SICO-LI COMPOSIT, MAKING METHOD, AND NON-AQUEOUS ELECTROLYTE SECONDARY CELL NEGATIVE ELECTRODE MATERIAL

摘要

A SiCO-Li composite which is an Si-C-O composite that enables to manufacture a negative electrode for a lithium ion secondary cell having better cycle performance, and which is doped with lithium to remove the Si-C-O composite's drawback of low initial efficiency, a method for preparing the same, and a non-aqueous electrolyte secondary cell negative electrode material comprising the same are provided. A SiCO-Li composite is prepared by sintering a crosslinked product of a reactive silane or siloxane having crosslinking groups or a mixture thereof to obtain an inorganic Si-C-O composite, and doping the Si-C-O composite with metallic lithium or an organolithium compound. The crosslinked product is spherical silicon powder. The crosslinked product is formed by adding additive particles selected from graphite and silicon powder, and graphite and silicon powder of which surfaces have been treated with an organosilicon surface treating agent to the reactive silane or siloxane having crosslinking groups or the mixture thereof. A method for preparing a SiCO-Li composite comprises: curing a reactive silane or siloxane having crosslinking groups or a mixture thereof by heat curing or catalytic reaction to form a crosslinked product; sintering the crosslinked product in an inert gas stream at a temperature ranging from 700 to 1,400 deg.C to obtain an inorganic Si-C-O composite; and adding metallic lithium or an organolithium compound to the Si-C-O composite to dope the Si-C-O composite with the metallic lithium or the organolithium compound.