Center for Relativistic Laser Science

2019 123rd KCS

 Electrolyte is one of the main components of lithium ion batteries, which acts as transport channels for lithium ions and is closely related to battery performance such as charge rate, capacitance, stability, and safety. Since the performance of these batteries is determined by the microscopicproperties of solvent molecules or lithium salts, understanding the solvation dynamics at the molecular level is very important and necessary. In the currently commercialized lithium ion battery, the electrolyte is formed by dissolving a lithium salt in a mixed organic solvent of cyclic carbonate and linear carbonate. The cyclic carbonatehas a high dielectric constant to stabilize the Li cation, and the linear carbonate has low viscosity to help transport the Li cation. Many previous studies have dealt withbulk state electrolyte which is not applied electric potential. However, it is very important and necessary to observe the solvation dynamics in operando condition to understand the operation mechanism of the lithium ion battery. To do that, A home-built spectro-electro-chemical cell capable of measuring the spectrum while applying potential to the electrolyte was fabricated. As a result of FT-IR measurements on various electrolytes with home-built spectro-electro-chemical cell, it was observed that the electrolyte have a different solvation dynamics than the bulk electrolyte.