講演情報
[17p-K503-7]Solvation Behavior of Lithium-Ion Battery Electrolytes on Clinochlore Surfaces Studied by Frequency Modulation AFM and Molecular Dynamics Simulation
〇Yilin Wang1, Kei Kobayashi1 (1.Kyoto Univ.)
キーワード：
frequency modulation atomic force microscopy、solid liquid interface、molecular dynamics simulation
Various phenomena occur at the electrode/electrolyte interface of lithium-ion batteries (LIBs), including interfacial charge transfer reactions, formation and growth of the solid electrolyte interphase (SEI), and solvation/desolvation processes. These interfacial phenomena critically influence the efficiency, capacity, and lifetime of the LIBs. Despite the growing use of computational methods in recent years, such as density-functional theory (DFT)-based simulations[1], experimental techniques for directly analyzing the microstructure and reaction mechanisms at this interface remain scarce. Frequency modulation atomic force microscopy (FM-AFM) is a powerful tool for this purpose, providing high spatial resolution and sensitivity in detecting force gradients[2,3] by detecting changes in the cantilever resonance frequency shift.
In this study, we investigated the solvation structure of lithium bis(trifluoromethanesulfonyl)imide (Li-TFSI) in propylene carbonate (PC) at the clinochlore surface, which features heterogeneously charged terraces. The aim was to elucidate the solvation structures at the solid-liquid interface and their dependence on the surface charge distributions. Figure 1 presents an AFM topographic image of the clinochlore surface, revealing two distinct surface regions: a brucite-like layer and a talc-like layer. Frequency shift mapping and analysis (Figure 2) demonstrated differences in solvation behavior between these regions. Notably, the talc-like layer exhibited a greater number of frequency shift valleys, indicative of the formation of some molecular assembly layers. Furthermore, molecular dynamics simulations provided additional insights, revealing the effective size of the molecular assemblies and offering a deeper understanding of the solvation behavior of the LIB electrolytes at the interface.
In this study, we investigated the solvation structure of lithium bis(trifluoromethanesulfonyl)imide (Li-TFSI) in propylene carbonate (PC) at the clinochlore surface, which features heterogeneously charged terraces. The aim was to elucidate the solvation structures at the solid-liquid interface and their dependence on the surface charge distributions. Figure 1 presents an AFM topographic image of the clinochlore surface, revealing two distinct surface regions: a brucite-like layer and a talc-like layer. Frequency shift mapping and analysis (Figure 2) demonstrated differences in solvation behavior between these regions. Notably, the talc-like layer exhibited a greater number of frequency shift valleys, indicative of the formation of some molecular assembly layers. Furthermore, molecular dynamics simulations provided additional insights, revealing the effective size of the molecular assemblies and offering a deeper understanding of the solvation behavior of the LIB electrolytes at the interface.