Anode active material, non-aqueous lithium secondary battery including the same, and manufacturing method thereof

Patent metadata

Field	Value
Publication number	US-8932763-B2
Application number	US-201113819073-A
Country	US
Kind code	B2
Filing date	Jun 15, 2011
Priority date	Sep 16, 2010
Publication date	Jan 13, 2015
Grant date	Jan 13, 2015

Abstract

The disclosure relates to an anode active material, a non-aqueous lithium secondary battery, and a manufacturing method thereof. The anode active material of this disclosure comprises a carbon-based material, and a coating film formed on the surface of the carbon-based material by performing heat treatment using an ammonia-based compound. The coating film may be formed on the surface of the carbon-based material through a thermal decomposition method using 10% or less by weight of the ammonia-based compound with respect to the carbon-based material. Since the surface of the carbon-based material is thermally treated using the ammonia-based compound, side reaction of the carbon-based material with an electrolyte at the surface thereof can be suppressed and structural stability can be enhanced, thereby improving battery lifespan and high-rate capability of a non-aqueous lithium secondary battery.

First claim

What is claimed is:

1. A method for manufacturing an anode active material for use in a non-aqueous lithium secondary battery, the method comprising:
preparing a carbon-based material and an ammonia-based compound; and
forming a coating film on the surface of the carbon-based material using the ammonia-based compound,
wherein the ammonia-based compound is expressed by a chemical formula of (NH 4 )xMyNz
where
M is B, P, Al, N, S, Mo, Mn, Pt or Cr,
N is F, O, Cl or I,
1≦x≦3, 0≦y≦2, and

1≦z≦8 (x, y and z being integers),

wherein the forming of the coating film comprises:
dissolving the carbon-based material and the ammonia-based compound in a solvent to form a solution;
uniformly mixing the carbon-based material and the ammonia-based compound in the solution;
vacuum-drying the solution; and
performing heat treatment on the dried material through thermal decomposition to form the coating film based on the ammonia-based compound on the surface of the carbon-based material.

2. The anode active material of claim 1 , wherein the preparing comprises preparing the ammonia-based compound to be 10% or less by weight of the carbon-based material.

3. The anode active material of claim 1 , wherein the forming the coating film comprises forming the coating film partially on the surface of the carbon-based material.

4. The anode active material of claim 1 , wherein the ammonia-based compound is at least one of NH 4 F, NH 4 BF 4 , NH 4 PF 6 , NH 4 AlF 6 , NH 4 NO 2 , NH 4 NO 3 , NH 4 ClO 3 , NH 4 ClO 4 , (NH 4 ) 2 SO 3 , (NH 4 ) 2 SO 4 , (NH 4 ) 2 CO 3 , (NH 4 ) 2 MoO 4 , (NH 4 ) 2 PO 4 , NH 4 PO 3 , NH 4 MnO 4 , (NH 4 ) 2 Cr 2 O 7 , NH 4 SO 4 , (NH 4 ) 2 MnSO 4 , (NH 4 ) 2 S 2 O 8 , NH 42 Cl, (NH 4 )PtCl 6 or NH 4 I.

5. The anode active material of claim 1 , wherein the carbon-based material includes at least one of artificial graphite, natural graphite, graphitized carbon fiber, graphitized mesocarbon microbeads, petroleum coke, plastic resins, carbon fiber or pyrocarbon.

6. A method for manufacturing an anode active material for use in a non-aqueous lithium secondary battery, the method comprising:
preparing a carbon-based material and an ammonia-based compound; and
forming a coating film on the surface of the carbon-based material using the ammonia-based compound,
wherein the ammonia-based compound is expressed by a chemical formula of (NH 4 )xMyNz
where
M is B, P, Al, N, S, Mo, Mn, Pt or Cr,
N is F, O, Cl or I,
1≦x≦3, 0≦y≦2, and
1≦z≦8 (x, y and z being integers),

wherein the forming of the coating film comprises:
dissolving the ammonia-based compound in a solvent to form a solution;
injecting the solution into the carbon-based material;
mixing the injected solution including the ammonia-based compound and the carbon-based material; and
performing heat treatment on the mixed carbon-based material and the solution to form the coating film based on the ammonia-based compound on the surface of the carbon-based material.

7. A method for manufacturing an anode active material for use in a non-aqueous lithium secondary battery, the method comprising:
preparing a carbon-based material and an ammonia-based compound; and
forming a coating film on the surface of the carbon-based material using the ammonia-based compound,
wherein the ammonia-based compound is expressed by a chemical formula of (NH 4 )xMyNz
where
M is B, P, Al, N, S, Mo, Mn, Pt or Cr,
N is F, O, Cl or I,
1≦x≦3, 0≦y≦2, and
1≦z≦8 (x, y and z being integers),

wherein the forming of the coating film comprises:
mixing powders of the carbon-based material and the ammonia-based compound; and
performing heat treatment on the mixed powders of the carbon-based material and the ammonia-based compound to form the coating film based on the ammonia-based compound on the surface of the carbon-based material.

