Development of novel composite bipolar plates using surface‐modified conductive carbon filler materials for polymer electrolyte membrane fuel cells

Abstract

The requirement for a lightweight bipolar plate (BP) for Proton Exchange Membrane Fuel Cell (PEMFC) is increasing to make it feasible to power hydrogen fuel cell electric vehicles. Composite BP with carbon materials as conductive fillers and polymer as the binder are preferable over pure graphite and metallic BP. This study investigates the effect of Surface‐enhanced flake graphite (SEFG) as a novel filler material in composite BP. A composite BP is developed with Epoxy Resin (ER) as the binder and Natural Flake Graphite (NFG), Carbon Black (CB) and SEFG as conductive fillers. Composite BP fabricated with 10 vol% SEFG, 10 vol% CB, and 40 vol% NFG exhibited an electrical conductivity of 158 S cm−1, flexural strength of 38 MPa, water contact angle of 90.410 and corrosion current density of 0.261 μA cm−2. The composite BP also achieved a density of 1.55 g cm−3, water absorption of 0.6% and thermal conductivity of 3.6 W m−1 K−1 at 120°C. These results are highly favorable for BPs used in PEMFC. This paper provides an insight into using surface‐modified conductive carbon filler materials to develop composite BP for application in PEMFC.