skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Electrolyte Solvation Structure at Solid/Liquid Interface Probed by Nanogap Surface-Enhanced Raman Spectroscopy

Journal Article · · ACS Nano

Understanding the fundamental factors that drive ion solvation structure and transport is key to design high performance, stable battery electrolytes. Reversible ion solvation and desolvation are critical to the interfacial charge transfer process across the solid-liquid interface as well as the resulting stability of the solid electrolyte interphase (SEI). Here in this paper, we report the first study of Li+ salt solvation structure in aprotic solution in the immediate vicinity (~ 20 nm) of the solid electrode-liquid interface using surface-enhanced Raman spectroscopy (SERS) from a gold nanoparticle (Au NP) monolayer. The plasmonic coupling between Au NPs produces strong electromagnetic field enhancement in the gap region, leading to 5 orders of magnitude increase in Raman intensity for electrolyte components and their mixtures namely, lithium hexafluorophosphate (LiPF6), fluoroethylene carbonate (FEC), ethylene carbonate (EC) and diethyl carbonate (DEC). Further, we estimate and compare the lithium-ion solvation number derived from SERS and Infra-Red (FTIR) spectroscopy experiments to monitor and ascertain the changes in the solvation shell diameter in the confined nanogap region where there is maximum enhancement of the electric field. Our findings provide a new multi-modal spectroscopic approach to gain fundamental insights into the molecular structure of the electrolyte at the solid-liquid interface.

Research Organization:
Energy Frontier Research Centers (EFRC) (United States). Fluid Interface Reactions, Structures and Transport Center (FIRST); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Organization:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Vehicle Technologies Office (EE-3V)
Grant/Contract Number:
AC05-00OR22725
OSTI ID:
1471928
Journal Information:
ACS Nano, Vol. 12, Issue 10; ISSN 1936-0851
Publisher:
American Chemical Society (ACS)Copyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 44 works
Citation information provided by
Web of Science

References (48)

