High-Performance Fluorinated Ethylene-Propylene/Graphite Composites Interconnected with Single-Walled Carbon Nanotubes

Herein, we report a novel method for the fabrication of highly conductive fluorinated ethylene-propylene (FEP)/graphite nanocomposites for high-temperature bipolar plates (BPs) by incorporating the well-dispersed single-walled carbon nanotube (SWCNT) as a secondary filler in the FEP matrix. The SWCNTs were pre-dispersed with FEP powder by sonication in ethanol and subsequently mixed with graphite powder by ball milling. The composite BPs were prepared from the mixed powder by compression molding. The resulting FEP/graphite/SWCNT nanocomposite containing 80 wt% graphite (500 µm particles) and 0.1 wt% SWCNT exhibited high electrical conductivity (210 S cm⁻¹) superior to that of the composite devoid of SWCNTs (120 S cm⁻¹) by modulating the electrical transportation pathways between graphite particles through the SWCNTs. A small amount of the incorporated SWCNTs (0.1 wt%) also improved chemical inertness to phosphoric acid. Hence, the prepared FEP/graphite nanocomposites with SWCNTs as a secondary filler exhibited a robust performance for application as high-temperature BPs for phosphoric acid fuel cells. [Figure not available: see fulltext.].