The 0.5Bi0.5Na0.5TiO3-0.5Ba0.3Sr0.7TiO3 (BNBST) ceramic is a relatively good relaxation component with tripartite phase and tetragonal phase coexisting at room temperature. Tripartite R3c is a polar phase, which can transform to long range ordered ferroelectric structures under the action of an applied electric ?eld, exhibiting large remnant polarization (P_r), which limits its application in energy storage. In this work, we designed NaNbO3 (NN) modi?ed Bi0.5Na0.5TiO3-Ba0.3Sr0.7TiO3 ceramics to prepare (1-x) (0.5Bi0.5Na0.5TiO3-0.5Ba0.3Sr0.7TiO3)-xNaNbO3 (abbreviated as (1-x)BNBST-Xnn, x = 0, 0.05, 0.10, 0.15, 0.20, 0.25) relaxor ferroelectrics. By increasing the NN amount, the phase composition is regulated to induce the transformation of the polar phase R_(3c) to the weakly polar phase P4bm, leading to a smaller P_r. The ferroelectric test results show that the ceramic sample with x = 0.1 achieves a high effective energy storage density (W_(rec )= 2.58 J cm~(-3) ) and energy storage ef?ciency (? = 91) at 140 kV cm~(-1).
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