Excellent energy storage properties in BNT-based relaxor ceramics via composition optimization strategy

In this work, lead-free energy storage ceramics, (1−x)(0.95Bi0.5Na0.5TiO3-0.05Ba0.85Ca0.15Zr0.1Ti0.9O3)-xSr0.7La0.2SnO3 (BNT-BZCT-xSLS, x = 0.05, 0.10, 0.15, and 0.20), were prepared. The crystal structure, microstructure, dielectric properties, ferroelectric properties, energy storage properties, and charge-discharge performance of BNT-BZCT-xSLS were systematically studied. Among the products, BNT-BZCT-0.15SLS exhibited the highest energy storage performances (W = 2.95 J/cm3, Wrec = 2.09 J/cm3, and η = 71%) due to its dense microstructure, finer grain size, and improved relaxation. Furthermore, the BNT-BZCT-0.15SLS also showed an ultra-fast charge and discharge speed (t0.9 = 0.033 μs) and a large power density (PD = 28.0 MW/cm3).