Electrode–Electrolyte Interface in Li-Ion Batteries: Current Understanding and New Insights journal October 2015
Differentiating Contributions to “Ion Transfer” Barrier from Interphasial Resistance and Li + Desolvation at Electrolyte/Graphite Interface journal July 2010
The Electrochemical Behavior of Alkali and Alkaline Earth Metals in Nonaqueous Battery Systems—The Solid Electrolyte Interphase Model journal January 1979
Atomic structure of sensitive battery materials and interfaces revealed by cryo–electron microscopy journal October 2017
Nanoscale Imaging of Fundamental Li Battery Chemistry: Solid-Electrolyte Interphase Formation and Preferential Growth of Lithium Metal Nanoclusters journal February 2015
Far-Field Optical Nanoscopy journal May 2007
Confocal Raman Microscopy: Why the Depth Resolution and Spatial Accuracy Can Be Much Worse Than You Think journal October 2000
Surface-enhanced Raman scattering journal January 1998
Probing Single Molecules and Single Nanoparticles by Surface-Enhanced Raman Scattering journal February 1997
Surface-Enhanced Raman Scattering:  From Noble to Transition Metals and from Rough Surfaces to Ordered Nanostructures journal September 2002
Surface enhanced Raman scattering from bare cobalt electrode surfaces journal January 2001
Simple Strategy To Improve Surface-Enhanced Raman Scattering Based on Electrochemically Prepared Roughened Silver Substrates journal June 2010
Electrochemical Tip-Enhanced Raman Spectroscopy journal September 2015
Shell-isolated nanoparticle-enhanced Raman spectroscopy journal March 2010
Nanostructured Surfaces and Assemblies as SERS Media journal October 2008
Self-assembly of large-scale crack-free gold nanoparticle films using a ‘drain-to-deposit’ strategy journal April 2016
Gold Nanoparticle Monolayers from Sequential Interfacial Ligand Exchange and Migration in a Three-Phase System journal October 2016
Self-Assembly of Large Gold Nanoparticles for Surface-Enhanced Raman Spectroscopy journal April 2017
Surface Enhanced Raman Spectroscopy of Individual Rhodamine 6G Molecules on Large Ag Nanocrystals journal November 1999
Effects of Solute–Solvent Hydrogen Bonding on Nonaqueous Electrolyte Structure journal July 2015
A Raman spectroscopic study of organic electrolyte solutions based on binary solvent systems of ethylene carbonate with low viscosity solvents which dissolve different lithium salts journal January 1998
Solvate Structures and Computational/Spectroscopic Characterization of LiPF 6 Electrolytes journal April 2015
Gold Nanoparticle Monolayers with Tunable Optical and Electrical Properties journal April 2016
Solvation Structure around the Li + Ion in Mixed Cyclic/Linear Carbonate Solutions Unveiled by the Raman Noncoincidence Effect journal July 2015
Li+ solvation in ethylene carbonate–propylene carbonate concentrated solutions: A comprehensive model journal October 1997
Activated vibrational modes and Fermi resonance in tip-enhanced Raman spectroscopy journal February 2013
Combined quantum chemical/Raman spectroscopic analyses of Li+ cation solvation: Cyclic carbonate solvents—Ethylene carbonate and propylene carbonate journal December 2014
Infrared and Raman spectra and vibrational assignment of ethylene carbonate journal September 1971
The Effect of Fluoroethylene Carbonate as an Additive on the Solid Electrolyte Interphase on Silicon Lithium-Ion Electrodes journal August 2015
Nanostructure-based plasmon-enhanced Raman spectroscopy for surface analysis of materials journal April 2016
Raman Spectra and Transport Properties of Lithium Perchlorate in Ethylene Carbonate Based Binary Solvent Systems for Lithium Batteries journal June 1998
Electrolytes and Interphases in Li-Ion Batteries and Beyond journal October 2014
Role of Mixed Solvation and Ion Pairing in the Solution Structure of Lithium Ion Battery Electrolytes journal June 2015
Vibrational spectra and structure of small ring compounds11For Part XVI see J.R. Durig and J.N. Willis, Jr., J. Mol. Spectry., in press. journal February 1970
Role of Solution Structure in Solid Electrolyte Interphase Formation on Graphite with LiPF 6 in Propylene Carbonate journal November 2013
Spectroscopic and Density Functional Theory Characterization of Common Lithium Salt Solvates in Carbonate Electrolytes for Lithium Batteries journal January 2017
Competitive lithium solvation of linear and cyclic carbonates from quantum chemistry journal January 2016
Ultrafast fluxional exchange dynamics in electrolyte solvation sheath of lithium ion battery journal March 2017
Preferential Solvation of Li+ Directs Formation of Interphase on Graphitic Anode journal January 2011
Understanding Li + –Solvent Interaction in Nonaqueous Carbonate Electrolytes with 17 O NMR journal May 2013
Lithium Hexamethyldisilazide:  A View of Lithium Ion Solvation through a Glass-Bottom Boat journal November 1999
Accurate Static and Dynamic Properties of Liquid Electrolytes for Li-Ion Batteries from ab initio Molecular Dynamics journal March 2011
Evaluating the Free Energies of Solvation and Electronic Structures of Lithium-Ion Battery Electrolytes journal June 2016
Nonaqueous Liquid Electrolytes for Lithium-Based Rechargeable Batteries journal October 2004
Surface-Enhanced Raman Trajectories on a Nano-Dumbbell: Transition from Field to Charge Transfer Plasmons as the Spheres Fuse journal October 2012
Liquid Structure with Nano-Heterogeneity Promotes Cationic Transport in Concentrated Electrolytes journal October 2017
Molecular Dynamics Simulation Studies of the Structure of a Mixed Carbonate/LiPF 6 Electrolyte near Graphite Surface as a Function of Electrode Potential journal December 2011
Merck molecular force field. II. MMFF94 van der Waals and electrostatic parameters for intermolecular interactions journal April 1996

Cited By (4)

Probing Electrolyte Solvents at Solid/Liquid Interface Using Gap-Mode Surface-Enhanced Raman Spectroscopy journal January 2019
Understanding the Role of Fluorination on the Interaction of Electrolytic Carbonates with Li + through an Electronic Structure Approach journal January 2019
High‐Curvature Transition‐Metal Chalcogenide Nanostructures with a Pronounced Proximity Effect Enable Fast and Selective CO 2 Electroreduction journal February 2020
High‐Curvature Transition‐Metal Chalcogenide Nanostructures with a Pronounced Proximity Effect Enable Fast and Selective CO 2 Electroreduction journal February 2020

Figures / Tables (9)