Positive electrode and lithium-sulfur battery comprising same

1 . A positive electrode for a lithium-sulfur battery, the positive electrode comprising a current collector and a positive electrode active material layer disposed on at least one side of the current collector,

wherein the positive electrode active material layer comprises a positive electrode active material and an additive, and the additive comprises a transition metal-ferrocyanide compound,

wherein the positive electrode active material consists of a sulfur-carbon composite,

wherein the sulfur-carbon composite comprises a porous carbon material that provides a framework in which sulfur is fixed,

wherein the transition metal-ferrocyanide compound is contained in the positive electrode active material layer in an amount of 1 to 20% by weight based on 100% by weight of the total of the positive electrode active material layer,

wherein the sulfur-carbon composite comprises the porous carbon material and the sulfur in at least a portion of inner and outer surfaces of the porous carbon material, and

wherein the transition metal-ferrocyanide compound is present as a separate additive distinct from the sulfur-carbon composite.

2 . The positive electrode according to claim 1 , wherein the transition metal-ferrocyanide compound comprises at least one selected from the group consisting of iron (III) ferrocyanide, cobalt (II) ferrocyanide, nickel (II) ferrocyanide, copper (II) ferrocyanide, and zinc (II) ferrocyanide.

3 . The positive electrode according to claim 1 , wherein the transition metal-ferrocyanide compound comprises iron (III) ferrocyanide.

4 . The positive electrode according to claim 1 , wherein the transition metal-ferrocyanide compound has a water content of 10% by weight or less.

5 . The positive electrode according to claim 1 , wherein the transition metal-ferrocyanide compound has a lattice structure, and is vacuum-dried to remove moisture in the lattice structure.

6 . The positive electrode according to claim 1 , wherein the porous carbon material comprises at least one selected from the group consisting of graphite, graphene, carbon black, carbon nanotubes, carbon fibers, graphite and activated carbon.

7 . The positive electrode according to claim 1 , wherein the sulfur comprise at least one selected from the group consisting of inorganic sulfur, Li 2 S n where n≥1, disulfide compounds, organosulfur compounds, and carbon-sulfur polymers (C 2 S x ) n where x=2.5 to 50, and n≥2.

8 . The positive electrode according to claim 1 , wherein the sulfur is contained in an amount of 65 to 90% by weight based on 100% by weight of the total of the sulfur-carbon composite.

9 . The positive electrode according to claim 1 , wherein the positive electrode has a loading amount of sulfur of 6 to 8 mg/cm 2 .

10 . A lithium-sulfur battery comprising the positive electrode according to claim 1 ; a negative electrode; and an electrolyte.