NOVELTY - Lithium secondary battery comprises cathode (1), and anode (2). The cathode is capable of storing and releasing lithium. The anode is capable of storing and releasing lithium. The cathode comprises a lithium-nickel-manganese-cobalt compound oxide with layered crystal structure and a lithium-manganese compound oxide having a layered crystal structure distributed in the lithium-nickel-manganese-cobalt compound oxide.    USE - The lithium secondary battery is used as power sources for environment friendly electric vehicles, and hybrid electric vehicles.    ADVANTAGE - The battery provides small volume variation caused by charge-discharge and has excellent cycle performance. The battery has longer life, i.e. greater than or equal to10 years, capacity retention rate after 1000 cycles of greater than or equal to85% and can be made at lower costs. The battery prevents electrolyte leakage and provides high output power.    DETAILED DESCRIPTION - INORGANIC CHEMISTRY - Preferred Components: The lithium-manganese compound oxide is di-lithium manganate. The lithium-nickel-manganese-cobalt compound oxide comprises primary particles agglomerating to form secondary particles. The lithium-manganese compound oxide is formed in the interface between the primary particles of the lithium-nickel-manganese-cobalt compound oxide. The lithium-manganese compound oxide is formed in the interior of the crystal of the lithium-nickel-manganese-cobalt compound oxide. The lithium-manganese compound oxide is an inactive material. The lithium-nickel-manganese-cobalt compound oxide has structure LiaNixMnyCozO2, provided that a=0-1.2, x=0.1-0.45, y=0.45-0.80, z=0.1-3, and x+y+z=1.    Preferred Properties: The ratio of 003 diffraction peak intensity of the lithium-nickel-manganese-cobalt compound oxide at a diffraction angle of 18.3greater than or equal to1degrees in an X-ray diffraction measurement using the copper Kalpha to the (020) diffraction peak intensity of dilithium manganate at a diffraction angle of 21.1greater than or equal to1degrees in the X-ray diffraction measurement using the copper Kalpha is 0.04-0.07. The lithium-nickel-manganese-cobalt compound oxide has a hexagonal crystal unit lattice. The output power density of the lithium secondary battery is greater than or equal to2500 W/kg under the condition that its depth of charge is 80%. The capacity retention rate after 1000 cycles is greater than or equal to85%.    DESCRIPTION OF DRAWING(S) - The figure shows schematic sectional view of the lithium secondary battery.    Cathode (1)    Anode (2)    Separator (3)    Battery can (4)    Anode lead (5)    Cap (6)    Cathode lead (7)    Packing (8)