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

Abstract

Given the necessity to spur the progress of energy-storage equipment for high pulse power systems, it is important to tackle the critical issue of concurrently optimizing energy storage density (W_rec), efficiency (η) and stability at elevated temperatures in Na_0.5Bi_0.5TiO₃-based ceramics. This work puts forward an innovative optimizing strategy via glass addition in 0.85(Na_0.5Bi_0.5)_0.75Sr_0.25TiO₃–0.15Ca(Mg_1/3Ta_2/3)O₃ (NBST–0.15CMT) ceramics to lower sintering temperature through liquid sintering, which in turn triggers refined grains and boosts breakdown strength (E_b). Moreover, a low but temperature-stable permittivity caused by 40Na₂O–18CaO–42SiO₂ (NCS) glass assists in ameliorating high-temperature stability of energy storage properties (ESPs) and enhances E_b by prolonging saturation polarization. Ultimately, 6.0 wt% NCS glass-additive composition accomplishes anticipated ESPs (W_rec = 5.5 J cm⁻³ and η = 92.0%) under a moderate electric field and maintains remarkable stability over the temperature range of 30–130 °C. This study verifies that multi-material mixture engineering is a promising candidate technique for fabricating pulse energy-storage ceramics with high-temperature stability under low/moderate electric fields.