Composite anode active material, method of preparing the same, and anode and lithium secondary battery including the composite anode active material

• US 10,164,252 B2
• Filed: 12/31/2015
• Issued: 12/25/2018
• Est. Priority Date: 12/31/2014
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd., Samsung SDI Company Limited
• Original Assignee: Samsung Electronics Co. Ltd., Samsung SDI Company Limited
• Inventors: Yang, Jeeeun, Jung, Heechul, Mun, Jinsoo
• Primary Examiner(s): Chandler, Kaity V
• Application Number:
  US14/985,544
• Publication Number:
  US 20160190568A1
• Time in Patent Office: 1,090 Days
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 4/364 as mixtures
• CPC Class Codes: H01M 4/366 as layered products
• CPC Class Codes: H01M 4/386 Silicon or alloys based on silicon
• CPC Class Codes: H01M 4/624 Electric conductive fillers
• CPC Class Codes: H01M 4/625 Carbon or graphite
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A composite anode active material includes a metal silicide core, a silicon shell, and a metal nitride and a carbon material that are dispersed in at least one surface of the silicon shell.

Claims

1. A composite anode active material comprising:

a metal silicide core;

a silicon shell which surrounds an entirety of the metal silicide core; and

a metal nitride and a carbon material which are directly disposed on an outer surface of the silicon shell,

wherein the metal silicide is TiSi_x (where, 0<

x≤

2).

2. The composite anode active material of claim 1, wherein the carbon material includes at least one of carbon nanotubes (CNTs), graphene, graphite, and carbon fibers.

3. The composite anode active material of claim 1, wherein an amount of the carbon material is in a range of about 1 part to about 70 parts by weight based on 100 parts by weight of a total weight of the composite anode active material.

4. The composite anode active material of claim 1, wherein the metal silicide and the metal nitride comprise the same metal.

5. The composite anode active material of claim 4, wherein the metal silicide and the metal nitride comprise at least one metal of titanium (Ti), vanadium (V), copper (Cu), zinc (Zn), molybdenum (Mo), nickel (Ni), aluminum (Al), calcium (Ca), magnesium (Mg), iron (Fe), and chrome (Cr).

6. A method of preparing a composite anode active material, the method comprising:

milling a metal silicide; and

heat-treating the milled metal silicide in a nitrogen atmosphere; and

combining the heat-treated resultant and a carbon material to obtain a combination and then milling the combination; and

wherein

the composite anode active material comprises;

a metal silicide core;

a silicon shell which surrounds an entirety of the metal silicide core; and

a metal nitride and a carbon material which are directly disposed on an outer surface of the silicon shell, wherein the metal silicide is TiSi_x (where, 0<

x<

or equal

     2).

7. The method of claim 6, wherein the milling the combination is performed for about 120 minutes or less.

8. The method of claim 6, wherein the heat-treating is performed at a temperature in a range of about 800 degrees Celsius to about 1200 degrees Celsius.

9. An anode comprising a composite anode active material, wherein the composite anode active material comprises:

a metal silicide core;

a silicon shell which surrounds an entirety of the metal silicide core; and

a metal nitride and a carbon material which are directly disposed on an outer surface of the silicon shell,

wherein the metal silicide is TiSi_x (where, 0<

x≤

2).

10. The anode of claim 9 further comprising a carbon material.

11. The anode of claim 9, wherein the carbon material includes at least one of carbon nanotubes (CNTs), graphene, graphite, and carbon fibers.

12. The anode of claim 9, wherein an amount of the carbon material is in a range of about 1 part to about 70 parts by weight based on 100 parts by weight of a total weight of the composite anode active material.

13. The anode of claim 9, wherein the metal silicide and the metal nitride comprise the same metal.

14. The anode of claim 9, wherein the metal silicide and the metal nitride comprise at least one metal of titanium (Ti), vanadium (V), copper (Cu), zinc (Zn), molybdenum (Mo), nickel (Ni), aluminum (Al), calcium (Ca), magnesium (Mg), iron (Fe), and chrome (Cr).

15. A lithium secondary battery comprising an anode comprising a composite anode active material, wherein the composite anode active material comprises:

a metal silicide core;

a silicon shell which surrounds an entirety of the metal silicide core; and

a metal nitride and a carbon material which are directly disposed on an outer surface of the silicon shell,

wherein the metal silicide is TiSi_x (where, 0<

x≤

2).