Improved energy storage performance of Ba(Ti,Ca)O₃ ceramics through tailoring phase structure and ferroelectric polarization

Abstract A novel strategy was adopted to prepare (1 − x )Ba(Ti 0.97 Ca 0.03 )O 2.97 – x (Bi 0.51 Na 0.47 ) 0.94 Ba 0.06 TiO 3 (abbreviated as (1 − x )BTC– x BNBT, x = 0.03–0.15) relaxor ferroelectric ceramics by precisely tailoring the phase structure and ferroelectric polarization. Significant enhancements in both polarization and dielectric breakdown strength are successfully achieved by realizing the phase structure dominated by the tetragonal phase in relaxor ferroelectrics. Notably, the 0.9BTC–0.1BNBT ceramic simultaneously shows an outstanding recoverable energy density of 2.17 J cm −3 and a high efficiency of 84.5% at 240 kV cm −1 , as well as superior temperature (20 °C–160 °C) and frequency (1–100 Hz) stability. In addition, the charge–discharge test results show that the 0.9BTC–0.1BNBT ceramic has an ultra-fast discharge rate of t 0.9 ∼ 75 ns, an ultra-high power density of 27.7 MW cm −3 and a high discharge energy density of 0.58 J cm −3 . This work not only provides a promising energy storage material for pulse capacitors, but also presents an effective method for developing new high-performance BaTiO 3 -based dielectric materials.