Spinel Structure Materials three dimensional

Spinel Structure Cathode Materials (three dimensional)... 

Many of the lithium battery cathode materials have a layered structure, which enables the two-dimensional diffusion of the lithium ion, or a spinel structure, which enables the three-dimensional diffusion. The structures of the cathode materials in the lithium- ion battery are summarized, together with its electrochanical properties and stability of structure, in Table 2.1. 

Conventional active materials in positive electrodes of lithium-ion batteries are metal oxides that accommodate lithium via the intercalation mechanism. Intercalation involves the insertion of lithium into unoccupied sites in the crystal lattice, thus resulting in a small change in the imit cell volume and reversibility on the order of hundreds or thousands of cycles. The most common intercalation materials for positive electrodes are LiCo02, which has a two-dimensional layered structure, and LiMn204, which has a three-dimensional spinel structure. Nanoparticulate or nanocrystalline versions of these materials have been examined with the hope of achieving enhanced capacity, rate capability, or cycling performance. 

Sadakane, M., Takahashi, C, Kato, N., Ogihara, H., Nodasaka, Y., Doi, Y., Hinatsu, Y., and Ueda, W. (2007) Three-dimensionally ordered macroporous (3DOM) materials of spinel-type mixed iron oxides. Synthesis, structural characterization, and formation mechanism of inverse opals with a skeleton structure. Bull. Chem. Soc. Jpn., 80, 677-685. 

Furthermore, the topotactic insertion/extraction reactions may occm by diSusion in onedimensional channels as in the hexagonal tungsten bronze, in two-dimensional as in layered transition metal dichalcogenides, or in three-dimensional as in the close-packed spinel structure. There are a large number of candidate materials which can be used in lithimn insertion... 

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