Enhanced energy storage performance in BaZr_xTi_1–xO₃ lead-free ferroelectrics near phase transitions

The present study explores the energy storage properties of BaZr_<i>x</i>Ti1-xO₃through phase-field modeling, focusing on the impact of composition and temperature on energy storage performance. The obtained results reveal a variety of polarization phases and configurations based on Zr compositions and temperatures. A detailed phase diagram for temperature-composition of BaZr_<i>x</i>Ti1-xO₃is established, closely aligning with experimental measurements. Variations in Zr content and temperature have a significant impact on the polarization-electric field (<i>P</i> - <i>E</i>) response, influencing the energy storage properties. Calculations of energy storage properties are derived from the<i>P</i> - <i>E</i>response. In addition, a thorough diagram is developed to illustrate the discharge energy density of BaZr_<i>x</i>Ti1-xO₃as a function of temperature and composition. Notably, high discharge energy density is achievable near the Curie temperature, corresponding to the transition from ferroelectric to paraelectric phase. Furthermore, the present study emphasizes the importance of the disparity between maximum and remanent polarization, as well as the electric field-dependent effective permittivity, in determining the discharge energy density.