A poly (ethylene oxide)/graphene oxide electrolyte membrane for low temperature polymer fuel cells

A novel method to prepare poly (ethylene oxide)/graphene oxide (PEO/GO) composite membrane aimed for the low temperature polymer electrolyte membrane fuel cells without any chemical modification is presented in this work. The membrane thickness is 80 μm with a GO content of 0.5 wt%. And SEM images show the PEO/GO membrane is condensed composite material without structure defects. Small angle XRD results for the membrane samples show that the d-spacing reflection (0 0 1) of GO in PEO matrix is shifted from 2θ = 11° to 4.5° as the PEO molecules intercalated into the GO layers during the membrane preparation process. FTIR tests show the typical -COOH vibration near 1700 cm⁻¹. Tensile tests show the resultant PEO/GO membrane tensile strength of 52.22 MPa and Young's modulus 3.21 GPa, and the fractured elongation was about 5%. The ionic conductivity of this PEO/GO membrane increases from 0.086 to 0.134 S cm⁻¹ when the operation temperature increases from 25 to 60 °C with 100% relative humidity. And further tests show the DC electronic resistance of this membrane is higher than 20 MΩ at room temperature with 100% relative humidity. Polarization curves in a single cell with this membrane give a maximum power density of 53 mW cm⁻² at the operation temperature around 60 °C, without optimizing the catalyst layer composition.