Method and material for lithium ion battery anodes

Patent metadata

Field	Value
Publication number	US-9917299-B2
Application number	US-201515528978-A
Country	US
Kind code	B2
Filing date	Nov 24, 2015
Priority date	Nov 25, 2014
Publication date	Mar 13, 2018
Grant date	Mar 13, 2018

Abstract

Highly porous synergistic combinations of silicon and carbon materials are provided, along with articles that incorporate such materials and processes for producing the materials. The compositions have novel properties and provide significant improvements in Coulombic efficiency, dilithiation capacity, and cycle life when used as anode materials in lithium battery cells including solid state batteries.

First claim

We claim:

1. A composite material comprising a core material and a coating material coating at least part of the outer surface of the core material, the core material comprising:
an outer surface and a porous core,
wherein the porous core of the core material has average pore size of from about 50 to about 1350 Å; and

particles having a surface area of from about 10 m 2 /g to about 250 m 2 /g;
wherein the core material comprises:
SiO x , wherein x is from 1-2, from about 3 wt % to about 40 wt %;
crystalline silicon from about 20 wt % to about 97 wt %;
wherein the ratio of crystalline silicon:SiO x is from about 1:1 to about 35:1; and
the core material further comprises from greater than 0 wt % to about 25 wt % crystalline Mg 2 SiO 4 .

2. The composite material of claim 1 , wherein the core material further comprises from greater than 0 wt % to about 45 wt % MgO.

3. The composite material of claim 2 , wherein the core material further comprises from greater than 0 wt % to about 10 wt % MgO.

4. The composite material of claim 1 , wherein the particles of the core material have an average diameter along the longest axis of from about 1 μm to about 10 μm.

5. The composite material of claim 1 , wherein the particles of the core material are in the form of sintered porous particles comprising subparticles comprising SiO x and crystalline silicon.

6. The composite material of claim 5 , wherein the subparticles have an average size along the longest axis of from about 10 nm to about 500 nm.

7. The composite material of claim 1 , wherein the core material comprises from greater than 0 wt % to about 10 wt % MgO, and the core material is in the form of particles with an average diameter along the longest axis of from about 1 μm to about 10 μm, and wherein the coating material comprises a carbon-containing material.

8. The composite material of claim 1 , wherein the coating material coats less than 80% of the surface area of porous core of the core material and coats at least about 40% of the outer surface of the core material.

9. The composite material of claim 1 , wherein the coating material comprises an organic material.

10. The composite material of claim 9 , wherein the organic material comprises an organic coating chemically bonded to the core material, for example, a polymer, such as PEO epoxy, PEG epoxy, or polyaniline.

11. The composite material of claim 9 , wherein the organic material comprises carbon in the form of activated carbon, amorphous carbon, graphene, graphite, mesoporous carbon, diamond-like carbon, nanocrystalline diamond, single or multiwalled nanotubes, fullerenes, nanobuds, nanofibers, glassy carbon, and combinations thereof.

12. The composition of claim 11 , further comprising an inorganic material present from greater than 0 wt % to about 10 wt %, however typically they are present in amounts less than 0.3 total combined wt %.

13. The composite material of claim 1 , further comprising a pre-coating material that improves adhesion of the coating material.

14. The composite material of claim 1 , wherein the coating material comprises an inorganic material, for example, gold, silver, aluminum, copper, and other transition metals, oxides, including alumina, tungsten oxide, aluminum zinc oxide, indium tin oxide and other TCOs, and other inorganic materials such as inorganic polymers such as polysilanes.

15. The composite material of claim 1 , wherein the coating material has a thickness from about 1 nm to about 5 μm.

16. The composite material of claim 15 , wherein the mass ratio of the core material to the coating material is from about 1000:1 to about 1:5.

17. The composite material of claim 1 , wherein the coating material is conductive or semiconductive.

18. An anode comprising the composite material of claim 1 , wherein the anode has a specific capacity of about 20% of the initial value or greater after 100 cycles at 0.2 C discharge rate.

19. An anode comprising the composite material of claim 1 , wherein the anode has a gravimetric capacity of 400 mAh/g or greater after 100 cycles at a 0.2 C discharge rate.

20. The anode of claim 19 , wherein the anode has a first cycle coulombic efficiency of 45% of the initial value or greater.

21. The anode of claim 18 , wherein the anode further comprises carbon.

22. The anode of claim 21 , wherein the carbon is in the form of graphite, activated carbon, or carbon nanotubes.

23. A method of making the material of claim 1 , wherein the method comprises:
a. subjecting a silica precursor to a metallothermic process;
b. removing reaction by-products to give a SiO x -silicon core material;
c. subjecting the core material to a coating material.

24. The method of claim 23 , wherein the subjecting a silica precursor to a metallothermic process comprises heating the silica precursor to a temperature of greater than 400° C. for more than 2 hours while in the presence of magnesium.

25. The method of claim 24 , wherein the subjecting comprises heating to a temperature of greater than 400° C. for more than 2 hours and subsequently, heating to a temperature of greater than 600° C. for more than 2 hours.

26. The method of claim 23 , wherein the silica precursor comprises a glass soot, glass powder or glass fiber.

27. The method of claim 26 , wherein the silica precursor comprises a glass soot or glass powder having an average size along the longest axis of from about 10 nm to about 1 μm.

28. The method of claim 23 , wherein the coating material comprises an organic material.

29. The method of claim 28 , wherein the organic material is chemically bonded to the core material.

30. The method of claim 28 , wherein the coating material comprises a carbon precursor.

31. The method of claim 28 , wherein the coating further comprises an inorganic material present from greater than 0 wt % to about 10 wt %, however typically they are present in amounts less than 3 total combined wt %.

32. The method of claim 28 , further comprising the step of pre-coating the core material with a material that improves adhesion of the coating material.

33. The method of claim 23 , wherein the coating material comprises an inorganic material, for example, gold, silver, aluminum, copper, and other transition metals, oxides, including alumina, tungsten oxide, aluminum zinc oxide, indium tin oxide and other TCOs, and other inorganic materials such as inorganic polymers such as polysilanes.

34. The method of claim 23 , wherein the coating material has a thickness from about 1 nm to about 5 μm.

35. The method of claim 23 , wherein the mass ratio of the core material to the coating material is from about 1000:1 to about 1:2.

36. The method of claim 23 , wherein the coating material is conductive, or semiconductive.

37. A method of making the material of claim 1 , wherein the method comprises:
a. combining a silica precursor and magnesium in a ratio of from about 0.5:1 to about 2:1 to form a mixture;
b. heating the mixture to a temperature greater than about 650° C. and less than 1000° C.; wherein the heating is done at a ramp rate from about 0.5 C°/min to about 50° C./min to form a core material; and
c. coating the core material with a carbon precursor

Assignees

• Corning Inc

Inventors

• Behan Francis Martin
• Dutta Indrajit
• O'Malley Shawn Michael
• Schneider Vitor Marino

Classifications

• H01M4/485

  of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy (H01M4/505, H01M4/525 take precedence) · CPC title

• H01M4/483

  for non-aqueous cells (H01M4/485 takes precedence) · CPC title

• H01M4/386

  Silicon or alloys based on silicon · CPC title

• H01M4/366 Primary

  as layered products · CPC title

• H01M4/364

  as mixtures · CPC title