Role of solvent-anion charge transfer in oxidative degradation of battery electrolytes
Abstract
Electrochemical stability windows of electrolytes largely determine the limitations of operating regimes of lithium-ion batteries, but the degradation mechanisms are difficult to characterize and poorly understood. Using computational quantum chemistry to investigate the oxidative decomposition that govern voltage stability of multi-component organic electrolytes, we find that electrolyte decomposition is a process involving the solvent and the salt anion and requires explicit treatment of their coupling. We find that the ionization potential of the solvent-anion system is often lower than that of the isolated solvent or the anion. This mutual weakening effect is explained by the formation of the anion-solvent charge-transfer complex, which we study for 16 anion-solvent combinations. This understanding of the oxidation mechanism allows the formulation of a simple predictive model that explains experimentally observed trends in the onset voltages of degradation of electrolytes near the cathode. This model opens opportunities for rapid rational design of stable electrolytes for high-energy batteries.
Additional Information
© 2019 The Author(s). This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/. Received 27 September 2018; Accepted 28 May 2019; Published 26 July 2019. Data availability: The datasets generated during and/or analysed during the current study are available in the figshare repository, with the identifier [https://doi.org/10.6084/m9.figshare.8162132.v1]. We acknowledge useful discussions with Heather Kulik and Mordechai Kornbluth. Funding for E.R.F. was provided by Robert Bosch LLC, partly through the MIT Energy Initiative fellowship. Author Contributions: E.R.F., G.S., F.F., and B.K. performed the quantum calculations, formulated, and verified the charge transfer model. N.M. and J.P.M. performed MD calculations and extracted the structures. W.A.G., B.V.M., and J.C.G. gave technical support and conceptual advice. B.K. conceived and supervised the study. The authors declare no competing interests.Attached Files
Published - s41467-019-11317-3.pdf
Submitted - effects-of-solvent-salt-charge-transfer-complexes-on-oxidative-stability-of-li-ion-battery-electrolytes.pdf
Supplemental Material - 41467_2019_11317_MOESM1_ESM.pdf
Supplemental Material - 41467_2019_11317_MOESM2_ESM.pdf
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Additional details
- Alternative title
- Effects of Solvent-Salt Charge-Transfer Complexes on Oxidative Stability of Li-Ion Battery Electrolytes
- PMCID
- PMC6659707
- Eprint ID
- 97510
- Resolver ID
- CaltechAUTHORS:20190730-090029535
- Robert Bosch LLC
- Massachusetts Institute of Technology (MIT)
- Created
-
2019-07-30Created from EPrint's datestamp field
- Updated
-
2023-06-01Created from EPrint's last_modified field
- Other Numbering System Name
- WAG
- Other Numbering System Identifier
- 1346