CoO对低钴贮氢电极电化学性能的影响

Effects of CoO on the electrochemical properties of low cobalt hydrogen-storing alloy electrode

介绍了采用傅立叶红外光谱、X射线衍射、循环伏安、交流阻抗方法研究CoO对低钴贮氢合金电化学性能的影响。结果表明,随着活化次数的增加,放电中值电压逐渐增大,出现第二放电平台,使放电容量进一步提高。1C放电时,放电电压和放电容量分别提高170mV和10.5 mAh/g;10C放电时,高倍率放电性能提高21.7%。CV表明,随着扫速的加快,电极的氧化、还原峰位差逐渐加大,可逆性降低,反应向Co生成的方向进行;EIS表明,添加CoO降低了合金电极接触电阻和电荷传递阻抗,改善了电化学反应活性。

The effect of CoO additive on the electrochemical performance of rare earth based hydrogen storage alloy electrode was studied by means of FTIR, XRD, CV and EIS. The results showed that, with increasing activiation munbers, the voltage at half discharge time increased gradually and second discharge platform appeared ,which further improved the specific capacity. When current density was 300 mA/g, the discharge voltage and specific capacity increased by 170 mV and 10.5 mAh/g, respectively. When current density was 3000 mA/g, high rate dischargeability increased by 21.7%. CV showed that the gap between oxidation peak and deoxidize peak enlarged with increasing of scanning speed, the reversibility of electrode decreased and then Co was formed. EIS showed that the contact resistance, charge-transfer resistance decreases and electrochem-reactivity was improved with addition of CoO.