Coated metal oxide particles with low dissolution rate, methods for preparing same and use thereof in electrochemical systems

Patent metadata

Field	Value
Publication number	US-11050059-B2
Application number	US-201715675184-A
Country	US
Kind code	B2
Filing date	Aug 11, 2017
Priority date	Jan 25, 2006
Publication date	Jun 29, 2021
Grant date	Jun 29, 2021

Abstract

Particles including a core and a coat covering at least part of the core surface. The core has more than 50% of an acidic metal oxide and the core coating is based on a polymer, preferably based on a solid polymer with high electrochemical stability. The particle has a solubility rate (ds), in fixed time, of the metal oxide migrating towards the electrolyte, per cycle, which is less than 5 per 10000. The particles are obtained by mixing the polymer and a metal oxide, via dry process with addition of solvent. The electrodes constituting an electrode substrate at least partly coated with a mixture consisting of at least 40 of those particles have remarkable electrochemical properties, in particular regarding the lifetime of batteries in which they are incorporated.

First claim

The invention claimed is:

1. A material comprising core-shell particles, wherein the core-shell particles comprise a core and a shell in the form of a coating that covers at least part of the surface of said core, wherein:
said core is composed of at least 90% by weight of LiV 3 O 8 , and comprises from 1% to 10% by weight of a carbon component selected from the group consisting of ethylene black, natural graphite, artificial graphite, carbon black, and mixtures of at least two thereof;
the coating of the core is based on a polymer, whose electrochemical stability is greater than or equal to 3.7 volts;
the coating comprises at least one salt selected from the group consisting of LiFSI, LiTFSI, LiBETI, LiDCTA, LiBF 4 and LiPF 6 ;
a mean thickness of the coating is between 500 nanometers and 2 micrometers and the core-shell particles have a mean size d 50 between 500 nanometers and 40 micrometers;
a degree of solubility (ds) of the metal oxide migrating toward an electrolyte, per cycle, is less than 5 per 10,000;
the coating based on a polymer is obtained from a non-electrically conductive star shape polyether which comprises at least four branches having end groups comprising functions selected from the group consisting of: acrylate or methacrylate and alkoxy, allyloxy and/or vinyloxy, of which at least one allows crosslinking; and
the core-shell particles, when incorporated into an electrode, lead to a capacity loss of about 1% or less when maintained at about 80° C. for 2 weeks in potentiostat mode at about 3.6 to about 4 volts.

2. The material of claim 1 , wherein the non-electrically conductive star shape polyether which comprises at least four branches having end groups comprises an acrylate or methacrylate which allows crosslinking.

3. The material of claim 1 , wherein the core is 5 microns in size.

4. The material of claim 1 , the coating further comprising 10% by weight maximum of a filler selected from the group consisting of SiO 2 , ZrO 2 and Al 2 O 3 , and mixtures of at least two thereof.

5. An electrode comprising an electrode support made of a metallic material or of a conductive plastic material, the electrode support being at least partially covered with the material of claim 1 .

6. The electrode of claim 5 , wherein the material comprises a polymer which is different from the polymer present in the coating and ensures binding between particles of the electrode.

7. The electrode of claim 5 , comprising at least one polymer containing at least one lithium salt and at least one carbon with a specific surface area of greater than or equal to 1 m 2 /g.

8. The electrode of claim 7 , wherein:
a composition of said at least one polymer represents from 1% to 70% by weight relative to total weight of a (polymer+salt+metal oxide+carbon) mixture;
a composition of said at least one carbon represents from 1% to 10% by weight relative to the total weight of the (polymer+salt+metal oxide+carbon) mixture; and
a concentration of the salt present in the (polymer+salt+metal oxide+carbon) mixture, expressed relative to said at least one polymer, is between 0.1 M and 3 M.

9. An electrochemical generator containing at least one constituent element comprising the material of claim 1 .

10. The material of claim 1 , wherein the core consists of LiV 3 O 8 and the carbon component.

11. The material of claim 1 , wherein the core is formed from mechanofusion of LiV 3 O 8 and the carbon component.

12. A material comprising core-shell particles, wherein the core-shell particles comprise a core and a shell in the form of a coating, wherein:
said core is a LiV 3 O 8 core, covered over 80% of its surface with a coating;
said core is composed of at least 90% by weight of LiV 3 O 8 , and comprises from 1% to 10% by weight of a carbon component selected from the group consisting of ethylene black, natural graphite, artificial graphite, carbon black and mixtures of at least two thereof;
said coating comprises at least one salt selected from the group consisting of LiFSI, LiTFSI, LiBETI, LiDCTA, LiBF 4 and LiPF 6 ;
said coating is obtained from a non-electrically conductive star shape polyether which comprises at least four branches having end groups comprising functions selected from the group consisting of: acrylate or methacrylate and alkoxy, allyloxy and/or vinyloxy, of which at least one allows crosslinking, having a mean thickness of between 10 nanometers and 5 micrometers, whose electrochemical stability is greater than or equal to 3.7 volts;
said particles comprise a degree of solubility (ds) of the of the LiV 3 O 8 migrating toward an electrolyte, per cycle, of less than 5 per 10,000; and
the core-shell particles, when incorporated into an electrode, lead to a capacity loss of about 1% or less when maintained at about 80° C. for 2 weeks in potentiostat mode at about 3.6 to about 4 volts.

13. The material of claim 12 , wherein the core is 5 microns in size.

14. The material of claim 12 , wherein the core consists of LiV 3 O 8 and the carbon component.

15. The material of claim 12 , wherein the core is formed from mechanofusion of LiV 3 O 8 and the carbon component.

Assignees

• Hydro Quebec

Inventors

• Charest Patrick
• Perrier Michel
• Dontigny Martin
• Petitclerc Michel
• Guerfi Abdelbast
• Zaghib Karim

Classifications

• H01M4/62

  Selection of inactive substances as ingredients for active masses, e.g. binders, fillers · CPC title

• H01M4/02

  Electrodes composed of, or comprising, active material · CPC title

• H01M4/48 Primary

  of inorganic oxides or hydroxides · CPC title

• H01M4/04

  Processes of manufacture in general · CPC title

• H01M4/483

  for non-aqueous cells (H01M4/485 takes precedence) · CPC title