Materials for Bipolar Plates in Polymer Electrolyte Membrane Fuel Cell: Performance Criteria and Current Benchmarks

Polymer electrolyte membrane fuel cell (PEMFC) has received a lot of attention as a promising clean, alternative energy source, compared to fossil fuel-based energy sources and the associated challenges of global warming, climate changes including depletion of fossil fuel sources. This is due to its several advantages such as high energy efficiency, high power density, low-temperature operation, rapid start up and environmental friendly characteristics. A key component of the PEMFC is the bipolar plates (BPs), which perform some critical functions to ensure acceptable levels of performance and durability of the fuel cell stack. Carbon-polymer composites and metals are two classes of materials that are mostly investigated for the production of BPs to attain PEMFC that can favorably compete with other energy sources for automotive and some other applications. Widespread commercialization of PEMFC depends on the level of success in research and development of materials that will meet the long term service and low cost requirements for BPs. After describing the functioning of the PEMFC and in particular the BPs, this paper presents a review of the various BP materials in current use, and discusses the key criteria for the materials selection and performance assessment of the plates. Research drivers towards materials for improved BPs are also identified.