Multiscale characterization of polymer electrolyte fuel cells elucidated by quantum beam analysis

Abstract Polymer electrolyte fuel cells (PEFCs) offer promising alternatives to conventional gasoline engines in automobiles and have been commercialized over the past decade. This progress can be attributed to state-of-the-art materials with high performance, long-term durability, and robust manufacturing technologies. The multiscale hierarchical structure inherent in PEFCs facilitates the transfer of protons, electrons, oxygen, and water. As various phenomena in PEFCs occur at different scales, multiscale analysis, including quantum beam analysis, is of great interest for materials development and for understanding the processes that take place in PEFCs. In particular, advancements in this field have enabled the further tailoring of properties in a controlled manner and the design of nanostructures processing superior material properties. Additionally, the expansion of quantum beam sources has facilitated the study of manufacturing protocols. This review presents the achievements in the use of synchrotron x-ray and neutron sources in the field of PEFCs, while also addressing remaining issues for the widespread commercialization of fuel cell electric vehicles.