Enhanced Temperature Stability of Dielectric Properties in BaLa ₂ Ti ₄ O ₁₂ ‐Modified NBT Ceramics for High Power Capacitors

To overcome the trade off between high permittivity and low loss at elevated temperatures, tungsten bronze‐structured BaLa 2 Ti 4 O 12 (BLTO) was introduced into sodium bismuth titanate‐based ceramics with the composition (1 − x )(0.93Na 0.5 Bi 0.5 TiO 3 ‐0.07LiTaO 3 )‐ x BaLa 2 Ti 4 O 12 .The sample with x = 0.03 achieves a high permittivity (1093, at 150°C and 1 kHz) and a low dielectric loss (tan δ ≤ 0.02) across a temperature range of 55°C–307°C, with a temperature coefficient of capacitance (TCC) within ±10%, outperforming other reported systems. All compositions exhibit excellent dielectric thermal stability from 40°C to 500°C, maintaining a TCC within ±15%. Moreover, the 0.99(NBT‐LT)‐0.01BLTO ceramic demonstrates a high energy storage density (5.17 J/cm 3 ) and breakdown strength (280 kV/cm). These findings provide valuable guidance for developing NBT‐based dielectric capacitors suitable for high‐temperature applications.