A review of performance enhancement strategies in proton exchange membrane fuel cells

Proton exchange membrane fuel cells (PEMFCs) are regarded as one of the most promising clean energy conversion technologies because of their high efficiency, rapid start-up capability, and near-zero local emissions. However, the overall performance of PEMFCs is still constrained by many factors, including the characteristics of proton exchange membrane (PEM) materials, water management mechanism, and interface structure. The high manufacturing cost further limits its development. Perfluorosulfonic acid membranes, represented by Nafion®, remain the benchmark PEMs owing to their high proton conductivity and excellent chemical stability. Nevertheless, their conductivity decreases markedly under high-temperature or low-humidity conditions, while high methanol permeability, strong water dependence, and high production cost continue to limit broader application. The development of next-generation PEMs with high ionic conductivity, robust thermal and chemical stability, satisfactory mechanical strength, and improved cost-effectiveness has become a central research focus. This review systematically summarizes recent strategies for improving PEMFC performance from both the material and system perspectives. At the material level, the review further examines flow-field design, gas diffusion layer engineering, and water-management optimization, highlighting their roles in enhancing reactant transport, mitigating flooding, and improving membrane electrode assembly performance. Finally, the key challenges and future directions for high-performance, durable, and scalable PEMFC technologies are outlined.