Pemion®, a High-Performance Hydrocarbon Proton-Exchange Membrane Demonstrating >100 °C Stability for Next-Generation Heavy Duty Fuel Cell Systems

Abstract

Until recently it was thought that hydrocarbon-based (i.e. non-fluorinated) proton-exchange membranes faced intractable issues in achieving the high performances, chemical stability, and mechanical integrity for effective integration into fuel cells. However, Pemion® PF1-HLF8-15-X, a composite membrane incorporating a new class of polyarylene sulfonic acids, has been commercialized to meet and exceed precedents set for decades by perfluorosulfonic acids (PFSAs) membranes. These attributes include: The first demonstrable success in all three categories of US Department of Energy accelerated stress tests (open circuit, humidity cycling, combined oxidative-mechanical cycling) without additives, using mass-market components and processes. This suggests greater system lifetimes are achievable and readily incorporated by fuel cell OEMs. Consistent high performances that exceed heavy duty targets (e.g. peak power densities >1.4 W/cm² with a 15 µm membrane) exhibiting comparable area resistances to state-of-the-art PFSA-based materials but across a broader operational temperature range, including a higher temperature operating window of 95 °C without area resistance gain and 110 °C without degradation, This enables long-targeted benefits, chief among which are heat exchanger size reductions and an end to over-specification for heavy duty transportation and aviation applications. Significantly reduced gas crossover in all conditions This enables greater fuel efficiency and the potential for increased component lifetimes or operational pressures. A green and “future proof” chemistry In light of EU-REACH and EPA threat of regulation and the fact that PFSAs emit fluorinated acid derivative PFAS of concern during operation, hydrocarbon materials are the only way to ensure a robust supply chain into the future, with additional benefits of simplifying recycling at end-of-life.These combined benefits represent the near-term potential to realize a step-function alteration in the economic viability of fuel cell systems for both transportation and stationary applications.