AFRL Advances Proton Exchange Membrane Fuel Cell Research

  • Published
  • By Plans and Programs Directorate
  • AFRL/XP
AFRL manages and conducts exploratory and advanced development programs to provide power systems and cooling technologies for aircraft, missile, terrestrial, and special applications. AFRL researchers are conducting in-house proton exchange membrane (PEM) fuel cell research to help these fuel cells become viable power sources for Air Force applications.

AFRL's investigation of critical fuel cell materials, including their reliability and issues with energy density, has resulted in new polymer systems. For instance, scientists synthesized and characterized a low-cost hydrocarbon-based 6F-SPTES [sulfonated polyarylenethioethersulfone]-50 polymeric system with endcapping groups for potential application as fuel cell membranes. In addition, they synthesized and fabricated high-molecular-weight polymers into tough films exhibiting high intrinsic proton conductivity.

AFRL researchers have now successfully fabricated operational membrane electrode assemblies, or single fuel cells, with this material. The demonstrated overall performance is similar to that of the state-of-the-art Nafion® at both low and high temperatures (100ºC). The high thermal stability and high intrinsic proton conductivities of 6F-SPTES-50 qualify these polymers as potential cost-effective alternatives to Nafion as electrolyte separators for PEM fuel cells. AFRL researchers presented their results at the 3rd International Energy Conversion Engineering Conference, held in San Francisco, California.