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

A method of manufacturing a separator, the method comprising:

• (a1) preparing an acid aqueous solution including a silane compound represented by Chemical Formula 1 and an acid component;
• (a2) preparing an inorganic slurry by stirring inorganic particles, an acid component, and water;
• (a3) preparing a coating slurry by mixing the inorganic slurry and the acid aqueous solution;
• and
• (b) applying the prepared coating slurry on at least one surface of a porous substrate and drying the coating slurry to provide an inorganic particle layer:
• AaSi(OR)b Chemical Formula 1
• wherein A is hydrogen, a polar functional group, or a C1-C10 alkyl group having a polar functional group, R is independently hydrogen or a C1-C5 alkyl group, a is 0 to 2, b is 2 to 4, and a+b is 4, and
• wherein the polar functional group of the silane compound includes one or two or more selected from an amino group, an epoxy group, a carboxyl group, a hydroxyl group, an amide group, a thiol group, a ketone group, an ester group, and an aldehyde group.