负极表面镀锌对氢镍电池性能的影响

Effect of zinc electrodeposition on the surface of negative electrode on the properties of nickel-hydrogen battery

采用电镀锌的方法对贮氢合金电极进行了表面处理.利用扫描电镜(SEM)、循环伏安、电化学阻抗等方法研究了镀锌层对贮氢合金电极表面形貌和电化学性能的影响,通过恒流充放电实验研究了其对氢镍电池充放电性能的影响.实验结果表明,贮氢合金表面镀锌后,加快了电极表面电子转移步骤的速度,降低了接触电阻,从而减小了电极的极化,使得电池充电电压降低,1 C放电容量提高了15.3%,放电平台电压提高了22 mV,明显改善了电池的充放电性能.

Zinc electrodeposition was introduced on the surface of hydrogen absorbing alloy electrodes. The morphology and electrochemical properties of the electrodes were characterized by using scanning electronic microscope （ SEM）, cyclic voltammetry, electrochemical impedance spectroscopy （EIS） and galvanostatic charge-discharge tests. The results showed that after zinc electrodeposition, the electron transfer rate on the surface of the electrodes was accelerated and the contact resistance decreased, thus resulting in a polariza- tion reduction of the electrodes. Furthermore, after zinc electrodeposition, the charge voltage of the batteries decreased,the discharge capacity at 1 C rate increased by 15.3% and the discharge plateau voltage in- creased 22 mV, the charge-discharge property was improved obviously.