King's College London

Research portal

Operando Measurement of Layer Breathing Modes in Lithiated Graphite

Research output: Contribution to journalArticlepeer-review

Hossein Yadegari, Mohamed A. Koronfel, Kang Wang, Daisy B. Thornton, Ifan E.L. Stephens, Carla Molteni, Peter D. Haynes, Mary P. Ryan

Original languageEnglish
Pages (from-to)1633–1638
Number of pages6
JournalACS Energy Letters
Volume6
Issue number4
DOIs
Published9 Apr 2021

Bibliographical note

Funding Information: This work was supported by the ISCF Faraday Challenge project: ‘‘Towards a Comprehensive Understanding of Degradation Processes in EV Batteries’’ and the financial support is gratefully acknowledged. M.P.R. gratefully acknowledges support from the Royal Academy of Engineering. Support from the Thomas Young Centre is acknowledged under grant number TYC-101. Calculations were performed on the Imperial College London Research Computing Service. Publisher Copyright: © Copyright: Copyright 2021 Elsevier B.V., All rights reserved.

King's Authors

Abstract

Despite their ubiquitous usage and increasing societal dependence on Li-ion batteries, there remains a lack of detailed empirical evidence of Li intercalation/deintercalation into graphite even though this process dictates the performance, longevity, and safety of the system. Here, we report direct detection and dissociation of specific crystallographic phases in the lithiated graphite, which form through a stepwise staging process. Using operando measurements, LiC18, LiC12, and LiC6 phases are observed via distinct low-frequency Raman features, which are the result of displacement of the graphite lattice by induced local strain. Density functional theory calculations confirm the nature of the Raman-active vibrational modes, to the layer breathing modes (LBMs) of the lithiated graphite. The new findings indicate graphene-like characteristics in the lithiated graphite under the deep charged condition due to the imposed strain by the inserted Li. Moreover, our approach also provides a simple experimental tool to measure induced strain in the graphite structure under full intercalation conditions.

View graph of relations

© 2020 King's College London | Strand | London WC2R 2LS | England | United Kingdom | Tel +44 (0)20 7836 5454