Energy storage properties and electrical behavior of lead-free (1 − x) Ba_0.04Bi_0.48Na_0.48TiO₃–xSrZrO₃ ceramics

(1 − x) Ba_0.04Bi_0.48Na_0.48TiO₃–xSrZrO₃ (x = 0.08, 0.12, 0.15, 0.18 and 0.2, abbreviation as ‘BBNT-xSZ’) lead-free ceramics were synthesized by conventional solid-state reaction processes. Microstructures and electrical properties of BBNT-xSZ ceramics were investigated. XRD analysis reveals a pure perovskite phase without obvious phase transition with the addition of SZ. All BBNT-xSZ ceramics show high density and the grain sizes increase slightly with an increase of SZ concentration. Meanwhile, the energy storage density increases drastically, and a maximum value of 1.32 J/cm³ at E = 155 kV/cm is achieved in BBNT-0.15SZ through increasing greatly its breakdown strength with more SZ content. The temperature dependence of dielectric constant and dielectric loss of BBNT-xSZ ceramics illustrated the obvious relaxor phase transition characteristics. The BBNT-0.15SZ ceramic exhibits a high ionic conductivity accompanied by a low electronic conductivity. These properties support that (1 − x)Ba_0.04Bi_0.48Na_0.48TiO₃–xSrZrO₃ ceramics might be a promising lead-free material for high energy-storage capacitor application.