Although substantial improvements have been demonstrated for fuel cell technology over the past decade, the major technical challenges as associated with cost and durability should be overcome for fuel cells to compete in real markets and achieve wide-spread commercial success. Most researchers agree that the catalyst and the membrane are key components for which significant improvement could lead to a for the solution to these issues. However, as a potential route to solve cost and durability problems, structures and properties at interfaces have not been appropriately understood due to a lack of experimental methods to characterize these complex systems. Recently, in an effort to understand the transport and structural properties of the triple phase interfaces within polyelectrolyte membrane (PEM) fuel cells, vapor and catalyst surface has been investigated widely using thin PEM films cast on flat substrates with a variety of techniques. Since the fuel cell is a highly integrated system of heterogeneous materials, the structure and activity at the various interfaces affect the overall performance as much as the individual components. In this review, we introduce recent efforts to measure structures and physical properties not only at the bulk PEM surface but also at the heterogeneous interfaces found within the catalyst layers. To overcome longstanding experimental limitatoins, neutron reflectivity is introduced as a powerful tool to probe the buried interfacial structure of the PEM within the catalyst layer.
Citation: Polymers for Energy Storage and Delivery: Polyelectrolytes for Batteries and Fuel Cells
Publisher Info: American Chemical Society, Washington, DC
Pub Type: Book Chapters
polylelectrolytes, interfaces, fuel cells