.8) LAVES PHASE HYDROGEN STORAGE ALLOYS

研究了ＡＢ２型锆基Ｌａｖｅｓ相贮氢合金ＺｒＭｎ０．９－ｘＶｘＮｉ１．１（ｘ＝０．１～０．８）的晶体结构及其电化学性能。研究表明，ＺｒＭｎＶＮｉ合金为多相组织，当Ｍｎ含量较高时，合金的主相为Ｃ１５型Ｌａｖｅｓ相结构；随着Ｖ含量增加，合金中Ｃ１４型Ｌａｖｅｓ相的含量逐渐增加；合金的主相结构与电子浓度有关。Ｍｎ、Ｖ含量影响Ｌａｖｅｓ相合金中的不同类型四面体间隙数目及合金热力学和电化学性能。当合金中的Ｖ／（Ｍｎ＋Ｖ）比率在２／９～４／９范围内，合金表现出较好的综合电化学性能。ＺｒＭｎ０．５Ｖ０．４Ｎｉ１．１合金的最高容量为３４２ｍＡｈ／ｇ，高倍率放电能力为Ｃ２００／（Ｃ２００＋Ｃ５０）＝７５％，经１００次１００％ＤＯＤ充放电循环后，容量保持率为８５％左右。

The crystal structure and electrochemical performances of AB 2 type Zr based Laves phase hydrogen storage alloy ZrMn 0. 9-x V x Ni 1. 1 ( x= 0.1～0.8) were studied. The results revealed that the alloys were multiphase structure. When the content of Mn was high, the alloys were mainly of C15 type Laves phase, however, as V content increased in alloys, the content of C14 type Laves phase increased gradually, which indicates that the main phase structure is related to the electron concentration. The variation of Mn and V content in alloys affected the numbers of various tetrahedral interstitial sites and the thermodynamic properties and electrochemical performances. It was found that the alloys with the ratio of V to (Mn+V) over the range of 2/9～4/9 exhibited good overall electrochemical performances. The ZrMn 0. 9-x V x Ni 1. 1 alloy exhibited excellent overall electrochemical performances. The highest capacity of this alloy was 342 mAh/g, the rate of dischargeability C 200 /( C 200 + C 50 ) was 75%, while after 100 charging discharging cycles under the condition of 100% DOD, the capacity retention was still 85% or so.