LiCoO2: formation, structure, lithium and oxygen nonstoichiometry, electrochemical behaviour and transport properties

The formation, structure and transport properties of LiCoO₂ are described. LiCoO₂ exhibits two crystal structures, depending on both the preparation method and synthesis temperature. High temperature lithium cobalt oxide (HT-LiCoO₂) has a hexagonal layered structure, while the low temperature oxide (LT-LiCoO₂) has a cubic spinel-related structure. The dependence of the morphological characteristics (grain size, size distribution, crystallinity) of LiCoO₂ on synthesis method as well as their effect on the electrochemical properties are extensively reviewed. As the electrochemical properties and the electrical conductivity strongly depend on the structure of the oxide, primary attention is given to lithium cobalt oxide with defect structure and lithium and oxygen nonstoichiometry.