title: Ultrafast fluxional exchange dynamics in electrolyte solvation sheath of lithium ion battery.
abstract: Lithium cation is the charge carrier in lithium-ion battery. Electrolyte solution in lithium-ion battery is usually based on mixed solvents consisting of polar carbonates with different aliphatic chains. Despite various experimental evidences indicating that lithium ion forms a rigid and stable solvation sheath through electrostatic interactions with polar carbonates, both the lithium solvation structure and more importantly fluctuation dynamics and functional role of carbonate solvent molecules have not been fully elucidated yet with femtosecond vibrational spectroscopic methods. Here we investigate the ultrafast carbonate solvent exchange dynamics around lithium ions in electrolyte solutions with coherent two-dimensional infrared spectroscopy and find that the time constants of the formation and dissociation of lithium-ion···carbonate complex in solvation sheaths are on a picosecond timescale. We anticipate that such ultrafast microscopic fluxional processes in lithium-solvent complexes could provide an important clue to understanding macroscopic mobility of lithium cation in lithium-ion battery on a molecular level.
authors.affiliation: Department of Chemistry, Kunsan National University, Kunsan, Jeonbuk 573-701, Korea.
authors.forename: Kyung-Koo
authors.initials: KK
authors.lastname: Lee
authors.affiliation: Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science (IBS), Korea University, Seoul 02841, Korea.|Department of Chemistry, Korea University, Seoul 02841, Korea.
authors.forename: Kwanghee
authors.initials: K
authors.lastname: Park
authors.affiliation: Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science (IBS), Korea University, Seoul 02841, Korea.|Department of Chemistry, Korea University, Seoul 02841, Korea.
authors.forename: Hochan
authors.initials: H
authors.lastname: Lee
authors.affiliation: Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science (IBS), Korea University, Seoul 02841, Korea.
authors.forename: Yohan
authors.initials: Y
authors.lastname: Noh
authors.affiliation: Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science (IBS), Korea University, Seoul 02841, Korea.|Department of Chemistry, Korea University, Seoul 02841, Korea.
authors.forename: Dorota
authors.initials: D
authors.lastname: Kossowska
authors.affiliation: Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science (IBS), Korea University, Seoul 02841, Korea.|Department of Chemistry, Korea University, Seoul 02841, Korea.
authors.forename: Kyungwon
authors.initials: K
authors.lastname: Kwak
authors.affiliation: Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science (IBS), Korea University, Seoul 02841, Korea.|Department of Chemistry, Korea University, Seoul 02841, Korea.
authors.forename: Minhaeng
authors.identifier: 0000-0003-1618-1056
authors.initials: M
authors.lastname: Cho