ELECTRODE ACTIVE MATERIAL, ELECTRODE, AND ELECTRICITY STORAGE DEVICE

This invention relates to an electrode active material, an electrode containing the active material, and an electricity storage device including the electrode. The electrode active material comprises a silicon-containing carbon-based composite material obtained by preparing a uniform phase comprising at least (A) a crosslinkable composition that includes a silicon-containing compound having a crosslinkable group, and (B) a liquid or melt that does not participate in the crosslinking reaction of the crosslinkable composition; then crosslinking the component (A), causing phase-separation from the component (B) for obtaining silicon-containing crosslinked particles or a dispersion wherein the silicon-containing crosslinked particles are dispersed in the component (B); and then baking the silicon-containing crosslinked particles or the dispersion in an inert gas or in a vacuum at 300 to 1,500°C. The electrode active material is particularly suitable as an electrode of a lithium secondary battery, displays high reversible capacity and stable charge and discharge cycle characteristics, and is characterized by having little electrical potential loss when lithium is discharged.