摘要
研究了电镀pH值对表面镀镍的La-Mg-Ni系贮氢电极的影响。电镀后,电极表面被电镀的镍层覆盖。随着pH值的升高,电极的耐蚀性能和循环性能先减弱,后增强,比容量先降低,后提高;极化电阻减小,交换电流增加。当pH=4时,电极1C循环40次后的放电比容量为270 mAh/g,容量衰减率为11%。当pH=5时,极化电阻最小、交换电流最大,电极表面的电催化活性最好,合金中的氢扩散系数为9.69×10-10cm2/s,电极的动力学性能最好。
The effects of electroplating pH value to the La-Mg-Ni hydrogen storage electrode plated Ni on the surface were studied. The surface of the electrode was covered with Ni layer after electroplating. With the increasing of pH value, the alkali-resistant performance and cycle performance of the electrode were weakened first and then enhanced, the specific capacity was decreased first and then increased, the polarization resistance decreased and the exchange current increased. When pH = 4, the specific discharge capacity of the electrode was 270 mAh/g after 40 cycles at 1 C, the capacity fading rate was 11%. When pH = 5, the pola-rization resistance was smallest and the exchange current was biggest, the electrocatalyst activity on the surface of electrode was best, the hydrogen diffusion coefficient in alloy was 9.69×10^-10cm^2/s and the kinetic performance of the electrode was best.
出处
《电池》
CAS
CSCD
北大核心
2009年第1期6-9,共4页
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