Superior energy storage performance in (Bi0.5Na0.5)TiO3-based ceramics via entropy engineering strategy

In order to meet the application requirements in the field of advanced pulse power capacitors, the energy storage performance of dielectric materials urgently needs to be enhanced. Due to the novel high-entropy effects being beneficial for improving energy storage performance, entropy engineering has received widespread attention in dielectric energy storage materials . Herein, CaHfO 3 modified (Bi 0.5 Na 0.5 )TiO 3 -based ceramics, (0.95- x )[(0.6BNT-0.4SBT)]-0.05La- x CaHfO 3 (BNT-SBT-La- x CH) (0.01 ≤ x ≤ 0.10) ceramics, were designed by entropy engineering strategy and synthesized via a hydrothermal-assisted method. It is found the introduction of CaHfO 3 enhances the configuration entropy and promotes the generation of high-entropy ceramics. The enhancement of configuration entropy leads to stable single phase structure, reduction of grain size, formation of polar nanoregions, enhancement of dielectric relaxation behavior, expansion of band gap, and increase in resistivity, resulting in large E b and η . Accordingly, BNT-SBT-La-0.07CH high-entropy ceramic displays superior energy storage performance ( W rec = 6.30 J/cm 3 , η = 86.5 %) under a great E b of 554 kV/cm along with good thermal, frequency, and cycle stability. These results confirm that entropy regulation provides a feasible way to produce high-performance energy storage ceramics.