Patent ID: 7510804

Claim:
A cathode material for use in a lithium secondary battery comprising a compound represented by the chemical formula: Li x Ni y Co z M m O 2 when not in a charged state, having high thermal stability and large discharging capacity in which M is selected from the group consisting of Ba and Ba with Sr, and x, y, z and m are values for the molar ratio of each element: 0.9â‰¦xâ‰¦1.1, 0.5â‰¦yâ‰¦0.95, 0.05â‰¦zâ‰¦0.5 and 0.0005â‰¦mâ‰¦0.005, wherein the compound represented by the chemical formula: Li x Ni y Co z M m O 2 when not in a charged state changes to a compound when in a charged state represented by the chemical formula: Li a Ni b Co c M n O 2 and a, b, c and n are values for the molar ratio of each element and are, respectively, 0.2â‰¦aâ‰¦0.4, 0.5â‰¦bâ‰¦0.95, 0.05â‰¦câ‰¦0.5, and 0.0005â‰¦nâ‰¦0.005 and the material is powdery, has a BET specific surface area 0.8 m 2 /g or less and has a DTG increase start temperature at 215Â° C. or higher.