Stable energy density of a PMN–PST ceramic from room temperature to its Curie point based on the synergistic effect of diversified energy

Abstract

Ferroelectric materials with stable energy storage performance used in a dynamic temperature environment have stimulated many recent studies. How to reach the temperature-independence of energy density by tuning the intrinsic structure of ferroelectrics is still a challenge. Here, an excellent thermal-stability of energy density in a 0.2Pb(Mg_1/3Nb_2/3)O₃–0.8Pb(Sn_0.48Ti_0.52)O₃ (PMN–PST) ceramic is achieved by a synergistic effect of diversified energy based on multiple polar structures. The maximum rate of change of the energy density is just 3.7% from room temperature to its Curie point (180 °C). It is proposed that multiple polar structures composed of ferroelectric domain, polar nanoregions (PNRs) and interfaces between relaxor phase and ferroelectric phase provide more degrees of freedom for the source of energy, leading to a balanced energy density based on the complementarity of energy at elevated temperature. This work highlights the approach to improve the thermal-stability of ferroelectric energy storage materials effectively based on structural engineering.