Patent ID: 8062560

Claim:
A method of preparing a cathode active material for lithium secondary batteries comprising: providing a first crystalline substance having one or more members with the general formulas Li xx M′ yy (XO 4 ) zz , LiM′XO 5 , LiM′XO 6 and LiM′X 2 O 7 , wherein: 0<xx/zz≦1 and 0<yy/zz≦1; M′ is selected from elements Na, Mn, Fe, Co, Ni, Ti, Nb and V; X is selected from elements P, S, As, Mo and W; providing a second crystalline substance having one or more members with the general formulas LiD c O 2 , Li i Ni 1-d-e Co d Mn e O 2 , LiNi 1-f-g Co f Al g O 2 , Li x Ni 1-y CoO 2 , Li a M b Mn 2-b O 4 and Li m Mn 2-n E n O j , wherein: D is selected from elements B, Mg, Al, Ti, Cr, Fe, Cu, Zn, Ga, Y, La and V; 0<c≦3, 0.9≦i≦1.2, 0≦d≦0.5, 0≦e≦0.3, 0≦f≦0.5, 0≦g≦0.3, 0.9≦x≦1.1 and 0≦y≦1; M is selected from elements boron, magnesium, aluminum, titanium, chromium, iron, cobalt, nickel, copper, zinc, gallium and yttrium; 0.9≦a≦1.2 and 0≦b≦1; E includes one or more transition metals; 0.9≦m≦1.1, 0≦n≦1 and 1<j<6; and sintering the first and second crystalline substances at a temperature ranging from about 500 to 800° C. for a time ranging from about 5 to 32 hours to provide a mixed crystal, wherein the first crystalline substance has a lattice, and at least a part of the second crystalline substance is received by and distributed in the lattice of the first crystalline structure, wherein the mixed crystal has an electrical conductivity ranging from about 0.001 to 10 S/cm at about 25° C.