B-site doping of ZrO 2 to improve the dielectric and energy storge performances of a BNBS-(Ti 1− x ,Zr x ) ceramic

A group of (0.65Bi 0.5 Na 0.5 –0.35Bi 0.2 Sr 0.7 )(Ti 1− x ,Zr x )O 3 (BNBS-(Ti 1− x ,Zr x )) lead-free energy storage ceramic sheets are prepared by a conventional solid-state sintering method. We find that B-site doping of ZrO 2 may minimize the grain size while not change the perovskite structure of BNBS-(Ti 1− x ,Zr x ). As such, BNBS-(Ti 1− x ,Zr x ) possesses the uniform grains and clear grain boundaries, resulting in a high dielectric permittivity ( ε r ) of about 2080 and a low dielectric loss (tan δ ) of 0.05 at 100 Hz. Due to the lattice distortion caused by Zr 4+ entering the TiO 6 octahedral lattice, T m of BNBS-(Ti 1− x ,Zr x ) decreases with the increase of ZrO 2 doping content. Attractively, BNBS-(Ti 1− x ,Zr x ) exhibits relatively slender polarization-electric field ( P - E ) loops at a high electric field of 100 kV/cm, and BNBS-(Ti 0.97 ,Zr 0.03 ) achieves considerable recycle discharging energy density ( W rec ) of 1.47 J/cm 3 and high efficiency ( η ) of 86.94%. Thus, as a block ceramic synthesized by convenient process, this result is superior to most of similar BNT-based materials, and may provide a reference for pulse power capacitors.