Review on factors of voltage consistency and inconsistent degradation in proton exchange membrane fuel cells

Proton exchange membrane fuel cell (PEMFC) has been extensively developed due to its benefits, such as high efficiency and zero emission. Durability and lifespan are currently the main factors impeding the widespread commercialization of fuel cells. During operational conditions, fuel cell experience continuous variations in temperature, pressure, humidity, and the concentration of reaction gases. These differential distributions ultimately lead to non-uniform degradation. Based on the analysis of degradation mechanism, the main factors contributing to the inconsistent degradation of the catalyst layer (CL), platinum, and ionomer have been identified. Furthermore, new trends in study of improving the consistency of fuel cells have been proposed, including gradient design of the CL and the design of novel electrodes and flow field structures. This review intends to guide further research in improving the consistency in fuel cells.