重稀土元素对氢氧化镍电极高温性能的影响

Effects of Heavy Rare Earth Element on High-Temperature Performance of

摘要:

研究了在覆钴球镍中低量添加重稀土元素对镍电极性能的影响。结果表明，60 ℃时添加1%(原子分数)重稀土的镍电极的1 C充放电效率比无添加剂的镍电极有所提高；重稀土氧化物的添加对镍电极的常温高倍率放电性能有一定的负面影响；在常温时，重稀土氧化物的加入增大镍电极氧化-还原反应的电位差，从而增大电极反应的不可逆性，其中添加氧化铥与氧化镥的电极最为明显；在60 ℃时，添加重稀土氧化物的镍电极的氧化峰与析氧峰区别明显，且镍电极的氧化峰电位与析氧电位普遍负移，还原峰电位普遍正移，显著提高镍电极在高温下的析氧过电位以及可逆性

Abstract:

The effects of heavy rare earth oxide additives on the high temperature performance of nickel electrodes were investigated. It is found that the 1 C charge acceptance ability of the spherical Ni(OH)2 electrode with heavy rare earth oxide additive is improved; however, the heavy rare earth oxide as additive has negative effect on the high rate discharge performance at room temperature. The cyclic voltammetry (CV) results indicate that the heavy rare earth oxide as additive can increase the overpotential of oxygen evolution at high temperatures. The oxygen evolution reaction is effectively depressed and leads to the increase of charge efficiency of Ni(OH)2 electrode at high temperatures. Moreover, the reversibility of Ni(OH)2 electrode is also improved at high temperatures.