Separator, method of manufacturing the separator, and electrochemical device including the separator

A separator for a secondary battery, the separator comprising:

• a porous substrate;
• and
• an inorganic particle layer including a binder and inorganic particles on at least one surface of the porous substrate,
• wherein the binder includes a water-soluble binder material including a unit derived from a (meth)acrylamide-based monomer, and the separator exhibits a value of the following Formula (1) satisfying 0.15 or more:
• BDV/t (1)
• wherein
• ‘BDV’ is a voltage in kilovolts (kV) measured in accordance with ASTM D 3755 Standard Test Method for Dielectric Breakdown Voltage and Dielectric Strength of Solid Electrical Insulating Materials Under Direct-Voltage Stress, when a leakage current value is 5 mA, measured under conditions of raising an applied voltage at 5 kV/10 sec after placing the separator between electrodes of a withstand voltage tester (Hipot Tester), and
• ‘t’ is an overall average thickness in microns (μm) of the separator.