Proton exchange membrane (PEM) is critical for the efficient, reliable and safe operation of proton exchange membrane fuel cells (PEMFC). The lifetime of PEM is the main factor restricting the commercialization of PEMFC. The complexity of operating conditions, such as open-circuit/idling, dynamic load and startup-shutdown under automotive conditions, on PEMFC will cause the mechanical and chemical degradation of PEM and affect the service life of PEMFC. In order to understand the degradation behavior and durability of PEM, this paper presents an overview of the degradation failure mechanism and mitigation strategies of PEM. The mechanical and chemical degradation behavior of PEM and its causes, as well as the mitigation strategies are discussed in order to give a direction for PEM design and fuel cell system control strategy. It is proposed as a primary principle in order to further develop and promote the durability of PEM, to focus on the material improvement and system engineering.

The fabrication approach of a membrane electrode assembly (MEA) is closely related to the performance and durability of the fuel cell. In this work, we combine reinforcement-embedding technology with a direct membrane deposition approach to prepare a gas diffusion electrode (GDE) with an expanded poly­(tetrafluoroethylene) (ePTFE)-reinforced membrane and then assemble a reinforced MEA. Compared with the traditional MEA, the reinforced MEA exhibits higher performance, especially under low-humidity operating conditions. Under H2/air operating conditions, the cell performance of the reinforced MEA reaches 724 mW cm–2 (80 °C, 100% relative humidity (RH), normal pressure). With the addition of ePTFE reinforcement, the mechanical durability of the reinforced MEA is significantly improved. After 3000 cycles of alternative dry/wet conditions, the reinforced MEA exhibited lower hydrogen permeation and less performance degradation compared with the unreinforced MEA. This work provides a new and facile way for improving the mechanical durability of MEAs.

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