Silicon-based composite and production method thereof
The present invention relates to a silicon-based composite including a silicon oxide which is coated thereon with carbon and bonded therein to lithium. The present invention also relates to a method of producing a silicon-based composite, comprising coating a surface of silicon oxide with carbon, mixing the silicon oxide coated with carbon with lithium oxide, and heat-treating a mixture of the silicon oxide coated with carbon and the lithium oxide in an inert atmosphere.
1. A silicon-based composite consisting of silicon oxide which is coated thereon with carbon and is bonded therein to lithium,
wherein the lithium is derived from at least one kind of a lithium compound selected from the group consisting of Li 2 O, Li 2 CO 3 and LiOH.H 2 O,
wherein the lithium in the silicon-based composite has a uniform concentration from a surface of the silicon-based composite to a center of the silicon-based composite.
2. The silicon-based composite of claim 1 , wherein the carbon is a crystalline carbon, an amorphous carbon, or a mixture thereof.
3. The silicon-based composite of claim 1 , wherein the amount of the carbon is in a range of 2 part by weight to 30 part by weight based on 100 parts by weight of the silicon oxide.
4. The silicon-based composite of claim 1 , wherein the amount of the lithium is in a range of 2 part by weight to 15 part by weight based on 100 parts by weight of the silicon oxide coated with carbon.
5. The silicon-based composite of claim 1 , wherein the silicon oxide is SiO x (0<x<2).
6. The silicon-based composite of claim 5 , wherein the silicon oxide is silicon monoxide.
7. A method of producing the silicon-based composite of claim 1 , comprising:
coating a surface of silicon oxide with carbon;
mixing the silicon oxide coated with carbon and a lithium compound to obtain a mixture; and
heat-treating the mixture in an inert atmosphere,
wherein the lithium compound comprises at least one selected from the group consisting of Li 2 O, Li 2 CO 3 and LiOH.H 2 O.
8. The method of claim 7 , wherein the coating with carbon is performed by supplying acetylene gas and performing a heat treatment at 800° C.
9. The method of claim 7 , wherein the amount of the carbon is in a range of 2 part by weight to 30 part by weight based on 100 parts by weight of the silicon oxide.
10. The method of claim 7 , wherein the heat-treating is performed by heating the mixture from a room temperature to 500-1000° C. at a temperature rising rate of 1-20° C./min.
11. The method of claim 7 , after the heat-treating, further comprising cooling the mixture to room temperature.
12. A secondary battery comprising:
a cathode comprising a cathode active material;
a separator;
an anode comprising an anode active material; and
an electrolyte,
wherein the anode active material comprises the silicon-based composite of claim 1 .
13. A silicon-based composite comprising silicon oxide which is coated thereon with carbon and is bonded therein to lithium,
wherein the lithium is derived from at least one kind of a lithium compound selected from the group consisting of Li 2 O, and LiOH.H 2 O,
wherein the lithium in the silicon-based composite has a uniform concentration from a surface of the silicon-based composite to a center of the silicon-based composite.
14. The silicon-based composite of claim 13 , wherein the carbon is a crystalline carbon, an amorphous carbon, or a mixture thereof.
15. The silicon-based composite of claim 13 , wherein the amount of the carbon is in a range of 2 part by weight to 30 part by weight based on 100 parts by weight of the silicon oxide.
16. The silicon-based composite of claim 13 , wherein the amount of the lithium is in a range of 2 part by weight to 15 part by weight based on 100 parts by weight of the silicon oxide coated with carbon.
17. The silicon-based composite of claim 13 , wherein the silicon oxide is SiO x (0<x<2).
18. The silicon-based composite of claim 17 , wherein the silicon oxide is silicon monoxide.
19. The silicon-based composite of claim 13 , wherein the silicon oxide bonded to the lithium comprises at least one selected from the group consisting of Li 4 SiO 4 , Li 2 SiO 3 and Li 2 Si 2 O 5 .
20. A method of producing the silicon-based composite of claim 13 , comprising:
coating a surface of silicon oxide with carbon;
mixing the silicon oxide coated with carbon and a lithium compound to obtain a mixture; and
heat-treating the mixture in an inert atmosphere,
wherein the lithium compound comprises at least one selected from the group consisting of Li 2 O, and LiOH.H 2 O.
21. The method of claim 20 , wherein the coating with carbon is performed by supplying acetylene gas and performing a heat treatment at 800° C.
22. The method of claim 20 , wherein the amount of the carbon is in a range of 2 part by weight to 30 part by weight based on 100 parts by weight of the silicon oxide.
23. The method of claim 20 , wherein the heat-treating is performed by heating the mixture from a room temperature to 500-1000° C. at a temperature rising rate of 1-20° C./min.
24. The method of claim 20 , after the heat-treating, further comprising cooling the mixture to room temperature.
25. A secondary battery comprising:
a cathode comprising a cathode active material;
a separator;
an anode comprising an anode active material; and
an electrolyte,
wherein the anode active material comprises the silicon-based composite of claim 13 .