TY - JOUR
T1 - Role of Solvent Isomerism in Mixed Carbonate Electrolytes for Li-Ion Batteries
AU - Koo, Bonhyeop
AU - Lee, Hyejin
AU - Hwang, Sunwook
AU - Lee, Jaeho
AU - Han, Young Kyu
AU - Ahn, Kyoung Ho
AU - Lee, Chulhaeng
AU - Lee, Hochun
N1 - Publisher Copyright:
© 2023 American Chemical Society.
PY - 2023/9/21
Y1 - 2023/9/21
N2 - Current Li-ion battery (LIB) electrolytes employ mixed solvents consisting of ethylene carbonate (EC) and linear carbonates (LCs). Notably, the ion conductivities of the EC/LC electrolytes follow the order dimethyl carbonate > ethyl methyl carbonate > diethyl carbonate despite the similar physicochemical properties of the three LCs. However, the origin of this order remains elusive. In this study, we elucidated the important role of conformational isomerism of the LC solvent on salt dissociation in 0.1-3.0 M LiPF6 EC/LC solutions, using Raman spectroscopy and dielectric relaxation spectroscopies, along with first-principles calculations. The conductivity trend is closely related to the difference in the degree of salt dissociation, which, in turn, is determined by the fraction of the polar cis-trans-LC conformer, as this conformer participates in Li-ion solvation as readily as EC does. This study demonstrates the critical role of the conformational isomerism of the solvents in the electrolyte conductivity, indicating the feasibility of utilizing solvent isomerism to tune the bulk transport properties of electrolytes.
AB - Current Li-ion battery (LIB) electrolytes employ mixed solvents consisting of ethylene carbonate (EC) and linear carbonates (LCs). Notably, the ion conductivities of the EC/LC electrolytes follow the order dimethyl carbonate > ethyl methyl carbonate > diethyl carbonate despite the similar physicochemical properties of the three LCs. However, the origin of this order remains elusive. In this study, we elucidated the important role of conformational isomerism of the LC solvent on salt dissociation in 0.1-3.0 M LiPF6 EC/LC solutions, using Raman spectroscopy and dielectric relaxation spectroscopies, along with first-principles calculations. The conductivity trend is closely related to the difference in the degree of salt dissociation, which, in turn, is determined by the fraction of the polar cis-trans-LC conformer, as this conformer participates in Li-ion solvation as readily as EC does. This study demonstrates the critical role of the conformational isomerism of the solvents in the electrolyte conductivity, indicating the feasibility of utilizing solvent isomerism to tune the bulk transport properties of electrolytes.
UR - http://www.scopus.com/inward/record.url?scp=85172920926&partnerID=8YFLogxK
U2 - 10.1021/acs.jpcc.3c03262
DO - 10.1021/acs.jpcc.3c03262
M3 - Article
AN - SCOPUS:85172920926
SN - 1932-7447
VL - 127
SP - 18271
EP - 18278
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
IS - 37
ER -