AB-INITIO STUDY OF LITHIUM INTERCALATION IN METAL-OXIDES AND METAL DICHALCOGENIDES

A study of the average voltage to intercalate lithium in various metal oxides is presented. By combining the ab initio pseudopotential metho d with basic thermodynamics the average intercalation voltage can be p redicted without the need for experimental data. This procedure is use d to systematically study the effect of metal chemistry, anion chemist ry, and structure. It is found that Li is fully ionized in the interca lated compounds with its charge transferred to the anion and to the me tal. The substantial charge transfer to the anion is responsible for t he large voltage difference between oxides, sulfides, and selenides. I onic relaxation, as a result of Li intercalation, causes nonrigid-band effects in the density of states of these materials. Suggestions for compounds that may have a substantially larger voltage than currently used materials are also presented.