Silicon particles for anode materials of lithium ion batteries

Patent metadata

Field	Value
Publication number	US-12015148-B2
Application number	US-201716484822-A
Country	US
Kind code	B2
Filing date	Feb 9, 2017
Priority date	Feb 9, 2017
Publication date	Jun 18, 2024
Grant date	Jun 18, 2024

Abstract

The invention relates to spherical, nonporous Silicon particles having average particle sizes (d50) of 1 to 10 pm and a silicon content of 97 to 99.8 wt. %, the silicon content relating to the total weight of the silicon particles minus any oxygen content.

First claim

The invention claimed is:

1. Anode materials for lithium-ion batteries comprising:
one or more binders,
optionally graphite,
optionally one or more further electrically conductive components,
optionally one or more additives, and
non-aggregated, spherical, non-porous silicon particles having average particle sizes of 1 to 10 μm and a silicon content of 97% to 99.8% by weight, wherein the silicon content is based on the total weight of the silicon particles minus any oxygen contents, the silicon is in elemental form, and wherein ≥80% of the silicon particles have an orthogonal axial ratio R of 0.60≤R≤1.0, wherein the orthogonal axial ratio R is the quotient of the two largest mutually orthogonal diameters through a silicon particle and the larger diameter forms the denominator and the smaller diameter forms the numerator of the quotient, as determined by SEM image.

2. The anode materials for lithium-ion batteries of claim 1 , wherein ≥85% of the silicon particles have an orthogonal axial ratio R of 0.70≤R≤1.0, wherein the orthogonal axial ratio R is the quotient of the two largest mutually orthogonal diameters through a silicon particle and the larger diameter forms the denominator and the smaller diameter forms the numerator of the quotient, as determined by SEM image.

3. The anode materials for lithium-ion batteries of claim 1 , wherein the silicon particles have an average orthogonal axial ratio R of 0.70≤R≤1.0, wherein the orthogonal axial ratio R is the quotient of the two largest mutually orthogonal diameters through a silicon particle and the larger diameter forms the denominator and the smaller diameter forms the numerator of the quotient, as determined by SEM image.

4. The anode materials for lithium-ion batteries of claim 1 , wherein the silicon particles have been coated with carbon.

5. The anode materials for lithium-ion batteries of claim 1 , wherein the spherical, non-porous silicon particles are obtained by atomizing silicon.

6. The anode materials for lithium-ion batteries of claim 5 , wherein the spherical, non-porous silicon particles are obtained from molten silicon, by melting silicon or employing silicon in the form of a melt, forming the molten silicon into droplets, and cooling the droplets to a temperature below the melting point of silicon.

7. The anode materials for lithium-ion batteries of claim 1 , wherein the spherical, non-porous silicon particles are obtained by plasma rounding of silicon particles.

8. The anode materials for lithium-ion batteries of claim 7 , wherein the spherical, non-porous silicon particles are obtained by fully or partially melting silicon particles by plasma irradiation, and subsequently cooling to a temperature below the melting point of silicon.

9. The anode materials of claim 1 , wherein the non-aggregated spherical, non-porous silicon particles have silicon oxide SiO x where x≥1.3 on surfaces thereof.

10. The anode materials of claim 1 , wherein the non-aggregated spherical, non-porous silicon particles are coated with carbon, the content of carbon being ≤20 weight percent based on the total weight of the carbon-coated silicon particles.

11. The anode materials of claim 1 , wherein the non-aggregated spherical, non-porous silicon particles have an average orthogonal axial ratio R of greater than or equal to 0.80.

12. The anode materials of claim 1 , wherein the non-aggregated spherical, non-porous silicon particles have an average orthogonal axial ratio R of greater than or equal to 0.85.

13. The anode materials of claim 1 , wherein non-aggregated, spherical, non-porous silicon particles are carbon-coated, wherein the carbon content is from 0.1 to 10% by weight based on the total weight of the carbon-coated particles.

14. The anode materials of claim 1 , wherein non-aggregated, spherical, non-porous silicon particles are carbon-coated, wherein the carbon content is from 0.5 to 5% by weight based on the total weight of the carbon-coated particles.

15. The anode particles of claim 1 , wherein the non-aggregated, spherical, non-porous silicon particles have a silicon oxide coating on surfaces thereof, having the formula SiO x where x≥1.3, and a further coating of carbon derived by carbonizing one or more carbon precursors which have been coated onto the silicon particles having a silicon oxide coating, with the proviso that the carbon precursors are converted into carbon, and the carbon content of the carbon-coated particles is ≤20 weight percent based on the total weight of the coated particles.

16. The anode material of claim 1 , wherein the non-aggregated, spherical, non-porous silicon particles have no coating thereon, or which are coated with a silicon oxide coating with a layer thickness of <10 nm.

17. The anode material of claim 1 , wherein the non-aggregated, spherical, non-porous particles are melt-rounded fragments of metallurgical grade silicon having a silicon content of from 98 to 99% by weight based on the total weight of said particles.

18. Lithium-ion batteries comprising:
a cathode,
an anode,
a separator, and
an electrolyte, wherein the anode is based on the anode material of claim 1 .

19. The lithium-ion batteries of claim 18 , wherein, in the fully charged lithium-ion battery, the ratio of lithium atoms to silicon atoms in the anode material is ≤2.2.

20. The lithium-ion batteries of claim 18 , wherein the capacity of the silicon of the anode material of the lithium-ion battery is utilized to an extent of ≤50%, based on the maximum capacity of 4200 mAh per gram of silicon.

Assignees

• Wacker Chemie Ag

Inventors

• Ay Sefer
• Jantke Dominik
• STOHRER JüRGEN
• Suckow Sebastian
• Voit Harald

Classifications

• H01M2004/027

  Negative electrodes · CPC title

• H01M2004/021

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

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• H01M4/625

  Carbon or graphite · CPC title

• H01M4/587

  for inserting or intercalating light metals · CPC title