NEGATIVE ELECTRODE ACTIVE MATERIAL FOR LITHIUM SECONDARY BATTERY, METHOD OF PREPARING THE SAME, AND LITHIUM SECONDARY BATTERY INCLUDING THE NEGATIVE ELECTRODE ACTIVE MATERIAL

摘要

PROBLEM TO BE SOLVED: To provide: a negative electrode active material for a lithium secondary battery, improved in capacity characteristics and cycle life characteristics; a method of preparing the negative electrode active material; and a lithium secondary battery including the negative electrode active material.SOLUTION: A negative electrode active material for a lithium secondary battery according to an embodiment of the present invention includes: a matrix including an Si-X-based alloy (the X is selected from among alkali metals, alkali earth metals, group 13-16 elements, transition metals, rare earth elements and a combination thereof, and is not Si); Si dispersed in the matrix; and an oxygen (O) atom. The negative electrode active material contains 20 at% or less of the oxygen (O) atom with respect to the total amount of atoms of the negative electrode active material.