A SEPARATOR AND ELECTROCHEMICAL DEVICE INCLUDING THE SAME

摘要

The present invention relates to a separator and an electrochemical device including the same. More specifically, the separator includes: a separator precursor including a porous polymer member; and a polymer layer swollen by an electrolyte formed on at least one surface of the separator precursor. The polymer layer has not higher than 1.0 MPa of a storage modulus when swollen by the electrolyte. According to the present invention, since the polymer layer, swollen by the electrolyte formed on the outermost layer of the separator, becomes flexible or melted by the injected electrolyte, stress by volume expansion in the event of the charge and discharge of the electrochemical device is sufficiently relieved to prevent a twist of a wound electrode assembly, and therefore, the performance and stability of the electrochemical device are maintained even by repeated charge and discharge.