Carbon-coated active particles and processes for their preparation

Patent metadata

Field	Value
Publication number	US-11563209-B2
Application number	US-201716313284-A
Country	US
Kind code	B2
Filing date	Jun 30, 2017
Priority date	Jun 30, 2016
Publication date	Jan 24, 2023
Grant date	Jan 24, 2023

Abstract

This application describes a process for the preparation of carbon-coated particles, where the particles comprise an electrochemically active material. The process comprises the steps of emulsion polymerization, drying and thermally treating the polymer to obtain a nano-layer of carbon on the particles, where the carbon layer comprises fibers and nitrogen-containing polyaromatics have a graphene-like structure. The application also further relates to the particles produced by the method as well as to electrode materials, electrodes and electrochemical cells comprising the particles.

First claim

The invention claimed is:

1. Carbon-coated particles, comprising:
particles comprising a porous electrochemically active material; and
a nano-layer of electron conductive carbon coating disposed on the surface and within a plurality of pores of said particles, the nano-layer of electron conductive carbon coating comprising carbon fibers and polyaromatics consisting of carbon and nitrogen atoms ,
wherein the nano-layer of electron conductive carbon coating consists of about 4 wt % to about 15 wt % of nitrogen atoms, the rest being carbon atoms.

2. The carbon-coated particles according to claim 1 , wherein the nano-layer of electron conductive carbon coating has an average thickness of below 20 nm.

3. The carbon-coated particles according to claim 1 , wherein the carbon-coated particles have a surface area of between about 2 m 2 /g and about 20 m 2 /g.

4. The carbon-coated particles of claim 3 , wherein the surface area is of about 8 m 2 /g.

5. The carbon-coated particles of claim 1 , wherein the electrochemically active material comprises a material selected from the group consisting of titanates, lithium titanates, lithium metal phosphates, vanadium oxides, lithium metal oxides, silicon, silicon oxides and combinations thereof.

6. The carbon-coated particles of claim 5 , wherein the electrochemically active material is selected from TiO 2 , Li 2 TiO 3 , Li 4 Ti 5 O 12 , H 2 Ti 5 O 11 and H 2 Ti 4 O 9 , or a combination thereof, LiM′PO 4 wherein M′ is Fe, Ni, Mn, Co, or a combination thereof, LiV 3 O 8 , V 2 O 5 , LiMn 2 O 4 , LiM″O 2 , wherein M″ is Mn, Co, Ni, or a combination thereof, Li(NiM′″)O 2 , wherein M′″ is Mn, Co, Al, Fe, Cr, Ti, or Zr, and combinations thereof.

7. An electrode material comprising the carbon-coated particles of claim 1 together with a binder.

8. The electrode material of claim 7 , wherein the binder is selected from SBR (styrene butadiene rubber), PAA (poly(acrylic acid)), PMAA (poly(methacrylic acid)), polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), NBR (butadiene acrylonitrile rubber), HNBR (hydrogenated NBR), CHR (epichlorohydrin rubber), ACM (acrylate rubber), and combination thereof, optionally comprising a thickening agent such as carbomethoxy cellulose (CMC).

9. The electrode material of claim 8 , wherein the binder comprises PAA or PMAA in combination with a binder selected from SBR, NBR, HNBR, CHR, ACM, and combinations thereof.

10. An electrode comprising the electrode material as defined in claim 7 on a current collector.

11. An electrochemical cell comprising an electrode as defined in claim 10 , an electrolyte and a counter-electrode.

12. The carbon-coated particles according to claim 2 , wherein the nano-layer of electron conductive carbon coating has an average thickness of below 10 nm.

13. The carbon-coated particles according to claim 2 , wherein the nano-layer of electron conductive carbon coating has an average thickness of below 5 nm.

14. The carbon-coated particles according to claim 2 , wherein the nano-layer of electron conductive carbon coating has an average thickness of below 2 nm.

15. The carbon-coated particles according to claim 1 , wherein the nano-layer of electron conductive carbon coating consists of about 6 wt % to about 11 wt % of nitrogen atoms, the rest being carbon atoms.

16. The carbon-coated particles according to claim 3 , wherein the carbon-coated particles have a surface area of between about 4 m 2 /g and about 15 m 2 /g.

17. The carbon-coated particles according to claim 3 , wherein the carbon-coated particles have a surface area of between about 6 m 2 /g and about 10 m 2 /g.

Assignees

• Hydro Quebec
• Sony Corp
• Murata Manufacturing Co

Inventors

• Daigle Jean-Christophe
• Asakawa Yuichiro
• Uesaka Shinichi
• Zaghib Karim

Classifications

• H01M4/525

  of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy · CPC title

• H01M4/485

  of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy (H01M4/505, H01M4/525 take precedence) · CPC title

• H01M4/623

  fluorinated polymers · CPC title

• H01M4/5825

  Oxygenated metallic salts or polyanionic structures, e.g. borates, phosphates, silicates, olivines · CPC title

• H01M4/366 Primary

  as layered products · CPC title