Coupling differential voltage analysis and distribution of relaxation times I: Evaluating the impact of NMC811 coating in the degradation of NMC811/Gr cells
File(s)
Published version
Author(s)
Leal de Souza, Matheus
Morcrette, Mathieu
Type
Journal Article
Abstract
This paper focuses on the coupling of the Differential Voltage Analysis (dV/dQ vs Q) and the Distribution of Relaxation Times (DRT), whose benefits to electrodes development are illustrated by the tracking of degradation effects in the cycling aging of NMC811/Gr coin cells, with and without an NMC electrode coating. The former technique allows monitoring of individual electrode loss of active material (LAM), chemistry change and state of charge (SOC) alignment of the electrodes, whose variation is related mainly to loss of Li inventory (LLI). DRT is a time domain representation of the impedance that offers a high resolution of the resistance processes, complementing the DVA analysis by bringing kinetics degradation of the cells and by identifying in which electrode the main resistance processes are originated. The protocol inserting those techniques in an aging regime is a non-invasive approach, and it indicated the consumption of Li+ ions as the main reason for capacity decay in both cells, with reduced or minimal NMC LAM and chemistry change when coating is applied. From the perspective of power decay, the coating decelerated the impedance rise (IR), mostly related to resistance processes in the positive electrode.
Date Issued
2025-07-30
Date Acceptance
2025-04-23
Citation
Journal of Power Sources, 2025, 645
ISSN
0378-7753
Publisher
Elsevier BV
Start Page
237184
End Page
237184
Journal / Book Title
Journal of Power Sources
Volume
645
Copyright Statement
© 2025 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
License URL
Publication Status
Published
Article Number
237184
Date Publish Online
2025-04-27