Enhanced energy storage and fast charge-discharge properties of (1-x)BaTiO3-xBi(Ni1/2Sn1/2)O3 relaxor ferroelectric ceramics.

In this work, we designed novel lead-free relaxor ferroelectric ceramics of (1- x)BaTiO 3 - x Bi(Ni 1/2 Sn 1/2)O 3 (abbreviated as (1- x)BT- x BNS, with x = 0–0.20). With an increasing concentration of BNS, (1- x)BT- x BNS solid solutions displayed a phase transition from tetragonal symmetry to pseudocubic symmetry with highly diffusive and frequency-dependent relaxor ferroelectric behavior. Modified by BNS, (1- x)BT- x BNS ceramics yielded slim polarization-electric field (P - E) loops and improved energy-storage performances. The optimal energy storage properties can be achieved at x = 0.10, and samples showed a high recoverable energy density of 2.526 J/cm3 and a remarkably high energy efficiency of 93.89% under 240 kV/cm simultaneously at ambient temperature, which represent enhancements by 925% and 286%, respectively, over pure BaTiO 3. The energy storage characteristics of the 0.9BT-0.1BNS ceramic manifested good thermal stability (−55–150 °C) and frequency stability (10 Hz-1 kHz), with a variation in recoverable energy density of less than 10%. Meanwhile, the pulsed charging-discharging measurement showed that the 0.9BT-0.1BNS ceramic had a fast discharge period of 67 ns and a large power density of 19 MW/cm3. Due to the outstanding characteristics, there is potential for this new and environmentally friendly BT-based ceramic to be used in high-power pulse capacitor applications. [ABSTRACT FROM AUTHOR]