†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.
ACS Appl Mater Interfaces. 2015 May 13;7(18):9573-80. doi: 10.1021/acsami.5b01024. Epub 2015 Apr 30.
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.
高锂盐浓度策略最近被报道为一种有效的方法，可以使各种有机溶剂成为锂离子电池的电解质。在这里，我们利用原位原子力显微镜（AFM）来研究不同浓度的二甲基亚砜（DMSO）基电解质中石墨电极的界面形态。结果表明，不同浓度电解质中石墨的界面特征有显著差异。在浓电解质中，初始电化学循环后，主要在石墨表面的台阶边缘和缺陷处形成稳定的薄膜。另一方面，在稀电解质中，DMSO 溶剂化的锂离子不断嵌入石墨层中，同时观察到溶剂的严重分解以及石墨表面结构的恶化。原位 AFM 结果为石墨电极与基于 DMSO 的电解质之间的浓度依赖性界面反应提供了直接证据。
