Production method for negative electrode active material for lithium secondary battery, and lithium secondary battery
The present invention relates to a production method for a negative electrode active material for a lithium secondary battery, and to a lithium secondary battery, and provides a production method for a lithium secondary battery negative electrode active material that is produced by mechanically grinding or crushing, in dry or wet conditions, particulate silicon, which is in a secondary particle state formed by agglomerating crystalline and amorphous silicon primary particles.
1. A method of preparing a negative electrode active material for a lithium secondary battery, the method comprising mechanically grinding or crushing, particulate silicon, which is in a secondary particle state formed by agglomerating crystalline and amorphous silicon primary particles, under dry or wet conditions; wherein the mechanically grinding or crushing is performed by a milling process and wherein the milling process is performed by using a bead mill or a ball mill; wherein an average particle diameter (D50) of negative electrode active material particles after the mechanically grinding or crushing is in a range of 1 μm to 15 μm; and wherein an additive that suppresses surface oxidation of silicon particles is added during the mechanically grinding or crushing.
2. The method of claim 1 , wherein the additive comprises coal tar pitch.
3. The method of claim 1 , wherein the particulate silicon in a secondary particle state, which is formed by agglomerating crystalline and amorphous silicon primary particles, is obtained as a silicon product by using a fluidized bed reactor (FBR) method.
4. A negative electrode active material for a lithium secondary battery prepared by using the method of claim 1 .
5. A negative electrode active material for a lithium secondary battery prepared by using the method of claim 2 .
6. A negative electrode active material for a lithium secondary battery prepared by using the method of claim 3 .
7. A lithium secondary battery comprising the negative electrode active material of claim 4 .