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
作者单位E-mail
汤争耀 四川大学材料科学与工程学院, 成都 610065  
周万海 四川大学材料科学与工程学院, 成都 610065  
朱丁 四川大学新能源与低碳技术研究院, 成都 610065  
吴朝玲 四川大学材料科学与工程学院, 成都 610065  
黄利武 四川大学材料科学与工程学院, 成都 610065  
刘昆 四川大学材料科学与工程学院, 成都 610065  
陈云贵 四川大学材料科学与工程学院, 成都 610065 ygchen60@aliyun.com 
摘要: 系统地研究了Al含量对富Ce储氢合金MmNi4-xCo0.7Mn0.3Alxx=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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