Effects of foam cathode electrode structure on alkaline water electrolysis for hydrogen production

• Published in: Chemical engineering science 2024-10, Vol.298, p.120307, Article 120307
• Main Authors: Liu, Fulin, Wang, Fangzhou, Hao, Xiaowen, Fan, Zhunfeng, Tan, Jianyu
• Format: Article
• Language: English
• Subjects: Alkaline water electrolysis; Hydrogen evolution electrode; Multi-physics field modeling; Porous structure
• ISSN: 0009-2509
• DOI: 10.1016/j.ces.2024.120307

•Three-dimensional modeling of the multi-physics field of alkaline water electrolysis cell with serpentine flow channels.•A comprehensive investigation of effects of porous structure parameters on HER.•Dynamic high-voltage single-cell tests of porous electrodes with a continuous electrolyte supply.•Hydrogen evolution rate and efficiency of nickel foams with different thicknesses and pore densities. Hydrogen is widely recognized as a clean and sustainable energy source. One of the most promising methods for hydrogen production is alkaline water electrolysis. The efficiency and cost-effectiveness of this process heavily depend on the choice of a suitable porous electrode structure. This paper aims to investigate impact of the porous structure on the performance of alkaline electrolytic water through experiments and multi-physics field simulation. Specifically, the whole cell performance test and hydrogen-evolution reaction (HER) test of nickel foam were conducted in an electrolytic cell using 1 M KOH. Results revealed that various parameters of the electrode structure, such as specific surface area, pore density, thickness, and electronic conductivity, significantly influenced the hydrogen evolution. Increasing the specific surface area or pore density proved to enhance the hydrogen evolution under conventional voltage. Reducing the thickness has a similar effect. Additionally, materials with high conductivities increase the reaction rate. Based on experimental results, the optimal nickel foam cathode structure was 1000 μm thickness and 75 PPI pore density. The results of stability tests and electrolysis voltage efficiency analysis provide further support for the positive effect of this structure on hydrogen evolution. This study provides rational reference for designing efficient and stable porous electrode structures.