Positive active material composition for rechargeable lithium battery and method of preparing positive electrode using same

A method of making a rechargeable lithium battery comprising:

• forming a positive electrode by physically mixing a positive active material with particles of an additive to prepare a positive active material composition, the positive active material being selected from the group consisting of lithiated transition metal compounds, and the additive at least one selected from the group consisting of Si, B, Ge, Ga, Ca, Sr, Ba, and oxides thereof, coating the positive active material composition on a current collector after heat treating to place the positive active material in a uniform crystalline form, and drying the current collector coated with the positive active material composition including the particles of the additive mixed in the positive active material;
• forming a negative electrode including a carbonaceous material as an active material;
• preparing an electrolyte including an organic solvent including a lithium salt dissolved in the organic solvent;
• wherein an amount of the additive is 1.0 to 10 wt % of the positive active material, and the lithiated transition metal compound is selected from the group consisting of formulas 1 to 13:
• LixMnA2
• (1)
• LixMnO2-zAz
• (2)
• LixMn1-yM′yA2
• (3)
• LixMn2A4
• (4)
• LixMn2O4-zAz
• (5)
• LixMn2-yM′yA4
• (6)
• LixBA2
• (7)
• LIxBO2-zAz
• (8)
• LixB1-yM″yA2
• (9)
• LixB1-yM″yO2-zAz
• (10)
• LixNiCoA2
• (11)
• LixNiCoO2-zA2
• (12)
• LixNi1-y-zCoyM″zA2
• (13)
• wherein 1.0≦x≦1.1, 0.01≦y≦0.1, 0.01≦z≦0.5, M′ is at least one transition metal or lanthanide metal selected from the group consisting of Al, Cr, Co, Mg, La, Ce, Sr and V, M″ is at least one transition metal or lanthanide metal selected from the group consisting of Al, Cr, Mn, Fe, Mg, La, Ce, Sr and V, A is selected from O, F, S or P, and B is Ni or Co.