Achieved excellent energy storage performance under moderate electric field in BaTiO-modified BiNaTiO-based lead-free ceramics multiple synergistic design

Dielectric capacitors show great potential for use in pulse power devices due to their high power density. However, achieving ultrahigh recoverable energy density ( W rec ) and efficiency ( η ) remains a challenge, limiting their applications. To address this, Na 0.5 Bi 0.5 TiO 3 -BaTiO 3 (NBT-BT) ceramics were optimized for energy storage devices operating at a relatively low electric field ( E ). This study introduces a synergistic optimization strategy by incorporating Ca(Hf 0.7 Zr 0.3 )O 3 (CHZ) into 0.93NBT-0.07BT (BNBT) ceramics. The addition of CHZ, in concentrations ranging from x = 0.00 to 0.18, significantly enhances the differences between saturation and remnant polarization from 15.6 μC cm −2 to 42.5 μC cm −2 , while reducing the grain size from 2.44 μm to 620 nm. An optimal W rec of ∼5.09 J cm −3 with η of ∼77% was achieved in BNBT-0.14CHZ ceramics at a moderate electric field (283 kV cm −1 ). Moreover, the energy storage density and efficiency exhibited good frequency stability (10-1000 Hz), temperature stability (25-150 °C) and fatigue resistance (1-10 4 cycles). A fast discharge time (∼72 ns) was concurrently realized at x = 0.14 ceramics. These results suggest that the eco-friendly BNBT-0.14CHZ ceramic is a promising candidate for application in dielectric energy storage capacitors under moderate electric field. The improved ESP via synergistic optimization strategy.