Nanoscale properties of polymer fuel cell materials—A selected review

摘要: The properties of the components a membrane electrode assembly in polymer electrolyte fuel cell (PEFC) determine its efficiency and performance. This paper aims at demonstrating importance nanoscale PEFC membranes electrodes discussing information obtained by various experimental techniques. nanostructure conductivity freshly prepared as well artificially degraded Nafion Pt/C are investigated contact atomic force microscopy (AFM), conductive AFM, pulsed mode (PFM)-AFM, situ scanning tunnelling (STM), electron microscopy. different techniques can provide complementary on structure conductivity. With STM Pt catalyst covered graphite, layer very small particles between is imaged, which probably not visible with TEM explain systematic discrepancy XRD particle size distribution. Conductive AFM used to investigate Nafion. images show quite inhomogeneous distribution current surface. The percentage surface increases humidity, but regions without any still present up 80% relative humidity (RH). Comparison PFM-AFM images, where differences adhesion forces measured, indicates that hydrophobic comparable dimensions, attributed to non-conductive PTFE-like backbone. changes hydrophilic parts after artificial degradation plasma etching air be imaged PFM. High-resolution were directly compare measured single channels model predictions from literature. Recent models literature propose formation water-filled inverted micelles, mean diameter 2.4 nm, their agglomeration into clusters agrees