Dispersion and coating composition containing lithium metal phosphate

Patent metadata

Field	Value
Publication number	US-12378117-B2
Application number	US-202217693763-A
Country	US
Kind code	B2
Filing date	Mar 14, 2022
Priority date	Mar 15, 2021
Publication date	Aug 5, 2025
Grant date	Aug 5, 2025

Abstract

A dispersion may include 1 to 50% by weight of lithium metal phosphate of a general formula

Li 1+a M 2−b N c (PO 4 ) 3+d ,

wherein M is Ti, Zr or Hf; N is a metal other than Li and M; 0≤a≤0.6, 0≤b≤0.6, 0≤c≤0.6, 0≤d≤0.8; and 50 to 99% by weight of trialkyl phosphate. A coating composition may include such a dispersion and such dispersions can be used in lithium ion batteries.

First claim

The invention claimed is:

1. A dispersion, comprising:
50 to 99 wt. % of trialkyl phosphate; and
1 to 50 wt. % of lithium metal phosphate of formula
Li 1+a M 2−b N c (PO 4 ) 3+d ,

wherein
M is Ti, Zr, or Hf,
N is metal other than Li and M,
0≤a≤0.6,
0≤b≤0.6,
0≤c≤0.6, and
0≤d≤0.8, and
wherein the lithium metal phosphate has a particle size d 99 of less than 1 μm, as determined by dynamic light scattering (DLS) at a temperature of 25° C. in a diluted form of the dispersion, with trialkyl phosphate, comprising 1 wt. % of the lithium metal phosphate.

2. The dispersion of claim 1 , wherein the lithium metal phosphate is in the form of aggregated primary particles.

3. The dispersion of claim 1 , wherein the lithium metal phosphate is obtained by a pyrogenic process.

4. The dispersion of claim 1 , wherein the lithium metal phosphate has a BET surface area in a range of from 5 to 100 m 2 /g.

5. The dispersion of claim 1 , wherein the particle size d 99 of the lithium metal phosphate is in a range of from 0.05 to 0.8 μm, as determined by dynamic light scattering (DLS) at a temperature of 25° C. in a diluted form of the dispersion, with trialkyl phosphate, comprising 1 wt. % of the lithium metal phosphate.

6. The dispersion of claim 1 , wherein the lithium metal phosphate has a tamped density in a range of from 20 to 200 g/L.

7. The dispersion of claim 1 , wherein the trialkyl phosphate comprises trimethyl phosphate, triethyl phosphate, tri-n-propyl phosphate, triisopropyl phosphate, methyl diethyl phosphate, or a mixture thereof.

8. A process for manufacturing the dispersion of claim 1 , the process comprising:
mixing the lithium metal phosphate and the trialkyl phosphate, to obtain a resulting dispersion; and
optionally grounding or milling the resulting dispersion.

9. The process of claim 8 , wherein grounding or milling is carried out by an ultrasound treatment, or with a wet-jet mill, or a ball mill.

10. A wet coating composition, comprising:
the dispersion of claim 1 ;
an organic binder; and
optionally, a solvent.

11. The composition of claim 10 , comprising:
50 to 99 wt. % of the dispersion;
1 to 50 wt. % of the organic binder; and
optionally, 1 to 50 wt. % of a solvent.

12. The composition of claim 10 , wherein the organic binder comprises polyethylene oxide, polyvinylidene fluoride, polyvinylidene chloride, polytetrafluoroethylene, polyacrylonitrile, polyamide, polyimide, polyether ether ketone, polymethyl methacrylate, polytetraethylene glycol diacrylate, polyvinylidene fluoride/hexafluoropropylene copolymer, polyvinylidene fluoride/chlorotrifluoroethylene copolymer, polysulfone, polyether sulfone, or a mixture of two or more of any of these.

13. A dry coating composition, obtained by evaporation of trialkyl phosphate and any solvents present from the wet composition of claim 10 .

14. A process for an coating electrode or separator of a lithium ion battery, the process comprising:
contacting the wet coating composition according to claim 10 or a dry coating composition, obtained by evaporation of trialkyl phosphate and any solvents present from the wet composition, with the electrode or separator of the lithium ion battery.

15. A lithium ion battery, comprising:
the dry coating composition of claim 13 .

16. The dispersion of claim 1 , wherein the trialkyl phosphate comprises trimethyl phosphate.

17. The dispersion of claim 1 , wherein the trialkyl phosphate comprises triisopropyl phosphate.

18. The dispersion of claim 1 , wherein the trialkyl phosphate comprises methyl diethyl phosphate.

19. The dispersion of claim 1 , wherein the lithium metal phosphate comprises a lithium zirconium phosphate.

20. The dispersion of claim 1 , wherein the particle size d 99 of the lithium metal phosphate is in a range of from 0.15 to 0.5 μm, as determined by dynamic light scattering (DLS) at a temperature of 25° C. in a diluted form of the dispersion, with trialkyl phosphate, comprising 1 wt. % of the lithium metal phosphate.

Assignees

• Evonik Operations Gmbh

Inventors

• Ness Daniel
• TAKATA Ryo
• Esken Daniel
• Dauth Katharina

Classifications

• H01M4/667

  in the form of layers, e.g. coatings · CPC title

• H01M50/449

  having a layered structure · CPC title

• C01P2006/10

  Solid density · CPC title

• H01M10/0562

  Solid materials · CPC title

• H01M10/052

  Li-accumulators · CPC title