2013 年 34 巻 12 号 p. 650-655
We have performed density-functional theory (DFT) calculations of ionic-liquid/Li-metal interface models to understand the nature of electrolyte/electrode interfaces in Li-ion batteries. First, we have clarified the microscopic interactions between a pair of constituent anionic and cationic molecules and a Li surface via EMI+ ([C6H11N2]+)-BF4− pair adsorption on various Li surfaces. Second, we have found that the features of the interfacial interactions in the molecular-pair adsorption are also applicable to an ionic-liquid/Li-metal interface, via examination of an EMI-BF4 crystal/Li-metal interface. Finally, we have examined the effects of variations of anionic molecules on the properties of ionic-liquid/Li-electrode interfaces via EMI+-FSFSA− (fluoroalkyl-fluorosulfonyl amid) pair adsorption calculations, which are compared with recent experimental results of electric transport properties at the interfaces between the same ionic liquid and Li electrode.