SEPARATOR FOR ELECTROCHEMICAL DEVICE AND ELECTROCHEMICAL DEVICE INCLUDING THE SAME

A separator for an electrochemical device includes a porous polymer substrate; a first coating layer provided on at least one surface of the porous polymer substrate and containing a first polymer resin of a first solubility in an electrolyte; and a second coating layer provided on the first coating layer and including a second polymer resin of a second solubility in the electrolyte, and inorganic particles, wherein the first solubility is higher than the second solubility in the electrolyte, and the separator is provided on a negative electrode containing a silicon (Si).