Effect of multi-walled carbon nanotubes on the properties of composite bipolar plate for polymer electrolyte membrane fuel cells

Polymer Composite Bipolar Plates (PCBP) with carbon fillers are emerging as a lightweight and compact alternative to pure graphite bipolar plate for Proton Exchange Membrane Fuel Cells (PEMFC). PCBP can reduce the weight and volume occupied by PEMFC assembly, enhancing the payload capacity of hydrogen-powered electric vehicles. This study focuses on the development of PCBP using Multi-Walled Carbon Nanotube (MWCNT) as tertiary filler, Carbon Black (CB) as secondary filler, Natural Flake Graphite (NFG) as primary filler and bisphenol A Epoxy resin (EPR) as binder. The fabrication is done by compression molding. The study aims to examine the effect of filler concentration of MWCNT on the mechanical, electrical, morphological, chemical and thermal properties of the PCBP. The optimized PCBP with 3.0 vol% MWCNT achieved a flexural strength of 46 MPa, in-plane electrical conductivity of 182 S cm-1 and a corrosion current density of 0.221 mu A cm-2, satisfying 2025 US Department of Energy targets. Additionally, it demonstrated a bulk density of 1.46 g cm-3, shore D hardness of 70, thermal conductivity of 5.45 W mK-1 and a water contact angle of 86.78 degrees, which are desirable values for PEMFC application. These results underline the potential of hybrid nanocomposite PCBPs to enhance the desired properties of PEMFC systems, paving the way for advancements in hydrogen fuel cell vehicles.