Lithium sulfonate-based polyether gel polymer electrolytes with high ionicconductivity and uniform Li-ion transport for high-performance lithiummetal batteries  

高离子电导率和均匀锂离子传输的磺酸基聚醚凝胶聚合物电解质用于高性能锂金属电池

作　　者：Zhenyuan Hu Ziying Liu Kai Liu Jinpeng Qin Wenfan Guo Weizhen Fan Yunfeng Zhang 胡振原;刘子莹;刘凯;秦金鹏;郭文凡;凡威震;张运丰(Hydrogen Energy Technology Innovation Center for Hubei Province,Faculty of Material Science and Chemistry,China University of Geosciences(Wuhan),Wuhan 430074,China;School of Environmental Studies,China University of Geosciences(Wuhan),Wuhan 430074,China)

机构地区：[1]Hydrogen Energy Technology Innovation Center for Hubei Province,Faculty of Material Science and Chemistry,China University of Geosciences(Wuhan),Wuhan 430074,China [2]School of Environmental Studies,China University of Geosciences(Wuhan),Wuhan 430074,China

出　　处：《Science China Materials》2025年第2期493-502,共10页中国科学(材料科学)(英文版)

基　　金：supported by the National Key Research and Development Program of China (2018YFB1502903);the National Natural Science Foundation of China (21603197);the Natural Science Foundation of Hubei Province (2016CFB181);China University of Geosciences (Wuhan) for the program of Center for Advanced Energy Research and Technologies。

摘　　要：Lithium metal batteries (LMBs) using gelpolymer electrolytes with satisfactory theoretical capacity andlow cost hold great promise for high energy density storagesystems. However, the inherently unwanted polarizations anduncontrolled lithium dendrites resulting from inferior Li-iontransporting efficiency hinder the practical application ofconventional gel electrolytes. Herein, a highly conductivecomposite gel polymer electrolyte with effective Li-ion conducting channels is designed via swelling nanofibrous membrane, where the single-ion conducting polymer of lithiumsulfonate-based polyether (DEBS-Li) used as the Li-ion accelerator is combined with poly(vinylidene fluoride-hexafluoropropylene)P(VDF-HFP) matrix by the electrospinningtechnology. The DEBS-Li having rich sulfonic groups canpromote lithium salts dissociation via electrostatic interaction,thus expediting the ionic migration and enabling the as-developed gel electrolyte with high ionic conductivity (~1.58×10^(−3) S cm^(−1)) and lithium transference number (0.62) at 25℃.Such optimization of ionic transfer kinetics can highly delaythe nucleation time of lithium dendrite and significantly inhibit dendritic formation, which leads to a stable Li plating/stripping in the symmetrical battery over 250 h at1.5 mA cm^(−2). Benefiting from these advantages, the Li||LiFePO_(4)cell using the electrolyte realizes ultralong stable cyclingover 500 cycles at a high rate of 10 C with ~90% capacityretention. We believe this novel lithium sulfonate-basedpolyether gel polymer electrolyte has profound potential forpractical applications in high-performance LMBs.凝胶聚合物电解质基锂金属电池由于高比容量和低成本的优势,对于发展高能量密度储存设备具有重要意义.然而,传统型凝胶电解质因其锂离子传输效率较低、易产生极化现象,从而导致不可控的锂枝晶生长,最终阻碍了其大规模实际应用.本文设计并合成出具有丰富离子传输位点的聚醚型锂单离子传导聚合物(DEBS-Li),随后将其与聚偏氟乙烯-六氟丙烯P(VDF-HFP)基质相复合,采用静电纺丝技术制备出高传导性复合纳米纤维膜.实验发现,具有丰富磺酸基团的DEBS-Li可通过静电作用促进锂盐解离,从而加快离子迁移,赋予凝胶电解质在25℃时具有高离子电导率(~1.58×10^(-3)S cm^(-1))和锂离子迁移数(0.62).离子传输动力学的优化可大大延迟锂枝晶的成核时间,并显著抑制锂枝晶的形成.因此,采用该电解质组装成的锂对称电池在1.5 mA cm^(-2)稳定运行250小时未发生短路,金属锂二次电池在10 C的高倍率下稳定循环500圈,容量保持率约为90%.本工作开发的新型聚醚凝胶聚合物电解质在高性能锂电池的实际应用中具有极大潜力.

关 键 词：gel polymer electrolyte fibrous membrane singleion conductor lithium metal battery 

分 类 号：TM9[电气工程—电力电子与电力传动]