Search

Dielectric capacitors have been extensively studied in electronic and power systems based on their high power density and ultra-fast discharge rates. In this study, the dielectric, energy storage and charge-discharge properties of Sr 0.7 Bi 0.2 TiO 3 -based lead-free relaxor ferroelectric ceramic were investigated. The dielectric breakdown strength was significantly improved by introducing the rare earth element Nd, which was attributed to the rise in resistivity and large band gap. The results show that Sr 0.7 Bi 0.15 Nd 0.05 TiO 3 obtain a high recoverable energy storage density of 2.34 J/cm3 with high efficiency of 92%. In addition, pulsed charge-discharge tests demonstrated that Sr 0.7 Bi 0.15 Nd 0.05 TiO 3 possesses a high power density of 73.5 MW/cm3, a short discharge period of 0.1 μs, and a pulsed discharge energy density of 2.0 J/cm3. Meanwhile, the energy storage performance of Sr 0.7 Bi 0.15 Nd 0.05 TiO 3 exhibits excellent stability of temperature, frequency and cycling. This work provides a systematic study and a new strategy for enhancing the performance of SBT ceramics. • Nd doping broadens the dielectric peak and enhances the relaxor properties. • The improved activation energy and band gap increase the breakdown strength. • Ceramics achieve excellent energy storage density and efficiency at 360 kV/cm. • Ceramics possess excellent charge-discharge performance and thermal stability. [ABSTRACT FROM AUTHOR]

By chemical substitutions with Ba2+ and La3+ at A-site in PbHfO 3 -based ceramics, an ultrahigh energy storage efficiency of 91% and high energy density of 7.3 J cm−3 are achieved simultaneously at 290 kV cm−1 in Pb 0.925 Ba 0.045 La 0.03 (Hf 0.6 Sn 0.4) 0.9925 O 3 ceramics. [Display omitted] Near-zero remanent polarization, high breakdown electric field, high saturation polarization and low electrical hysteresis are necessary conditions for antiferroelectric ceramics to obtain excellent energy storage performance. Here, Pb 0.925 Ba x La 0.075−x (Hf 0.6 Sn 0.4) 0.98125+x/4 O 3 lead-based antiferroelectric ceramics were prepared by a rolling process. The composition modulations of Ba and La are beneficial to adjust the phase switching field, improve the saturation polarization and reduce the electrical hysteresis, leading to an enhanced energy storage performance. Simultaneously, the Pb 0.925 Ba 0.045 La 0.03 (Hf 0.6 Sn 0.4) 0.9925 O 3 ceramic exhibited a high energy storage density of 7.3 J cm−3 and an energy storage efficiency of 91%, revealing that this composition is an outstanding candidate in pulsed energy storage application and lays a foundation for further study on the energy storage performances of PbHfO 3 -based antiferroelectric ceramics. [ABSTRACT FROM AUTHOR]

Ceramics of 0.2 wt% Mn-doped (1- x)AgNbO 3 - x CaTiO 3 (x = 0.00–0.04) were prepared in flowing oxygen with the solid state method. The microstructure, antiferroelectricity and energy storage performance were investigated to explore the potential for use in energy storage capacitors. Incorporation of CaTiO 3 in AgNbO 3 effectively inhibits the grain growth and gives rise to high dielectric breakdown strength. The temperature-dependent dielectric property and Raman spectroscopy measurements demonstrate the enhanced stability of antiferroelectricity by CaTiO 3 addition through adjusting the M 1 – M 2 phase transition. As a result of both improved antiferroelectricity and dielectric breakdown strength, a high recoverable energy density of 3.7 J/cm3 was achieved in the 2 mol% CaTiO 3 -modified AgNbO 3 ceramic, which represents one of the highest recoverable energy density in recently studied lead-free ceramics. Furthermore, the energy storage performance displays an excellent thermal stability with a low variation (3%) over a wide temperature range (20–120 °C). These results indicate that modifying AgNbO 3 simultaneously on the A- and B-sites in the ABO 3 perovskite structure may lead to the discovery of new antiferroelectric materials with a high energy density. • Enhanced stability of antiferroelectricity by CaTiO 3 addition. • High recoverable energy density of 3.7 J/cm3 in the 2 mol% CaTiO 3 -modified AgNbO 3 ceramic. • Excellent thermal stability with low variation (3%) over a wide temperature range (20–120 °C). [ABSTRACT FROM AUTHOR]