Z.C. Xu and Z.-S. Wu *

eScience, 2024, Accepted.

Electrochemical water splitting is a pivotal technology for the large-scale production of green hydrogen for sustainable future energy provisions. High-activity and stable electrocatalysts have been extensively explored, but the majority suffer from low current densities and small sizes, rendering them unsuitable for industrial applications. Recently, the scalable production of electrocatalysts with high-performance at large current densities have been progressed tremendously. In this review, the current achievements in outstanding large-sized electrocatalysts for large-current-density water electrolysis are elaborately overviewed. Firstly, fundamentals of water electrolysis, criterions for performance evaluation, and requirements for scalable producing electrocatalysts under large current densities are introduced. Secondly, key approaches to realize large-sized electrocatalysts with excellent performance including electrodeposition, corrosion engineering, and thermal treatment, etc. as well as their combinations are summarized. Finally, perspectives on research challenges and directions for mass-produced high-performance electrocatalysts with large current densities water electrolysis are proposed for guiding the further industrialization of water-electrolysis catalysts.