A Critical Analysis of Chemical and Electrochemical Oxidation Mechanisms in Li-Ion Batteries

Electrolyte decomposition limits the lifetime of commercial lithium-ion batteries (LIBs) and slows the adoption of next-generation energy storage technologies. A fundamental understanding of electrolyte degradation is critical to rationally design stable and energy-dense LIBs. To date, most explanat...

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Bibliographic Details
Published in:	The journal of physical chemistry letters 2024-01, Vol.15 (2), p.391-400
Main Authors:	Spotte-Smith, Evan Walter Clark, Vijay, Sudarshan, Petrocelli, Thea Bee, Rinkel, Bernardine L. D., McCloskey, Bryan D., Persson, Kristin A.
Format:	Article
Language:	eng
Subjects:	Letter Physical Insights into Energy Science
Online Access:	Get full text
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Summary:	Electrolyte decomposition limits the lifetime of commercial lithium-ion batteries (LIBs) and slows the adoption of next-generation energy storage technologies. A fundamental understanding of electrolyte degradation is critical to rationally design stable and energy-dense LIBs. To date, most explanations for electrolyte decomposition at LIB positive electrodes have relied on ethylene carbonate (EC) being chemically oxidized by evolved singlet oxygen (1O2) or electrochemically oxidized. In this work, we apply density functional theory to assess the feasibility of these mechanisms. We find that electrochemical oxidation is unfavorable at any potential reached during normal LIB operation, and we predict that previously reported reactions between the EC and 1O2 are kinetically limited at room temperature. Our calculations suggest an alternative mechanism in which EC reacts with superoxide (O2 –) and/or peroxide (O2 2–) anions. This work provides a new perspective on LIB electrolyte decomposition and motivates further studies to understand the reactivity at positive electrodes.
ISSN:	1948-7185 1948-7185