Anode material particles with porous carbon-based shells

Patent metadata

Field	Value
Publication number	US-10903530-B2
Application number	US-201916390837-A
Country	US
Kind code	B2
Filing date	Apr 22, 2019
Priority date	Apr 7, 2016
Publication date	Jan 26, 2021
Grant date	Jan 26, 2021

Abstract

Improved anodes and cells are provided, which enable fast charging rates with enhanced safety due to much reduced probability of metallization of lithium on the anode, preventing dendrite growth and related risks of fire or explosion. Anodes and/or electrolytes have buffering zones for partly reducing and gradually introducing lithium ions into the anode for lithiation, to prevent lithium ion accumulation at the anode electrolyte interface and consequent metallization and dendrite growth. Various anode active materials and combinations, modifications through nanoparticles and a range of coatings which implement the improved anodes are provided.

First claim

The invention claimed is:

1. Composite anode material particles comprising:
anode material cores that are at least partly de-oxidized, and
at least partially porous carbon-graphite shells over the anode material cores,
wherein the at least partial porous graphite shells are configured to retain electronic conductivity to the anode material cores through the graphite of the shell while providing ionic conductivity through pores of the porous shells; and to provide a buffering zone that receives lithium ions from an interface of the composite anode active material particles with an electrolyte, partially reduces the received lithium ions, and enables the partially reduced lithium ions to move into an inner zone of the composite anode active material particles for lithiation therein.

2. The composite anode material particles of claim 1 , comprising one at least partially porous carbon-graphite shell per anode material core.

3. The composite anode material particles of claim 1 , wherein the at least partially porous carbon-graphite shells comprise carbonized graphite-carbohydrate layers formed over at least part of a surface of the respective anode material cores.

4. The composite anode material particles of claim 1 , wherein the at least partially porous carbon-graphite shells comprise at least partially porous graphite shells.

5. The composite anode material particles of claim 1 , wherein the at least partially porous carbon-graphite shells have a lower surface energy than the anode material core, reducing agglomeration of the composite anode material particles in a water-based slurry.

6. The composite anode material particles of claim 1 , wherein the at least partially porous carbon-graphite shells have a lower surface energy than the anode material core, reducing agglomeration of the composite anode material particles in an organic solvent.

7. The composite anode material particles of claim 1 , wherein the at least partially porous carbon-graphite shells are de-oxidized.

8. The composite anode material particles of claim 1 , wherein the at least partially porous carbon-graphite shells are de-hydrated.

9. The composite anode material particles of claim 1 , wherein the at least partially porous carbon-graphite shells electrically conductive via the carbon-graphite shell materials and ionically conductive through pores of the the at least partially porous carbon-graphite shells.

10. The composite anode material particles of claim 1 , wherein the at least partially porous carbon-graphite shells are bonded to the anode material cores in a mechanically stable manner, under expansion of the anode material cores during lithiation thereof.

11. The composite anode material particles of claim 1 , further comprising at least one polymer coating and/or lithiated coating.

12. The composite anode material particles of claim 1 , wherein the anode material cores are at least partly metalloid, comprising at least one of Si, Ge and Sn.

13. An anode for a lithium ion battery, comprising consolidated composite anode material particles of claim 1 .

14. A lithium ion battery comprising at least one anode of claim 13 and at least one cathode, enclosed with electrolyte within a pouch.

15. A carbonized mixture of graphite-carbohydrate particles with anode material particles having a native oxide layer,
wherein carbonization of the carbonized mixture replaces, be de-oxidation, at least part of the native oxide layer with a graphite-carbohydrate layer formed from the graphite-carbohydrate particles over at least part of a surface of the anode material particles and forms an at least partial porous graphite shell over the anode material particles.

16. The carbonized mixture of claim 15 , wherein the graphite-carbohydrate particles comprise co-milled graphite particles and carbohydrate particles.

17. The carbonized mixture of claim 15 , wherein the carbonization is carried out at between 600° C. and 900° C. in a dry and inert environment.

18. The carbonized mixture of claim 15 , wherein the at least partial porous graphite shell has a lower surface energy than the anode material particles.

19. The carbonized mixture of claim 15 , wherein the at least partial porous graphite shells are configured to retain electronic conductivity to the anode material particles through the graphite of the shell while providing ionic conductivity through pores of the porous shells; and to provide a buffering zone that receives lithium ions from an interface of the carbonized mixture with an electrolyte in an anode consolidated therefrom, partially reduces the received lithium ions, and enables the partially reduced lithium ions to move into an inner zone of the composite anode active material particles for lithiation therein.

Assignees

• Storedot Ltd

Inventors

• Jacob David
• Remizov Sergey
• Shadmi Nitzan
• FARRAN Hani
• Aronov Daniel
• Brudnik Boris

Classifications

• H01M4/386

  Silicon or alloys based on silicon · CPC title

• H01M10/4235 Primary

  Safety or regulating additives or arrangements in electrodes, separators or electrolyte (H01M10/4242 takes precedence) · CPC title

• Y02E60/10

  Energy storage using batteries · CPC title

• H01M4/387

  Tin or alloys based on tin · CPC title

• C09D5/24

  Electrically-conducting paints {(conductive materials H01B1/00)} · CPC title