Novel application of Hicon Black in PEMFC microporous sublayer: Effects of composition and subsequent membrane selection

This research was carried out to prepare high performance membrane electrode assemblies (MEAs) for a proton exchange membrane fuel cell (PEMFC). The MEAs were prepared by introducing a microporous sublayer (MPS) between the gas diffusion layer and the catalyst layer. Main parameters for MPS preparation, which are microporous carbon types and the polytetrafluoroethylene (PTFE) content in the MPS, were investigated. Three microporous carbon types, which are Hicon Black, RGN and Vulcan, were evaluated. Then, Nafion membranes with two thicknesses were employed to form an MEA. The preliminary results demonstrated that a high performance could be achieved with the presence of Hicon Black in the MPS and the performance was comparable to those with the presence of Vulcan XC-72, particularly in the high current density region. The optimum PTFE content was found to be 6 wt% and the thinner membrane provided a better cell performance. The highest current density was 858 mA cm−2 at the cell potential of 0.6 V.