P.N. Pintauro, J. Slack, R. Wycisk, M. Brodt
Keywords: nanofiber electrospinning, high power density, high durability
Summary:A new method of preparing fuel cell electrodes has been developed. Electrode mats composed of particle/polymer nanofibers work exceptionally well in a hydrogen/air fuel cell, in terms of power output and long-term durability. Abstract: The hydrogen/air proton-exchange membrane (PEM) fuel cell is a promising candidate for automotive power plants, but Pt/C catalyst electrode cost and durability are still issues that require further study. Recently, there has been considerable work on identifying new catalyst electrode materials for low Pt-loading fuel cell operation, including metal alloys and core-shell nanostructures. Another way to reduce the amount of Pt in a fuel cell without a loss in power output is to improve the cathode morphology in order to maximize catalyst contact with feed gases and enable facile water expulsion while maintaining a sufficient number of pathways for proton and electron conduction. Electrodes with such properties can be created by nanofiber electrospinning. The method offers the possibility of creating high performance fibrous electrode mats from a wide variety of polymeric binders and catalytic powders. In this talk, recent work on the electrospinning of particle/polymer nanofiber electrodes will be presented, with a focus on improving the performance of the oxygen cathode in a hydrogen/air PEM fuel cell. Procedures for fabricating high particle-loaded nanofibers will be presented. The effects of catalyst type (carbon supported Pt and PtCo), catalyst loading, and binder composition (Nafion, Nafion/PVDF blends, and PVDF) on fuel cell power output and cathode durability will be discussed.