Assessment of surface resistance reduction on polypyrrole-coated composite bipolar plates

New applications of electronic devices come with integrated functionalization, size diminishment, and ultralight weight. An alternative electricity source is also demanded for effective commercialization of devices. Direct Methanol Fuel Cells (DMFCs) have the potential to play a major role as energy generators for portable applications, thus they can be a choice for new generation electronic devices. Fabricating bipolar plates (BPs) to meet the application requirements is received great attention due to their lightweight and possibility for mass production. This research focused on using polypropylene/carbon filler composites as BP materials, offering a major advantage of mass production by a conventional low-cost injection moulding technique. The purpose of this research is to inspect the feasibility of polypyrrole (PPy) coating on the composite BPs via a chemical polymerization of PPy. To accomplish effective coating, composite BPs were surface-pretreated by UV photografting prior to the PPy coating process. Effects of surface treatment and polymerization conditions, such as time of treatment or polymerization and doping agent, were investigated via physicochemical characterizations using several techniques; Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, contact angle measurement, and scanning electron microscopy. Indispensable determination is an electrical conductivity measurement of the composite BP surfaces. Experimental results confirm successful PPy coating, however; the adhesion test indicates that the surface interaction between the PPy layer and the BP surface needs further improvements before applying the promising BP to commercialization.