The influences of B-site doping on ferroelectric and energy-storage properties of Bi0.5(Na0.82K0.18)0.5TiO3–LiSbO3 ceramics

Abstract

Abstract Single-phase Bi0.5(Na0.82K0.18)0.5Ti1−xMxO3–0.01LiSbO3 (BNKT–LS-xM) (M = Ta, Nb or Zr, 0 ≤ x ≤ 0.05) lead-free ceramics are prepared by a solid-state reaction method. The influences of Ta5+, Zr4+or Nb5+ doping at B-site of perovskite structures on the crystal structure, chemical structure, ferroelectric and energy-storage properties of BNKT–LS ceramics are systematically investigated. Although the introduction of Ta5+, Zr4+ and Nb5+ at B-site could disturb the long-range ferroelectric ordering, Ta5+ or Nb5+ doping results in excellent thermal stability of the energy-storage density (as large as 0.7 J cm−3) at elevated temperatures (50 °C–200 °C) with a high energy-storage efficiency (>90%). The results demonstrate that the lead-free BNKT–LS-xM ceramics are promising dielectric materials that can be finely tuned for electrical energy storage with high energy storage efficiency and a wide range of operating temperature.