LAYERED TITANIUM DISILICIDE, METHOD OF PREPARATION AND APPLICATIONS THEREOF

• US 20140295268A1
• Filed: 03/11/2014
• Published: 10/02/2014
• Est. Priority Date: 03/12/2013
• Status: Active Grant

• Current Assignee: Trustees of Boston College (Boston College)
• Original Assignee: Trustees of Boston College (Boston College)
• Inventors: Wang, Dunwei, Zhou, Sa
• Granted Patent: US 9,564,632 B2
• Time in Patent Office: Days
• US Class Current: 429/218.1
• CPC Class Codes: C22C 29/18 based on silicides
• 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 4/366 as layered products
• CPC Class Codes: H01M 4/58 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 Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

The invention generally relates to new materials based on C49 titanium disilicide (TiSi₂) as a new, layered anode material, within which lithium ions can react with the Si-only layers. Stabilization by a coating a thin layer of oxide on the surface of TiSi₂ significantly improves the charge and discharge performance.

Claims

1. A titanium disilicide (TiSi₂) substrate characterized by a layered crystalline structure exhibiting Si only layers, wherein the TiSi₂ substrate is at least partially coated with a thin layer of an oxide having a thickness from about 0.1 nm to about 10 nm.

2. The titanium disilicide substrate of claim 1, wherein the oxide is SiO₂.

3. The titanium disilicide substrate of claim 1, wherein the thin layer of oxide having a thickness from about 0.1 nm to about 5 nm.

4. The titanium disilicide substrate of claim 1, wherein Si only layers are flat, planar layers.

5. The titanium disilicide substrate of claim 4, wherein the layered crystalline structure is C49 (base-centered orthorhombic).

6. The titanium disilicide substrate of claim 1, being in the form of nanonets.

7. The titanium disilicide substrate of claim 1, wherein the nanonets have dimensions from 0.1 μ

m to about 50 μ

m.

8. The titanium disilicide substrate of claim 1, prepared from TiCl₄ and SiH₄.

9. The titanium disilicide substrate of claim 8, wherein the preparation is conducted in a H₂-rich environment at an elevated temperature.

10. An anode material comprising the titanium disilicide substrate of claim 1.

11. A battery comprising an anode that comprises the titanium disilicide substrate of claim 1.

12. The battery of claim 11, being a lithium-ion battery.

13. The battery of claim 12, having 80% of the original capacity retained after 500 cycles.

14. An article of manufacture comprising a battery of claim 12.

15. A method for preparing nanonets of titanium disilicide (TiSi₂) useful as an anode material, comprising:

reacting TiCl₄ and SiH₄ in a H₂-rich environment at an elevated temperature for a time sufficient to form TiSi₂ nanonets;

exposing as-formed TiSi₂ nanonets to ambient air; and

allowing exposed TiSi₂ nanonets to cool to room temperature naturally to form a layer of SiO₂ thereon.

16. The method of claim 15, wherein the reaction of TiCl₄ and SiH₄ in a H₂-rich environment is carried out at a temperature of about 675°

C.

17. The method of claim 15, wherein exposing as-formed TiSi₂ nanonets to ambient air is performed at a temperature of about 350°

C.

18. The method of claim 15, wherein the formed nanonets have dimensions from about 0.1 μ

m to about 50 μ

m.

19. The method of claim 15, wherein the layer of oxide has a thickness from about 0.1 to about 10 nm.

20. The method of claim 15, wherein the TiSi₂ nanonets are characterized by a layered crystalline structure exhibiting Si only layers.

21. (canceled)

22. (canceled)