SEPARATOR AND ELECTROCHEMICAL DEVICE INCLUDING THE SAME

A separator including: a porous polymer substrate having a plurality of pores; and a porous coating layer on at least one surface of the porous polymer substrate. The porous coating layer comprises inorganic particles, core-shell type polymer particles having a core portion and a shell portion surrounding the core portion, and a binder polymer positioned on the whole or a part of the surface of the inorganic particles and core-shell type polymer particles to connect and fix the inorganic particles and core-shell type polymer particles with one another. The core portion has a glass transition temperature, T, higher than the shell portion in the core-shell type polymer particles. The ratio of the average diameter of the core-shell type polymer particles to the average diameter of the inorganic particles is 80% to 200%.