Positively charged silicon for lithium-ion batteries

Patent metadata

Field	Value
Publication number	US-10340516-B2
Application number	US-201715454142-A
Country	US
Kind code	B2
Filing date	Mar 9, 2017
Priority date	Dec 14, 2011
Publication date	Jul 2, 2019
Grant date	Jul 2, 2019

Abstract

This invention relates to a negative electrode material for lithium-ion batteries comprising silicon and having a chemically treated or coated surface influencing the zeta potential of the surface. The active material consists of particles or particles and wires comprising a core comprising silicon, wherein the particles have a positive zeta potential in an interval between pH 3.5 and 9.5, and preferably between pH 4 and 9.5. The core is either chemically treated with an amino-functional metal oxide, or the core is at least partly covered with O y SiH x groups, with 1<x<3, 1≤y≤3, and x>y, or is covered by adsorbed inorganic nanoparticles or cationic multivalent metal ions or oxides.

First claim

The invention claimed is:

1. A negative electrode material for a lithium rechargeable battery, the material comprising a core comprising silicon, wherein the core has an average particle size between 20 nm and 200 nm, wherein the surface of the core is at least partly covered by a coating comprising inorganic nanoparticles, and wherein the material has a positive zeta potential in an interval between pH 3.5 and 9.5.

2. The negative electrode material of claim 1 , wherein the inorganic nanoparticles comprise an aluminum compound, a zinc compound or an antimony compound.

3. The negative electrode material of claim 2 , wherein the aluminum compound is either aluminum or Al 2 O 3 , the zinc compound is either zinc or zinc oxide, and the antimony compound is either antimony or antimony oxide.

4. The negative electrode material of claim 1 , wherein the nanoparticles form a first coating layer on the core, the first coating layer having a thickness of less than 10 nm.

5. The negative electrode material of claim 4 , wherein the particles further comprise a second coating layer located between the core and the nanoparticles, the second coating layer comprising either carbon or aluminum.

6. The negative electrode material of claim 5 , wherein either one or both of the first and second coating layer is electrochemically active.

7. The negative electrode material of claim 4 , wherein the first coating layer has a thickness between 1 and 5 nm.

8. The negative electrode material of claim 4 , wherein the first coating layer is either conformal or porous.

9. The negative electrode material of claim 1 , wherein the nanoparticles comprise a precursor material susceptible of being converted to aluminum, zinc or antimony by reduction.

10. The negative electrode material of claim 1 , wherein the material has a positive zeta potential in an interval between pH 4 and 9.5.

11. The negative electrode material of claim 1 , wherein the material has a point of zero-charge at pH 4 or higher.

12. The negative electrode material of claim 1 , comprising either particles or a mixture of particles and wires.

13. The negative electrode material of claim 12 , wherein both the particles and the wires are nano-sized, and wherein the average particle size of the particles is at least 5 times the average width of the wires.

14. The negative electrode material of claim 1 , wherein the comprises either
pure silicon; or
a silicon monoxide powder, which comprises a mixture at nanometric scale of Si and SiO 2 ; or
silicon having a SiO x surface layer, with 0<x<2, the surface layer having an average thickness between 0.5 nm and 10 nm; or
a homogeneous mixture of silicon- and metal-oxides, having the formula SiO x .(M a O b ) y , with 0<x<1 and 0≤y<1, wherein a and b are selected to provide electroneutrality, and wherein M is selected from the group consisting of Ca, Mg, Li, Al, and Zr; or
an alloy Si—X, wherein X is either one or more metals selected from the group consisting of Sn, Ti, Fe, Ni, Cu, Co and Al.

15. The negative electrode material of claim 1 , wherein the material has a BET value between 1 and 60 m 2 /g.

16. A negative electrode material for a lithium rechargeable battery, the material comprising a core comprising silicon, wherein the surface of the core is at least partly covered by adsorbed cationic multivalent metal ions, and wherein the material has a positive zeta potential in an interval between pH 3.5 and 9.5.

17. The negative electrode material of claim 16 , wherein the metal ions are selected from the group consisting of Al-, Sb-, Fe-, Ti- and Zn-ions and combinations thereof.

18. A negative electrode material for a lithium rechargeable battery, the material comprising a core comprising silicon, wherein the surface of the core is at least partly covered by silanol groups covalently bound to amino-functional metal compounds, wherein the metal compound is selected from the group consisting of Si, Al and Ti and combinations thereof, and wherein the material has a positive zeta potential in an interval between pH 3.5 and 9.5.

19. A negative electrode material for a lithium rechargeable battery, the material comprising a core comprising silicon, wherein the surface of the core is at least partly covered by adsorbed nanoparticles of cationic multivalent metal oxides, and wherein the material has a positive zeta potential in an interval between pH 3.5 and 9.5.

20. The negative electrode material of claim 19 , wherein the metal oxides are selected from the group consisting of Al-oxide, Ca-oxide, Mg-oxide, Pb-oxide, Sb-oxide, Fe-oxide, Ti-oxide, Zn-oxide and In-hydroxide and combinations thereof.

Assignees

• Umicore Nv

Inventors

• Put Stijn
• Gilleir Jan
• Driesen Kris
• Bridel Jean-Sébastien
• Marx Nicolas
• Longrie Delphine
• Goia Dan V
• Njagi John I

Classifications

• H01M10/0525

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

• H01M2004/027

  Negative electrodes · CPC title

• H01M4/0492

  Chemical attack of the support material · CPC title

• H01M4/1395

  of electrodes based on metals, Si or alloys · CPC title

• H01M4/386

  Silicon or alloys based on silicon · CPC title