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用XRD、SEM等方法与手段,研究TiMn2-5x(V4Fe)x(x=0.30,0.35)贮氢合金的相结构及电化学性能。结果表明:主相为体心立方(bcc)结构的合金,其晶胞参数随x的增加而增大;SEM显示在基体中存在岛状结构,随着x的增加,岛状结构较基体的比率减少;电化学测试表明,x=0.35合金在常温下难以活化,加热到327K才能活化;而x=0.30合金常温下即可活化,该合金在充电过程中出现钝化,327K温度下钝化消除。比较合金在298K的PCT曲线,发现x=0.30合金的平台氢压约为0.2MPa,平台宽度较大,更有开发价值;同时计算x=0.30合金放氢过程的焓和熵,分别为–36.1kJ/mol,–126.9J/(mol·K)。
The phase structure and electrochemical performance of TiMn2-5x (V4Fe) x (x = 0.30,0.35) hydrogen storage alloys were investigated by XRD, SEM and other methods. The results show that the main phase is an alloy of bcc structure, and the unit cell parameters increase with the increase of x. The SEM shows that island structure exists in the matrix. With the increase of x, The electrochemical test shows that the alloy x = 0.35 is hard to be activated at room temperature and activated to 327K, whereas x = 0.30 can be activated at ambient temperature. The alloy is passivated during charging and passivated at 327K eliminate. Comparing the PCT curve of alloy at 298K, it is found that the hydrogen pressure of the platform of x = 0.30 alloy is about 0.2MPa, and the platform width is larger and more valuable for development. Meanwhile, the enthalpy and entropy of x = 0.30 alloy desorption process are -36.1 kJ / mol, -126.9J / (mol · K).