Fabricated And Energy-storage Performance Of Lead-based Antiferroelectric Multilayer Ceramic Capacitor

With increasing attention to energy,economic and social sustainable development,energy storage materials have aroused great research interest.Multilayer ceramic capacitors?MLCC?in energy-storage applications have received increasing attention due to the advantages of high power density,low drive voltage and fast discharge rates.However,the low energy density is a great challenge which limits the applications of multilayer ceramic capacitors,and the improving their energy storage performance is mainly the research of high energy-storage density dielectric materials.Among the popular dielectric materials.Antiferroelectric?AFE?materials exhibit high saturation polarization and low remanent polarization,which is beneficial to obtain higher energy-storage density.In the present investigation,lead zirconate-based?PZ?antiferroelectric materials were prepared by tape-casting method,and the phase structure,surface morphology,antiferroelectricity,dielectric properties and energy-storage properties were systematically studied.And the components with the best energy-storage performance were multilayered by printing electrodes and stacking,etc.The purpose is to prepare a multilayer ceramic capacitor with high energy storage performance.Firstly,(Pb_0.98La_0.02)(Zr_0.9Sn_0.1)_0.995O₃?PLZS?ceramics were fabricated.The PbO-B₂O₃-SiO₂ glass as a sintering aid to increase the density of ceramics.On this basis,in order to further improve the energy-storage performance of the ceramics,Sr-doped(Pb0._98-x8-x La_0.02Sr_x)(Zr_0.9Sn_0.1)_0.995O₃ antiferroelectric ceramics were prepared,which stabilized the antiferroelectric phase.It is found that the Sr²⁺-doping led to the appearance of multiple phase transitions,and increased the phase transition electric field and dielectric breakdown.Calculated by hysteresis loop,the recoverable energy-storage density of 11.2J/cm³ and the energy efficiency value of 82.2%at 395 kV/cm were atachieved for the ceramic with x=0.04.Measured by resistance-inductance-capacitance circuit,the maximum pulsed discharge energy-storage density was 8.6 J/cm³.Moreover,90%of the energy was released in a short time of about 165 ns,displaying super-fast discharging characteristic.Secondly,combined with the above results,the multilayer ceramic capacitor was studied.It was found that when the thickness of the tape-casting film was reduced,the addition of PbO-B₂O₃-SiO₂ glass powder would lead to a decrease in the density of the tape-casting thick film,resulting in breakdown strength significantly reduced.Combining the above mentioned factors,(Pb_0.98La_0.02)(Zr_xSn_1-x)_0.995O₃ antiferroelectric ceramic without PbO-B₂O₃-SiO₂ were prepared.The composition of Zr/Sn of the samples were studied in detail.The enhanced Zn/Sn ratio effectively increased the saturated polarization and switching of the electric field between the antiferroelectric and ferroelectric phase.As a result,an optimal energy-storage density of 10 J/cm³ and energy efficiency of 83%were achieved for the ceramic with x=0.7.Based on the above-mentioned results,MLCC with x=0.7 was fabricated.As expected,an ultrahigh energy-storage density of 12.6 J/cm³ and a high energy efficiency of 80%were achieved at 560 kV/cm.Finally,on the basis of the above work,in order to further improve the energy-storage performance of MLCC,Ca-doped(Pb_0.98-xLa_0.02Ca_x)(Zr_0.7Sn_0.3)_0.995O₃ antiferroelectric ceramics were prepared.Ca-doping gave rise to a colossal increase in dielectric breakdown and phase transition electric field.As a result,an optimal energy-storage density of 11 J/cm³ and high energy efficiency of 88.2%were achieved for the ceramic with x=0.04.Based on the above-mentioned results,multilayer ceramic capacitors were fabricated.An ultrahigh energy-storage density of 16 J/cm³ and a high energy efficiency of83.2%were achieved at 650 kV/cm.Antiferroelectric multilayer ceramic capacitors with high energy-storage performance are expected to play a potential application in high power pulse capacitors.