Predicting the Voltage Dependence of Interfacial Electrochemical Processes at Lithium-Intercalated Graphite Edge Planes

Abstract

The applied potential governs lithium-intercalation and electrode passivation reactions in lithium ion batteries, but are challenging to calibrate in condensed phase DFT calculations. In this work, the "anode potential" of charge-neutral lithium-intercalated graphite (LiC(6)) with oxidized edge planes is computed as a function of Li-content n(Li)) at edge planes, using ab initio molecular dynamics (AIMD), a previously introduced Li+ transfer free energy method, and the experimental Li+/Li(s) value as reference. The voltage assignments are corroborated using explicit electron transfer from fluoroethylene carbonate radical anion markers. PF6- is shown to decompose electrochemically (i.e., not just thermally) at low potentials imposed by our voltage calibration technique. We demonstrate that excess electrons reside in localized states-in-the-gap in the organic carbonate liquid region, which is not semiconductor-like (band-state-like) as widely assumed in the literature.

arXiv comment17 pages, 4 figures, 1 table

References in corpus (6)

• Localization and delocalization errors in density functional theory and implications for band-gap prediction
• Ab initio Molecular Dynamics Simulations of the Initial Stages of Solid-electrolyte Interphase Formation on Lithium Ion Battery Graphitic Anodes
• Surface Dipoles and Work Functions of Alkylthiolates and Fluorinated Alkylthiolates on Au(111)
• Modeling Electrochemical Decomposition of Fluoroethylene Carbonate on Silicon Anode Surfaces in Lithium Ion Batteries
• Two-electron reduction of ethylene carbonate: a quantum chemistry re-examination of mechanisms
• Towards First Principles prediction of Voltage Dependences of Electrolyte/Electrolyte Interfacial Processes in Lithium Ion Batteries

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• First Principles, Explicit Interface Studies of Oxygen Vacancy and Chloride in Alumina Films for Corrosion Applications
• Anodic Decomposition of Surface Films on High Voltage Spinel Surfaces -- Density Function Theory and Experimental Study
• Enhancing ReaxFF for Molecular Dynamics Simulations of Lithium-Ion Batteries: An interactive reparameterization protocol