Anion Exchange Membrane Water Electrolysis at 10 A·cm‐2 Over 800 Hours

Anion exchange membrane water electrolyzer (AEMWE) is a potentially cost‐effective technology for green hydrogen production. Although the normal current densities of AEMWEs are below 3 A·cm‐2, operating them at higher current densities represents an efficient, but little‐explored approach to decrease the total cost of hydrogen production. We show here that a benchmark AEMWE has an operational lifetime of only seconds at an ultrahigh current density of 10 A·cm‐2. By using a more conductive and robust AEM, and judicious choices of ionomers, catalyst, and porous transport layer, we have developed AEMWEs that stably operate at 10 A·cm‐2 with extended lifetimes. The optimized AEMWE has an operational lifetime of more than 800 hours, a 5‐order magnetite improvement over the current benchmark. The cell voltage is only 2.3 V at 10 A·cm‐2, comparable to those of the state‐of‐the‐art devices operating at current densities lower than 3 A·cm‐2. This work demonstrates the potential of ultrahigh current density AEMWEs.