LiBr/MoO_(3)/PE隔膜对锂硫电池循环稳定性的影响  

Effect of LiBr/MoO_(3)/PE Separator on Cyclic Stability of Lithium Sulfur Batteries

作　　者：王前[1,2] 魏祎 贾洪声 WANG Qian;WEI Yi;JIA Hongsheng(Journal of Tonghua Normal University,Tonghua 134002,Jilin Province,China;Key Laboratory of Functional Materials Physics and Chemistry of the Ministry of Education,Jilin Normal University,Siping 136000,Jilin Province,China)

机构地区：[1]通化师范学院学报,吉林通化134002 [2]吉林师范大学功能材料物理与化学教育部重点实验室,吉林四平136000

出　　处：《吉林大学学报（理学版）》2023年第6期1469-1475,共7页Journal of Jilin University:Science Edition

基　　金：吉林省自然科学基金(批准号:20200201236JC);吉林省发展和改革委员会产业技术研究与开发项目(批准号:2022C040-6)。

摘　　要：通过在聚乙烯(PE)隔膜上引入三氧化钼(MoO_(3))和溴化锂(LiBr)涂层制备LiBr/MoO_(3)/PE多功能复合隔膜,采用X射线衍射和扫描电子显微镜对膜的结构和形貌进行表征,并通过循环伏安、电化学阻抗和充放电性能测试等方法研究涂覆修饰层后的LiBr/MoO_(3)/PE隔膜对Li金属负极稳定性和锂硫(Li-S)电池性能的影响.结果表明:LiBr提高了多硫化锂(LiPSs)的溶解度,MoO_(3)层对LiPSs具有化学吸附作用,可提高活性物质S的利用率,并抑制Li-S电池的穿梭效应;以LiBr/MoO_(3)/PE为隔膜的Li-Li对称电池在0.6 mA/cm^(2)的电流密度和1(mA·h)/cm^(2)的容量下稳定循环时间为1600 h,Li-S电池在0.2 C下的初始放电比容量可达1229.2(mA·h)/g,500次充放电循环后的比容量为628(mA·h)/g.A multifunctional LiBr/MoO_(3)/PE composite separator was prepared by introducing molybdenum trioxide(MoO_(3))and lithium bromide(LiBr)coatings onto polyethylene(PE)separators.The structure and morphology of the separator were characterized by X-ray diffraction and scanning electron microscope,and cyclic voltammetry,electrochemical impedance and charge discharge performance testing were used to investigate the effect of LiBr/MoO_(3)/PE separator coated with a modified layer on the stability of lithium metal negative electrodes and the performance of lithium sulfur batteries.The results show that LiBr increases the solubility of lithium polysulfide(LiPSs),and the MoO_(3)layer has a chemical adsorption effect on LiPSs,which can improve the utilization rate of active substance sulfur and suppress the shuttle effect of Li-S batteries.The Li-Li symmetric battery with LiBr/MoO_(3)/PE as the separator has a stable cycle time of 1600 h at a current density of 0.6 mA/cm^(2)and a capacity of 1(mA·h)/cm^(2).The initial discharge specific capacity of the lithium sulfur battery at 0.2 C can reach 1229.2(mA·h)/g,and the specific capacity after 500 charge discharge cycles is 628(mA·h)/g.

关 键 词：三氧化钼 溴化锂 LiBr/MoO_(3)/PE隔膜 锂硫电池 电化学性能 

分 类 号：O485[理学—固体物理]