NEGATIVE ACTIVE MATERIAL FOR LITHIUM SECONDARY BATTERY AND METHOD OF PREPARING SAME AND LITHIUM SECONDARY BATTERYS COMPRISING THEREOF

摘要

The present invention relates to a negative electrode active material for a lithium secondary battery, a method for preparing the same, and a lithium secondary battery. Provided is a negative electrode active material for a lithium secondary battery, which includes first particles which are a crystalline earthy graphite particles having average diameter of 0.2-3 μm; second particles formed by having Si particles having average diameter of 5-100 nm physically and chemically coupled on the surface of the first particles in regular and irregular phases; and assembly particles having the second particles distributed in amorphous or soft carbon matrix, and the negative electrode active material can be used in manufacturing of a lithium secondary battery with high capacity, long cycle life, and excellent performance.