CATHODE ACTIVE MATERIAL OF LAYERED STRUCTURE COMPRISING LI AND NI-BASED FIRST COMPOSITE OXIDE AND LI AND TI-BASED SECOND COMPOSITE OXIDE, AND NONAQUEOUS ELECTROLYTE SECONDARY BATTERY USING THE CATHODE ACTIVE MATERIAL

摘要

PURPOSE: A cathode active material and a nonaqueous electrolyte secondary battery using the cathode active material are provided, to improve both lithium ion conductivity and high temperature characteristics. CONSTITUTION: The cathode active material has a layered structure and comprises a first composite oxide comprising lithium and nickel as a main component; and a second composite oxide comprising lithium and titanium as a main component which is coated on at least some part of the surface of the particle of the first composite oxide. Preferably the ratio of the first composite oxide to the second composite oxide is 96:4 to 65:35 by weight; and the second composite oxide has a spinel structure of cubic system. Preferably the cathode active material has an average diameter of 5-20 micrometers.