METHOD FOR MANUFACTURING ANODE ACTIVE MATERIAL FOR LITHIUM SECONDARY BATTERY, ANODE ACTIVE MATERIAL FOR LITHIUM SECONDARY BATTERY MANUFACTURED THEREBY AND LITHIUM SECONDARY BATTERY USING SAME

摘要

The present invention provides a method for manufacturing anode active material for a lithium secondary battery and anode active material for a lithium secondary battery manufactured thereby, comprising the following steps: a) simultaneously mixing in a reactor a first metallic salt aqueous solution including nickel, cobalt, manganese, and selectively a transition metal, a chelating agent, and a basic aqueous solution, and mixing and firing with a lithium raw material for manufacturing a core portion including the compound of Chemical Formula 1 below [Chemical Formula 1] Li_x1[Ni_1-y1-z1-w1Co_y1Mn_z1M_w1]O₂ (where, in the above formula, 0.9≤x₁≤1.3, 0.1≤y₁≤0.3, 0.0≤z₁≤0.3, 0≤w₁≤0.1, and M is at least one metal selected from Mg, Zn, Ca, Sr, Cu, Zr, P, Fe, Al, Ga, In, Cr, Ge, and Sn); b) simultaneously mixing in a reactor a second metallic salt aqueous solution including nickel, cobalt, manganese, and selectively a transition metal, the chelating agent, and the basic aqueous solution, mixing and firing with the lithium raw material, and grinding same for manufacturing a compound for forming an exterior portion including the compound of Chemical Formula 2 below [Chemical Formula 2] Li_x2[Ni_1-y2-z2-w2Co_y2Mn_z2M_w2]O₂ (where, in the above formula, 0.9≤x₂≤1+z₂, 0≤y₂≤0.33, 0≤z₂≤0.5, 0≤w₂≤0.1 and M is at least one metal selected from Mg, Zn, Ca, Sr, Cu, Zr, P, Fe, Al, Ga, In, Cr, Ge, and Sn); c) mixing the core portion manufactured from step a) and the compound for forming the exterior portion manufactured from step b); and heat-treating the compound prepared from step c) at 500-800℃ for forming a double layer structure in which lithium is present at a continuous density gradient from the contacting border surface of the core portion and the exterior portion to the surface portion of the exterior portion.