Study On The Energy Storage Performance Of PBLZST Anti-Ferroelectric Ceramics

Because of its unique electric hysteresis loop and phase transition properties, the anti-ferroelectric materials can be used in pulse capacitors of high energy storage density. In this paper, we have studied the lead zirconate stannate titanate lanthanum barium(PBLZST) anti-ferroelectric ceramics, which have excellent energy storage performance. Many methods can be used to improve the energy storage density of anti-ferroelectric ceramics, such as regulation of components, element doping and materials composites. However, the effect of ceramic preparation process on its performance of energy storage, has not been studied deeply. Therefore, this article has used the hot- press sintering method to study the energy storage properties of PBLZST from the following aspects:Firstly, in this paper, the hot-press sintering process had been carefully designed. Some factors such as sintering temperature, soaking time and sintering pressure had been studied.The experimental results showed that the PBLZST prepared by hot-press sintering methods were sintered at 1100 ℃,which reduced nearly 200 ℃ than normal sintering.At the same time, the ceramics would be sintered adequately when the soaking time was 2 hour sand the pressure was 70 MPa.Secondly, we designed five different sets of lead excess components due to the lead volatilization during the sintering process. Then we studied the influence of different sintering process on the microstructure and energy storage performance of PBLZST as the PbO excess amount changed. The results showed that the microstructure of hot-pressed samples were more homogeneous and had lower porosity by SEM analysis.The sample H3, in which PbO excessive amount was 6 mol%, had an average grain size of 1.8μm and a density of 99.5%. The hot-pressed samples owned higher breakdown strength analyzed using a two-parameter Weibull distribution function.The highest breakdown strength of 180 kV/cm can be obtained in H3. The hot-pressed PBLZST showed high resistivity >1013Ωm, which was two orders of magnitude greater than that of the conventional sintered samples. The samples prepared by hot-pressed sintering method showed an higher recoverable energy density of 3.2J/cm3. which was 100% greater than the conventional sintered specimens.In addition, the samples sintered by hot-pressed method were usually in a hypoxic state, so the samples would produce oxygen deficiency, which affected the electrical properties of ceramics. By designing the different oxidation processes, we studeid the effect of oxidization on the energy storage property of PBLZST. The results showed that the oxidation was better when PBLZST antiferroelectric ceramics oxide 3 hours in air, or oxidizing 1.5 hours(oxygenation rate 50 mL/min) at 850℃. Recoverable energy density of PBLZST treated by oxidation had been further improved, reaching 3.45 J / cm3.