Preoaration and Effect of Carbon Nano-fabric Using Electrospinning Method for Nano-current-collect-layer in DMFC

Abstract

Effects of carbon nano-fabric (CNFbc) as a nano-current-collect-layer on performances of direct methanol fuel cells (DMFCs) were determined. CNFbc was made using the electro-spinning method. CNFbc with an average diameter of 130 nm was placed between a cathode diffusion layer and a cathode catalyst layer. By using CNFbc with thickness of 27±2 μm DMFC, the maximum power density was improved from 46 to 74 mW cm^-2 at the cell temperature of 60°C. From SEM images of cross sections of the membrane-electrode-assemblies, it was observed that the CNFbc interlayer has closely contact with both the cathode catalyst layer and the diffusion electrode. By using the CNFbc interlayer the electrical conductivity as well as the cell voltage at 200 mA cm^-2 in the DMFC increased to 1.4 times. These results showed that the CNFbc interlayer improved the DMFC performance by decreasing the contact resistance between the cathode catalyst layer and the diffusion electrode. On the other hand, it was also found that too many microbeads in CNFbc reduce the effects of CNFbc interlayer. It was proved that the uniform CNFbc interlayer has useful effects as a nano-current-collect-layer in the DMFC.