Electron Microscopy Study of the LiFePO4 to FePO4 PhaseTransition

Journal Article · Fri Jan 06 00:00:00 EST 2006 · Journal of Electrochemical Society

OSTI ID:903125

Chen, Guoying; Song, Xiangyun; Richardson, Thomas J

The mechanism by which LiFePO4 is transformed intoisostructural FePO4 has been elucidated using electron microscopy onlarge, hydrothermally-grown LiFePO4 crystals following chemicaldelithiation. Lithium is extracted at narrow, disordered transition zoneson the ac crystal surface as the phase boundary progresses in thedirection of the a-axis. The substantial lattice mismatch along a (ca. 5percent) causes crack formation in the bc plane. Despite considerabledisorder in the transition zone, the general structural arrangement ispreserved, leading to good crystallinity in the newly created FePO4domains. Implications for improved electrode performance arediscussed.

• Research Organization: Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
• Sponsoring Organization: USDOE. Assistant Secretary for Energy Efficiency andRenewable Energy. Office of the FreedomCAR and Vehicle TechnologiesProgram
• DOE Contract Number: DE-AC02-05CH11231
• OSTI ID: 903125
• Report Number(s): LBNL-59284; R&D Project: 674602; BnR: VT0301030; TRN: US200720%%91
• Journal Information: Journal of Electrochemical Society, Vol. 9, Issue 6; Related Information: Journal Publication Date: 06/2006
• Country of Publication: United States
• Language: English

Related Subjects

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ELECTRODES
ELECTRON MICROSCOPY
LITHIUM
PERFORMANCE
lithium batteries iron phosphate intercalationcompounds