湿化学法制备石榴石型固态电解质Li_(7)La_(3)Zr_(2)O_(12)  

Preparation Li_(7)La_(3)Zr_(2)O_(12) garnet solid-state electrolyte by wet-chemical technique

作　　者：潘迪 孔江榕 刘欣楠 黄美琪 周涛 PAN Di;KONG Jiangrong;LIU Xinnan;HUANG Meiqi;ZHOU Tao(Hunan Provincial Key Laboratory of Efficient and Clean Utilization of Manganese Resources,College of Chemistry and Chemical Engineering,Central South University,Changsha,410083,Hunan,China)

机构地区：[1]中南大学化学化工学院,锰资源高效清洁利用湖南省重点实验室,湖南长沙410083

出　　处：《化工进展》2021年第S02期334-339,共6页Chemical Industry and Engineering Progress

基　　金：国家自然科学基金(21506259);湖南省科技计划(2016TP1007);湖南省教育厅优秀青年项目(19B038)。

摘　　要：锂电池因能量密度高、循环寿命长、绿色清洁等特点被广泛应用,但其液态电解质易泄漏、挥发,且隔膜易被锂枝晶刺穿造成短路,引发危险。固态电解质大多是不具燃烧性的无机材料,室温下离子电导率较高、电化学窗口宽且适用温度范围广。因此,采用固态电解质替代液态电解质具有十分重要的意义。相对于其他类型固态电解质,石榴石型氧化物Li_(7)La_(3)Zr_(2)O_(12)(LLZO)具有离子电导率高、电化学窗口宽(>5V vs.Li/Li^(+))、对锂稳定性好和热稳定性高等特点,是非常具有发展潜力的无机固态电解质。本文采用溶胶-凝胶法和低温燃烧法两种湿化学法合成LLZO粉末,对应的电解质片在40℃时的离子电导率分别为1.22×10^(-5)S/cm和3.87×10^(-6)S/cm,活化能分别为0.34eV和0.32eV。从实验结果综合比较,溶胶-凝胶法为最佳制备方法。Lithium-ion batteries are widely used as high energy density,long cycle life and green cleaning.However,lithium dendrite occurs easily in lithium-ion batteries with conditional leaky and volatile liquid electrolyte,which will cause short circuit and further danger.Solid-state electrolyte is nonflammable because most of them are inorganic material such as glass,ceramics and so on.Furthermore,solid-state has high ion conductivity at room temperature,wide electrochemical window,and extensive applicable temperature range.Therefore,it is very significant to replace traditional liquid electrolyte with solid-state electrolyte.Compared with other kinds of solid electrolytes,garnet oxide solidstate electrolyte Li_(7)La_(3)Zr_(2)O_(12)(LLZO)with high ionic conductivity,wide electrochemical window(>5V vs.Li/Li+),stability to lithium metal and thermostabilization is a very promising inorganic solid electrolyte.Sol-gel method and low temperature combustion method were used to prepare LLZO powder in this work.The ionic conductivity at 40℃and activation energy of the electrolyte pellets prepared by two methods were 1.22×10^(−5) S/cm,0.34eV and 3.87×10^(−6) S/cm,0.32eV,respectively.The result shows that sol-gel is more likely to be selected to prepare LLZO powder.

关 键 词：石榴石型LLZO电解质 溶胶-凝胶法 低温燃烧法 

分 类 号：TQ152[化学工程—电化学工业]