title: In situ observation of electrolyte-concentration-dependent solid electrolyte interphase on graphite in dimethyl sulfoxide.
abstract: High lithium salt concentration strategy has been recently reported to be an effective method to enable various organic solvents as electrolyte of Li-ion batteries. Here, we utilize in situ atomic force microscopy (AFM) to investigate the interfacial morphology on the graphite electrode in dimethyl sulfoxide (DMSO)-based electrolyte of various concentrations. The significant differences in interfacial features of the graphite in electrolytes of different concentrations are revealed. In the concentrated electrolyte, stable films form primarily at the step edges and defects on the graphite surface after initial electrochemical cycling. On the other hand, in the dilute electrolyte, DMSO-solvated lithium ions constantly intercalate into graphite layers, and serious decomposition of solvent accompanied by structural deterioration of the graphite surface is observed. The in situ AFM results provide direct evidence for the concentration-dependent interface reactions between graphite electrode and DMSO-based electrolyte.
authors.affiliation: †CAS Key Laboratory of Molecular Nanostructure and Nanotechnology, Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, People's Republic of China.|‡University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China.
authors.forename: Xing-Rui
authors.initials: XR
authors.lastname: Liu
authors.affiliation: †CAS Key Laboratory of Molecular Nanostructure and Nanotechnology, Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, People's Republic of China.|‡University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China.
authors.forename: Lin
authors.initials: L
authors.lastname: Wang
authors.affiliation: †CAS Key Laboratory of Molecular Nanostructure and Nanotechnology, Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, People's Republic of China.
authors.forename: Li-Jun
authors.initials: LJ
authors.lastname: Wan
authors.affiliation: †CAS Key Laboratory of Molecular Nanostructure and Nanotechnology, Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, People's Republic of China.
authors.forename: Dong
authors.initials: D
authors.lastname: Wang
keywords: dimethyl sulfoxide; graphite anode; in situ atomic force microscopy; solid electrolyte interphase