Porous anode active material, method of manufacturing the same, anode comprising the same, and lithium battery comprising the anode
A porous anode active material including a Group 14 element oxide and a non-active material having no reactivity with lithium; a method of manufacturing the porous anode active material; an anode including the porous anode active material; and a lithium battery including the anode. The non-active material may be silica.
1. A porous anode active material comprising:
85-99 parts by weight of a mesoporous Group 14 element oxide; and
1-15 parts by weight of silica that is formed in particles attached to the surface of the mesoporous Group 14 element oxide and exists in a non-active phase having no reactivity with lithium.
2. The porous anode active material of claim 1 , wherein the mesoporous Group 14 element oxide is selected from the group consisting of tin oxide (SnO 2 ), silicon oxide (SiO x where 0<x<2), germanium oxide (GeO 2 ) and lead oxide (PbO).
3. The porous anode active material of claim 1 , wherein the mesoporous Group 14 element oxide has mesopores having a diameter of 2 to 50 nm.
4. A method of manufacturing a porous anode active material, the method comprising:
immersing ordered mesoporous silica (OMS) in a Group 14 element salt-containing aqueous solution that comprises a Group 14 element salt and a solvent;
heat treating the resultant product to form an OMS-Group 14 element oxide complex; and
etching the OMS-Group 14 element oxide complex with an acid solution or a base solution to obtain a porous anode active material comprising: 85-99 parts by weight of a mesoporous Group 14 element oxide; and 1-15 parts by weight of silica that exists in a non-active phase having no reactivity with lithium.
5. The method of claim 4 , wherein the Group 14 element salt comprises at least one compound selected from the group consisting of SnCl 4 , SnCl 2 , SnSO 4 , Na 2 SnO 3 , PbSO 4 , PbCl 2 , GeCl 4 , GeOCl 2 , Na 2 SiO 3 , Li 2 SiO 3 , and Li 4 SiO 4 .
6. The method of claim 4 , wherein the base solution is selected from an NaOH solution and a KOH solution.
7. The method of claim 4 , wherein the acid solution is an HF solution.
8. The method of claim 4 , wherein the heat treating is performed in an oxygen atmosphere at a temperature of 300 to 800° C.
9. An anode comprising the porous anode active material of claim 1 .
10. An anode comprising the porous anode active material of claim 2 .
11. An anode comprising the porous anode active material of claim 3 .
12. A lithium battery comprising an anode that comprises the porous anode active material of claim 1 .
13. The porous anode active material of claim 2 , wherein the X in SiO x is 1.
14. The porous anode active material of claim 3 , wherein the mesoporous Group 14 element oxide mesopores have a diameter of 5 to 10 nm.
15. The porous anode active material of claim 3 , wherein:
the mesoporous Group 14 element oxide is tin oxide,
and
the average diameter of the silica particles is 20 to 200 nm.
16. The method of claim 4 , wherein the heat treating is performed for 2 to 3 hours.
17. A method of manufacturing an anode comprising a porous anode active material, the method comprising:
mixing the porous anode active material with a conductive material, a binder and a solvent to form an anode active material forming composition;
coating the anode active material forming composition on a collector; and
drying the combination of the anode active material forming composition and the collector, wherein:
the porous anode active material comprises 85-99 parts by weight of a mesoporous Group 14 element oxide,
the porous anode active material comprises 1-15 parts by weight of silica that exists in a non-active phase having no reactivity with lithium,
the mesoporous Group 14 element oxide is selected from the group consisting of tin oxide (SnO 2 ), silicon oxide (SiO x where 0<x<2), germanium oxide (GeO 2 ) and lead oxide (PbO), and
the mesoporous Group 14 element oxide has mesopores having a diameter of 2 to 50 nm.