Improved Electrochemical Kinetic Performances of La-Mg-Ni-based Hydrogen Storage Alloy Modified by Ni-Polypyrrole Complex Surface Treatment

• 来源期刊: 高等学校化学研究（英文版）
• 年，卷（期）: 2019,（6）
• 页码范围: 1052-1057
• 页数: 6页
• 语种: 英文
• DOI: 10.1007/s40242-019-9169-3

摘要

In order to improve the electrochemical kinetic performances of La-Mg-Ni-based alloy,complex surface modification of Ni with excellent catalytic activity and conducting polymer polypyrrole(PPy) was performed via electroless plating method.FESEM images revealed that the complex Ni-PPy treatment resulted in more rnicropores at the alloy surface,with Ni particles and cotton fiber-shape PPy microspheres attached.Both the larger surface area induced by the micropore and the higher catalytic activity and conductivity on account of the dispersed Ni particles/PPy microspheres promoted the electrode reaction,thereby increasing the discharge capacity of the modified alloy electrode.Electrochemical impedance spectroscopy(EIS) and linear polarization results showed that the Ni-PPy treatment decreased the charge-transfer resistance and increased the exchange current density greatly,far more than the single-component Ni or PPy treatment.Consequently,a notable improvement in high rate dischargeability(HRD) was observed,and at a high discharge current density of 1800 mA/g,the HRD of the modified electrode increased by 10.4％ compared with that of the bare electrode.