Anode active material and method of preparing the same

• US 8,906,557 B2
• Filed: 03/22/2007
• Issued: 12/09/2014
• Est. Priority Date: 04/17/2006
• Status: Expired due to Fees

• Current Assignee: Samsung SDI Company Limited
• Original Assignee: Samsung SDI Company Limited
• Inventors: Kim, Gue-sung, Ham, Yong-nam, Kim, Han-su, Im, Dong-min
• Primary Examiner(s): Li, Jun
• Application Number:
  US11/689,941
• Publication Number:
  US 20070243469A1
• Time in Patent Office: 2,819 Days
• Field of Search: 429/218.1, 429/218.2, 429/223, 429/231.1, 429/231.2, 429/231.3, 429/224, 429/623.5, 252/182.1, 252/504, 252/506, 252/507
• US Class Current: 429/232
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 2004/021 Physical characteristics, e.g. porosity, surface area
• CPC Class Codes: H01M 4/0471 involving thermal treatment, e.g. firing, sintering, backing particulate active material, thermal decomposition, pyrolysis
• CPC Class Codes: H01M 4/133 Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
• CPC Class Codes: H01M 4/134 Electrodes based on metals, Si or alloys
• CPC Class Codes: H01M 4/364 as mixtures
• CPC Class Codes: H01M 4/38 of elements or alloys
• CPC Class Codes: H01M 4/386 Silicon or alloys based on silicon
• CPC Class Codes: H01M 4/387 Tin or alloys based on tin
• CPC Class Codes: H01M 4/625 Carbon or graphite
• CPC Class Codes: H01M 4/626 Metals
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

Anode active materials and methods of preparing the same are provided. One anode active material includes a carbonaceous material capable of improving battery cycle characteristics. The carbonaceous material bonds to and coats metal active material particles and fibrous metallic particles to suppress volumetric changes.

Claims

1. An anode active material comprising a composite anode active material comprising:

metal active material particles consisting of a metal selected from the group consisting of Si, Ge, and combinations thereof;

fibrous carbon-metallic composite particles consisting essentially of carbon and a metal selected from the group consisting of Co, Ag, Ti, Zn, Mo, W, Mn, Cr, and combinations thereof; and

a carbonaceous material coated on and bonded to the metal active material particles and the fibrous carbon-metallic composite particles.

2. The anode active material of claim 1, wherein an aspect ratio of the fibrous carbon-metallic composite particles ranges from about 1:

2 to about 1;

200.

3. The anode active material of claim 1, wherein a specific resistance of the fibrous carbon-metallic composite particles is less than about 20×

10<sup>−

8</sup> Ω

m.

4. The anode active material of claim 1, wherein the fibrous carbon-metallic composite particles have an average particle diameter of less than 1000 nm.

5. The anode active material of claim 1, wherein the fibrous carbon-metallic composite particles have a shape selected from the group consisting of rods and tubes.

6. The anode active material of claim 1, wherein the carbonaceous material is prepared by carbonizing a resin selected from the group consisting of vinyl-based resins, phenol-based resins, cellulose-based resins, pitch-based resins, tar-based resins, and combinations thereof.

7. An anode electrode comprising the anode active material of claim 1.

8. A lithium battery comprising the anode electrode of claim 7.

9. The anode active material of claim 1, wherein the fibrous carbon-metallic composite particles consist essentially of carbon and a metal selected from the group consisting of Co, Ti, Zn, Mo, W, Mn, Cr, and combinations thereof.

10. A method of preparing the anode active material of claim 1, the method comprising:

mixing a metal active material powder, fibrous carbon-metallic composite particles and a carbonaceous material precursor to obtain a mixture;

pulverizing the mixture to prepare a pulverized mixture; and

calcining the pulverized mixture.

11. The method of claim 10, wherein the carbonaceous material precursor comprises a resin selected from the group consisting of vinyl-based resins, phenol-based resins, cellulose-based resins, pitch-based resins, tar-based resins and combinations thereof.

12. The method of claim 10, wherein the pulverizing the mixture comprises a technique selected from the group consisting of high-energy milling, mechano-fusion, ball milling, hammer milling and combinations thereof.

13. The method of claim 10, wherein the calcining the pulverized mixture comprises heat-treating the pulverized mixture at a calcination temperature ranging from about 500 to about 1400°

C.

14. The method of claim 10, wherein the fibrous carbon-metallic composite particles are present in the anode active material in an amount ranging from about 0.01 to about 20 parts by weight based on the weight of the metal active material powder, and the carbonaceous precursor is present in the anode active material in an amount ranging from about 0.1 to about 20 parts by weight based on the weight of the metal active material powder.

15. A lithium battery comprising:

a cathode;

an anode comprising a composite anode active material comprising;

metal active material particles consisting of a metal selected from the group consisting of Si, Ge, and combinations thereof;

fibrous carbon-metallic composite particles consisting essentially of carbon and a metal selected from the group consisting of Co, Ag, Ti, Zn, Mo, W, Mn, Cr, and combinations thereof; and

a carbonaceous material coated on and bonded to the metal active material particles and the fibrous carbon-metallic composite particles; and

a separator positioned between the cathode and anode.

16. The lithium battery of claim 15, wherein an aspect ratio of the fibrous carbon-metallic composite particles ranges from about 1:

2 to about 1;

200.

17. The lithium battery of claim 15, wherein a specific resistance of the fibrous carbon-metallic composite particles is less than about 20×

10<sup>−

8</sup> Ω

m.

18. The lithium battery of claim 15, wherein the fibrous carbon-metallic composite particles have an average particle diameter of less than 1000 nm.

19. The lithium battery of claim 15, wherein the fibrous carbon-metallic composite particles consist essentially of carbon and a metal selected from the group consisting of Co, Ti, Zn, Mo, W, Mn, Cr, and combinations thereof.