| 摘要 |
The present invention relates to a lithium secondary battery having improved rate characteristics, and more particularly, to a lithium secondary battery having a positive electrode, a negative electrode, and a separation membrane and an electrolyte interposed between the positive electrode and the negative electrode, wherein the electrolyte contains a mixed solvent of a ring-shaped carbonate material and a propionate material, the positive electrode contains lithium-manganese composite oxide expressed by the following chemical formula 1 as an active material, and the negative electrode contains lithium metal oxide expressed by the following chemical formula 2 as an active material. LixMyMn2-yO4-zAz (1) (In the formula, 0.9<=x<=1.2, 0<y<2, and 0<=z<0.2; M is at least one element selected from a group consisting of Al, Mg, Ni, Co, Fe, Cr, V, Ti, Cu, B, Ca, Zn, Zr, Nb, Mo, Sr, Sb, W, Ti and Bi; and A is at least one monovalent or divalent negative ion), LiaM'bO4-cAc (2) (In the formula, M' is at least one element selected from a group consisting of Ti, Sn, Cu, Pb, Sb, Zn, Fe, In, Al and Zr; a and b are determined by the oxidation number of M' within the range of 0.1<=a<=4 and 0.2<=b<=4; c is determined by the oxidation number within the range of 0<=c<0.2; and A is at least one monovalent or divalent negative ion). |
