Morphology and modulus evolution of graphite anode in lithium ion battery:An in situ AFM investigation  

作　　者：DENG Xin LIU XingRui YAN HuiJuan WANG Dong WAN LiJun 

机构地区：[1]Institute of Chemistry,Chinese Academy of Sciences [2]University of Chinese Academy of Sciences

出　　处：《Science China Chemistry》2014年第1期178-183,共6页中国科学（化学英文版）

基　　金：supported by the National Basic Research Program of China(2012CB932900,2011YQ03012415,and 2011CB808700);the National Natural Science Foundation of China(21073204,21121063,21373237,21127901),and the Chinese Academy of Sciences

摘　　要：We investigated the interfacial electrochemical processes on graphite anode of lithium ion battery by using highly oriented pyrolytic graphite(HOPG)as a model system.In situ electrochemical atomic force microscopy experiments were performed in 1M lithium bis(trifluoromethanesulfonyl)imide/ethylene carbonate/diethyl carbonate to reveal the formation process of solid electrolyte interphase(SEI)on HOPG basal plane during potential variation.At 1.45 V,the initial deposition of SEI began at the defects of HOPG surface.After that,direct solvent decomposition took place at about 1.3 V,and the whole surface was covered with SEI.The thickness of SEI was 10.4±0.2 nm after one cycle,and increased to 13.8±0.2 nm in the second cycle,which is due to the insufficient electron blocking ability of the surface film.The Young’s modulus of SEI was measured by a peak force quantitative nanomechanical mapping(QNM).The Young’s modulus of SEI is inhomogeneous.The statistic value is 45±22 MPa,which is in agreement with the organic property of SEI on basal plane of HOPG.We investigated the interfacial electrochemical processes on graphite anode of lithium ion battery by using highly oriented pyrolytic graphite（HOPG）as a model system.In situ electrochemical atomic force microscopy experiments were performed in 1M lithium bis（trifluoromethanesulfonyl）imide/ethylene carbonate/diethyl carbonate to reveal the formation process of solid electrolyte interphase（SEI）on HOPG basal plane during potential variation.At 1.45 V,the initial deposition of SEI began at the defects of HOPG surface.After that,direct solvent decomposition took place at about 1.3 V,and the whole surface was covered with SEI.The thickness of SEI was 10.4±0.2 nm after one cycle,and increased to 13.8±0.2 nm in the second cycle,which is due to the insufficient electron blocking ability of the surface film.The Young’s modulus of SEI was measured by a peak force quantitative nanomechanical mapping（QNM）.The Young’s modulus of SEI is inhomogeneous.The statistic value is 45±22 MPa,which is in agreement with the organic property of SEI on basal plane of HOPG.

关 键 词：LITHIUM ion battery in SITU electrochemical AFM SEI modulus 

分 类 号：TM912[电气工程—电力电子与电力传动]