【摘要】 采用溶胶凝胶法制备了Li_1.3Al_0.3Ti_1.7（PO₄）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,Li₃PO₄以促进晶粒长大,减少晶界数量来促进锂离子迁移,B₂O₃是通过弱化晶界来提高离子电导率,LiBF₄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LiBF₄提高固态电解质的电导率效果最佳,当LiBF₄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。更多还原

【Abstract】 Li_1.3Al_0.3Ti_1.7（PO₄）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. Li₃PO₄ will promote grain growth, reduce the number of grain boundaries to promote lithium ion migration, but B₂O₃ will weaken grain boundaries to obtain higher ionic conductivity. LiBF₄ can enhance the mass transfer and reduce porosity to promote the realization of solid electrolyte density in order to improve the ion conductivity. LiBF₄ 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 LiBF₄ is 3 wt%, the optimum conductivity obtained is as high as 8.5×10^-4 S/cm.更多还原