Mechanism Analysis and Optimization Strategies for the Performance of Composite Bipolar Plates in Proton Exchange Membrane Fuel Cells

As the core components of proton exchange membrane fuel cells (PEMFCs), bipolar plates (BPs) serve to conduct current, support the membrane electrode assembly (MEA), and separate reaction gases, among others. Composite bipolar plates (CBPs) have attracted considerable attention from researchers due to their ability to address the mechanical limitations of graphite plates while offering superior corrosion resistance without surface coatings. However, achieving synergistic improvement in electrical conductivity, mechanical properties, and gas permeability presents significant challenges in maximizing the overall performance of CBPs. In this review, we conduct an in-depth analysis of conductivity theory, fracture mechanisms, and gas permeation mechanisms and provide a detailed overview of methods for enhancing conductivity, reinforcing mechanical properties, and reducing gas permeability, including assistance and surface functionalization of carbon-based materials, modification and blending of resins, improvement of process methods, and innovative structural designs. By integrating these insights, this review aims to offer valuable guidance for developing high-performance CBPs tailored specifically to PEMFC applications.