Effect of Bi(Li_(0.5)Nb_(0.5))O_3 addition on structural, dielectric, and energy storage properties of Na_(0.5)Bi_(0.5)TiO_3-BaZrO_3 lead-free ceramics

摘要

Lead-free dielectric ceramic capacitors have wide applications in pulsed power systems due to their high power density. In this study, (0.95-x)Na_(0.5)Bi_(0.5)TiO_3-0.05BaZrO_3-xBi(Li_(0.5)Nb_(0.5))O_3(BNT-BZ-xBLN) ceramics were successfully prepared by solid-state methods, and their structural, dielectric, and energy storage properties were systematically investigated. The introduction of Bi(Li_(0.5)Nb_(0.5))O_3 leads to dense microstructure and small pore size. The stability of dielectric properties can be significantly enhanced by Bi(Li_(0.5)Nb_(0.5))O_3 modification. A high and stable dielectric permittivity of 2382 (△ε'/ ε'_(150°C) ≤ ± 15%) over a wide temperature range of 103-450 °C (@1 kHz) was achieved in NBT-BZ-0.03BLN ceramic. Meanwhile, this sample also shows a maximum energy storage density of 1.59 J/cm~3 featured with good temperature stability from 20 to 140°C. In addition, a large current density (581 A/cm~2), high power density (29 MW/cm~3) and fast charge-discharge speed (41 ns) are also obtained in the NBT-BZ-0.03BLN ceramic. Our results indicate that the BNT-BZ-xBLN system would be promising lead-free materials for pulsed power capacitors.