低温烧结时间对AB_5型贮氢合金电极电化学动力学性能的影响  

Effect of sintering time at low temperature on the electrochemical dynamic performance of AB_5 type hydrogen storage alloy

作　　者：张珑玲[1] 

机构地区：[1]湖南省吉首市湘西电业局,湖南吉首416000

出　　处：《功能材料》2010年第11期1978-1981,1985,共5页Journal of Functional Materials

摘　　要：在流动Ar气氛保护下,将AB5型贮氢合金电极置于管式电阻炉中进行573K不同时间(30、60min,1、5h)烧结处理。通过恒流充放电,极化曲线和交流阻抗等测试方法研究了烧结电极的电化学性能。结果表明,0.2C(60mA/g)放电时,各合金电极最大放电容量不同程度降低,烧结时间增大到1h后,最大放电容量基本保持稳定。烧结处理电极高倍率放电性能(HRD)明显优于未处理电极,烧结时间越长,HRD值越高。1500mA/g电流放电时,烧结1h电极HRD值提高12.5%,烧结5h电极提高15%。同时各烧结电极极化电阻Rp,电荷转移电阻Rct随烧结时间增加而呈逐渐减小趋势,交换电流密度I0,极限电流密度IL以及氢扩散系数D均逐渐增大,烧结处理明显改善AB5型贮氢合金电极的动力学性能。AB5-type hydrogen storage alloy electrodes were sintered in flowing Ar atmosphere in tube-type resistance furnace at 573K for different time（30,60min,1,5h）.Galvanostatic charge/discharge test,polarization curves and electrochemical impedance spectroscopy（EIS）have been performed to investigate the electrochemical performances of sintered electrode.The results indicate that the maximum discharge capacity of sintered electrodes in different time at the current density of 0.2C（60mA/g）decrease with the sintering time increasing until 60min.The high rate dischargeablity（HRD）of sintered electrodes are better than the untreated electrode obviously,the longer the sintering time is,the higher the HRD is.The HRD of the sintered electrode for 60min increases 12.5% and 15% of sintered electrode for 5h when discharge at the current density of 1500mA/g.The polarization resistance（Rp）and charge-transfer reaction resistance（Rct）of the sintered electrode decrease with the sintering time increase,while the exchange current density（I0）,hydrogen diffusion coefficient Dand limitting current density（IL）of the sintered electrodes increase significantly,the electrochemical dynamic performance of the alloy electrode is performed remarkably by sintering treatment at 573K.

关 键 词：贮氢合金电极 低温烧结 电化学性能 高倍率性能 

分 类 号：TG139.7[一般工业技术—材料科学与工程]