Precursor particles of lithium composite transition metal oxide for lithium secondary battery and cathode active material comprising the same

1. Precursor particles of a lithium composite transition metal oxide for lithium secondary batteries, wherein the precursor particles are composite transition metal hydroxide particles comprising at least two transition metals and having an average diameter of 1 μm to 8 μm, wherein the composite transition metal hydroxide particles exhibit monodisperse particle size distribution and have a coefficient of variation of 0.2 to 0.7,

wherein the composite transition metal hydroxide particles contain an impurity derived from a transition metal salt for preparation of a composite transition metal hydroxide, wherein an amount of the impurity is 0.3 wt % to 0.4 wt % based on of total weight of the composite transition metal hydroxide particles,

wherein the impurity is a salt ion comprising a sulfate ion (SO 4 2 ), and

wherein the composite transition metal hydroxide is a compound represented by Formula 1 below:

M(OH 1-x ) 2   (1),

wherein M includes two or more transition metals selected from the group consisting of nickel, cobalt and manganese; and 0≦x≦0.8.

2. The precursor particles according to claim 1 , wherein the average diameter of the composite transition metal hydroxide particles is 1 μm to 5 μm.

3. The precursor particles according to claim 1 , wherein the amount of the impurity is 0.3 wt % to 0.4 wt % based on the total weight of the composite transition metal hydroxide particles.

4. The precursor particles according to claim 1 , wherein the transition metal salt is a sulfate.

5. The precursor particles according to claim 4 , wherein the sulfate is at least one selected from the group consisting of nickel sulfate, cobalt sulfate, and manganese sulfate.

6. The precursor particles according to claim 1 , wherein the salt ion further comprises a nitrate ion (NO 3 − ).

7. The precursor particles according to claim 1 , wherein M further includes at least one additional transition metal selected from the group consisting of aluminum (Al), copper (Cu), iron (Fe), magnesium (Mg), boron (B), chromium (Cr), and period 2 transition metals.

8. The precursor particles according to claim 1 , wherein M includes each of nickel, cobalt and manganses, and optionally further includes at least one additional transition metal selected from the group consisting of aluminum (Al), copper (Cu), iron (Fe), magnesium (Mg), boron (B), chromium (Cr), and period 2 transition metals.