Electro and Surface Properties of Graphene-Modified Stainless Steel for PEMFC Bipolar Plates

Abstract

Chemical converted graphene (CCG) were coated on 316L stainless steel as a bipolar plate which is a component of proton exchange membrane fuel cell (PEMFC) by electro spray coating (ESC). Scanning electron microscope (SEM) and X-ray diffraction (XRD) were used to examine the thickness and surface properties of coating layer. Electrochemical potentiodynamic test was conducted in acidic atmosphere (0.1N H2SO4+2ppm F-) at 80°C using Versastat 4 and analysis program for corrosion resistance measurement. After packing bipolar plates for PEMFC stack, the electrical performances of graphite, bare SS316L and graphene coated SS316L bipolar plates were evaluated by PEMFC evaluating device. The chemical converted graphene was founded on the surface of coated SS316L, and the thickness was 12μm. Graphene coated bipolar plate showed high corrosion resistance of 1.32×10-7A/cm2beside bare SS316L bipolar plate. In electrical performance evaluation, the graphene coated bipolar plate was shown 0.978V on Voc and 0.5A/m2on the reduction potential (0.6V). Although the electrical performance of the graphene coated bipolar plate is lower than graphite bipolar plate, the thickness and weight is lower than graphite bipolar plate. These advantages can enable the PEMFC system more efficiently and economically.

A review of bipolar plates materials and graphene coating degradation mechanism in proton exchange membrane fuel cell

“…3,58 The electrical and contact resistance property of this coated material was considered in the test. 85 As per the simulated fuel cell, the graphene-coated Ti sheet showed an impressive diminishing of both corrosion current and interfacial contact resistance, making the graphene coating an excellent material for the BPP and a promising candidate for applications in PEMFC. Iqbal et al 62 studied the effect of coating copper BPPs with graphene on corrosion resistance.…”

“…This should be possible by either coating the substrate or modifying the base material with alloying components. 3,85 Studies have shown that uncoated stainless steel BPPs show oxide layers on the metal surface prompting a progressively decline in the performance of the PEMFC. 86 Consequently, it is required that some surface modification techniques or self-protective coating be applied to stainless steel to improve their protection against corrosion.…”