Microstructures and energy storage properties of BSN ceramics with crystallizable glass addition

Barium strontium niobate (BSN) ceramics with different amounts of BaO–SrO–Nb2O5–Al2O3–B2O3–SiO2 (BSNABS) glass additive were prepared via the conventional solid-state sintering method, and their sintering behavior, microstructure, electric properties and energy storage properties were systematically investigated. It was found that the addition of BSNABS glass could significantly lower the sintering temperature, refine the grain size and enhance the breakdown strength of ceramics. Meanwhile, the reduction of the dielectric constant for BSN ceramics was slowed down due to the precipitation of ferroelectric phase BSN and BaAl2Si2O8 from the glass during the sintering process. In addition, impedance spectra results showed that high grain boundary resistance was the main reason of the enhancement for breakdown strength. The sample with 4 wt% glass addition possessed the highest breakdown strength of 240 kV/cm, the maximum energy density of 0.982 J/cm3 and the energy efficiency of 76.5%, which may be used as a suitable candidate ceramic material for high energy storage density capacitor.