Novel barium titanate based capacitors with high energy density and fast discharge performance

Recently, dielectric capacitors have attracted much attention due to their high power density based on fast charge-discharge capability. However, their energy storage applications are limited by their low discharge energy densities. In this work, we designed novel lead-free relaxor-ferroelectric 0.88BaTiO(3)-0.12Bi(Li0.5Nb0.5)O-3 (0.88BT-0.12BLN) ceramics with high breakdown strength and high discharge energy density. The 0.88BT-0.12BLN ceramics were prepared by a conventional solid state reaction method. Optimal energy storage properties were obtained in 0.88BT-0.12BLN ceramics sintered at 1220 degrees C with an impressive discharge energy density of 2.032 J cm(-3) and a charge-discharge efficiency of beyond 88% at 270 kV cm(-1). The energy storage properties of the 0.88BT-0.12BLN also displayed good thermal stability from 20 to 120 degrees C at an electric field of 150 kV cm(-1). Moreover, the discharge speed behavior was investigated by using pulsed current. The pulsed discharge current waveforms showed that all the samples have fast discharge times ( less than 0.5 mu s) under different electric fields. This work significantly increases the intrinsic breakdown strength and discharge energy density of BaTiO3-based materials with high charge-discharge efficiency for high power energy storage devices.