Method of forming silicon nanowires and method of fabricating lithium secondary battery using the same

1. A method of preparing a silicon nanowire, comprising:

forming a catalyst layer comprising metal particles separated from one another on a silicon material;

selectively etching the silicon material contacting the metal particles; and

removing the metal particles,

wherein the forming of a catalyst layer comprises:

forming mask particles with a material different from the metal particles and the silicon material; and

forming the metal particles among the mask particles.

2. The method of claim 1 , wherein the silicon silicon material is wet etched.

3. The method of claim 2 , wherein the wet etching are performed using a mixed solution of a fluoric acid (HF) aqueous solution and a hydrogen peroxide (H 2 O 2 ) aqueous solution as an etching solution.

4. The method of claim 1 , wherein the mask particles comprise a core layer including metal ions and a polymer layer surrounding the core layer.

5. The method of claim 4 , wherein the mask particles are post-treated after forming the catalyst layer, and

the polymer layer is removed through the post-treatment.

6. The method of claim 5 , wherein the metal ions are oxidized into a metal oxide through the post-treatment, and

the metal oxide comprises Fe 2 O 3 , Fe 3 O 4 , Al 2 O 3 , ZrO 2 , TiO 2 , SnO 2 , MnO, or a combination thereof.

7. The method of claim 4 , wherein the polymer layer is a copolymer including blocks A and B, and the blocks A and B independently comprise polystyrene, polyisoprene, poly(2-vinylpyridine), poly(4-vinylpyridine), poly(ethylene oxide), poly(caprolactone), poly(lactide), poly(methylmethacrylate), poly(ethylmethacrylate), poly(butylmethacrylate), poly(acrylic acid), poly(α-methyl styrene), poly(styrene sulfonate), polybutadiene, polyurethane, polyacrylonitrile, poly(propylene oxide), or a combination thereof.

8. A method of fabricating a lithium secondary battery, comprising:

forming a silicon material on a current collector layer;

forming a catalyst layer comprising metal particles arranged at a predetermined distance on the silicon material which is formed on the current collector layer;

etching the silicon material using the metal particles as a catalyst to form silicon nanowires; and

removing the metal particles.

9. The method of claim 8 , wherein the silicon material is etched through a wet etching process.

10. The method of fabricating a lithium secondary battery of claim 8 , wherein the formation of the catalyst layer comprises:

forming mask particles separated from one another on the silicon material; and

forming the metal particles among the mask particles.

11. The method of claim 10 , wherein the mask particles comprise a core layer comprising metal ions and a polymer layer surrounding the core layer.

12. The method of claim 8 , wherein the silicon material is etched until the current collector layer is exposed.

13. A method of fabricating a lithium secondary battery, comprising:

forming a catalyst layer comprising metal particles arranged at a predetermined distance on silicon material;

etching the silicon material using the metal particles as a catalyst to form silicon nanowires;

removing the metal particles; and,

coating the silicon nanowires with carbon.