离子取代对铌酸银反铁电陶瓷储能性能影响的研究进展

Progress on Ion Substitution on Energy Storage Performances of Silver Niobate Antiferroelectric Ceramics

相对于其他储能方式,电介质储能电容器具有功率密度高、循环次数高和充放电速度快等优点,因而电介质储能材料受到了广泛关注。在现有的电介质材料中,具有双电滞回线特征的反铁电材料因其具有大的饱和极化强度和小的剩余极化强度,被认为在电介质储能领域具有比铁电体和线性电介质更好的应用前景。虽然锆钛酸铅基等反铁电材料具有优异的储能性能,但由于含铅,逐渐受到限制,发展具有优异储能性能的无铅反铁电材料具有重要的意义。近年来,AgNbO_(3)陶瓷作为一种重要的无铅反铁电材料,表现出较为优异的储能性能,已被成功应用于电介质储能领域,但其储能密度和储能效率仍存在较大的提升空间。综述了AgNbO_(3)反铁电陶瓷储能性能掺杂改性的研究现状,基于电介质储能的基本原理和AgNbO_(3)结构特征,从稳定反铁电相、引入弛豫行为、晶粒尺寸效应等角度详细阐述了AgNbO_(3)反铁电陶瓷储能性能优化策略以及A位、B位及A/B位离子取代对其储能性能的影响机制,最后对AgNbO_(3)反铁电陶瓷亟待解决的问题和未来发展方向进行了展望。

Energy is very important for our life and becomes the most important item in the world today.The energy crisis has become an important issue in the world.Due to the lack of limited fossil fuels,the energy crisis can lead to deterioration of social lifestyles and national economies.The increasingly serious energy crisis and environmental pollution have prompted countries worldwide to commit themselves to the development and utilization of new energy such as solar energy,wind energy,hydrogen energy,et al.In order to make full use of the above-mentioned new energy,the efficient energy storage technology is an urgent problem to be solved.It is of great strategic significance to improve the comprehensive utilization efficiency of energy and realize the sustainable development of energy.For electrical energy storage,fuel cells,batteries,supercapacitors and dielectric capacitors are regarded as four promising devices.Compared to other forms of energy storage,the dielectric energy storage capacitor has the characteristics of ultrahigh power density(~1×10^(8)W·kg^(-1)),high cycle number(>1×10^(6))and fast charging and discharging rates(<100 ns),because they store and release electrical energy through polarization and depolarization in the electric field instead of chemical reaction.Thus,the dielectric energy storage is especially suitable for electronic pulse devices.To further meet the needs of devices integration,lightweight and miniaturization,it is urgent to improve the energy storage density and efficiency of dielectric energy storage capacitors.Among the dielectric materials,the antiferroelectric materials with double hysteresis loops have better application prospects in the field of dielectric energy storage than ferroelectrics and linear dielectrics because of their high saturation polarization and low remnant polarization.Although lead zirconate titanate-based antiferroelectric materials have excellent energy storage properties,they are gradually limited due to lead content.It is of great significance to develop lead-free antiferroelectric materials with excellent energy storage properties.Recently,the significantly enhanced energy storage performances of AgNbO_(3)ceramics as an important lead-free antiferroelectric material have attracted wide attention.Although AgNbO_(3)ceramics exhibit relatively excellent energy storage performances(its energy storage density and energy storage efficiency reach 2.1 J·cm-3and 56%,respectively),its remnant polarization is relatively higher due to the ferrielectricity of AgNbO_(3)ceramics at room temperature,which has an adverse effect on its energy storage performances.The ion substitution is an important approach to further improve electrical energy storage performances of AgNbO_(3)antiferroelectric ceramics.The research progress on the effects of doping on energy storage performances of AgNbO_(3)ceramics was reviewed.Based on the basic principle of dielectric energy storage and the structural characteristics of AgNbO_(3),the optimization strategies of energy storage performances of AgNbO_(3)antiferroelectric ceramics were elaborated from the aspects of stabilizing antiferroelectric phase,introducing relaxation behavior and grain size effect,et al.The influence mechanism of ion substitution for Site A,B and A/B on the energy storage performances of AgNbO_(3)ceramics was also elaborated.The introduction of suitable metal cations into the A-site or B-site of AgNbO_(3)ceramics was one of the important methods to improve its energy storage performance.The optimization strategies mainly included:(1)The introduction of metal cations with smaller ionic radius and higher valence at Site A reduced the tolerance factor of AgNbO_(3)or form silver vacancies,which was helpful to establish chemical pressure in the structure and led to the tilting and compression of the oxygen octahedron,thus enhancing the stability of the antiferroelectric phase structure.(2)The introduction of cations with lower polarizability at Site B was not only more conducive to stabilizing the antiferroelectric phase structure of AgNbO_(3)ceramics but also reduces the sensitivity of the external electric fields,thereby increasing the induced ferroelectric phase-antiferroelectric phase transition electric field(EA)and the antiferroelectric phase-ferroelectric phase transition electric field(EF).(3)The enhanced relaxor behaviors of AgNbO_(3)ceramics reduced its remnant polarization and electric hysteresis(ΔE=EF-EA)so that its energy storage density and energy storage efficiency increased.(4)The saturation polarization of silver niobate increases,thereby increasing the energy storage density.(5)The grain size of silver niobate ceramics was refined to increase its electric breakdown strength to improve the energy storage density.Finally,the problems to be solved and the future development direction of AgNbO_(3)antiferroelectric ceramics were prospected.The reduction of the tolerance factor could improve the oxygen octahedral instability.However,the correlation between the oxygen octahedron and the energy storage performances of AgN-bO3was still lacking in-depth understanding.Although the energy storage density of AgNbO_(3)ceramics was improved by doping modification,its energy storage efficiency was still relatively low.The construction of the multiphase coexistence region and alternating current polarization were helpful to reduce the size of the ferroelectric domains and enhance the relaxor behaviors to further improve the energy storage performances of AgNbO_(3)ceramics.In addition,the electric breakdown strength of AgNbO_(3)-based antiferroelectric ceramics was relatively lower.Therefore,exploring the composite of AgNbO_(3)antiferroelectric ceramics with polymers,glass powder,MgO,Al_(2)O_(3)and other materials with high electric breakdown strength could improve the energy storage performance of AgNbO_(3)-based materials.