Silicon-based anode material for lithium ion battery

Patent metadata

Field	Value
Publication number	US-11069885-B2
Application number	US-201816130778-A
Country	US
Kind code	B2
Filing date	Sep 13, 2018
Priority date	Sep 13, 2017
Publication date	Jul 20, 2021
Grant date	Jul 20, 2021

Abstract

A porous reduced silica fiber material has a diameter of about 0.1 to about 20 microns and a surface area of about 5 m2/g to about 400 m2/g. The porous reduced fiber material may be used to form an electrode having a high capacity and improved cycle life over comparable commercial silicon electrodes.

First claim

What is claimed is:

1. A porous reduced silica fiber having a diameter of about 0.1 to about 20 microns, a surface area of about 5 m 2 /g to about 400 m 2 /g, and a porosity of about 0.01 cm 3 /g to about 1.5 cm 3 /g,
wherein the porous reduced silica fiber comprises SiO x where x=0-2; and
wherein the porous reduced silica fiber comprises greater than about 20 weight percent silicon.

2. The porous reduced silica fiber of claim 1 , having a diameter of about 2 to about 15 microns.

3. The porous reduced silica fiber of claim 1 , having a surface area of about 30 m 2 /g to about 300 m 2 /g.

4. The porous reduced silica fiber of claim 1 , having a porosity of about 0.1 cm 3 /g to about 0.7 cm 3 /g.

5. The porous reduced silica fiber of claim 1 , having a median pore diameter of about 1 nm to about 90 nm.

6. The porous reduced silica fiber of claim 1 , having pore diameters of about 0.1 nm to about 150 nm.

7. The porous reduced silica fiber of claim 6 , having pore diameters of about 1 nm to about 100 nm.

8. A process for producing the porous reduced silica fiber of claim 1 , comprising:
providing a solution comprising a silica precursor, a polymer, and a surface active agent;
fiberizing the solution to produce fibers;
heating the fibers to produce silica-based precursor fibers;
subjecting the silica-based precursor fibers to a magnesiothermic reduction to remove at least some oxygen from the silica-based precursor fibers and to produce reduced silica fibers; and
washing the reduced silica fibers in an acid to remove magnesium-bearing reaction products and to produce the porous reduced silica fiber.

9. A process for producing the porous reduced silica fiber of claim 1 , comprising:
providing a melt comprising silica (SiO 2 ) and at least one of sodium oxide (Na 2 O), boron trioxide (B 2 O 3 ), lithium oxide (Li 2 O), calcium oxide (CaO) and magnesia (MgO);
fiberizing the melt to produce fibers;
treating the fibers to remove at least a portion of non-silica components and produce silica-based precursor fibers;
subjecting the silica-based precursor fibers to a magnesiothermic reduction to remove at least some oxygen from the silica-based precursor fibers and to produce reduced silica fibers; and
washing the reduced silica fibers in an acid to remove magnesium-bearing reaction products and to produce the porous reduced silica fiber.

10. A battery electrode comprising a binder and the porous reduced silica fiber of claim 1 .

11. The battery electrode of claim 10 , having a Coulombic efficiency of about 30% to about 100%.

12. The battery electrode of claim 10 , having a capacity ratio cycle 3/cycle 1 of about 0.4 to about 1.0.

13. The battery electrode of claim 10 , having a capacity ratio cycle 10/cycle 1 of about 0.1 to about 1.0.

14. A lithium ion battery comprising the electrode of claim 10 .

15. A porous reduced silica fiber having a diameter of about 0.1 to about 20 microns, a surface area of about 5 m 2 /g to about 400 m 2 /g, and a porosity of about 0.01 cm 3 /g to about 1.5 cm 3 /g,
wherein the porous reduced silica fiber comprises SiO x where x=0-2; and
wherein the porous reduced silica fiber comprises (i) greater than about 20 weight percent silicon and (ii) silicon dioxide.

16. The porous reduced silica fiber of claim 15 , having a surface area of about 30 m 2 /g to about 300 m 2 /g.

17. The porous reduced silica fiber of claim 15 , having a porosity of about 0.1 cm 3 /g to about 0.7 cm 3 /g.

18. The porous reduced silica fiber of claim 15 , having a median pore diameter of about 1 nm to about 90 nm.

19. A battery electrode comprising a binder and the porous reduced silica fiber of claim 15 .

20. A lithium ion battery comprising the electrode of claim 19 .

21. A porous reduced silica fiber consisting essentially of SiO x where x=0-2, wherein the porous reduced silica fiber has a diameter of about 0.1 to about 20 microns, a surface area of about 5 m 2 /g to about 400 m 2 /g, a porosity of about 0.01 cm 3 /g to about 1.5 cm 3 /g, and greater than about 20 weight percent silicon.

Assignees

• Unifrax I Llc

Inventors

• Zoitos Bruce K
• Kelsall Adam
• Cross Jonathan
• Cannan Chad

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

• H01M4/5825

  Oxygenated metallic salts or polyanionic structures, e.g. borates, phosphates, silicates, olivines · CPC title

• H01M2004/021

  Physical characteristics, e.g. porosity, surface area · CPC title

• H01M4/525

  of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy · CPC title

• H01M4/625

  Carbon or graphite · CPC title