BaTiO3-based high-entropy ceramics for enhanced capacitive energy storage performance

Capacitors based on dielectric ceramic can be used in capacitive energy storage for pulse power application. High-entropy ceramics are one of the candidates due to their unique structure and properties. The Ba0.2(KBi)x(SrCa)(0.4-x)TiO3 high-entropy ceramics were designed for improving energy storage. The samples showed perovskite phase structure and dense microstructure. The ferroelectric phase increased with increasing the (KBi), and the decreased stability of the BaTiO3 system was confirmed by first-principles calculations. The ceramics with x = 0.18 demonstrated superior performance, achieving an energy storage density of 4.35 J/cm3and an efficiency of 89.5 % under an applied field of 320 kV/cm. The samples exhibited excellent stability in terms of temperature (20-160 degrees C) and frequency (1-200 Hz). The outstanding performance was attributed to the increased polarization and voltage withstand capacity by introducing entropy concept. These findings provide a way of designing and optimizing BaTiO3-based high-entropy ceramics for energy storage applications.