Research progress and prospect of the materials of bipolar plates for proton exchange membrane fuel cells (PEMFCs)

Bipolar plates are recognized as an important component of proton exchange membrane fuel cells (PEMFCs) because of their critical duties of separating reactant gas, cooling medium, conducting electricity, as well as discharging heat and product water. Recognizing the importance of bipolar plates to the functioning of PEMFCs, researchers have been committed to create bipolar plates with high conductivity, good air tightness, appropriate mechanical qualities, corrosion resistance, and cheap cost. In this review, we provide an overview of the functional requirements and parameter specifications for bipolar plates, followed by a detailed analysis of research developments in recent years for three categories of bipolar plates: graphite, metallic, and composite. Meanwhile, the influence of physicochemical parameters, such as the morphologies, internal structure and composition, on the corrosion-resistance ability, mechanical strength, electrical and thermal conductivities of bipolar plates are examined and reported. This review covers various research directions and highlights the most promising avenues for future research. The objective of this review is to give guidelines for researchers who intend to create high-performance bipolar plates for use in PEMFCs.