8. The method of claim 1 , wherein ammonia contained in the ammonia-based compound is removed through the heat treatment, and other inorganic materials form the coating film on the surface of the carbon-based material during heat treatment as a result of the decomposition of the ammonia-based compound.

9. The method of claim 8 , wherein the heat treatment is performed at a temperature in the range of 200 to 3000° C. for one hour or longer.

10. The anode active material of claim 1 , wherein forming the coating film comprises forming the coating film uniformly on the surface of the carbon-based material.

11. The anode active material of claim 6 , wherein the preparing comprises preparing the ammonia-based compound being 10% or less by weight of the carbon-based material.

12. The anode active material of claim 6 , wherein the ammonia-based compound is at least one of NH 4 F, NH 4 BF 4 , NH 4 PF 6 , NH 4 AlF 6 , NH 4 NO 2 , NH 4 NO 3 , NH 4 ClO 3 , NH 4 ClO 4 , (NH 4 ) 2 SO 3 , (NH 4 ) 2 SO 4 , (NH 4 ) 2 CO 3 , (NH 4 ) 2 MoO 4 , (NH 4 ) 2 PO 4 , NH 4 PO 3 , NH 4 MnO 4 , (NH 4 ) 2 Cr 2 O 7 , NH 4 SO 4 , (NH 4 ) 2 MnSO 4 , (NH 4 ) 2 S 2 O 8 , NH 42 Cl, (NH 4 )PtCl 6 or NH 4 I.

13. The anode active material of claim 6 , wherein the carbon-based material includes at least one of artificial graphite, natural graphite, graphitized carbon fiber, graphitized mesocarbon microbeads, petroleum coke, plastic resins, carbon fiber or pyrocarbon.

14. The method of claim 6 , wherein ammonia contained in the ammonia-based compound is removed through the heat treatment, and other inorganic materials form the coating film on the surface of the carbon-based material during heat treatment as a result of the decomposition of the ammonia-based compound.

15. The method of claim 14 , wherein the heat treatment is performed at a temperature in the range of 200 to 3000° C. for one hour or longer.

16. The anode active material of claim 7 , wherein the preparing comprises preparing the ammonia-based compound being 10% or less by weight of the carbon-based material.

17. The anode active material of claim 7 , wherein the ammonia-based compound is at least one of NH 4 F, NH 4 BF 4 , NH 4 PF 6 , NH 4 AlF 6 , NH 4 NO 2 , NH 4 NO 3 , NH 4 ClO 3 , NH 4 ClO 4 , (NH 4 ) 2 SO 3 , (NH 4 ) 2 SO 4 , (NH 4 ) 2 CO 3 , (NH 4 ) 2 MoO 4 , (NH 4 ) 2 PO 4 , NH 4 PO 3 , NH 4 MnO 4 , (NH 4 ) 2 Cr 2 O 7 , NH 4 SO 4 , (NH 4 ) 2 MnSO 4 , (NH 4 ) 2 S 2 O 8 , NH 42 Cl, (NH 4 )PtCl 6 or NH 4 I.

18. The anode active material of claim 7 , wherein the carbon-based material includes at least one of artificial graphite, natural graphite, graphitized carbon fiber, graphitized mesocarbon microbeads, petroleum coke, plastic resins, carbon fiber or pyrocarbon.

19. The method of claim 7 , wherein ammonia contained in the ammonia-based compound is removed through the heat treatment, and other inorganic materials form the coating film on the surface of the carbon-based material during heat treatment as a result of the decomposition of the ammonia-based compound.

20. The method of claim 7 , wherein the heat treatment is performed at a temperature in the range of 200 to 3000° C. for one hour or longer.

Assignees

• Kim Young Jun
• Jo Yong Nam
• Park Min Sik
• Korea Electronics Technology

Inventors

• Kim Young Jun
• Jo Yong Nam
• Park Min Sik

Classifications

• Y02E60/122

  Cross-Sectional Technologies · mapped topic

• H01M4/366

  as layered products · CPC title

• H01M4/133 Primary

  Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx · CPC title

• H01M4/0471

  involving thermal treatment, e.g. firing, sintering, backing particulate active material, thermal decomposition, pyrolysis · CPC title

• H01M4/58 Primary

  of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates · CPC title