High energy density, temperature stable lead-free ceramics by introducing high entropy perovskite oxide

Dielectric capacitors with fast charge-discharge rate and high power density are drawing more attention in pulse power equipment field. In this work, bismuth-based high entropy compound (HEC), Bi(Zn0.2Mg0.2Al0.2Sn0.2Zr0.2)O-3 (BZMASZ), was introduced into BaTiO3-Na0.5Bi0.5TiO3 (BT-NBT) matrix, in order to improve the comprehensive energy storage performance. The addition of BZMASZ induced phase transition from tetragonal phase to cubic phase, along with the enhancement of relaxor behavior and local nanodomains. The 0.1 BZMASZ modified 0.75BT-0.25NBT ceramics exhibited excellent recoverable energy density of W-rec similar to 3.74 J/cm(3), high conversion efficiency of eta similar to 82.2 % and superior temperature stability of +/- 4.5 % from -30 to 200 degrees C. Combined with the high power density of P-D similar to 34.76 MW/cm(3) and rapid discharge rate of t(0.9) similar to 67 ns, the x = 0.1 ceramics are considered to be the promising candidate for future wide-temperature pulse power applications.

Automated summary

This study successfully introduced the high entropy compound BZMASZ into the BT-NBT matrix to improve the energy storage performance of ceramics. The 0.1 BZMASZ modified ceramics exhibited excellent energy density, conversion efficiency, and temperature stability after phase transition and enhancement of relaxor behavior.