Progress on graphite-based bipolar plates for use in proton exchange membrane fuel cells
Graphite-based bipolar plates (GBPs) are critical components in proton exchange membrane fuel cells (PEMFCs), offering excellent electrical and thermal conductivity, corrosion resistance, and durability. However, their inherent brittleness and porous structure lead to inadequate mechanical strength and high gas permeability, limiting practical application and large-scale manufacture. This review summarizes recent advances in GBP fabrication, focusing on the effects of graphite raw materials, polymer matrices, conductive and reinforcing fillers, and molding processes on GBP performance. The relationships among graphite particle size, morphology, surface characteristics, filler dispersion, interfacial bonding, resin content, and the electrical conductivity, mechanical strength, gas permeability, and corrosion resistance of GBPs are discussed. The effects of material composition, microstructure, and processing conditions on overall performance are analyzed. Trade-offs between electrical conductivity, mechanical strength, gas permeability, corrosion resistance, and processability are highlighted. Strategies for improving performance are summarized, including optimization of graphite raw materials, multiscale filler design, interfacial regulation, resin-content optimization, and improvements in molding processes.