Hybrid materials for energy storage
Marilena RE (ENEA)
Conducting polymers (CPs) have arisen wide interest as electrode materials and the development of their study and processing allow their use in various applications such as sensors, membranes for the separation of gas mixtures, corrosion protection, and so forth. Several studies have introduced the possibility to use conducting polymers as suitable matrices to disperse conductive nanostructures (better if carbon nanostructures). In such a way hybrid conducting nanocomposites have been constituted showing some synergistic properties, such as a better electrical conductivity and mechanical properties than those of the original polymer matrix, with a variety of applications in energy field.
Among the CPs, polyaniline (PANI) is one of the most studied because of its facile synthesis, electrical conductivity, low cost and environmental stability. It is also one of the most promising materials for its good supercapacitive behaviour, thanks to its excellent capacity for energy storage and high conductivity. However, the stability during cycling is not so good due to swelling and shrinkage that can lead to degradation of the electrode based on PANI. In order to increase the mechanical stability of polymer, without decreasing the specific capacitance and the energy per total mass of supercapacitor electrode [1-2], Carbon nanostructures can be introduced in the PANI matrix. Moreover, a small amount of tubular structures, such as carbon nanotubes (CNTs), could assure a mesoporous network that allows an easier diffusion of ions.
In this work PANI-CNTs nanocomposite films were obtained by using different combinations of two methods, Electrochemical Deposition (ELD) and Electrophoretic Deposition (EPD). The so prepared samples were compared with the pure PANI. Therefore, the nanocomposite films were characterised and their electrochemical properties were investigated.
[1] C. Peng, S. Zhang, D. Jewell, G. Z. Chen, Carbon nanotubes and conducting polymer composites for supercapacitors, Prog. Nat. Sci., 18 (2008) 777-788
[2] G.A. Snook, P. Kao, A.S. Best, Conducting-polymer-based supercapacitors devises and electrodes, J, Pow. Sources, 196 (2011) 1-12
