Influence of fluoroethylene carbonate on the solid electrolyte interphase of silicon anode for Li-ion batteries:A scanning force spectroscopy study  

作　　者：Jieyun Zheng Jialiang Liu Suijun Wang Fei Luo Liubin Ben Hong Li 郑杰允;刘家亮;王绥军;罗飞;贲留斌;李泓(Beijing National Laboratory for Condensed Matter Physics.Institute of Physics.Chinese Academy of Sciences,Beijing 100190,China;State Key Laboratory of Operation and Control of Renewable Energy&Storage Systems,China Electric Power Research Institute,Beijing 100192,China)

机构地区：[1]Beijing National Laboratory for Condensed Matter Physics.Institute of Physics.Chinese Academy of Sciences,Beijing 100190,China [2]State Key Laboratory of Operation and Control of Renewable Energy&Storage Systems,China Electric Power Research Institute,Beijing 100192,China

出　　处：《Chinese Physics B》2020年第4期58-66,共9页中国物理B（英文版）

基　　金：Project supported by the State Grid Technology Project,China(Grant No.DG71-17-010)。

摘　　要：Silicon is an important high capacity anode material for the next generation Li-ion batteries.The electrochemical performances of the Si anode are influenced strongly by the properties of the solid electrolyte interphase(SEI).It is well known that the addition of flouroethylene carbonate(FEC)in the carbonate electrolyte is helpful to improve the cyclic performance of the Si anode.The possible origin is suggested to relate to the modification of the SEI.However,detailed information is still absent.In this work,the structural and mechanical properties of the SEI on Si thin film anode in the ethylene-carbonate-based(EC-based)and FEC-based electrolytes at different discharging and charging states have been investigated using a scanning atomic force microscopy force spectroscopy(AFMFS)method.Single-layered,double-layered,and multi-layered SEI structures with various Young’s moduli have been visualized three dimensionally at nanoscale based on the hundreds of force curves in certain scanned area.The coverage of the SEI can be obtained quantitatively from the two-dimensional(2D)project plots.The related analysis indicates that more soft SEI layers are covered on the Si anode,and this could explain the benefits of the FEC additive.

关 键 词：Si fluoroethylene CARBONATE solid electrolyte INTERPHASE atomic FORCE microscopy FORCE SPECTROSCOPY 

分 类 号：TM912[电气工程—电力电子与电力传动] O646.1[理学—物理化学]