Investigation of the Phase Transition Mechanism in LiFePO4 Cathode Using In Situ Raman Spectroscopy and 2D Correlation Spectroscopy during Initial Cycle

Yeonju Park; Soo Min Kim; Sila Jin; Sung Man Lee; Isao Noda; Young Mee Jung

doi:10.3390/molecules24020291

Molecules (Jan 2019)

Investigation of the Phase Transition Mechanism in LiFePO4 Cathode Using In Situ Raman Spectroscopy and 2D Correlation Spectroscopy during Initial Cycle

Yeonju Park,
Soo Min Kim,
Sila Jin,
Sung Man Lee,
Isao Noda,
Young Mee Jung

Affiliations

Yeonju Park: Department of Chemistry, Institute for Molecular Science and Fusion Technology, Kangwon National University, Chuncheon 24341, Korea
Soo Min Kim: Department of Chemistry, Institute for Molecular Science and Fusion Technology, Kangwon National University, Chuncheon 24341, Korea
Sila Jin: Department of Chemistry, Institute for Molecular Science and Fusion Technology, Kangwon National University, Chuncheon 24341, Korea
Sung Man Lee: Department of Nano Applied Engineering, Kangwon National University, Chuncheon 24341, Korea
Isao Noda: Department of Materials Science and Engineering, University of Delaware, Newark, DE 19716, USA
Young Mee Jung: Department of Chemistry, Institute for Molecular Science and Fusion Technology, Kangwon National University, Chuncheon 24341, Korea

DOI: https://doi.org/10.3390/molecules24020291
Journal volume & issue: Vol. 24, no. 2
p. 291

Abstract

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The phase transition of the LiFePO4 and FePO4 in Li-ion cell during charging-discharging processes in the first and second cycles is elucidated by Raman spectroscopy in real time. In situ Raman spectroscopy showed the sudden phase transition between LiFePO4 and FePO4. Principal component analysis (PCA) results also indicated that the structural changes and electrochemical performance (charge-discharge curve) are correlated with each other. Phase transition between LiFePO4 and FePO4 principally appeared in the second charging process compared with that in the first charging process. 2D correlation spectra provided the phase transition mechanism of LiFePO4 cathode which occurred during the charging-discharging processes in the first and second cycles. PCA and 2D correlation spectroscopy are very helpful methods to understand in situ Raman spectra for the Li-ion battery.

Published in Molecules

ISSN: 1420-3049 (Online)
Publisher: MDPI AG
Country of publisher: Switzerland
LCC subjects: Science: Chemistry: Organic chemistry
Website: http://www.mdpi.com/journal/molecules

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