Microporous layer in proton exchange membrane fuel cells: Advancement in materials and properties

The microporous layer (MPL) is one of the components in the membrane electrode assembly (MEA), the heart of a proton exchange membrane fuel cell (PEMFC), and plays a vital role in managing mass transport and water management in PEMFCs, where these two aspects can negatively impact fuel cell performance if not tackled properly. Thus, the development of MPLs, in terms of material used, preparation methods, and its physical characteristics, has been widely investigated in recent years, to ensure its functionality for improved fuel cell performance. This paper aims to highlight recent MPL studies, focusing on the aforementioned development factors. This paper also addresses the challenges for optimum MPL performance and future trends in MPL development. Thus, the past findings and future outlooks discussed in this paper can act as a useful guideline for future works related to MPL development, to produce good quality MPLs for enhanced fuel cell performance.