B.T.S. Ramanujam, H. Mehta, A. Khare, S. Radhakrishnan
Maharashtra Institute of Technology, IN
conducting composites, percolation, graphite, polypropylene, crystalline structure, carbon nanotube, fuel cell
Low cost conducting composites are required for bipolar plates of fel cells and battery electrodes. Polypropylene filled with graphite has been tried in the past but acceptable level of conductivity is reached only at high loading of graphite. On the other hand ternary composites containing multiple conducting nano-sized fillers together with graphite give high conductivity at low concentrations of the additives. These type of hybrid composites have been investigated in detail for structure development, electrical conductivity, impedance spectroscopy etc. so as to understand the interfacial / intergranular resistance in such composites. The nucleation of the beta crystalline phase of polypropylene by graphite is one of the major source of high intergranular resistivity. The addition of third components lead to lowering the contact resistance as well as formation of the specific crystalline phase. Better thermal and dimensional stability is expected in such materials which can be used for the bipolar electrodes.