摘要
采用溶胶凝胶法制备了Li_(1.3)Al_(0.3)Ti_(1.7)(PO_(4))_(3)(LATP)固态电解质,研究了不同烧结助剂对LATP固态电解质离子电导率的影响。利用X射线衍射(XRD)、扫描电子显微镜(SEM)、电化学阻抗谱(EIS)等方法探究了样品的晶体结构、形貌特征以及离子导电性能。研究结果表明,虽然添加烧结助剂会产生少量二次相,仍有助于提高固态电解质的电导率。引入不同烧结助剂提高LATP固态电解质电导率的机制不同,Li_(3)PO_(4)以促进晶粒长大,减少晶界数量来促进锂离子迁移,B_(2)O_(3)是通过弱化晶界来提高离子电导率,LiBF_(4)则是通过促进传质,减少孔隙,提高固态电解质致密化实现离子电导率的提高;3种烧结助剂中以添加LiBF_(4)提高固态电解质的电导率效果最佳,当LiBF_(4)的添加量为3%(质量分数)时,获得的固态电解质电导率高达8.5×10^(-4)S/cm。
Li_(1.3)Al_(0.3)Ti_(1.7)(PO_(4))_(3)(LATP)solid electrolyte is prepared by sol-gel method,and the effect of different sintering aids on ionic conductivity of LATP solid electrolyte is investigated.The crystal structure,morphology and ionic conductivity of the samples are investigated by X ray diffraction(XRD),scanning electron microscopy(SEM)and electrochemical impedance spectroscopy(EIS).The results show that adding sintering aids creates a small amount of secondary phase but still improves the conductivity of the solid electrolyte.However,different sintering aids promote the sintering of LATP solid electrolyte in different ways.Li_(3)PO_(4)will promote grain growth,reduce the number of grain boundaries to promote lithium ion migration,but B_(2)O_(3)will weaken grain boundaries to obtain higher ionic conductivity.LiBF_(4) can enhance the mass transfer and reduce porosity to promote the realization of solid electrolyte density in order to improve the ion conductivity.LiBF_(4) has the best effect among the three sintering aids,which can greatly improve the conductivity of the solid electrolyte,and when the addition amount of LiBF_(4) is 3 wt%,the optimum conductivity obtained is as high as 8.5×10^(-4) S/cm.
作者
戴丽静
王晶
史忠祥
于丽娜
时军
DAI Lijing;WANG Jing;SHI Zhongxiang;YU Lina;SHI Jun(Key Laboratory of Inorganic Ultrafine Powder Preparation and Application of Liaoning Province,Dalian Jiaotong University, Dalian 116028, China)
出处
《功能材料》
CAS
CSCD
北大核心
2022年第1期1117-1122,共6页
Journal of Functional Materials
基金
国家重点研发计划项目(2017YFB0310300)
辽宁省教育厅资助项目(JDL2016002)。
关键词
烧结助剂
固态电解质
致密性
二次相
电导率
sintering aid
solid electrolyte
compactness
secondary phase
conductivity
