Effect of Bi(Zn1/2Nb2/5)O3 addition on phase transition and energy storage properties of BaTiO3 ceramics

Bi(Zn1/2Nb2/5)O3-modified BaTiO3 ceramics were designed with formula (1‒x)BaTiO3‒xBi(Zn1/2Nb2/5)O3 (0 ≤ x ≤ 0.15) and fabricated using conventional solid-state route. With increasing Bi(Zn1/2Nb2/5)O3 concentration, grain volume increased and phase structure was transformed from tetragonal to pseudo-cubic. Dielectric properties changed from temperature-dependent to temperature-insensitive and curves were flattened. Additionally, higher pseudo-cubic phase content induced slim P-E loop and low Pr. Therefore, 0.94BaTiO3‒0.06Bi(Zn1/2Nb2/5)O3 ceramic achieved energy storage density of 1.85 J/cm3 and high energy efficiency of 91.2% under electric field of 230 kV/cm. This energy storage density was 5 times higher than that of pure BT ceramic. Meanwhile, energy storage properties of this ceramic exhibited excellent thermal stability in the range of 30–120 °C and good frequency stability over 10–100 Hz. This work provides promising alternative option in energy storage materials.