Enhancing the durability of anion exchange membrane water electrolysis cells via interfacial membrane–ionomer crosslinking

Abstract Research into enhancing the performance and durability of anion exchange membrane (AEM)‐based water electrolysis (AEMWE) cells has primarily aimed to facilitate commercialization efforts and improve the chemical stability of AEMs, with anion exchange ionomers (AEIs) playing an increasingly important role. This study aimed to reduce ionomer swelling and enhance AEM–catalyst adhesion via AEM–ionomer crosslinking within a membrane electrode assembly (MEA), using allyl‐ and quaternary ammonium‐functionalized poly(phenylene oxide) (PPO), allyl‐m‐PPO, as both the AEM and AEI. Bis(aryl azide) was added as a crosslinker to an ionomer solution to generate the MEA, which was heated to induce allyl–azide crosslinks at the membrane–ionomer interface. Peel test indicated an increased adhesion at both electrodes for the crosslinked x‐allyl‐0.05‐PPO (5 mol% allyl content relative to the total ion‐conducting head group content). Further, x‐allyl‐0.05‐PPO exhibited a smaller voltage increase due to crosslinking compared to TA‐PPO, signifying a notable improvement in durability.