Structural features of low-temperature LiCoO{sub 2} and acid-delithiated products

Journal Article · Thu Oct 01 04:00:00 EDT 1998 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1006/jssc.1998.7873· OSTI ID:305395

Shao-Horn, Y; Hackney, S A ^[1]; Johnson, C S; Kahaian, A J; Thackeray, M M ^[2]

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1. Michigan Technological Univ., Houghton, MI (United States). Dept. of Metallurgical and Materials Engineering
2. Argonne National Lab., IL (United States). Chemical Technology Div.

X-ray diffraction and transmission electron microscopy were used to study the structural features of low-temperature LiCoO{sub 2} (LT-LiCoO{sub 2}) samples prepared at 400 C either by a simple solid-state reaction or via a sol-gel process. Single-crystal electron diffraction analysis showed that both a lithiated-spinel Li{sub 2} [Co{sub 2}]O{sub 4} (Fd3m) and a layered-type structure (R{bar 3}m) were present in LT-LiCoO{sub 2} samples but that the lithiated-spinel structure was the major phase. Electron diffraction analysis also indicated that some crystallites in the LT-LiCoO{sub 2} samples had a cation distribution in the spinel notation, {l_brace}(Li{sub 16{minus}4x}){sub 16c}[Li{sub 4x}]{sub 16d}{r_brace}{sub layer1} between the ideal layered (x = 1) and ideal lithiated-spinel (x = 0) structures. Electron diffraction confirmed that acid-delithiation of LT-LiCoO{sub 2} resulted in a lithium-deficient spinel, Li{sub 0.8}[Co{sub 2}]O{sub 4}, with lithium ions on the tetrahedral sites of the spinel structure. The structural features of LT-LiCoO{sub 2} and the acid-delithiated Li{sub 0.4}CoO{sub 2} products provide reasons for the poor electrochemical properties of Li/LT-LiCoO{sub 2} cells and are consistent with earlier studies.

• Research Organization: Argonne National Laboratory (ANL), Argonne, IL
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 305395
• Journal Information: Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Journal Issue: 1 Vol. 140; ISSN 0022-4596; ISSN JSSCBI
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
COBALT OXIDES
CRYSTAL STRUCTURE
ELECTRON DIFFRACTION
ELECTRON MICROSCOPY
EXPERIMENTAL DATA
LATTICE PARAMETERS
LITHIUM OXIDES
X-RAY DIFFRACTION