Enhanced energy-storage properties of BaZrO₃-modified 0.80Bi_0.5Na_0.5TiO₃–0.20Bi_0.5K_0.5TiO₃ lead-free ferroelectric ceramics

Large energy-storage density is observed in BaZrO₃ (BZ)-modified 0.80Bi_0.5Na_0.5TiO₃-0.20Bi_0.5K_0.5TiO₃ (BNBK) lead-free ferroelectric (FE) ceramics synthesized by conventional solid-state reaction. The energy-storage property of (1 − x)BNBK–xBZ has been investigated. Certain content of BZ can enhance the energy-storage property of BNBK by enhancing the breakdown strength. The largest energy-storage density W₁ = 0.73 J/cm³ and efficiency of energy storage η = 0.75 at E = 70 kV/cm are achieved in the 0.96BNBK–0.04BZ, which is significantly higher than that of BNT-based and lead-containing FE materials reported. Its energy-storage density exhibits the superior thermal stability with temperature range of 30–100 °C. Those properties promise that the environmental friendly (1 − x)BNBK–xBZ ceramics are candidate for applications of energy-storage devices.