COMPOSITE OXIDE CONTAINING LITHIUM, NICKEL, COBALT, MANGANESE, AND FLUORINE, PROCESS FOR PRODUCING THE SAME, AND LITHIUM SECONDARY CELL EMPLOYING IT

摘要

A positive electrode active material for a readily-available high-safety lithium secondary cell having a wide usable voltage range, a high charge/discharge cycle resistance, and a high capacity. A composite oxide containing lithium, nickel, cobalt, manganese, and fluorine and having an R-3m rhombohedral structure represented by a general formula LipNixMn1-x-yCoyO2-qFq (where 0.98<=p<=1.07, 0.3<=x<=0.5, 0.1<=y<=0.38, 0