Patent ID: 8003256

Claim:
A method for manufacturing a positive electrode active material for a lithium secondary battery, the method comprising the steps of: using a magnesium halide as a magnesium compound in a method for manufacturing a lithium-transition metal compound oxide containing magnesium atoms and sulfate groups by mixing compounds Li 2 CO 3 , MgF 2 , CaSO 4 and at least one of Co 3 O 4 or CoOOH; and calcining the compounds to form the positive electrode; wherein said step of using includes having an average particle diameter of the magnesium halide in a range between 1.0 to 30.0 μm, and having an average particle diameter of the sulfate groups in a range between 1.0 to 500 μm; said step of using also includes eluting a content of 5,000 ppm or less free anions into water; and wherein said step of using further includes mixing MgO, Mg(OH) 2 and MgCO 3 together to prevent the compounds from adhering to a container due to a reaction between an anionic substance and a container during said step of calcining so that the compounds calcined in said step of calcining are easily releasable from the container.