Precursor of transition metal oxide, composite of lithium and transition metal oxide, positive electrode comprising same, and secondary battery
Provided is a precursor of transition metal oxide represented by chemical formula 1 below. Ni a Mn b Co 1-(a+b+c+d) Zr c M d [OH (1-x)2-y ]A (y/n) [Chemical formula 1]
1. A precursor of transition metal oxide represented by the following chemical formula 1:
Ni a Mn b Co 1-(a+b+c+d) Zr c M d [OH (1-x)2-y ]A (y/n) [Chemical formula 1]
wherein, M is at least one of W and Nb, A is one or more anions except OH, 0.3≤a≤0.9, 0.05≤b≤0.5, 0<c<0.05, 0<d<0.05, a+b+c+d≤1, 0<x<0.5, 0≤y≤0.05, n is the oxidation number of A,
wherein c:d mole ratio is between 2:1 and 3:2 when the M is W or Nb, and
the A is at least one selected from the group consisting of PO 4 , CO 3 , BO 3 , and F.
2. The precursor of transition metal oxide according to claim 1 , wherein the A includes PO 4 and F.
3. The precursor of transition metal oxide according to claim 1 , wherein the precursor of transition metal oxide has a tap density of between 1.0 and 2.5 g/cc.