Investigation of Phenolic Vinyl Resin/Graphite Composite Bipolar Plates for Proton Exchange Membrane Fuel Cells

In order to examine the impact of phenolic vinyl resin contents on the performance of composite bipolar plates (BPs), we manufactured a sample of graphite composite BPs for proton exchange membrane fuel cells (PEMFCs) utilizing phenolic vinyl resin as a binding agent by using a hot press molding procedure. Composite BPs were mixed by dry ball milling, with natural graphite and expanded graphite (EG) as conductive fillers and carbon fiber and graphene as additives. The results showed that the composite BP with different resin contents had good hydrophobicity and thermal stability, which met the operating temperature conditions of fuel cells. An elevation in the phenolic vinyl resin content resulted in a decreased conductivity of the graphite composite BP material, increased contact resistance, and enhanced flexural strength. When the content of phenolic vinyl resin reached 38%, composite BPs showed the best overall performance. The resin was most uniformly distributed in the BP, and the conductivity was above 100 S/cm and the flexural strength was greater than 40 MPa, which meet the U.S. Department of Energy (DOE) indicators.