不同尺寸Li_(6.4)La_(3)Zr_(2)Ga_(0.2)O_(12)颗粒与PEO复合制备高性能柔性固态电解质  

High Performance Flexible Solid Electrolyte was Prepared by Combining Li_(6.4)La_(3)Zr_(2)Ga_(0.2)O_(12) Particles with PEO

作　　者：卢名亮 吕义玮 刘志亮 李栋[1,3] 李小成 闵志宇[2] Lu Mingliang;Lu Yiwei;Liu Zhiliang;Li Dong;Li Xiaocheng;Min Zhiyu(Faculty of Materials Metallurgy and Chemistry,Jiangxi University of Science and Technology,Ganzhou 341000,China;School of Materials Science and Engineering,Luoyang Institute of Science and Technology,Luoyang 471023,China;China Jiangxi Key Laboratory of Power Battery and Materials,Jiangxi University of Science and Technology,Ganzhou 341000,China)

机构地区：[1]江西理工大学材料冶金化学学部,江西赣州341000 [2]洛阳理工学院材料科学与工程学院,河南洛阳471023 [3]江西理工大学动力电池与材料重点实验室,江西赣州341000

出　　处：《中国稀土学报》2024年第4期742-751,I0004,共11页Journal of the Chinese Society of Rare Earths

基　　金：国家自然科学基金项目(51862013);江西省教育厅基金(GJJ190428);国家大学生创新创业项目(202110407001)资助。

摘　　要：固体聚合物电解质具有良好的灵活性、低界面阻抗、易加工等特点,具有广阔的应用前景。目前,聚合物电解质存在着室温下离子输运困难和离子电导率低的问题。采用溶液铸造法制备了石榴石Li_(6.4)La_(3)Zr_(2)Ga_(0.2)O_(12)(LLZGO)/聚乙烯氧化物(PEO)复合聚合物电解质。通过优化LLZGO粒径,并与PEO结合,制备了高离子电导率的复合电解质。结果表明,当LLZGO粒径为0.5μm时,室温离子电导率为1.5×10^(-4)S·cm^(-1),制备的复合电解质的离子迁移数为0.343,在锂沉积/剥离试验中可稳定循环400 h。在60℃,2.7~4.0 V条件下,组装的Li/复合电解质/LiFePO_(4)电池首次放电比容量为141 mAh·g^(-1),在0.5 C倍率下,循环60次后放电比容量为121.4 mAh·g^(-1),具有良好的循环稳定性。通过优化LLZGO粒径,为提高复合电解质的界面性能、优化机械和电化学性能、开发高性能固体锂金属电池提供了一种可行的方法。Solid polymer electrolyte has broad application prospects due to the characteristics of good flexibility,low interfacial impedance and easy processing.At present,polymer electrolytes have the problems of difficult ion transport and low ion conductivity at room temperature.In this paper,the solution casting method was used to prepare polyethylene oxide(PEO)/garnet Li_(6.4)La_(3)Zr_(2)Ga_(0.2)O_(12)(LLZGO)composite polymer electrolyte(CPE).By optimizing LLZGO particle size,it is combined with polymer electrolyte to improve the conductivity of polymer electrolyte.It is found that when the particle size of garnet electrolyte powder is 0.5μm,the CPE prepared has the highest ion migration number of 0.343 and room temperature ion conductivity of 1.5×10^(-4)S·cm^(-1),and can cycle stably for 400 h in lithium deposition/peeling test.At 60℃,2.7~4.0 V,the assembled Li/CPE/LiFePO_(4) cells exhibit discharge specific capacity of 141 mAh·g^(-1)for the first time and 121.4 mAh·g^(-1)after 60cycles at 0.5 C,which shows good cycle stability.By optimizing the particle size of LLZGO powder,the composite polymer electrolyte provides a feasible method to improve the interfacial performance and optimize the mechanical and electrochemical properties of CPE and develop high performance solid lithium metal batteries.

关 键 词：复合电解质 全固态电池 石榴石电解质粉 离子电导率 稀土 

分 类 号：O611.3[理学—无机化学] O611.66[理学—化学]