Study of electro-elastocaloric effect and pyroelectric energy density in piezocomposites

Ferroelectric materials are soon to be considered as an alternate replacement for the vapour compression, and vapour absorption cooling systems and efficient energy harvesters from low-grade waste heat due to their electrocaloric and elastocaloric response. In the current work, a theoretical framework based on a thermodynamical approach is proposed to estimate the electrocaloric, elastocaloric and electro-elastocaloric effect as an isothermal change in the entropy or adiabatic temperature change (ΔT) in the piezocomposites. The proposed nonlinear constitutive model has been incorporated into a non-iterative algorithmic setup to capture the ferroelectric and ferroelastic response at different temperatures for piezocomposites. The model parameters are obtained by performing experiments for various fibre volume fractions of 1-3 type piezocomposites and are used to simulate the relations between polarization-temperature and strain-temperature at different external mechanical and electric fields. Using the present model, an Olsen cycle (pyroelectric energy harvesting cycle) is drawn to predict the pyroelectric energy density (ND) of piezocomposites.