Negative active material for a rechargeable lithium battery, a method of preparing the same, and a rechargeable lithium battery comprising the same

• US 9,012,082 B2
• Filed: 04/24/2014
• Issued: 04/21/2015
• Est. Priority Date: 03/08/2004
• Status: Active Grant

• Current Assignee: Samsung SDI Company Limited
• Original Assignee: Samsung SDI Company Limited
• Inventors: Lee, Sang-Min, Jeong, Goo-Jin, Kim, Sung-Soo, Nitta, Yoshiaki
• Primary Examiner(s): Conley, Helen O
• Application Number:
  US14/261,059
• Publication Number:
  US 20140234535A1
• Time in Patent Office: 362 Days
• Field of Search: 429/218.1, 429/209
• US Class Current: 429/218.1
• CPC Class Codes: C01B 35/12 Borates C01B35/1063 takes precedence
• CPC Class Codes: H01M 10/0525 Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• CPC Class Codes: H01M 4/0402 Methods of deposition of the material
• CPC Class Codes: H01M 4/13 Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
• CPC Class Codes: H01M 4/139 Processes of manufacture
• CPC Class Codes: H01M 4/362 Composites
• CPC Class Codes: H01M 4/485 of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy H01M4/505, H01M4/525 take precedence
• CPC Class Codes: H01M 4/587 for inserting or intercalating light metals
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

The present invention relates to a negative active material for a rechargeable lithium battery, which includes a silicon-based composite having a silicon oxide of the form SiO_x where x≦1.5 and at least one element selected from the group consisting of B, P, Li, Ge, Al, and V, and a carbonaceous material. The negative active material of the present invention can improve the cycle-life and high-rate charge/discharge characteristics of a rechargeable lithium battery.

Claims

1. A method for preparing a negative active material for a rechargeable lithium battery, comprising:

mixing one or more compounds selected from the group consisting of B₂O₃, B₂O, P₂O₅, P₂O₃, Li₂O, Li₂CO₃, LiOH, GeO₂, Al₂O₃, V₂O₅, and combinations thereof, with SiO₂ and Si to thereby produce a mixture;

heat treating the mixture to prepare a silicon-based composite comprising a silicon oxide of the form SiO_x where x≦

1.5, and one or more elements selected from the group consisting of B, P, Li, Ge, Al, and V;

quenching the silicon-based composite; and

coating the silicon-based composite with a carbonaceous material.

2. The method for preparing a negative active material for a rechargeable lithium battery according to claim 1, wherein the SiO₂ and Si are mixed in a weight ratio between 3:

1 and 1;

1.

3. The method for preparing a negative active material for a rechargeable lithium battery according to claim 1, wherein the one or more compounds selected from the group consisting of B-containing compounds, P-containing compounds, Li-containing compounds, Ge-containing compounds, Al-containing compounds, and V-containing compounds is a glass network former.

4. The method for preparing a negative active material for a rechargeable lithium battery according to claim 1, wherein the one or more compounds are added in an amount between 10 and 30 wt % based on the total weight of SiO₂ and Si.

5. The method for preparing a negative active material for a rechargeable lithium battery according to claim 1, wherein the heat treating is performed at a temperature between 600°

C. and 1000°

C.

6. The method for preparing a negative active material for a rechargeable lithium battery according to claim 1, wherein x is between 0.5 and 1.5.

7. The method for preparing a negative active material for a rechargeable lithium battery according to claim 1, wherein the carbonaceous material is crystalline carbon or amorphous carbon.

8. A method for preparing a negative active material for a rechargeable lithium battery, comprising:

mixing SiO₂ and Si with one or more compounds selected from the group consisting of B₂O₃, B₂O, P₂O₅, P₂O₃, Li₂O, Li₂CO₃, LiOH, GeO₂, Al₂O₃, and V₂O₅ to thereby produce a mixture;

heat treating the mixture to prepare a silicon-based composite comprising;

a silicon oxide of the form SiO_x where x≦

1.5, and one or more elements selected from the group consisting of B, P, Li, Ge, Al, and V; and

mixing the silicon-based composite with a carbonaceous material.

9. The method for preparing a negative active material for a rechargeable lithium battery according to claim 8, wherein the SiO₂ and Si are mixed in a weight ratio between 3:

1 and 1;

1.

10. The method for preparing a negative active material for a rechargeable lithium battery according to claim 8, wherein the one or more compounds are a glass network former.

11. The method for preparing a negative active material for a rechargeable lithium battery according to claim 8, wherein the heat treating is performed at a temperature between 600°

C. and 1000°

C.

12. The method for preparing a negative active material for a rechargeable lithium battery according to claim 8, further comprising quenching after performing the heat treatment.

13. The method for preparing a negative active material for a rechargeable lithium battery according to claim 8, wherein x is between 0.5 and 1.5.

14. The method for preparing a negative active material for a rechargeable lithium battery according to claim 8, wherein the one or more compounds are added in an amount between 10 and 30 wt % based on the total weight of SiO₂ and Si.

15. The method for preparing a negative active material for a rechargeable lithium battery according to claim 8, wherein the carbonaceous material is crystalline carbon or amorphous carbon.

16. The method for preparing a negative active material for a rechargeable lithium battery according to claim 8, wherein the silicon-based composite and the carbonaceous material are provided in weight ratio between 10:

90 and 90;

10.

17. The method for preparing a negative active material for a rechargeable lithium battery according to claim 16, wherein the weight ratio of the silicon-based composite to the carbonaceous material is between 30:

70 and 70;

30.

18. The method for preparing a negative active material for a rechargeable lithium battery according to claim 8, wherein the carbonaceous material is a first carbonaceous material, the method further comprising coating the mixture of the silicon-based composite and the first carbonaceous material with a second carbonaceous material.