Bipolar plates are critical components in hydrogen fuel cells, serving multiple functions such as connecting individual cells, separating reactant gases, collecting current, dissipating heat, and removing water. To fulfill these roles, the materials used for bipolar plates must exhibit high mechanical strength, excellent gas tightness, good corrosion resistance, as well as high electrical and thermal conductivity.
Currently, the main types of bipolar plate materials include graphite plates, metal plates, and composite plates. Graphite bipolar plates are the most mature technology and have been localized in production. The manufacturing process is gradually shifting from machining to more cost-effective molding methods. Metal bipolar plates offer outstanding mechanical properties, electrical conductivity, and thermal conductivity. However, they are prone to surface corrosion, which shortens their service life, and thus often require surface plating or coating to enhance durability. Composite bipolar plates, made from a mixture of resin, graphite powder, and reinforcing fibers, combine the advantages of both graphite and metal plates. They are lightweight and highly corrosion-resistant, but currently face challenges such as complex processing and high costs, requiring further optimization to reduce expenses.
