Provided is a production method for obtaining high purity nickel sulfate having low levels of impurities, particularly low levels of magnesium and chloride, by adjusting the concentration of an extractant and the pH concentration at the time of treatment i...

Provided is a method for preparing a positive electrode active material for a lithium secondary battery, the method comprising: mixing and reacting a nickel source, a cobalt source, and an aluminum source, ammonia water, sucrose, and a pH adjusting agent t...