Patent ID: 7923157

Claim:
A lithium secondary battery comprising: (a) a cathode active material including a lithium-containing transition metal oxide having reversible lithium intercalation/deintercalation capacity, the lithium-containing transition metal oxide being at least one selected from the group consisting of LiCO a Mn b Ni c M d O 2 and Li X Mn 2-Y M′ Y O 4 , wherein 0≦a≦1; 0≦b—1; 0≦d≦1, with the proviso that a+b+c+d=1; 0.9≦X≦2; 0≦Y≦0.5; M′ is selected from the group consisting of Al, B, Ga, Mg, Si, Ca, Ti, Zn, Ge, Y, Zr, Sn, Sr, Ba and Nb; and M′ is selected from the group consisting of Fe, Co, Ni, Cu, Zn, Al, Sn, Cr, V, Ti, Mg, Ca, Sr, B, Ga, In, Si and Ge; (b) an anode active material including carbon-based material having reversible lithium intercalation/deintercalation capacity, the carbon-based material being graphitized carbon having a lattice spacing (d002) of less than 0.338 nm, as measured by X-ray diffraction, and a specific surface area of less than 10 m 2 /g, as measured by a BET method; (c) a porous separator; and (d) a non-aqueous electrolyte containing (i) a lithium salt, (ii) an electrolyte compound, and (iii) a compound of formula (I): wherein R 1 is C 1 -C 5 lower alkyl, and R 2 is hydrogen or C 1 -C 5 lower alkyl.