Proton exchange membrane fuel cells (PEMFCs) consist of bipolar plates, end plates, membrane electrode assemblies, and gas diffusion layers. Among these components, the bipolar plates (BPs) are the main components because they contribute significantly to the volume, cost, and weight of the PEMFC. Owing to their good electrical and thermal conductivities, graphite and metallic materials are conventional materials for BPs. However, graphite BPs lack mechanical strength, and it is difficult to machine channels on these BPs due to the intrinsic brittleness of the material. Metallic BPs have relatively high density and require surface modification and coating to suppress surface corrosion. Recently, thermoplastic or thermosetting composites reinforced with carbon-based conductive fillers have attracted significant attention because of their superior corrosion resistance and low density. In this paper, we comprehensively review the electrical conductivities of composite BPs in terms of their carbon-based fillers, matrix materials, and the manufacturing process. Next, various surface treatments aimed at improving the interfacial contact resistance of composites are discussed. Finally, methods used for reducing gas permeabilities of composite BPs are summarized.

质子交换膜燃料电池（PEMFC）由双极板，端板，膜电极组件和气体扩散层组成。在这些组件中，双极板（BPs）是主要组件，因为它们极大地影响了PEMFC的体积，成本和重量。由于石墨和金属材料具有良好的导电性和导热性，因此它们是用于BP的常规材料。但是，石墨BP缺乏机械强度，由于材料固有的脆性，很难在这些BP上加工通道。金属BP具有相对较高的密度，需要进行表面改性和涂层处理以抑制表面腐蚀。最近，碳基导电填料增强的热塑性或热固性复合材料因其优异的耐腐蚀性和低密度而备受关注。在本文中，我们从复合BP的碳基填料，基体材料和制造工艺方面全面回顾了其电导率。接下来，讨论了旨在改善复合材料的界面接触电阻的各种表面处理。最后，总结了用于降低复合BP气体渗透率的方法。讨论了旨在改善复合材料界面接触电阻的各种表面处理方法。最后，总结了用于降低复合BP气体渗透率的方法。讨论了旨在改善复合材料界面接触电阻的各种表面处理方法。最后，总结了用于降低复合BP气体渗透率的方法。