Layered LiCoO[sub 2] with a Different Oxygen Stacking (O2 Structure) as a Cathode Material for Rechargeable Lithium Batteries

was prepared from by ion exchange in LiBr dissolved in hexanol. The structure of was investigated by X‐ray diffraction and in situ X‐ray diffraction during electrochemical charging. The possibility of application as cathode materials in rechargeable lithium batteries was investigated. We find that the electrochemical properties of as cathodes in lithium batteries are competitive with "conventional: . During cycling, the O2 structure of remains stable and does not convert to the thermodynamically stable . Both O2 and show a strong feature in their differential capacity vs. voltage at x near one‐half, which is probably caused by the ordering of Li atoms within each layer, suggesting that this is not strongly perturbed by the details of the stacking of the " " sheets. Finally, the reactivity of with electrolyte was studied by differential scanning coulometry of charged cathodes and compared to that of conventional . shows similar reactivity. © 2000 The Electrochemical Society. All rights reserved.