Process for producing carbon particles for electrode, carbon particles for electrode, and negative-electrode material for lithium-ion secondary battery

Abstract

Provided is a method of producing carbon particles for an electrode, each containing particles of a metal capable of forming an alloy with lithium, being formed by an aggregation of numerous fine particles composed of carbon, and having a hollow open-cell structure in which cells among the fine particles form a plurality of interconnected pores. The method includes mixing together a monomer having a low compatibility with a polymer to be formed, an organic solvent having a low compatibility with the polymer to be formed, and particles of a metal capable of forming an alloy with lithium, to prepare a monomer-containing mixture; dispersing the monomer-containing mixture in an aqueous phase to prepare a suspension containing, dispersed therein, oil droplets of the monomer-containing mixture; polymerizing the oil droplets in the suspension to prepare resin particles; and curing the resin particles. The carbon particles find use for negative-electrode in lithium-ion secondary batteries.

1 . Carbon particles for an electrode,
 which comprise particles of a metal capable of forming an alloy with lithium in an amount of 1 to 95% by weight relative to the carbon particles for an electrode, are formed by an aggregation of numerous fine particles composed of carbon, have a hollow open-cell structure in which cells among the fine particles form a plurality of interconnected pores, contain the particles of a metal capable of forming an alloy with lithium inside the plurality of the interconnected pores so that the particles of a metal come into contact with the fine particles composed of carbon, and have an average particle diameter of 10 nm to 1 mm and a porosity of 5 to 95%.   
     
     
         2 . A negative-electrode material for a lithium-ion secondary battery, comprising:
 the carbon particles for an electrode according to  claim 1 ; and   a binder resin.   
     
     
         3 . The negative-electrode material for a lithium-ion secondary battery according to  claim 2 , comprising at least one electrically conductive additive selected from the group consisting of graphite, carbon black, carbon nanotube, graphene and fullerene.