Lithium extraction from orthorhombic lithium manganese oxide and the phase transformation to spinel

Journal Article · Wed Dec 01 00:00:00 EST 1993 · Materials Research Bulletin; (United States)

DOI:https://doi.org/10.1016/0025-5408(93)90172-A· OSTI ID:5528174

Gummow, R J; Liles, D C; Thackeray, M M ^[1]

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1. CSIR, Pretoria (South Africa). Div. of Materials Science and Technology

Development of rechargeable lithium batteries is limited by a concern regarding their safety. Current efforts are focused on rocking-chair'' cells which avoid the use of metallic lithium electrodes and are therefore potentially far safer than conventional lithium cells. Carbon is the anode material of choice for rocking-chair'' cells as it gives good reversibility, high capacity and low average voltage versus lithium, resulting in high energy density cells. Carbon anodes must be coupled with lithium-rich or discharged cathodes. When the cell is first charged, lithium is transferred from the lithium-rich cathode to the carbon anode. However, not all the lithium can be recovered from the anode on the subsequent discharge; surplus cathode capacity is therefore required in the initial cathode to counteract this loss. Lithium transition-metal oxides are being developed as cathode materials for rocking-chair'' batteries. Lithium manganese oxides, which are cheap and non-toxic, are favored over the lithium-cobalt-oxide, LiCoO[sub 2], and lithium-nickel-oxide, LiNiO[sub 2].Here, orthorhombic LiMnO[sub 2] products, synthesized by the reaction of [gamma]-MnO[sub 2] and LiOH in argon at 600--620 C using carbon as a reducing agent, have been evaluated as electrode materials in lithium cells. Products that contained a minor proportion of a lithiated spinel phase showed greater electrochemical activity than pure LiMnO[sub 2]. On delithiation, LiMnO[sub 2] transforms irreversibly to a spinel-type structure. A mechanism for the orthorhombic Li[sub x]MnO[sub 2]-spinel phase transformation is proposed.

• OSTI ID: 5528174
• Journal Information: Materials Research Bulletin; (United States), Vol. 28:12; ISSN 0025-5408
• Country of Publication: United States
• Language: English

Related Subjects

25 ENERGY STORAGE
36 MATERIALS SCIENCE
ELECTRIC BATTERIES
ELECTRODES
MATERIALS
LITHIUM OXIDES
CRYSTAL-PHASE TRANSFORMATIONS
MANGANESE OXIDES
ELECTROCHEMISTRY
SYNTHESIS
ALKALI METAL COMPOUNDS
CHALCOGENIDES
CHEMISTRY
ELECTROCHEMICAL CELLS
LITHIUM COMPOUNDS
MANGANESE COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PHASE TRANSFORMATIONS
TRANSITION ELEMENT COMPOUNDS
250903* - Energy Storage- Batteries- Materials
Components
& Auxiliaries
360602 - Other Materials- Structure & Phase Studies