Lithium-sulfur battery separation film having composite coating layer including polydopamine, manufacturing method therefor, and lithium-sulfur battery comprising same

A separator for a lithium-sulfur battery comprising:

• a separator body;
• a composite coating layer formed on at least one surface of the separator body;
• and
• a polydopamine coating layer between the separator body and the composite coating layer,
• wherein the composite coating layer comprises polydopamine and a conductive material.

A method for preparing a separator for a lithium-sulfur battery comprising:

• i) preparing a separator body;
• ii) preparing a mixture slurry by mixing polydopamine, a conductive material and a solvent,
• wherein mixture of the polydopamine and the conductive material is in a weight ratio of 3:1 to 7:1;
• iii) coating the mixture slurry on at least one surface of the separator body;
• and
• iv) forming a composite coating layer by drying the coated separator.

A method for preparing a separator for a lithium-sulfur battery, comprising:

• i) preparing a separator body;
• ii) preparing a polydopamine slurry;
• iii) coating the polydopamine slurry on the separator body;
• iv) drying the coated separator body;
• v) preparing a mixture slurry by mixing polydopamine, a conductive material and a solvent;
• vi) coating the mixture slurry on at least one surface of the separator body;
• and
• vii) forming a composite coating layer by drying the coated separator body.