Energy‐Storage Properties of 0.89 Bi 0.5 Na 0.5 TiO 3 –0.06 BaTiO 3 –0.05 K 0.5 Na 0.5 NbO 3 Lead‐Free Anti‐ferroelectric Ceramics

Energy‐storage properties of 0.89 Bi 0.5 Na 0.5 TiO 3 –0.06 BaTiO 3 –0.05 K 0.5 Na 0.5 NbO 3 (0.89 BNT –0.06 BT –0.05 KNN ) lead‐free ceramics were first investigated. Measurements of dielectric properties together with switching current curves indicate a rather diffuse ferroelectric ( FE ) to anti‐ferroelectric ( AFE ) phase transition when heating from 20°C to 90°C. The energy density ( W ), which was calculated from P–E hysteresis loops, increases linearly with the external electric field when E exceeds AFE ‐ FE transition field. W is independent of temperature and frequency, and maintains around 0.59 J/cm 3 under 5.6 kV/mm in the stable AFE phase region. These properties indicate that 0.89 BNT –0.06 BT –0.05 KNN ceramics might be a promising lead‐free AFE material for energy‐storage capacitor application.