▎ 摘　　要

NOVELTY - Nano silicon-graphene micro ball composite anode material comprises crystalline graphene having a two-dimensional structure and nano-silicon particles formed between the crystalline graphene. The composite powder formed by bonding the nano-silicon particles to inside and outside of crystalline graphene is formed in a micro-sized three-dimensional ball shape, and composite powder has a specific surface area of 1-30 m2/g. USE - The negative electrode is useful for secondary battery (claimed). ADVANTAGE - The nano silicon-graphene micro ball composite anode material is simple in process and mass production is possible; improves the performance of the negative electrode for secondary batteries because electrochemical properties are stable because the initial efficiency and capacity retention rate are good while having a high irreversible capacity by reducing side reactions that may occur in the nano-sized silicon particles. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for manufacturing nano silicon-graphene micro ball composite negative electrode material, comprising preparing crystalline graphene having a two-dimensional structure, preparing a nano-silicon-graphene dispersion solution by mixing the crystalline graphene with a water-soluble polymer and nano-silicon particles, and spray-drying the nano-silicon-graphene dispersion solution to prepare a micro-sized three-dimensional ball-shaped composite powder by combining the nano-silicon particles inside and outside the crystalline graphene. The composite powder has a specific surface area of 1-30 m2/g.