Ionic liquids (ILs) have been intensively studied as one promising candidate for an electrolyte in lithium ion batteries (LIBs). Structural analysis of interfaces between an IL-based electrolyte and a LIB electrode would provide beneficial information for improving LIBs. In this study, we investigated the interfacial structures between an IL, 1-ethyl-3-methylimidazolium bis (trifluoromethylsulfonyl)imide (EMI-TFSI), and a spinel-type lithium titanate (Li₄Ti₅O₁₂) electrode in the presence and absence of Li-salt by frequency modulation atomic force microscopy (FM-AFM) utilizing a quartz tuning fork sensor. Solvation structures on the interface were successfully visualized by two-dimensional frequency shift mapping. Electrochemical impedance spectroscopy measurement was also performed to measure the rate of Li⁺-ion insertion/extraction on the interface and we found that the interfacial ion-transfer may prevent the formation of layered solvation structure.

离子液体 (ILs) 作为锂离子电池 (LIBs) 中电解质的一种有希望的候选材料，已被深入研究。基于 IL 的电解质和 LIB 电极之间界面的结构分析将为改进 LIB 提供有益的信息。在这项研究中，我们研究了 IL、1-乙基-3-甲基咪唑鎓双（三氟甲基磺酰基）亚胺（EMI-TFSI）和尖晶石型钛酸锂（Li ₄ Ti ₅ O ₁₂) 使用石英音叉传感器通过调频原子力显微镜 (FM-AFM) 在存在和不存在锂盐的情况下电极。通过二维频移映射成功地可视化界面上的溶剂结构。还进行了电化学阻抗谱测量以测量界面上Li ⁺离子的插入/脱出速率，我们发现界面离子转移可能会阻止层状溶剂化结构的形成。