摘要
Anodic electrodes with the mixture of hydrogen storage alloys and different contents of Co3O4（2%,4%,6% and 8%,mass fraction） powders were made.The effects of Co3O4 on the electrochemical performance of the alloy electrodes were studied.The constant charge-discharge tests show that the discharge capacity of alloy electrodes with Co3O4 significantly increases,and the maximum discharge capacities of electrodes with 2%,4%,6% and 8% Co3O4 are higher than the electrode with no Co3O4 by 0.83%,4.86%,7.18% and 9.21%,accordingly.Linear polarization（LP） and electrochemical impedance spectroscopy（EIS） tests suggest that charge-transfer resistance decreases by the addition of Co3O4.Cyclic voltammogram（CV）,scanning electron microscopy（SEM） and energy dispersive spectrum（EDS） tests indicate that Co3O4 can partly dissolve and experience a reversible oxidation-reduction process of Co to Co（OH）2,leading to the improvement in the electrochemical performance of hydrogen storage alloy.
将不同含量的Co3O4(2%,4%,6%,8%,质量分数)作为添加剂加入到储氢合金中,采用机械混合法进行改性处理。对添加Co3O4的合金电极的电化学性能和电极过程进行研究。结果表明:放电容量有了较大增加,添加2%、4%、6%、8%Co3O4的电极放电容量比空白电极容量分别增加0.83%,4.86%,7.18%和9.21%。线性极化曲线和电化学阻抗谱测试表明,添加Co3O4降低了电极的电荷转移电阻。循环伏安、扫描电镜和EDS测试表明,添加的Co3O4可部分溶解,发生Co-Co(OH)2可逆氧化?还原反应,从而改善储氢合金的电化学性能。
基金
Projects(21071153,20976198)supported by the National Natural Science Foundation of China
