Tailoring electrode hydrophobicity to improve anode performance in alkaline media

Abstract

Limitations in anode performance have been a major obstacle to widespread alkaline fuel cell usage. In contrast to water management in acidic cathodes, water management in alkaline anodes has not received a lot of attention. Here, we use a methodology based on individual electrode plots to analyze and improve anode performance, especially by changing the hydrophobicity. Specifically, we determine the role of hydrophobicity as it affects performance for backing layers, catalyst layers, and catalyst binders. We use both individual electrode plots and recirculating experiments to determine the optimal PTFE loading was 20 wt% in alkaline media. We investigated PTFE and Fumion binders, determining that their use yields higher overpotentials than when using Nafion in alkaline media. Furthermore, we determined that Nafion alternatives for application in alkaline media would require significant hydrophilicity and anion-conductivity to result in good fuel cell performance.