Enhanced Energy-Storage Performance in Silver Niobate-Based Dielectric Ceramics Sintered at Low Temperature

Silver niobate (AgNbO 3 , AN) dielectric ceramics and their antiferroelectric behavior have attracted increasing attention for their potential applications in energy-storage capacitors. However, AN’s inferior dielectric breakdown strength, recoverable energy storage density, and efficiency have limited its application. In this work, a combination of chemical composition design and liquid-phase sintering was considered for the fabrication of highly insulated and desensitized AN-based ceramics for enhancing E b , W rec , and η of AN. We design and prepare (1− x )AgNbO 3 – x (Sr 0.7 Bi 0.2 )HfO 3 (AN-100 x SBH, x = 0.00–0.06) ceramics with the addition of 1 mol% BaCu(B 2 O 5 ) (BCB) as a sintering aid to realize this. It is found that highly desensitized ceramics can be formed at 980 –1000 o C over the course of 2 h. The electrical property characterization results indicate that the AFE state and E b are significantly enhanced with increasing SBH concentration. High W rec and η values of 6.1 J/cm 3 and 73%, respectively, under an applied field of 330 kV/cm are achieved in the AN-5.5SBH ceramic. Meanwhile, the AN-5.5SBH ceramic shows excellent thermal stability over a wide temperature range (room temperature–120 °C) under an externally applied field of 290 kV/cm, in which the fluctuations of W rec and η are 3.8% and 1.5%, respectively. These results provide an effective method for obtaining AN-based ceramics with excellent electrical properties under a lower sintering temperature than that required for pure AN ceramics. This method could be further generalized to develop new lead-free energy-storage dielectric materials