Particulate anode materials and methods for their preparation by inductively-coupled plasma

Patent metadata

Field	Value
Publication number	US-2024097110-A1
Application number	US-202318223212-A
Country	US
Kind code	A1
Filing date	Jul 18, 2023
Priority date	Mar 3, 2017
Publication date	Mar 21, 2024
Grant date	—

Abstract

There is provided a method of manufacturing nanoparticles comprising the steps of feeding a core precursor into a plasma torch in a plasma reactor, thereby producing a vapor of silicon or alloy thereof; and allowing the vapor to migrate to a quenching zone of the plasma reactor, thereby cooling the vapor and allowing condensation of the vapor into a nanoparticle core made of the silicon or alloy thereof, wherein the quenching gas comprises a passivating gas precursor that reacts with the surface of the core in the quenching zone produce a passivation layer covering the core, thereby producing said nanoparticles. The present invention also relates to nanoparticles comprising a core covered with a passivation layer, the core being made of silicon or an alloy thereof, as well as their use, in particular in the manufacture of anodes.

First claim

What is claimed is:

1 . Nanoparticles comprising a core and a passivation layer covering the core,
wherein the core comprises silicon or an alloy thereof, wherein the passivation layer is a layer of nitride of the silicon or alloy thereof, wherein the nanoparticles are substantially spherical in shape, wherein the nanoparticles have an average particle size of about 70 nm or more, and wherein the nanoparticles are substantially free of SiO x and SiOH surface species.

2 . The nanoparticles of claim 1 , wherein the passivation layer is a layer of Si 3 N 4 .

3 . The nanoparticles of claim 1 , wherein the core is made of silicon or ferrosilicon.

4 . The nanoparticles of claim 1 , wherein the core is made of silicon.

5 . The nanoparticles of claim 1 , having an average particle size up to about 300 nanometers.

6 . The nanoparticles of claim 1 , having an average particle size up to about 100 nm.

7 . The nanoparticles of claim 1 , wherein the nanoparticles further comprise a layer of conductive carbon covering at least part of the surface of the nanoparticles.

8 . The nanoparticles of claim 7 , comprising between about 0.1 and about 10 wt % of conductive carbon, based on the total weight of the nanoparticles

9 . The nanoparticles of claim 1 , wherein the nanoparticles are comprised within a composite Si/carbon agglomerate.

10 . A method of manufacturing the nanoparticles of claim 1 ,
the method comprising the steps of:
a. providing a core precursor comprising the silicon or alloy thereof,
b. providing a plasma reactor comprising an induction plasma torch generating a plasma at a temperature allowing production of a vapor of the silicon or alloy thereof from the core precursor, the plasma torch being in fluid communication with a quenching zone located downstream from the plasma torch, the quenching zone being cooled down by a quenching gas to a temperature allowing condensation of the vapor,
c. feeding the core precursor into the plasma torch, thereby producing the vapor of the silicon or alloy thereof, and
d. allowing the vapor to migrate to the quenching zone, thereby cooling the vapor and allowing condensation of the vapor into the core made of the silicon or alloy thereof,
wherein the quenching gas comprises a passivating gas precursor that reacts with the surface of the core in the quenching zone to produce the passivation layer covering the core, and wherein the passivating gas precursor is ammonia or nitrogen, thereby producing said nanoparticles.

11 . The method of claim 1 , wherein the core precursor is:
the silicon or alloy thereof in metal form or a hydride or chloride of the silicon or alloy thereof.

12 . The method of claim 1 , wherein the core precursor is in micropowder form and is metallurgical grade silicon metal (MG-Si), or ferrosilicon.

13 . The method of claim 1 , wherein the core precursor is in gaseous form and is silane, trichlorosilane, or silicon tetrachloride.

14 . The method of claim 1 , wherein feeding step c) comprises mixing the core precursor with a carrier gas, which transports the core precursor into and through the plasma torch and then transports the vapor of the silicon or alloy thereof to the quenching zone.

15 . The method of claim 1 , wherein the quenching gas consist of the passivating gas precursor, or is a mixture of argon and the passivating gas precursor.

16 . The method of claim 1 , further comprising the step of discharging the nanoparticles from the plasma reactor.

17 . The method of claim 16 , further comprising producing of a layer of conductive carbon on the nanoparticles.

18 . The method of claim 17 , wherein the layer of conductive carbon is produced by:
mixing the nanoparticles with a carbon precursor to form a mixture, and pyrolizing the mixture in the absence of oxygen to form a layer of conductive carbon on at least part of the surface of the nanoparticles.

19 . The method of claim 17 , further comprising activating the surface of the nanoparticles using an aqueous acid solution and then functionalizing the nanoparticles.

20 . The method of claim 19 , wherein the nanoparticles are mixed with the aqueous acid solution and then the functionalizing reagent is added to the mixture.

Assignees

• Hydro Quebec
• Tekna Plasma Systems Inc

Inventors

• Guo Jiayin
• Dolbec Richard
• Boulos Maher
• Leblanc Dominic
• Guerfi Abdelbast
• Zaghib Karim

Classifications

• H01M4/366 Primary

  as layered products · CPC title

• B22F1/054

  Nanosized particles · CPC title

• B22F1/056

  Submicron particles having a size above 100 nm up to 300 nm · CPC title

• B22F1/102

  Metallic powder coated with organic material · CPC title

• B22F1/145

  Chemical treatment, e.g. passivation or decarburisation · CPC title