10.1021/am405150c.s001
Qi Liu
Qi
Liu
Hao He
Hao
He
Zhe-Fei Li
Zhe-Fei
Li
Yadong Liu
Yadong
Liu
Yang Ren
Yang
Ren
Wenquan Lu
Wenquan
Lu
Jun Lu
Jun
Lu
Eric A. Stach
Eric A.
Stach
Jian Xie
Jian
Xie
Rate-Dependent,
Li-Ion Insertion/Deinsertion Behavior of LiFePO<sub>4</sub> Cathodes
in Commercial 18650 LiFePO<sub>4</sub> Cells
American Chemical Society
2014
Commercial 18650 LiFePO 4 CellsWe
LiFePO 4 Cathodes
cycling conditions
mechanism
nonequilibrium lithium insertion
LiFePO 4 phase
operando synchrotron
XRD
LiFePO 4
LiFePO 4 cathode
FePO 4 phase
voltage plateau
rate capability
2014-03-12 00:00:00
Journal contribution
https://acs.figshare.com/articles/journal_contribution/Rate_Dependent_Li_Ion_Insertion_Deinsertion_Behavior_of_LiFePO_sub_4_sub_Cathodes_in_Commercial_18650_LiFePO_sub_4_sub_Cells/2315041
We have performed operando synchrotron
high-energy X-ray diffraction (XRD) to obtain nonintrusive, real-time
monitoring of the dynamic chemical and structural changes in commercial
18650 LiFePO<sub>4</sub>/C cells under realistic cycling conditions.
The results indicate a nonequilibrium lithium insertion and extraction
in the LiFePO<sub>4</sub> cathode, with neither the LiFePO<sub>4</sub> phase nor the FePO<sub>4</sub> phase maintaining a static composition
during lithium insertion/extraction. On the basis of our observations,
we propose that the LiFePO<sub>4</sub> cathode simultaneously experiences
both a two-phase reaction mechanism and a dual-phase solid-solution
reaction mechanism over the entire range of the flat voltage plateau,
with this dual-phase solid-solution behavior being strongly dependent
on charge/discharge rates. The proposed dual-phase solid-solution
mechanism may explain the remarkable rate capability of LiFePO<sub>4</sub> in commercial cells.