SILICON-BASED COMPOSITE NEGATIVE ELECTRODE MATERIAL FOR LITHIUM ION SECONDARY BATTERIES, MANUFACTURING METHOD, AND BATTERY

摘要

PROBLEM TO BE SOLVED: To provide a silicon-based composite negative electrode material which is superior in cycle characteristics (the capacity-keeping rate for 300 cycles is 90% or higher), high in initial efficiency (>90%), and high in specific energy and press density, and which can fulfill the need for a high-output density lithium ion secondary battery, and is simple in its manufacturing process, low in raw material cost, environmentally friendly and pollution-free.SOLUTION: The problem can be solved by a silicon-based composite negative electrode material for lithium ion secondary batteries, which has an embedded composite core-shell structure. The silicon-based composite negative electrode material for lithium ion secondary batteries comprises: a core having a structure in which silicon nanoparticles are embedded in interior layer gaps of hollow graphite; and a shell including a non-graphite carbon material.