(Invited) Reaching New Heights in Anion Exchange Membrane Fuel Cell Performance and Stability: Catalysts, Membranes, Water, and Beyond

Abstract

Anion exchange membrane fuel cells (AEMFCs) have seen a massive surge in interest in recent years to displace incumbent proton exchange membrane fuel cells (PEMFCs) because of their possible advantages: the possibility to eliminate platinum group metals (PGM) in the catalyst layers; lower cost cell components (i.e. bipolar plates); lower cost membranes; and lower cost balance of plant (i.e. humidification and air circulation systems) [1-2]. Unfortunately, an overwhelming majority of AEMFCs studied in the literature i) achieve extremely low performance that is not competitive with PEMFCs; ii) use higher PGM loadings than modern PEMFC; and/or iii) use catalysts and membranes whose elaborate synthesis limits their applicability. All of these limitations have stifled the practical application of AEMFC, leaving nearly all of them far away from automotive OEM and DOE targets for activity, stability and PGM loading. This talk will focus on recent work by our group, our collaborators and other groups that has led to new records in the literature with regards to the achievable current and peak power density for Pt-containing AEMFCs, Pt-free AEMFCs, low PGM loading AEMFCs and completely PGM-free AEMFCs [2-6]. AEMFCs have also been demonstrated that are able to i) achieve high peak power densities (> 2 W cm-2); ii) operate stably for several hundred hours of operation; and iii) meet strategic DOE targets – including meeting performance targets while reducing the total PGM loading to 0.1 mg cm-2. It is intended that this talk will provide a roadmap to guide the future direction of AEMFC components and their operation. The advances and demonstrations that will be discussed show that despite the fact that AEMFCs are still in their infancy relative to PEMFCs, they are nearing a point where they are ready to be taken seriously in the open market.