High-performance energy storage in BaTiO3-based oxide ceramics achieved by high-entropy engineering

Dielectric energy-storage capacitors are of great importance for modern electronic technology and pulse power systems. However, the energy storage density (Wrec) of dielectric capacitors is much lower than lithium batteries or supercapacitors, limiting the development of dielectric materials in cutting-edge energy storage systems. This study presents a single-phase BaTiO3-based high-entropy (BT-H) ceramic, which is synthesized using a conventional solid-state reaction method. It is found that the BT-H ceramic exhibits a remarkable energy storage performance, with a Wrec of 5.18 J/cm3 and an ultrahigh η of 93.7% at 640 kV/cm electric field. Moreover, it also features wide temperature stability and excellent frequency stability. It is proposed that the introduction of high entropy enhances the random electric field and stress field, leading to lattice distortion and reduction of nanometer domain size, which in turn reduces remnant polarization and increases electric breakdown strength. This research provides a novel approach to improve the energy storage performance of ceramics through the high-entropy strategy.