Separator for electrochemical device and electrochemical device containing same

A separator for an electrochemical device which comprises:

• a porous polymer substrate having a plurality of pores;
• a first porous coating layer formed on at least one surface of the porous polymer substrate, the first porous coating layer comprising first inorganic particles and a first binder polymer positioned on a whole or a part of a surface of the first inorganic particles to connect and fix the first inorganic particles with one another;
• a second porous coating layer formed on at least one surface of the first porous coating layer opposite the porous polymer substrate, the second porous coating layer comprising second inorganic particles and a second binder polymer positioned on a whole or a part of a surface of the second inorganic particles to connect and fix the second inorganic particles with one another,
• wherein the first inorganic particles and the second inorganic particles each independently comprise an inorganic material selected from the group consisting of boehmite, zinc oxide, magnesium oxide, magnesium hydroxide, aluminum hydroxide, alumina, and aluminum nitride,
• wherein the first inorganic particles have a Mohs hardness of 4.5 or less and the second inorganic particles have a Mohs hardness of 7 or more, and a difference in Mohs hardness between the first inorganic particles and the second inorganic particles is 2.5 to 6.5;
• and
• an adhesive layer formed on at least one surface of the second porous coating layer,
• wherein the adhesive layer comprises adhesive resin particles, and
• wherein the adhesive resin particles comprise at least one selected from styrene butadiene rubber, acrylonitrile-butadiene rubber, acrylonitrile-butadiene-styrene rubber, polyethylhexyl acrylate-co-methyl methacrylate, polybutylacrylate-co-methyl methacrylate, polyacrylonitrile, polyvinyl chloride, polyvinyl alcohol, styrene or polycyanoacrylate.