Hierarchical microporous Ni-based electrodes enable “Two Birds with One Stone” in highly efficient and robust anion exchange membrane water electrolysis (AEMWE)

Abstract

Anion exchange membrane water electrolysis (AEMWE) is currently the most promising technology to produce green hydrogen. However, the lack of cost-effective and scalable methods for fabricating robust and highly active non-noble metal electrodes primarily inhibits its large-scale industrialization. This study unveils an effective strategy for tackling this challenge by creating a novel hierarchical conical-microporous nickel-based electrode, through a synergistic implementation of both rapid and scalable atmospheric plasma spraying (APS) and laser texturing (LT) processes. The resultant NA-LT-CA electrodes exhibits remarkable catalytic performances for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Notably, the AEMWE cell with NA-LT-CA electrodes yields a remarkable enhancement of cell efficiency, toward a reduction in cell voltage of 244 mV at 0.8 A cm⁻², compared to the NA-CA electrode (without LT) cell. The notable achievements stem from the improved bubble dynamic contributed by the introduced hierarchical micropores into NA-LT-CA electrodes by the LT process. Moreover, the cell equipped with the NA-LT-CA electrodes demonstrates an outstanding durability, maintaining its performance for 1000 h without visible degradation under 0.8 A cm⁻², which can be ascribed to the distinctive “pinning effect” produced by the transition layer during the LT process, adeptly preventing the catalytic layer peeling off even under industrial-scale current densities. Notably, introducing the LT process delivers a dual benefit, akin to achieving “Two Birds with One Stone.”. This work supports the effectiveness of combining APS and LT processes as a potent strategy for fabricating high-efficiency and enduring electrodes, thus advancing AEMWE for practical industrial applications.