Natural clay frameworks in membrane electrode assembly: Challenges and perspectives

As a key component of polymer electrolyte membrane fuel cells, membrane electrode assemblies (MEAs) directly influence the performance of the fuel cell. In recent years, due to the unique pore and layered nanostructures as well as active sites of natural clay framework materials, which provide a large specific surface area and surface effects, along with introducing abundant organic functional groups on their surfaces and interlayers, the development of natural clay composite MEAs has become an important approach to enhancing the mechanical properties, electrochemical performance, and methanol resistance as well as reducing costs. Although there are many related studies, there is still a lack of comprehensive reviews. This paper provides a comprehensive review from various nanoscale perspectives on the structures and properties of different types of clay framework materials and their research progress in application to MEAs in both proton exchange membrane fuel cells (PEMFCs) and direct methanol fuel cells (DMFCs). The review summarizes current research on natural clay framework material composite MEAs and provides perspectives for future directions.