Method for size-reduction of silicon and use of the size-reduced silicon in a lithium-ion battery

Patent metadata

Field	Value
Publication number	US-10637050-B2
Application number	US-201414907889-A
Country	US
Kind code	B2
Filing date	Jul 25, 2014
Priority date	Aug 2, 2013
Publication date	Apr 28, 2020
Grant date	Apr 28, 2020

Abstract

The invention relates to a method for size-reducing silicon, wherein a mixture containing a suspension containing silicon to be size-reduced and silicon grinding media is set in motion in the grinding space of a grinding media mill. The size-reduced silicon is used as the active material in the anode of a lithium-ion battery.

First claim

The invention claimed is:

1. A process for comminuting silicon, wherein: (a) a mixture containing a suspension comprising a silicon to be comminuted and milling media comprising silicon is set into motion in a milling space of a closed milling medium mill, (b) the milling media have a volume-weighted size distribution in a range of 50 μm<d50<5 mm and a relative width of the volume-weighted size distribution of (d90−d10)/d50<1, and (c) silicon particles produced by the process have a volume-weighted particle size distribution in a range of 50 nm<d50<1000 nm, wherein the suspension further comprises an organic liquid comprising at least one alcohol and the mixture comprises less than 5% by weight of water.

2. The process as claimed in claim 1 , wherein a median d50 of diameters of the milling media is from 10 to 1000 times greater than a d90 value of a particle size distribution of the silicon to be comminuted.

3. The process as claimed in claim 1 , wherein the silicon to be comminuted is a member selected from the group consisting of elemental silicon, doped silicon, metallurgical silicon, silicon oxide, binary silicon-metal alloy, ternary silicon-metal alloy and multinary silicon-metal alloy.

4. The process as claimed in claim 1 , wherein the silicon to be comminuted has a volume-weighted particle size distribution having a d90<300 μm.

5. The process as claimed in claim 1 , wherein the milling media are silicon particles comprising round edges with approximately equal measurements in three dimensions.

6. The process as claimed in claim 1 , wherein the organic liquid has a viscosity of less than 100 mPas at 20° C.

7. The process as claimed in claim 1 , wherein the silicon comminuted by the process is used as an active material in an anode of a lithium ion battery.

8. An electrode material for a lithium ion battery, which contains silicon particles which have a volume-weighted particle size distribution with 50 nm<d50<1000 nm and metallic impurities of less than 1% by weight and is produced by the process as claimed in claim 1 .

9. A lithium ion battery comprising a cathode, an anode, a membrane arranged as a separator between the cathode and the anode, and an electrolyte containing lithium ions, wherein the anode contains the electrode material as claimed in claim 8 .

10. The process as claimed in claim 2 , wherein the silicon to be comminuted is a member selected from the group consisting of elemental silicon, doped silicon, metallurgical silicon, silicon oxide, binary silicon-metal alloy, ternary silicon-metal alloy and multinary silicon-metal alloy.

11. The process as claimed in claim 10 , wherein the silicon to be comminuted has a volume-weighted particle size distribution having a d90<300 μm.

12. The process as claimed in claim 11 , wherein the milling media are silicon particles comprising round edges with approximately equal measurements in three dimensions.

13. The process as claimed in claim 12 , wherein the organic liquid has a viscosity of less than 100 mPas at 20° C.

14. The process as claimed in claim 13 , wherein the silicon comminuted by the process is used as an active material in an anode of a lithium ion battery.

15. An electrode material for a lithium ion battery, which contains silicon particles which have a volume-weighted particle size distribution with 50 nm<d50<1000 nm and metallic impurities of less than 1% by weight and is produced by the process as claimed in claim 13 .

16. A lithium ion battery comprising a cathode, an anode, a membrane arranged as a separator between the cathode and the anode, and an electrolyte containing lithium ions, wherein the anode contains the electrode material as claimed in claim 15 .

17. The process as claimed in claim 1 , wherein the silicon particles produced by the process have metallic impurities of less than 1% by weight.

18. The process as claimed in claim 1 , wherein the suspension further comprises an organic liquid and the mixture comprises less than 1% by weight of water.

19. The process as claimed in claim 1 , wherein the relative width of the volume-weighted size distribution of the milling media is (d90−d10)/d50<0.5.

20. The process as claimed in claim 1 , wherein the volume-weighted size distribution of the milling media is in a range of 50 μm<d50<2 mm.

21. The process as claimed in claim 6 , wherein the volume-weighted particle size distribution of the silicon particles produced by the process is in a range of 50 nm<d50<500 nm.

Assignees

• Wacker Chemie Ag

Inventors

• Hanelt Eckhard

Classifications

• C01P2006/40

  Electric properties · CPC title

• H01M10/052

  Li-accumulators · CPC title

• C01P2006/11

  Powder tap density · CPC title

• H01M10/0525

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

• H01M2004/021

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