Onset Potential for Electrolyte Oxidation and Ni-Rich Cathode Degradation in Lithium-Ion Batteries



Dose, Wesley M, Li, Weiqun, Temprano, Israel, O'Keefe, Christopher A, Mehdi, B Layla ORCID: 0000-0002-8281-9524, De Volder, Michael FL and Grey, Clare P
(2022) Onset Potential for Electrolyte Oxidation and Ni-Rich Cathode Degradation in Lithium-Ion Batteries. ACS ENERGY LETTERS, 7 (10). pp. 3524-3530.

Access the full-text of this item by clicking on the Open Access link.
[thumbnail of Onset Potential for Electrolyte Oxidation and Ni-Rich Cathode Degradation in Lithium-Ion Batteries.pdf] PDF
Onset Potential for Electrolyte Oxidation and Ni-Rich Cathode Degradation in Lithium-Ion Batteries.pdf - Published version

Download (4MB) | Preview

Abstract

High-capacity Ni-rich layered metal oxide cathodes are highly desirable to increase the energy density of lithium-ion batteries. However, these materials suffer from poor cycling performance, which is exacerbated by increased cell voltage. We demonstrate here the detrimental effect of ethylene carbonate (EC), a core component in conventional electrolytes, when NMC811 (LiNi<sub>0.8</sub>Mn<sub>0.1</sub>Co<sub>0.1</sub>O<sub>2</sub>) is charged above 4.4 V vs Li/Li<sup>+</sup>-the onset potential for lattice oxygen release. Oxygen loss is enhanced by EC-containing electrolytes-compared to EC-free-and correlates with more electrolyte oxidation/breakdown and cathode surface degradation, which increase concurrently above 4.4 V. In contrast, NMC111 (LiNi<sub>0.33</sub>Mn<sub>0.33</sub>Co<sub>0.33</sub>O<sub>2</sub>), which does not release oxygen up to 4.6 V, shows a similar extent of degradation irrespective of the electrolyte. This work highlights the incompatibility between conventional EC-based electrolytes and Ni-rich cathodes (more generally, cathodes that release lattice oxygen such as Li-/Mn-rich and disordered rocksalt cathodes) and motivates further work on wider classes of electrolytes and additives.

Item Type: Article
Uncontrolled Keywords: 7 Affordable and Clean Energy
Depositing User: Symplectic Admin
Date Deposited: 22 Nov 2022 18:10
Last Modified: 15 Mar 2024 13:39
DOI: 10.1021/acsenergylett.2c01722
Open Access URL: https://doi.org/10.1021/acsenergylett.2c01722
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3166324