Boosting Anhydrous Cathode Performance in Anion Exchange Membrane Water Electrolyzers through Efficient Water Diffusion and Retention Strategies

Conventional bipolar symmetric feeding configuration in anion exchange membrane water electrolyzers (AEMWEs) induces bubble accumulation at the catalyst layer-gas diffusion layer interface, which can hinder gas transport and reduce electrolytic efficiency. Furthermore, operation under anhydrous cathode conditions creates critical durability challenges due to the insufficient water supply required for hydrogen evolution reaction. Herein, we achieve the durable operation of anhydrous-cathode electrolyzers via an efficient water diffusion and retention strategy. The sterically hindered and rotatable binaphthol configuration drives exceptional membrane water permeability. Meanwhile, the strong interactions between polyhydroxy cations and water create a coordination network, effectively preventing water loss from the catalyst surface at high temperatures. The high performance (current density of 8.32 A cm–2) and robust stability (voltage fade of only 12.5 μV h–1) have proved the feasibility of the anhydrous cathode operation mode, surpassing most bipolar symmetric feeding water electrolyzers. This strategy avoids the detrimental effects of bubble formation on catalytic efficiency and the integrity of the membrane electrode structure, providing insights for advancing cost-effective, scalable AEMWEs.