POSITIVE ELECTRODE ACTIVE MATERIAL HAVING IMPROVED SAFETY AND LIFESPAN CHARACTERISTICS, AND LITHIUM SECONDARY BATTERY COMPRISING SAME

Abstract

Provided is a secondary battery comprising a positive electrode active material represented by the following Chemical Formula 1, Li {LiaMnxM1-a-x-yM'y}O2 where 0<a≤0.2, x>(1-a)/2, and 0<y<0.2(1-a), and M is simultaneously applied by any one element or two or more elements selected from the group consisting of group 3 and 4 elements, and M' is a metal having an ion diameter of 70 pm or more with an oxidation number of 4 as well as a six-coordinate octahedral structure (specifically, any one element or two or more elements selected from the group consisting of titanium (Ti), vanadium (V), and iron (Fe) are simultaneously applied). According to the present invention, a high capacity lithium secondary battery having improved safety and processability may be provided.