Anode active material for lithium secondary battery, method of preparing the same, and lithium secondary battery including the same
View Patent ↗Disclosed herein is a non-carbon-based anode active material for lithium secondary batteries, including: a core containing silicon (Si); and silicon nanoparticles formed on the surface of the core. The non-carbon-based anode active material is advantageous in that the increase in the volume expansion during charging-discharging can be prevented by the application of silicon nanoparticles, and in that SiOx(x<1.0) can be easily prepared.
1. A non-carbon-based anode active material for lithium secondary batteries, comprising:
a core containing silicon (Si); and
silicon nanoparticles formed on the surface of the core.
2. The non-carbon-based anode active material of claim 1 , wherein the silicon nanoparticles are included in an amount of 20 to 200 parts by weight, based on 100 parts by weight of the core.
3. The non-carbon-based anode active material of claim 1 , wherein the silicon nanoparticles are included in an amount of 50 to 100 parts by weight, based on 100 parts by weight of the core.
4. The non-carbon-based anode active material of claim 1 , wherein the silicon nanoparticles have a particle diameter of 5 to 100 nm.
5. The non-carbon-based anode active material of claim 4 , wherein the silicon nanoparticles have a particle diameter of 20 to 80 nm.
6. The non-carbon-based anode active material of claim 1 , wherein the core has a particle diameter of 1 to 30 μm.
7. The non-carbon-based anode active material of claim 6 , wherein the core has a particle diameter of 3 to 10 μm.
8. The non-carbon-based anode active material of claim 1 , further comprising a coating layer formed on the surface of the core and containing carbon (C).
9. The non-carbon-based anode active material of claim 8 , wherein the coating layer is included in an amount of 5 to 70 wt %, based on a total amount of the anode active material.
10. The non-carbon-based anode active material of claim 1 , wherein the core is made of SiOx (0<x≦1).
11. The non-carbon-based anode active material of claim 10 , wherein the core is made of SiO.
12. The non-carbon-based anode active material of claim 10 , wherein the SiOx (0<x≦1) is amorphous.
13. A method of preparing a non-carbon-based anode active material for lithium secondary batteries, comprising the steps of:
preparing a core containing silicon (Si); and
mixing silicon nanoparticles with the core to attach the silicon nanoparticles to the surface of the core.
14. The method of claim 13 , wherein the silicon nanoparticles and the core are mixed by ball milling or planetary ball mill.
15. The method of claim 13 , wherein the silicon nanoparticles and the core are mixed by dispersing the silicon nanoparticles using a dispersant and then stirring the dispersed silicon nanoparticles and the core in a solvent.
16. The method of claim 13 , further comprising the step of forming a coating layer containing carbon on the surface of the core attached with the silicon nanoparticles.
17. The method of claim 15 , wherein the dispersant is included in an amount of 2 to 10 wt % based on the amount of the mixed solution of the silicon nanoparticles and the core.
18. The method of claim 16 , wherein the coating layer is formed by chemical vapor deposition (CVD) or pitch coating.
19. A lithium secondary battery, comprising:
an anode including the anode active material of claim 1 ;
a cathode including a cathode active material; and
an electrolyte.