Positive electrode for lithium ion secondary battery and lithium ion secondary battery including the same

1. A composite positive electrode material for a lithium ion secondary battery, the positive electrode comprising:

a positive electrode particle comprising a positive active material particle, wherein the positive electrode particle comprises

a first coating layer on a surface of the positive active material particle wherein the first coating layer comprises a carbonaceous material, and

a second coating layer on the first coating layer, wherein the second coating layer comprises a lithium-containing compound; and

a sulfide solid electrolyte contacting the second coating layer of the positive electrode particle,

wherein the lithium-containing compound of the second coating layer comprises a lithium-containing oxide, a lithium-containing phosphorus oxide, or a combination thereof,

wherein the lithium-containing oxide is a lithium zirconium oxide, a lithium niobium oxide, a lithium titanium oxide, a lithium aluminum oxide, or a combination thereof, and

wherein the lithium-containing phosphorus oxide is a lithium titanium phosphorus oxide, a lithium zirconium phosphorus oxide, or a combination thereof.

2. The composite positive electrode material of claim 1 , wherein the carbonaceous material comprises amorphous carbon.

3. The composite positive electrode material of claim 1 , wherein the carbonaceous material comprises carbon and further comprises a hydrocarbon represented by the formula C 4n+6 H 4n+12 , where n is a positive integer.

4. The composite positive electrode material of claim 1 , wherein the carbonaceous material comprises diamond-like-carbon.

5. The composite positive electrode material of claim 4 , wherein the diamond-like-carbon comprises hydrogen atoms in an amount in a range of about 1 atomic percent to about 50 atomic percent, based on a total content of the diamond-like-carbon.

6. The composite positive electrode material of claim 4 , wherein the diamond-like-carbon comprises carbon atoms having sp 2 hybrid bonds and carbon atoms having sp 3 hybrid bonds, and

wherein a content of the carbon atoms having sp 3 hybrid bonds in the diamond-like-carbon is in a range of about 10% to about 100%, based on a total carbon atom content of the diamond-like-carbon.

7. The composite positive electrode material of claim 1 , wherein a thickness of the first coating layer is in a range of about 1 nanometer to about 50 nanometers.

8. The composite positive electrode material of claim 1 , wherein the lithium-containing oxide comprises aLi 2 O—ZrO 2 , where 0.1≤a≤2.0.

9. The composite positive electrode material of claim 1 , wherein a sum of a thickness of the first coating layer and a thickness of the second coating layer is in a range of about 1 nanometer to about 500 nanometers.

10. The composite positive electrode material of claim 1 , wherein the positive active material particle comprises a lithium salt of a transition metal oxide having a layered rock-salt type structure.

11. The composite positive electrode material of claim 10 , wherein the lithium salt of a transition metal oxide having a layered rock-salt type structure is of the formula LiNi x Co y M z O 2 , wherein M is Al or Mn, 0<x<1, 0<y<1, and x+y+z=1.

12. The composite positive electrode material of claim 1 , wherein the sulfide solid electrolyte comprises

sulfur,

lithium, and

phosphorus, silicon, boron, aluminum, germanium, zinc, gallium, indium, a halogen element, or a combination thereof.

13. The composite positive electrode material of claim 1 , wherein the sulfide solid electrolyte comprises

a lithium sulfide, and

a silicon sulfide, a phosphorus sulfide, a boron sulfide, or a combination thereof.

14. The composite positive electrode material of claim 1 , wherein the sulfide solid electrolyte comprises Li 2 S and P 2 S 5 .

15. The composite positive electrode material of claim 1 , wherein the sulfide solid electrolyte is in a form of a particle.

16. A lithium ion secondary battery comprising the composite positive electrode material according to claim 1 .