The effect of compression molding parameters on the electrical and physical properties of polymer composite bipolar plates

The performance of polymer electrolyte membrane fuel cell (PEMFC) greatly depends on the properties of the components. Bipolar plate is one of the key components of PEMFC and the properties of the plates on fuel cell performance are critical. Electrical conductivity and surface roughness of the bipolar plate appear very important properties to minimize ohmic resistance and optimize water management, respectively. The composite bipolar plates having conductive fillers and thermosetting resin binder are produced by compression molding. Response Surface Methodology (RSM) has been applied to optimize the production conditions of bipolar plate. Electrical conductivity, physical appearance and roughness are chosen as response parameters and molding temperature, pressure and time are chosen as independent parameters. The main challenges of this study are observation of the individual and combined effects of these parameters on bipolar plate properties by RSM. The optimization of the production conditions of polymer composite plate is carried out by aiming maximum electrical conductivity and minimum time. The maximum electrical conductivity of 107.4 Scm−1 is obtained at temperature of 187 °C, pressure of 119 bar and time of 5 min. It is found that the polymer composite plates produced by the compression molding process at minimum time satisfied the electrical conductivity target of Department of Energy (DoE).