Glass modified Na0.5Bi0.5TiO3-based energy-storage ceramics for high-temperature applications at low/moderate electric fields

Abstract

Given the necessity to spur progress of energy-storage equipment for high pulse power systems, it is of great concern to tackle the critical issue for concurrently optimizing energy storage density (Wrec), efffciency (η) and stability at elevated temperature in Na0.5Bi0.5TiO3-based ceramics. This work puts forward an innovative optimizing tactic via glass addition in 0.85(Na0.5Bi0.5)0.75Sr0.25TiO3-0.15Ca(Mg1/3Ta2/3)O3 (NBST-0.15CMT) ceramics, endeavoring to lower sintering temperature by introducing liquid sintering, which in turn triggers refined grains and boosted breakdown strength (Eb). Moreover, a low but temperature-stable permittivity caused by 40Na2O-18CaO-42SiO2 (NCS) glass assists to ameliorate high-temperature stability of energy storage properties (ESPs) and enhance Eb by prolonging saturation polarization. Ultimately, 6.0 wt% NCS glass-additive composition accomplishes anticipated ESPs (Wrec~5.5 J/cm3, η~92.0%) under a moderate electric field and remains remarkable stability over the temperature range of 30 ~ 130 ℃. This study verifies that multi-material mixture engineering is a promising candidate technique to fabricate pulse energy-storage ceramics with high-temperature stability under low/moderate electric fields.