Pyrochlore-based high-entropy ceramics for capacitive energy storage

High-performance dielectrics are widely used in high-power systems, electric vehicles, and aerospace, as key materials for capacitor devices. Such application scenarios under these extreme conditions require ultra-high stability and reliability of the dielectrics. Herein, a novel pyrochlore component with high-entropy design of Bi1.5Zn0.75Mg0.25Nb0.75Ta0.75O7 (BZMNT) bulk endows an excellent energy storage performance of W-rec approximate to 2.72 J/cm(3) together with an ultra-high energy efficiency of 91% at a significant enhanced electric field E-b of 650 kV/cm. Meanwhile, the temperature coefficient (TCC) of BZMNT (similar to -220 ppm/degrees C) is also found to be greatly improved compared with that of the pure Bi1.5ZnNb1.5O7 (BZN) (similar to -300 ppm/degrees C), demonstrating its potential application in temperature-reliable conditions. The high-entropy design results in lattice distortion that contributes to the polarization, while the retardation effect results in a reduction of grain size to submicron scale which enhances the E-b. The high-entropy design provides a new strategy for improving the high energy storage performance of ceramic materials.