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

ABSTRACT: 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.

SUBMITTER: Park Y 

PROVIDER: S-EPMC6359707 | biostudies-literature | 2019 Jan

REPOSITORIES: biostudies-literature