| Al含量对AB5型储氢合金电极低温和高倍率性能的影响 | |
| Effects of Al Content on Low-Temperature and High-Rate Performance of MmNi4.0-xCo0.7Mn0.3Alx Alloys | |
| 摘要: 系统地研究了Al含量对富Ce储氢合金MmNi4-xCo0.7Mn0.3Alx（x=0，0.1，0.2，0.3）电极综合电化学性能，尤其是对低温和高倍率性能的影响。在常温下，储氢合金电极放电容量和循环性能均随着Al含量的增加而增加，而高倍率放电性能严重下降。-20℃时，放电容量仍随着Al含量的增加而增加，但在-40℃下放电容量随之严重衰退。电化学动力学结果表明，常温下高Al合金高倍率性能的降低主要是由于电极表面电荷转移过程的恶化；低温-40℃下，Al同时降低了合金电极的表面电催化活性以及体相H扩散能力，严重恶化电极过程动力学，从而导致了高Al合金极低的容量及电压输出。考虑到各电极的综合电化学性能，MmNi3.8Co0.7Mn0.3Al0.2为最佳的成分配比。 | |
| 关键词: AB5型储氢合金 低温电化学性能 Al替代 镍氢电池 电化学动力学 | |
| 基金项目: 四川省科技创新苗子工程（No.2017RZ0033）资助项目 | |
| Abstract: Effects of Al content on the comprehensive electrochemical performance of Ce-rich MmNi4-xCo0.7Mn0.3Alx (x=0, 0.1, 0.2, 0.3) hydrogen storage alloys, particularly the low-temperature and high-rate capacity have been systematically investigated. At room temperature, both the discharge capacity and cycling stability of the electrode increase with the Al content increases, but the high-rate dischargeability seriously deteriorates. The discharge capacity still increases with the increase of Al content at -20℃, but gradually deteriorates when the temperature drops down to -40℃. Electrochemical kinetics results demonstrate that the high-rate capacity recession of the high-Al alloy at room temperature is contributed to the deterioration of the charge-transfer process. When the temperature drops down to -40℃, Al deteriorates both the surface catalytic ability and the bulk hydrogen diffusion ability, leading to the severe drop of discharge capacity and potential of the high-Al alloy. Based on the comprehensive electrochemical properties of the electrodes, the optimal composition of MmNi4-xCo0.7Mn0.3Alx is obtained when x=0.2. | |
| Keywords: AB5-type hydrogen storage alloy low-temperature electrochemical performance aluminum substitution nickel metal hydride battery electrochemical kinetics | |
| 投稿时间：2017-05-26 修订日期：2017-09-04 | |
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| 汤争耀,周万海,朱丁,吴朝玲,黄利武,刘昆,陈云贵.Al含量对AB5型储氢合金电极低温和高倍率性能的影响[J].无机化学学报,2017,33(10):1881-1888. | |
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