NEGATIVE ELECTRODE ACTIVE MATERIAL, METHOD OF PREPARING THE SAME, AND NEGATIVE ELECTRODE AND LITHIUM SECONDARY BATTERY WHICH INCLUDE THE NEGATIVE ELECTRODE ACTIVE MATERIAL

The present invention relates to a negative electrode active material including a silicon-based composite and a carbon-based material, wherein the silicon-based composite includes SiO(0≤x≤2) including pores, a polymer disposed in the pores, and a metal compound disposed on a surface of the SiO(0≤x≤2) or on the surface and inside of the SiO(0≤x≤2), wherein the metal compound is a compound including at least one element selected from the group consisting of lithium (Li), magnesium (Mg), calcium (Ca), and aluminum (Al), a method of preparing the same, and a negative electrode and a lithium secondary battery which include the negative electrode active material.