Outstanding energy-storage and charge–discharge performances in Na0.5Bi0.5TiO3 lead-free ceramics via linear additive of Ca0.85Bi0.1TiO3

Lead-free relaxor ferroelectric ceramic capacitors have attracted increasing attention for their excellent energy-storage performance. In this work, Na0.5Bi0.5TiO3 was modified by linear dielectric Ca0.85Bi0.1TiO3 to improve its energy storage performance. The samples of (1-x)Na0.5Bi0.5TiO3-xCa0.85Bi0.1TiO3, namely Na0.5-0.5xBi0.5-0.4xCa0.85xTiO3 (xNBCT, x = 0, 0.14, 0.21, 0.28, and 0.35) were prepared by solid-state reaction method. The structure, dielectric, energy storage capability, and pulsed charging/discharging behaviors of the ceramics were investigated in detail. Our results showed that CBT doping into the NBT-based ceramics is beneficial to energy storage. A large recoverable energy storage density of 7.13 J/cm3 and a high efficiency of 83% can be achieved simultaneously in the 0.28NBCT ceramic. The 0.28NBCT ceramic also exhibits good temperature and frequency stability with an ultrahigh power density of 161 MW/cm3, a transient discharge time of 40 ns, and high discharge energy density of 3.4 J/cm3. These findings indicate that the sample of 0.28NBCT has great prospects in pulsed-power applications.