Achieving Enhanced Energy‐Storage Performances in Bi0.5(K0.15Na0.85)0.5TiO3 Ceramics Modified by Sr(Ti0.85Zr0.15)O3

Lead‐free (1−x)Bi0.5(K0.15Na0.85)0.5TiO3‐xSr(Ti0.85Zr0.15)O3 ((1−x)BKNT‐xSTZ, x = 0.1–0.4) ceramics are synthesized by citrate combustion method. The grain size is reduced, and the high‐temperature shoulder dielectric peak (Tm) shifts toward low temperature, while the low‐temperature shoulder dielectric peak (Ts) shifts toward high temperature as x increases. The remnant polarization decreases and slimmer hysteresis loops are realized with x increasing. The optimal energy density (Wre ≈2.85 J cm−3) with high efficiency (η ≈ 81%) is obtained for 0.7BKNT‐0.3STZ at 160 kV cm−1. More importantly, excellent frequency stability and enhanced temperature‐dependent energy properties (Wre ≈ 1.12 J cm−3 and η ≈ 94%) of 0.7BKNT‐0.3STZ ceramic are obtained at 100 kV cm−1 and 120 °C. Lead‐free (1 − x)Bi0.5(K0.15Na0.85)0.5TiO3‐xSr(Ti0.85Zr0.15)O3 ((1 − x)BKNT‐xSTZ, x = 0.1–0.4) ceramics are synthesized by citrate combustion method. The slimmer hysteresis loops are realized with x increasing. The optimal energy density with high efficiency is obtained for 0.7BKNT‐0.3STZ. More importantly, excellent frequency stability and enhanced temperature‐dependent energy properties of 0.7BKNT‐0.3STZ ceramic are obtained.