Comparative analysis of electrode materials for alkaline water electrolysis : performance evaluation through electrochemical characterization

Abstract

Alkaline water electrolysis is a mature and important green hydrogen production technology. But its efficiency is greatly affected by electrode materials. This thesis compares four nickel-based electrodes: pure nickel, nickel-plated stainless steel, foam nickel and Reney nickel, and focuses on their electrochemical properties in alkaline water electrolysis.

This study is based on experimental data obtained using a 30 wt.% KOH electrolyte at temperatures of 25 °C and 50 °C. The polarization behavior, resistance and dynamic parameters were evaluated by methods such as electrochemical impedance spectroscopy (EIS), IR correction and Tafel analysis. The results show that porous electrodes have better performance than dense electrodes due to their larger active surface area and better reaction kinetics. Raney nickel shows the best comprehensive performance, while nickel foam provides a more balanced option for practical application. By increasing the temperature from 25℃ to 50℃, the performance of all materials has been improved, but the relative ranking remains unchanged.