Ba0.04Bi0.48Na0.48TiO3-SrTiO3陶瓷微结构和储能性能

采用传统固相反应法制备了一种无铅储能铁电陶瓷(1-x)Ba0.04Bi0.48Na0.48TiO3-xSrTiO3 (x=0.27、0.28、0.30、0.32、0.34、0.36),研究了该陶瓷体系的微观结构、铁电、介电和电导率特征.所有陶瓷均形成了钙钛矿结构固溶体,晶粒尺寸均匀且致密.各陶瓷所得铁电曲线趋于双电滞回线,呈现反铁电特征,剩余极化强度较小,击穿强度高.当x=0.34时,可获得0.977J/cm3的较优储能值,陶瓷弥散程度高,表现为典型的弛豫特性.此含量对应低频下陶瓷的离子电导率为2.4×10-8 S/cm,电子电导率为6.02×10-13 S/cm,表明离子电导居于主导地位.

Microstructures and Energy-storage Properties of Ba0.04Bi0.48Na0.48TiO3-SrTiO3 Ceramics

(1-x)Ba0.04Bi0.48Na0.48TiO3-xSrTiO3 (x=0.27,0.28,0.30,0.32,0.34 and 0.36) lead-free energy storage ceramics were produced by conventional solid-state reaction processes.Microstructures,electrical properties,dielectric properties and conductivity characteristic of BBNT-xST ceramics were investigated.All of the ceramics formed solid solutions with simple perovskite structure and grain size of the ceramics is uniform and compact.Ferroelectric curves of all the ceramics showed a double hysteresis loop owning a quite low remnant polarization and high breakdown strength,demonstrating an antiferroelectric characteristic.Up to x=0.34,the largest energy-storage density of 0.977 J/cm3 was obtained and high dielectric dispersion of the ceramic suggested a typical relaxor behavior.Electronic conductivity of the ceramic with x=0.34 was ～6.02× 10-13 S/cm while the corresponding ionic conductivity ～2.4 × 10-8 S/cm at low frequency,denoting that the ionic conductivity was dominant in conduction processes.