Preparation, Characterization And Properties Of Sodium Bismuth Titanate-based Lead-free Energy Storage Dielectric Ceramic Materials

With the development of Electronic Science and technology,the status of the ceramic capacitor in the whole information industry is becoming increasingly prominent.High energy density dielectrics are crucial in miniaturization of power pulse system.Lead-based antiferroelectric materials have excellent storage performance.But,with the lead-free requirements for environment protection,it is imperative to find lead-free materials whose energy storage properties are comparable to that of lead-based material.For all kinds of lead-free ferroelectric materials,Na_0.5Bi_0.5TiO₃?BNT?based ceramics have been widely studied for energy storage.It has high Curie temperature?Tc=320^oC?and displays antiferroelectric features between Td and Tm?200-320^oC?.Transition between antiferroelectric and ferroelectric under an application electric field lead to tremendous storage and release energy,which makes NBT-based materials to become an phase transition energy storage materials with high temperature stability and high density.However,it is hard but important to slim the hysteresis loop under the premise of keeping the large polarization intensity through modification on NBT-based ceramics.By this method,higher energy density and energy storage efficiency will be obtained.This paper analyzes and discusses the doped aspect experimental design and research effect on morphology,dielectric and ferroelectric properties and mechanism,aiming to improve ferroelectric and energy storage performance.By this method,in this paper,we modified0.94 Na_0.5Bi_0.5TiO₃-0.06BaTiO₃ using the method of Sr?La?Nb-doping in order to fabricate lead-free antiferroelectric ceramics with high energy storage performance.[(Na_0.5Bi_0.5)_0.94Ba_0.06]_1-xSr_xTiO₃?x=0.15,0.20,0.25,0.30??NBBST?ceramic powders were synthesized by liquid phase method.Amount of Sr doped effect on NBT-6BT was discussed.The highest NBBST ceramics of energy storage density is obtained by XRD,SEM,dielectric and ferroelectric properties test and characterization.The remanent polarization?Pr?and saturation polarization?Ps?decreases,the grain size decreases,the ferroelectricpropertydecreaseswiththeincreasingSrcontent.When[(Na_0.5Bi_0.5)_0.94Ba_0.06]_1-xSr_xTiO₃?x=0.15,0.20,0.25,0.30?x=0.25,the ferroelectric property of ceramics samples decreases obviously,the Grain size is more uniform.The highest energy storage density is 0.318J/cm³.In order to increase the energy storage density of ceramics,the La-doping in A-site method is used for[(Na_0.5Bi_0.5)_0.94Ba_0.06]_0.75Sr_0.25TiO₃ in this paper.It could increase the energy storage density of NBBST ceramics though decreasing polarization?Pr?,coercivity?Ec?and increasing saturation polarization?Ps?,maximum electric field?Emax?.The highest ceramics of energy storage density is obtained by XRD,SEM,dielectric and ferroelectric properties test and characterization.The energy storage density and energy storage efficiency increase first and then decrease with the increasing La content.When La-doping content is 0.04,the energy storage performance of ceramics samples is excellent.In order to increase the energy storage density of ceramics,the Nb-doping in B-site method is used for[(Na_0.5Bi_0.5)_0.94Ba_0.06]_0.75Sr_0.25TiO₃ in this paper.It could increase the energy storage density of NBBST ceramics though decreasing polarization?Pr?,coercivity?Ec?and increasing saturation polarization?Ps?,maximum electric field?Emax?.The highest ceramics of energy storage density is obtained by XRD,SEM,dielectric and ferroelectric properties test and characterization.The energy storage density and energy storage efficiency increase first and then decrease with the increasing Nb content.When Nb-doping content is 0.09,the energy storage performance of ceramics samples is excellent.In this paper,the energy storage performance of NBT-based materials are modificated through Sr,La,Nb doping.It is discussed detail that the effect on ceramics materials of phase structure,morphology,dielectric properties and electric properties for element doping.The appropriate doping-amount of Sr,La,Nb could improve the energy storage performance of ceramics materials.