Integrated MEAs with radical-scavenging PANI/CeOx layer for durable PEMFCs

Proton exchange membrane fuel cells (PEMFCs) are a promising clean energy technology due to their high efficiency and environmentally friendly energy conversion. However, their widespread deployment is hindered by limitations in power density and chemical durability of membrane electrode assemblies (MEAs). In this study, we report an integrated MEA fabrication strategy that incorporates a protective polyaniline/cerium oxide (PANI/CeO x , PC) layer via a full spray-coating method. This antioxidant interfacial layer effectively mitigates free radical-induced membrane degradation. CeO x nanoparticles embedded within the PANI matrix exhibit excellent radical scavenging activity, resulting in improved long-term stability. After 150 h of operation at 90 °C and 30% relative humidity (RH), the open-circuit voltage declined by less than 10%. The spray-coating process also enhances MEA structural integrity, promoting strong membrane–catalyst adhesion and reducing interfacial mass transfer resistance and dimensional instability. Under H 2 /O 2 testing, the optimized MEA achieved a high peak power density of 2.04 W cm -2 at 80 °C and 100% RH. This integrated approach, combining chemical protection and interfacial engineering, significantly advances the performance and durability of PEMFCs for practical applications.