Li-Co-O Spinels

I The Structural Stability of Transition Metal Oxide Insertion Electrodes for Lithium Batteries 

Stability on cycling compared to LT-LiCoOj products 1160], Acid treatment of LT-L1C0O2 generates the ideal spinel Li[Co2]04 structure [43], according to the reaction  

Note that this reaction is similar to that used by Hunter in his preparation of A.-Mn02 in acid medium at room temperature [121]  

Electrodes that are prepared from acid-leached LT-LiCo, Ni 02 compounds (0 x 0.2) show significantly enhanced electrochemical behavior over the parent LT-LiCo, Ni 02 structure. The improved performance has been attributed to the formation of compounds with a composition and cation arrangement close to the ideal Li [62104 spinel structure (B = Co, Ni) [62]. These spinel-type structures have cubic symmetry, which is maintained on lithiation the unit cells expand and contract by only 0.2 percent during lithium insertion and extraction. 

Lithium-titanium-oxide spinels provide a relatively low voltage of 1.5V vs. lithium. They ai e, therefore, of interest as possible negative electrode materials for lithium-ion cells [161-163] they can be coupled, for example, to Li[Mn2]04 (4V vs. Li) to yield a 2.5V lithium-ion cell, or to Li MnOj (3V vs. Li) to yield a 1.5V lithium-ion cell. Although these cells have a voltage lower than that of commercial 

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