碳酸乙烯酯
溶剂化
电解质
化学
碳酸二甲酯
电化学
溶剂
介电谱
无机化学
循环伏安法
化学工程
电极
物理化学
有机化学
催化作用
工程类
作者
Chunlei Li,Shumin Wu,Peng Wang,Shiyou Li,Jingjing Zhang,Qian Yin,Yulong Zhang,Hongcheng Liang,Dongni Zhao,Xiaoling Cui
标识
DOI:10.1016/j.electacta.2023.143189
摘要
While the solid electrolyte interphase (SEI) film in carbonate-based lithium-ion batteries (LIBs) has been extensively studied, less is known about the formation of SEI due to the complexity and instability of interfacial chemical reactions between Li+ and solvent. This study presents new insights into the formation mechanism of SEI film on graphite anode in ethylene carbonate (EC) and dimethyl carbonate (DMC) co-solvent-based electrolytes. The potential-resolved in-situ electrochemical impedance spectroscopy technology and density functional theory calculations combined with multi-sweep cyclic voltammetry are utilized to confirm that EC prefers to solvate with Li+. Then, a large amount of Li+-EC and a small amount of Li+-DMC solvent molecules undergo solvent migration process and de-solvation at the electrode/electrolyte interface. It was found that Li+-DMC is preferentially de-solvation and reduced to form an unstable SEI film, while Li+-EC inhibits the reduction of DMC and turns the reduction process to be diffusion-controlled. This work provides a fresh perspective on the formation of SEI film by Li+-solvent interaction, which could guide the construction of a stable interface by regulating the Li+-solvation kinetic for high-performance LIBs.
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