{alpha}-Fe{sub 2}O{sub 3} as an anode material with capacity rise and high rate capability for lithium-ion batteries
- Institute for Superconducting and Electronic Materials, University of Wollongong, NSW 2522 (Australia)
- School of Mechanical, Mechatronic and Materials Engineering, University of Wollongong, NSW 2522 (Australia)
Graphical abstract: Nanosized porous {alpha}-Fe{sub 2}O{sub 3} powder was successfully synthesized via the molten salt method. Electrochemical measurement results demonstrated that the electrode properties of the {alpha}-Fe{sub 2}O{sub 3} could offers excellent cycling performance and high rate capability. The capacity of the product shows two different trends during cycling which are rarely reported in the literature, a decrease in capacity in the first 100 cycles and an increase afterwards up to 600 cycles, with the lowest and highest capacity around 970 and 1972 mAh/g, respectively. Research highlights: {yields} Nanosized {alpha}-Fe{sub 2}O{sub 3} as an anode material for lithium-ion battery. {yields} The nanosized {alpha}-Fe{sub 2}O{sub 3} shows excellent electrochemical performance and exhibits the feature of capacity increase upon cycling. {yields} The porous rhombohedral structures of {alpha}-Fe{sub 2}O{sub 3} could provides the short Li{sup +} diffusion length, decreases the traverse time for electrons and Li{sup +} ions, and reduces the volume expansion to some extent. {yields} The cubic structure of {alpha}-Fe{sub 2}O{sub 3} has been modified to a needle-like structure after prolonged cycling. -- Abstract: We report a simple molten salt method to prepare nanosize {alpha}-Fe{sub 2}O{sub 3}, as well as its electrochemical performance as anode material for lithium ion batteries. The structure and morphology were confirmed by Raman spectroscopy, X-ray diffraction, and transmission electron microscopy. The as-prepared {alpha}-Fe{sub 2}O{sub 3} is a rhombohedral phase of hematite with crystal size in the range of 20-40 nm. The electrochemical measurements were performed using the as-prepared powders as the active material for a lithium-ion cell. The nanosized {alpha}-Fe{sub 2}O{sub 3} shows excellent cycling performance and rate capability. It also exhibits the feature of capacity increase upon cycling. The outstanding electrochemical performance of the {alpha}-Fe{sub 2}O{sub 3} can be related to several factors, namely, the short Li{sup +} diffusion length along the porous rhombohedral structures and the nanosized nature of the materials, which decreases the traverse time for electrons and Li{sup +} ions, and reduces the volume expansion to some extent during charge/discharge reactions.
- OSTI ID:
- 22212130
- Journal Information:
- Materials Research Bulletin, Vol. 46, Issue 6; Other Information: Copyright (c) 2011 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0025-5408
- Country of Publication:
- United States
- Language:
- English
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