采用以聚乙烯醇为聚合剂的湿化学法合成Li1.3Al0.3Ti1.7(PO4)3(LATP)锂离子导电材料,以Li4P2O7(LP)为助烧剂制备LATP-xLP(x=0,0.01,0.03,0.05,摩尔分数)锂离子导电固体电解质材料。利用X射线衍射、扫描电子显微镜和交流阻抗技术分别对材料的相组成、微观组织和离子导电性进行表征。通过分析材料晶体结构和交流阻抗特性,对材料的导电机理进行研究。结果表明:LATP粉体和LATP-xLP陶瓷具有菱方晶系结构,空间群为R3-c,该晶体结构具有三维离子导电通道;添加LP助烧剂使陶瓷的烧结温度降低了150℃、电导率得到了提高。交流、直流导电特性测量得出LATP-0.03LP的离子导电性占总导电性的99.5%。
The Li1.3Al0.3Ti1.7(PO4)3(LATP) lithium-ion conductive materials were prepared by a wet chemical method which is polymerized by polyvinyl alcohol.The LATP-xLP(x=0,0.01,0.03,0.05,mole fraction) ceramics were prepared by using Li4P2O7(LP) as sintering additive.The phases and microstructures of the prepared materials were investigated by X-ray diffraction and scanning electron microscope.Ionic conductivities were measured by AC impedance measurement.The conduction mechanism of the materials was studied by analyzing the crystal structure and AC impedance characteristics of the materials.The results show that the LATP powder and LATP-xLP(x=0,0.01,0.03,0.05) ceramics have the rhombohedral crystalline structure with the space group of R3-c,which has 3-dimensional ionic conducting path.The LP sintering additive can decrease the sintering temperature of LATP by 150 ℃ and improve the ionic conductivity.The analysis of the DC and AC conductivities of the LATP-0.03LP ceramics reveals that the ionic conductivity is 99.5% of the total conductivity.