Lithium Insertion Chemistry of Some Iron Vanadates
Lithium insertion into various iron vanadates has been investigated. Fe{sub 2}V{sub 4}O{sub 13} and Fe{sub 4}(V{sub 2}O{sub 7}){sub 3} {center_dot} 3H{sub 2}O have discharge capacities approaching 200 mAh/g above 2.0 V vs. Li{sup +}/Li. Although the potential profiles change significantly between the first and subsequent discharges, capacity retention is unexpectedly good. Other phases, structurally related to FeVO{sub 4}, containing copper and/or sodium ions were also studied. One of these, {beta}-Cu{sub 3}Fe{sub 4}(VO{sub 4}){sub 6}, reversibly consumes almost 10 moles of electrons per formula unit (ca. 240 mAh g{sup -1}) between 3.6 and 2.0 V vs. Li{sup +}/Li, in a non-classical insertion process. It is proposed that both copper and vanadium are electrochemically active, whereas iron(III) reacts to form LiFe{sup III}O{sub 2}. The capacity of the Cu{sub 3}Fe{sub 4}(VO{sub 4}){sub 6}/Li system is nearly independent of cycling rate, stabilizing after a few cycles at 120-140 mAh g{sup -1}. Iron vanadates exhibit better capacities than their phosphate analogues, whereas the latter display more constant discharge potentials.
- Research Organization:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- DE-AC02-05CH11231
- OSTI ID:
- 928486
- Report Number(s):
- LBNL-61528; R&D Project: 000000; BnR: VT0301030; TRN: US200815%%345
- Journal Information:
- Electrochemistry Communications, Vol. 9, Issue 3; Related Information: Journal Publication Date: 03/2007; ISSN 1388-2481
- Country of Publication:
- United States
- Language:
- English
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