SEPARATOR AND ELECTROCHEMICAL DEVICE HAVING SAME

The present invention provides a separator having a porous coating layer comprising: a porous substrate; and a mixture of inorganic particles and a macromolecular binder, which mixture is formed on at least one surface of the porous substrate, wherein the value of "void ratio x thickness-based air permeability" is in a range of between 5 and 40. In the separator of the present invention, which has the porous coating layer, the void ratio is adjusted in accordance with the air permeability of the porous substrate, and thus the separator has outstanding ionic conductivity at the same time as having outstanding mechanical properties and can contribute to improving the performance and safety of electrochemical devices.