Pyroelectric effect in lead zirconate titanate/polyurethane composite for thermal energy harvesting

We deal with the thermal energy which is one of the ambient energy sources surely exploitable, but it has not been much interest as the mechanical energy. In the last decades, direct energy conversion devices received particular attention because of the need to develop flexible systems, autonomous and self-powered. The energy harvesting aims to make the systems, autonomous in terms of energy and to contribute to sustainable development by the total respect of the environment. In this paper, our aim is to use thermal energy and show that it's an important source for producing the electrical energy through pyroelectric effect: first, elaborate charged polyurethane (PU) with different proportions (20%, 30% and 40%) of lead zirconate titanate (PZT), then to use those PZT/PU composites as a pyroelectric energy harvesting systems. Secondly, the optimization of energy harvesting and storage. The PZT/PU composite prepared is considered as one of the most promising composites for energy harvesting systems, due its various advantages, such as mechanical flexibility, high temperature sensitivity, low cost as well as its high electro-active functional properties. The current generated by all samples for temperature fluctuations over a period of time in the order of 140 s have been rectified and stored in a charge capacitor of 1μF. The stored energy can reach a maximum value in the order of 14μW for a composite loaded with 40% PZT. Therefore, these composites show an interesting potential to be used in various applications. These results shed light on the thermoelectric energy conversion by a new composite of PZT/PU having the pyroelectric property.