Figure 1 - Layered, spinel and olivine structures of positive electrode materials for lithium batteries.


From the following article

Lithium-ion batteries: An unexpected conductor

Michael Thackeray

Nature Materials 1, 81 - 82 (2002)

doi:10.1038/nmat736

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These materials are required to be good conductors of both lithium ions (green circles) and electrons. a, In the layered structure of LiCoO2, a cubic-close-packed oxygen array provides a two-dimensional network of edge-shared CoO6 octahedra (blue) for the lithium ions. b, In the spinel structure of LiMn2O4 the cubic-close-packed oxygen array provides a three-dimensional array of edge-shared MnO6 octahedra (brown) for the lithium ions. c, The olivine structure of LiFePO4 has a hexagonally-close-packed oxygen array in which there are corner-shared FeO6 octahedra (red) and PO4 tetrahedra (purple). The lithium ions are octahedrally coordinated to oxygen (grey circles), forming edge-sharing chains of LiO6 octahedra (the Li-O coordination has been omitted from the figure for clarity). This structure is a poor electron conductor. Chiang and colleagues2 have now greatly improved the electronic conductivity of LiFePO4 by doping it with low levels of a multivalent cation.

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