FABRICATION AND USE OF CARBON-COATED SILICON MONOXIDE FOR LITHIUM-ION BATTERIES

• US 20140004426A1
• Filed: 12/21/2012
• Published: 01/02/2014
• Est. Priority Date: 12/21/2011
• Status: Active Grant

• Current Assignee: Nexeon Limited
• Original Assignee: Leyden Energy
• Inventors: Kerlau, Marie, Goertzen, Sarah
• Granted Patent: US 10,135,062 B2
• Time in Patent Office: Days
• US Class Current: 429/231.8
• 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 4/1395 of electrodes based on metals, Si or alloys
• 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 4/48 of inorganic oxides or hydroxides
• CPC Class Codes: H01M 4/483 for non-aqueous cells H01M4/485 takes precedence
• CPC Class Codes: H01M 4/621 Binders
• CPC Class Codes: H01M 4/622 being polymers
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y10S 977/773 Nanoparticle, i.e. structure having three dimensions of 100 nm or less
• CPC Class Codes: Y10S 977/809 Organic film on silicon
• CPC Class Codes: Y10S 977/814 Group IV based elements and compounds, e.g. CxSiyGez, porous silicon

Abstract

The present invention provides anode materials, methods of producing them, anodes, methods of producing them, electrochemical cells, and lithium-ion batteries, where the anode material comprises a silicon monoxide nanoparticle. In certain embodiments, the silicon monoxide is porous or mesoporous. In certain embodiments, the porous or mesoporous silicon additionally comprises other materials within its pores, such as lithium.

Claims

1. An anode material comprising a silicon monoxide nanoparticle, wherein the nanoparticle comprises a carbon-containing outer phase and a silicon monoxide inner phase, and

wherein the carbon-containing outer phase is covalently bonded to the silicon monoxide inner phase.

2. The anode material of claim 1, wherein the nanoparticle has a particle diameter of from about 50 nm to 250 nm.

3. The anode material of claim 1, wherein the carbon-containing phase comprises an alkyl or a hydroxyalkyl group, and the group is covalently bonded to the silicon monoxide inner phase.

4. The anode material of claim 1, further comprising a binder;

wherein the binder encompasses a plurality of nanoparticles.

5. The anode material of claim 4, wherein the binder is selected from the group consisting of carboxymethyl cellulose, styrene butadiene rubber, alginate, polyacrylic acid, and a salt thereof.

6. The anode material of claim 1, the anode material comprising:

mesoporous silicon particles having an average pore diameter from about 1 nm to 500 nm; and

carboxymethyl cellulose.

7. The anode material of claim 6, wherein the mesoporous silicon particle has a particle diameter of from about 50 nm to 250 nm.

8. The anode material of claim 6, wherein the mesoporous silicon particles comprise lithium in the pores.

9. A lithium-ion battery comprising the anode material of claim 1.

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

contacting a silicon tetrahalide with a reducing agent under conditions sufficient to form a reduced silicon particle; and

contacting the reduced silicon particle with an alkylating agent or an alkoxide to form a silicon monoxide nanoparticle, wherein the nanoparticle comprises a carbon-containing outer phase and a silicon monoxide inner phase; and

wherein the carbon-containing outer phase is covalently bonded to the silicon monoxide inner phase.

11. The method of claim 10, wherein the silicon tetrahalide is silicon tetrachloride.

12. The method of claim 10, wherein the reducing agent is sodium naphthalide.

13. The method of claim 10, wherein the alkylating agent is alkyl lithium.

14. The method of claim 10, wherein the alkylating agent comprises a C_1-6 alkyl group.

15. The method of claim 10, further comprising the step of mixing a plurality of silicon monoxide nanoparticles with a binder.

16. The method of claim 15, wherein the binder is selected from the group consisting of carboxymethyl cellulose, styrene butadiene rubber, alginate, polyacrylic acid, and a salt thereof.

17. The method of claim 10, further comprising the step of heating the reduced silicon particle to remove the reducing agent.

18. The method of claim 10, further comprising the step of washing the reduced silicon particle to remove the reducing agent.

19. The method of claim 10, further comprising the step of annealing a mixture, wherein the mixture comprises a plurality of silicon monoxide nanoparticles.

20. An anode material prepared by the method of claim 10.

21. A lithium-ion battery comprising the anode material of claim 20.

22. A method for preparing the anode material of claim 1, comprising:

contacting a silicon tetrahalide with a reducing agent under conditions sufficient to form a reduced silicon;

contacting the reduced silicon with an alkylating agent or an alkoxide to form an alkyl-capped silicon gel;

annealing a mixture of the alkyl-capped silicon gel and a template to form a mesoporous silicon particle having an average pore diameter from about 1 nm to 500 nm; and

mixing the mesoporous silicon particle with carboxymethyl cellulose, thereby preparing the anode material of claim 1.

23. The method of claim 22, wherein the template is a nanoparticle silica template.

24. The method of claim 22, further comprising heating the alkyl-capped silicon gel to remove the reducing agent.

25. The method of claim 22, further comprising before the mixing step, removing the template.

26. The method of claim 22, further comprising before the mixing step, depositing lithium in the pore to form a lithiated mesoporous silicon particle.

27. The method of claim 26, wherein the depositing is performed via chemical vapor deposition.

28. An anode material prepared by the method of claim 22.

29. A lithium-ion battery comprising the anode material of claim 28.

30. A method for preparing the anode material of claim 1, comprising:

contacting a silicon tetrahalide with a reducing agent under conditions sufficient to form a reduced silicon;

contacting the reduced silicon with an alkylating agent or an alkoxide to form an alkyl-capped silicon gel;

drying the alkyl-capped silicon gel;

contacting the dried, alkyl-capped silicon gel with hydrofluoric acid to form porous silicon particles having an average pore diameter from about 1 to 500 nm; and

mixing the porous silicon particles with carboxymethyl cellulose, thereby preparing the anode material of claim 1.

31. An anode material prepared by the method of claim 30.

32. A lithium-ion battery comprising the anode material of claim 31.

33. A method for preparing an anode, comprising the steps of:

preparing a slurry, wherein the slurry comprises an anode material of claim 4 and a solvent; and

adjusting the slurry to a pre-specified pH;

wherein the pre-specified pH improves the contact between the nanoparticle and the binder.

34. The method of claim 33, wherein the pre-specified pH is at most 3.

35. The method of claim 33, wherein the pre-specified pH is between about 3 and 6.

36. The method of claim 35, wherein the binder comprises carboxymethyl cellulose or a salt thereof.

37. The method of claim 33, wherein the pre-specified pH is between about 6 and 8.5.

38. The method of claim 37, wherein the pre-specified pH is between about 6 and 7;

and

wherein the binder comprises a sodium salt of polyacrylic acid.

39. The method of claim 33, wherein the pre-specified pH is between about 7.5 and 8.5;

and

wherein the binder comprises a lithium salt of polyacrylic acid.

40. An anode prepared by the method of claim 33.

41. A lithium-ion battery comprising the anode of claim 40.