▎ 摘 要
NOVELTY - A negative electrode active material comprises silicon particles comprising a coating portion derived from a coupling agent, an amorphous carbon portion on the silicon particles, and a carbon-based conductive material on the amorphous carbon portion. The carbon-based conductive material comprises a coating portion derived from the coupling agent. USE - Active material used for negative electrode for lithium secondary battery for battery pack (all claimed) for mobile device, and electric vehicle. ADVANTAGE - The negative electrode active material has reduced the problem of volume expansion, improved the cycle characteristics, lifespan characteristics and initial capacity. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: preparation of negative electrode active material, which involves (a) preparing silicon particles comprising the coating portion derived from the coupling agent by mixing the silicon particles with the coupling agent, (b) mixing the silicon particles comprising the coating portion derived from the coupling agent with the amorphous carbon source and the carbon-based conductive material, and (c) carbonizing the mixture of the step (b), and preparing the carbon-based conductive material containing the coating portion derived from the coupling agent by mixing the carbon-based conductive material with the coupling agent; and a lithium secondary battery, which comprises a positive electrode, a negative electrode facing the positive electrode, and an electrolyte between the positive electrode and the negative electrode. The negative electrode includes the negative electrode active material.