PEMFC bipolar plates fabricated via 3d printing using twin-screw extruded graphene/polyaniline: Fabrication, characterization, and performance evaluation

This study explores the potential of graphene-infused polyaniline (PANI) composite-based bipolar plates (BPPs) for Polymer Electrolyte Membrane Fuel Cells (PEMFCs), developed via twin-screw extrusion and Fused Deposition Modeling (FDM). Analyzing composites with varying graphene proportions (2 to 12 wt%), Plates D and E containing 8wt% and 10 wt% graphene respectively emerged as superior, showcasing in-plane conductivities of 82.15 S/cm and 82.35 S/cm, and through-plane conductivities of 20.61 S/cm and 20.56 S/cm. While approaching the US Department of Energy's (US DoE) target of 100 S/cm in-plane conductivity, these results highlight the challenges in balancing conductivity optimization with other properties. Both plates exceeded DoE benchmarks for thermal conductivity and mechanical strength, demonstrating values of up to 20.19 W/mK and exceeding 40 MPa. In a single-cell PEMFC configuration, these plates achieved power densities of 471 mW/cm2 and 551 mW/cm2, accentuating their potential for practicability. Further advancements are anticipated, with the next phase of this study, poised to explore the functionalization of graphene into graphene oxide (GO), thereby refining the electrical characteristics through strategic chemical modifications. This approach aims to surmount the existing conductivity limitations to further elevate the performance of BPPs.