SEPARATOR FOR AN ELECTROCHEMICAL DEVICE INCLUDING A POROUS ORGANIC/INORGANIC COMPOSITE COATING LAYER AND AN ELECTROCHEMICAL DEVICE INCLUDING SAME

Disclosed is a separator suitable for an electrochemical device a porous including polymer substrate and an organic/inorganic composite porous coating layer on at least one side of the porous polymer substrate. The organic/inorganic composite porous coating layer includes particulate binder polymers and first inorganic particles, the particulate binder polymers include (a) hybrid polymer particles of a fluorine-containing polymer and an acrylic-containing polymer and (b) acrylic-containing polymer particles, the average particle diameter D50 of the acrylic-containing polymer particles “a” is in a range of 1 μm to 7.5 μm, the average particle diameter D50 of the inorganic particles “b” is in a range of 200 nm to 800 nm, a/b is in a range of 2 to 15, and the average particle diameter D50 of the hybrid polymer particles is smaller than the average particle diameter D50 of the acrylic-containing polymer particles.