Positive active material for rechargeable lithium battery and method of preparing same

摘要

Disclosed is a positive active material of for a rechargeable lithium battery and a method of preparing the same. The positive active material is represented by formula 1: LixMn2-a-bCraMbO4+z [formula 1]where x>=2; 0.25=0; M is an alkali earth metal, a transition metal or a mixture thereof. The method includes the steps of dissolving a chromium salt, a manganese salt, and a metal salt(s) in a solvent to produce a solution; performing a first heat-treatment step on the obtained solution at 400 to 500° C. to produce a chromium manganese metal oxide; mixing the chromium manganese metal oxide with a lithium salt; and performing a second heat-treatment step at 600 to 800° C.