Investigation On Energy-storage Performances Of Lead Zirconate Based Antiferroelectric Ceramic Capacitors Fabricated By Tape-casting Method

Multilayer ceramic capacitor（MLCC）has great potential in advanced power electronic and/or pulsed power systems due to high power density and fast charge-discharge rate.However,the unsatisfactory recoverable energy density(W_rec)and the mismatch between W_rec and the energy conversion efficiency（η）of dielectrics limit the development and applications of MLCC.Therefore,to develop dielectrics with excellent performances is significant for the improvement of MLCC.Featured with high breakdown strength（BDS）,unique field-induced phase transition behavior,and large polarization response,lead lanthanum zirconate stannate titanate（PLZST）antiferroelectric dielectrics（AFEs）have a promising prospect in energy-storage field.In this paper,systematical investigation on phase structure,microstructure,phase transition behavior,breakdown strength,polarization response and so on was proposed by composition optimizing strategy to reveal the composition dependent energy-storage performances for PLZST AFEs.Combined with previous work,PLZST AFEs with outstanding performances were fabricated into MLCCs,and then their energy-storage performances and charge-discharge properties were investigated.It is expected to provide experimental references for the fabrication of MLCC and promote the practical process of MLCC in pulsed power technology.The detailed results consist of the following parts:（1）(Pb_0.94La_0.04)(Zr_0.85-ySn_0.15Ti_y)O₃（abbreviated as PLZST-1;y=0.01,0.03,0.05,0.07,and 0.10,name as AO2,AO5,AT8,AT11,and AT13,respectively）,(Pb_0.94La_0.04)(Zr_0.70-ySn_0.30Ti_y)O₃（abbreviated as PLZST-2;y=0.01,0.03,0.05,0.07 and 0.10,named as AO3,AO6,AT9,AT12,and AT14,respectively）,and(Pb_0.94La_0.04)(Zr_1-x-ySn_xTi_y)O₃（abbreviated as PLZST-3;x=0.50,y=0.01;x=0.45,y=0.05;and x=0.40,y=0.10;named as AT13,AT14,and AT15,respectively）ceramics were fabricated by tape-casting method.The energy-storage performances of PLZST ceramics with varying Zr/Ti or Sn/Ti ration were investigated.It is found that PLZST ceramics with low content of Ti⁴⁺exhibit high electric breakdown strength（BDS）,contributing to excellent Wrec.As the content of Ti⁴⁺decreases from 0.1 to 0.01,the BDS of PLZST-1 ceramics increases from 220 kV/cm to 400 kV/cm,contributing to a huge augment in W_rec from 4.2 J/cm³ to 11.2 J/cm³.（2）(Pb_0.94La_0.04)(Zr_0.99-xSn_xTi_0.01)O₃（abbreviated as PLZST-4;x=0,0.15,0.30,and0.50,name as AO1,AO2,AO3,and AT4,respectively）,(Pb_0.94La_0.04)(Zr_0.95-xSn_xTi_0.05)O₃（abbreviated as PLZST-5;x=0,0.15,0.30,and 0.45,named as AO7,AT8,AT9,and AT10,respectively）,and(Pb_0.94La_0.04)(Zr_0.90-xSn_xTi_0.10)O₃（abbreviated as PLZST-6;x=0.15,0.30,and 0.40,named as AT13,AT14,and AT15,respectively）ceramics were fabricated by tape-casting method.The energy-storage performances of PLZST ceramics with varying Zr/Sn ration were investigated.It is found that PLZST ceramics with high content of Sn⁴⁺exhibit slim polarization-electric field（P-E）hysteresis loop and small electric hysteresis（ΔE）,contributing to highη.As the content of Sn⁴⁺increases from 0 to 0.45,theΔE of PLZST-5ceramics decreases from 40 kV/cm to 13 kV/cm,contributing to a huge augment inηfrom68%to 93.3%.（3）Based on the aforementioned results,AO1,AO3,and AT4 MLCCs（abbreviated as M1,M2,and M3,respectively）were fabricated.Investigations on their energy-storage performances were carried out.Consequently,M1 shows high W_recbut lowη;M2 exhibits high W_recand highη;M3 demonstrates low W_recbut highη.Especially,outstanding W_rec of15.9 J/cm³ andηof 90.9%are achieved in M2 at 900 kV/cm,simultaneously.With the load resistor of 200Ω,a great discharge energy density(W_dis)of 8.8 J/cm³ with a fast discharge rate of 1.4μs for releasing 90%of W_dis is realized in M2 at 500 kV/cm.A large current density（C_D）of 662.5 A/cm² and a high power density（P_D）of 165.6 MW/cm³ are obtained in M2 at 500 kV/cm.