Nonmonotonic Screening and Solvation Dynamics of the Electrical Double Layer in Concentrated Lithium Salt Electrolytes
Abstract
Abstract Understanding the electrical double layer in lithium-ion battery electrolytes is fundamental to improving interfacial processes that govern battery performance and lifetime. However, the microstructure and dynamics of the electrical double layer in highly concentrated lithium salt solutions remain elusive. Herein, combining electrochemical analyses, in situ gap-enhanced Raman spectroscopy and molecular dynamics simulations, we reveal nonmonotonic variation of electrostatic screening with concentration and different exchange kinetics of anions and solvent molecules in the solvation sheath of lithium ions. We find that increasing solvation entropy favors the formation of an anion-rich solvation environment in highly concentrated electrolytes, accelerating Li + –anion exchange relative to Li + –solvent exchange. This dynamic coordination behavior enables Li + to reorganize its solvation structure more readily during intercalation and deintercalation, thereby improving the kinetics and reversibility of these processes. Overall, this work provides thermodynamic and kinetic insights for the electrolyte design of advanced lithium-ion battery systems.
Article Details
Authors (12)
Xiaoting Yin
State Key Laboratory of Physical Chemistry of Solid Surfaces and College of Chemistry and Chemical Engineering
Feng Wang
Zengming Zhang
Forschungszentrum Jülich GmbH , , ,
Ru-Yu Zhou
College of Materials, State Key Laboratory of Physical Chemistry of Solid Surfaces, iChEM, College of Chemistry and Chemical Engineering, College of Energy, School of Life Sciences, College of Physical Science and Technology, and Discipline of Intelligent Instrument and Equipment
Zhaobin Chen
Tairui Wu
State Key Laboratory of Physical Chemistry of Solid Surface, Collaborative Innovation Center of Chemistry for Energy Materials, and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University 1 , Xiamen 361005,
Li Zhang
Jun Huang
Deyin Wu
State Key Laboratory of Physical Chemistry of Solid Surface, Collaborative Innovation Center of Chemistry for Energy Materials, and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University 1 , Xiamen 361005,
Jun Cheng
Bingwei Mao
Jiawei Yan
State Key Laboratory of Physical Chemistry of Solid Surfaces and College of Chemistry and Chemical Engineering