High-temperature energy storage properties of PbHfO3-based antiferroelectric ceramics with low phase transition electric fields via the phase boundary engineering

Antiferroelectric materials near the morphotropic phase boundary (MPB) are ideal candidates for highperformance energy storage devices owing to their low phase transition electric fields, large polarization difference and strong controllability. However, many established antiferroelectric ceramics that are far from the morphotropic phase boundary often exhibit performance degradation at high temperatures, which limits their practical applications. In this work, compositions near the morphotropic phase boundary of (Pb0.97La0.02) (HfxSn0.9-xTi0.1)O3 (PLHST) antiferroelectric materials are evaluated to enhance high-temperature energy storage performance. The experimental results demonstrate that temperature regulation can induce a transition from ferroelectric hysteresis loops with large remanent polarization to transition into antiferroelectric behavior with double hysteresis loops and near-zero remanent polarization. Overall, the PLHST ceramic with x = 0.85 demonstrates a low antiferroelectric to ferroelectric phase transition electric field (EAFE-FE) of 3.5 kV mm-1 at a high temperature of 120 degrees C. This material also has an impressive recoverable energy storage density (Wrec) of 3.4 J cm-3, a satisfactory energy efficiency (eta) of 75.5 %, and an ultrahigh figure of merit (FOM = Wrec/EAFE-FE) of 0.097 J center dot kV-1 center dot cm-2. Additionally, it maintains stable energy storage performance without appreciable deterioration for up to 5000 fatigue cycles at a high temperature of 120 degrees C. The findings presented herein highlight the potential of PLHST ceramics developed through phase boundary engineering as robust candidates for hightemperature energy storage applications, offering a path forward for the development of more efficient and durable capacitors in advanced technologies.