Rational electrode design for low-cost proton exchange membrane water electrolyzers

Proton exchange membrane water electrolysis (PEMWE) is in the early stage of industrial explosion, and there is an urgent need for cost reduction to advance its commercialization. The key technologies for cost reduction are to reduce the precious metal loading and to increase the operating current density. Based on the progress of developing high-performance low-cost electrodes, we systematically analyze the main obstacles encountered in achieving these two goals and current progress. Subsequently, we summarize and emphasize some potential electrode design strategies for reducing precious metal loading and to increase the operating current density. Furthermore, we discuss the current state of the relatively imbalanced electrode development, as well as future challenges and opportunities, and envision the next step in the research regarding electrodes for low-cost PEMWE.