High‐Energy Storage Density and Efficiency of the xBi(Mg_2/3Nb_1/3)O₃‐(1 − x)(Ba_0.8Sr_0.2)TiO₃ (0.08 ≤ x ≤ 0.14) Lead‐Free Perovskite Structured Ceramics

Abstract

The compounds xBi(Mg2/3Nb1/3)O3‐(1 − x)(Ba0.8Sr0.2)TiO3 (xBMN‐(1 − x)BST, 0.08 ≤ x ≤ 0.14) are prepared via the traditional solid‐state reaction method and the ceramics are well densified in the sintering temperature range of 1280–1330 °C. X‐ray diffraction analysis shows that all the ceramics crystallize into perovskite structure. Proper amounts of BMN additions can effectively reduce grain sizes of the xBMN‐(1 − x)BST ceramics, resulting in more uniform microstructures. Accordingly, breakdown strength Eb is improved and a maximum value 250 kV cm−1 is obtained in ceramic with x = 0.10. Meanwhile, recoverable energy storage density Wrec of the 0.1BMN‐0.9BST ceramics reaches 2.03 J cm−3, and energy storage efficiency (η) is 96.8%. When the operating temperature increases to 150 °C, the Wrec and η values are about 1.02 J cm−3 under 150 kV cm−1 and 89.8%, respectively.