铌酸钠基陶瓷的相界调控及储能性能  

Phase Boundary Modulation and Energy Storage Properties of NaNbO_(3)-Based Ceramics

作　　者：常凡 罗庚光 罗能能 CHANG Fan;LUO Gengguang;LUO Nengneng(State Key Laboratory of Featured Metal Materials and Life-Cycle Safety for Composite Structures,School of Resources,Environment and Materials,Guangxi University,Nanning 530004,China)

机构地区：[1]省部共建特色金属材料与组合结构全寿命安全国家重点实验室,广西大学资源环境与材料学院,南宁530004

出　　处：《硅酸盐学报》2024年第4期1392-1402,共11页Journal of The Chinese Ceramic Society

基　　金：国家自然科学基金面上项目(52072080);广西杰出青年基金项目(2022GXNSFFA035034)。

摘　　要：铌酸钠(NaNbO_(3))基无铅陶瓷具有超高的储能密度,在高功率介电储能电容器领域引起了广泛关注。然而,纯NaNbO_(3)陶瓷在室温表现为矩形形状的类铁电电滞回线,并伴随着大的回滞和高的剩余极化强度,往往导致大的能量损耗。为优化NaNbO_(3)的储能性能,基于相界调控策略采用传统固相法制备了(1–x)NaNbO_(3)–xCaTiO_(3)(0.08≤x≤0.18)陶瓷,并使用CuO作为助烧剂。结果表明,该体系在0.09≤x≤0.16范围内存在因晶体结构改变而引起的多晶型相界区域,其中相界组分0.84NaNbO_(3)–0.16CaTiO_(3)在590 kV/cm时的最大极化强度为42.2μC/cm^(2),可逆储能密度达到6.1 J/cm^(3),储能效率为77%。同时该陶瓷表现出良好的频率和温度稳定性,以及优异的放电性能。为铌酸钠基高性能储能电容器材料的开发提供了新思路。Introduction Lead-free sodium niobate(NaNbO_(3))based ceramics with a superior energy storage density have attracted recent attention in high power dielectric energy storage applications.However,a pure NaNbO_(3)(NN)ceramic exhibits a square-like square hysteresis loop associating with a large hysteresis and a high remnant polarization at room temperature,leading to a high energy dissipation.In general,stabilizing the antiferroelectricity in NN ceramic is one of the effective measures to solve the problems above.However,despite efforts are made on this measure,the large hysteresis is still kept due to the existence of antiferroelectricferroelectric phase transition.The compositions in the phase boundary region usually exhibit abnormally enhanced electrical properties and relaxation characteristics,thus constructing a phase boundary region in NN through composition modulation is another promising method.Moreover,sodium element volatilizes inevitably during the high-temperature and long-time sintering process,giving rise to a poor sintering quality in NN system,which is not beneficial to achieving superior energy storage performance.In this paper,(1–x)NaNbO_(3)–xCaTiO_(3)(NN–CT100x,0.08≤x≤0.18)ceramics were prepared by a conventional solid-state method with CuO as a sintering aid.The phase structure and polymorphic phase boundary in NN–CT100x system were investigated,and the energy storage performance of compositions in the phase boundary region was analyzed.Materials and method For the synthesis of NN–CT100x powder,Na2CO_(3)(≥99.8%,in mass fraction,the same below),Nb2O5(≥99.9%),CaCO_(3)(≥99.0%),TiO_(2)(≥98.0%)and CuO(≥99.0%)were used as raw materials(Shanghai Sinopharm Chemical Reagent Co.,Ltd.,China).The raw materials were weighed/mixed according to the stoichiometric ratio and ground with anhydrous ethanol in a ball mill with zirconia balls for 12 h.After dried and sieved,the powder was calcined at 900℃for 6 h.The calcined powders were mixed with 1.5%(in mole fraction)of CuO as a sinteri

关 键 词：铌酸钠 多晶型相界 弛豫特性 储能性能 

分 类 号：TQ174.75[化学工程—陶瓷工业]