Synergistic optimization of energy storage performance in Na_0.5Bi_0.5TiO₃-based high-entropy ceramics via A/B-site co-doping

Abstract: High-power pulse systems demand dielectric ceramics with high recoverable energy storage density (W_rec), efficiency, and stability. Relaxor ferroelectrics are promising due to high polarization and low loss. In this work, a binary solid solution of 0.7Na_0.5Bi_0.5TiO₃-0.3Sr_0.7Bi_0.2TiO₃ was used as the base composition. A series of high-entropy relaxor ferroelectric ceramics, (1-x)(0.7NBT-0.3SBT)-x(Ca_0.5Ba_0.5)(In_0.5Ta_0.5)O₃ (x = 0.05 ~ 0.30), featuring highly disordered crystal structures, were synthesized via a solid-state reaction method through simultaneous multi-cation doping at both the A- and B-sites. Characterization techniques including structural analysis, morphology observation, and basic electrical property measurements demonstrated that this A/B-site co-doping strategy effectively enhanced the relaxor characteristics. Systematic evaluation of energy storage performance identified the optimal composition (x = 0.1), which achieves a W_rec of 1.1 J·cm⁻³ at 110 kV·cm⁻¹, representing a relatively high value for bulk ceramics under moderate electric fields. These findings provide experimental support and a technical reference for developing high-performance energy storage ceramics.