Carbon nanotubes reinforced proton exchange membranes in fuel cells: An overview

The proton exchange membrane (PEM) is the core component in a fuel cell. In this review, recent progress and developments on per-fluorinated and non-fluorinated membranes with carbon nanotubes (CNTs) as reinforced fillers have been summarized on many key topics. Topics reviewed stem from correlating the mechanical stability, thermal stability, water retention capacity and proton conductivity of various membranes across different functionalized CNTs. In addition, topics such as the preparation strategies of membrane matrix and CNTs filler, the reinforced mechanism of CNTs in membrane are presented. Throughout, the impact of interactions between CNTs and various types of PEM is also discussed to present a deeper perspective. Finally, the strategy for improving the performance of PEM and the challenges of CNTs-based membranes are analyzed for prospects.