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

ABSTRACT: The phase transition of the LiFePO? and FePO? 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 LiFePO? and FePO?. 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 LiFePO? and FePO? principally appeared in the second charging process compared with that in the first charging process. 2D correlation spectra provided the phase transition mechanism of LiFePO? 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