Porous Composite Separator for Secondary Battery, and Lithium Secondary Battery Comprising Same

The present invention relates to: a porous composite separator for a secondary battery including a porous substrate, and a coating layer formed on the porous substrate, wherein the coating layer has a plurality of inorganic particles, which are connected and fixed by a composite binder including a particulate polymer binder and an interpenetrating polymer network (IPN)-type binder having no melting point and having a thermal decomposition temperature of 300° C. or higher; and a lithium secondary battery including the same.