Enhanced Energy Storage using Ba(Zr_0.2Ti_0.8)O₃–0.15(Ba_0.7Ca_0.3)TiO₃ Ceramics with BaO–SrO–TiO₂–Al₂O₃–SiO₂–BaF₂ Glass Addition

The addition of the glass BaO–SrO–TiO₂–Al₂O₃–SiO₂–BaF₂ was employed to improve the microstructures and energy storage properties of Ba(Zr_0.2Ti_0.8)O₃–0.15(Ba_0.7Ca_0.3)TiO₃ ceramics, which exhibited a large dielectric constant of 3458 at 25 °C under 1 kHz, slim hysteresis loop with the maximum polarization of 12.53 μC cm⁻², and a remnant polarization of 4.05 μC cm⁻². Characterization of the microstructure indicated that the average grain size was reduced significantly with increasing glass concentration. Macroscopically the glass ceramics exhibited diffusion phase transition with reduced peak dielectric constant, but a broad peak with a relatively large dielectric constant of approximately 1000 near room temperature. Meanwhile the electrical breakdown strength (BDS) of the glass modified ceramics was nearly quadruple that of the pure ceramic. The energy storage performance of the glass-modified ceramics (419.4 kJ m⁻³ calculated from the product of dielectric constant and square of BDS and 192.8 kJ m⁻³ from the integration of the hysteresis loop under an electric field of 9.6 kV mm⁻¹) showed significant superiority to that of the pure ceramic material.