Precursor for preparing lithium composite transition metal oxide and method for preparing the same
Disclosed is a transition metal precursor used for preparation of lithium composite transition metal oxide, the transition metal precursor comprising a composite transition metal compound represented by the following Formula 1: M(OH 1−x ) 2−y A y/n (1) wherein M comprises two or more selected from the group consisting of Ni, Co, Mn, Al, Cu, Fe, Mg, B, Cr and second period transition metals; A comprises one or more anions except OH 1−x ; 0<x<0.5; 0.01≦y≦0.5; and n is an oxidation number of A. The transition metal precursor according to the present invention contains a specific anion. A lithium composite transition metal oxide prepared using the transition metal precursor comprises the anion homogeneously present on the surface and inside thereof, and a secondary battery based on the lithium composite transition metal oxide thus exerts superior power and lifespan characteristics, and high charge and discharge efficiency.
1. A lithium composite transition metal oxide using a transition metal precursor used for preparation of the lithium composite transition metal oxide, the transition metal precursor comprising a composite transition metal compound represented by the following Formula 2:
Ni b Mn c Co 1−(b+c+d)M′ d (OH 1−x ) 2−y A y/n (2)
wherein
0.3≦b≦0.9;
0.1≦c≦0.6;
0≦d≦0.1;
b+c+d≦1;
M′ comprises one, or two or more selected from the group consisting of Al, Mg, Cr, Ti, Cu, Fe and Zr;
A is PO4;
0<x<0.5;
0.01≦y≦0.5; and
n is an oxidation number of A.
2. The lithium composite transition metal oxide according to claim 1 , wherein the anion A is present in an amount of 0.05 to 3% by weight, based on the total amount of the lithium composite transition metal oxide.
3. The lithium composite transition metal oxide according to claim 1 , wherein the composite transition metal compound has a tap density of 1.5 to 2.5 g/cc.
4. The lithium composite transition metal oxide according to claim 1 , wherein the composite transition metal compound is present in an amount of 30% by weight or more, based on the total amount of the transition metal precursor.
5. The lithium composite transition metal oxide according to claim 1 , wherein the anion A is homogenously present on the surface and inside thereof.