Encapsulated cathode active material particles, lithium secondary batteries containing same, and method of manufacturing

Patent metadata

Field	Value
Publication number	US-10483533-B2
Application number	US-201715483342-A
Country	US
Kind code	B2
Filing date	Apr 10, 2017
Priority date	Apr 10, 2017
Publication date	Nov 19, 2019
Grant date	Nov 19, 2019

Abstract

Provided is particulate of a cathode active material for a lithium battery, comprising one or a plurality of cathode active material particles being embraced or encapsulated by a thin layer of a high-elasticity polymer having a recoverable tensile strain no less than 5%, a lithium ion conductivity no less than 10−6 S/cm at room temperature, and a thickness from 0.5 nm to 10 μm, wherein the polymer contains an ultrahigh molecular weight (UHMW) polymer having a molecular weight from 0.5×106 to 9×106 grams/mole. The UHMW polymer is preferably selected from polyacrylonitrile, polyethylene oxide, polypropylene oxide, polyethylene glycol, polyvinyl alcohol, polyacrylamide, poly(methyl methacrylate), poly(methyl ether acrylate), a copolymer thereof, a sulfonated derivative thereof, a chemical derivative thereof, or a combination thereof.

First claim

We claim:

1. A particulate of a positive electrode active material for a lithium battery, said particulate comprising one or a plurality of positive electrode active material particles being embraced or encapsulated by a thin layer of a polymer having a recoverable tensile strain no less than 5%, a lithium ion conductivity no less than 10 −6 S/cm at room temperature, and a thickness of the thin layer is from 0.5 nm to 10 μm, wherein said polymer contains an ultrahigh molecular weight polymer having a molecular weight from 0.5×10 6 to 9×10 6 grams/mole and said ultrahigh molecular weight polymer is selected from polyethylene oxide, polypropylene oxide, polyethylene glycol, polyvinyl alcohol, polyacrylamide, poly(methyl methacrylate), poly(methyl ether acrylate), a copolymer thereof, a sulfonated derivative thereof, a chemical derivative thereof, and combinations thereof, and wherein said lithium battery is selected from a lithium-ion battery or lithium metal battery, excluding metal-air and metal-sulfur battery.

2. The particulate of claim 1 , wherein said ultrahigh molecular weight polymer has the molecular weight from 0.5×10 6 to less than 5×10 6 grams/mole.

3. The particulate of claim 1 , wherein said ultrahigh molecular weight polymer has the molecular weight from 1×10 6 to less than 3×10 6 grams/mole.

4. The particulate of claim 1 , wherein said thin layer of polymer has the thickness from 1 nm to 1 μm.

5. The particulate of claim 1 , wherein said thin layer of polymer has the thickness less than 100 nm.

6. The particulate of claim 1 , wherein said thin layer of polymer has the thickness less than 10 nm.

7. The particulate of claim 1 , wherein said polymer has the lithium ion conductivity from 10 −4 S/cm to 10 −2 S/cm.

8. The particulate of claim 1 , wherein said polymer is a neat polymer having no additive or filler dispersed therein.

9. The particulate of claim 1 , wherein said ultra-high molecular weight polymer contains from 0.1% to 50% by weight of a lithium ion-conducting additive dispersed therein, or contains therein from 0.1% by weight to 10% by weight of a reinforcement nano filament selected from carbon nanotube, carbon nano-fiber, graphene, or a combination thereof.

10. The particulate of claim 1 , wherein said ultra-high molecular weight polymer is mixed with a lithium ion-conducting additive to form a composite wherein said lithium ion-conducting additive is dispersed in said polymer and is selected from Li 2 CO 3 , Li 2 O, Li 2 C 2 O 4 , LiOH, LiX, ROCO 2 Li, HCOLi, ROLi, (ROCO 2 Li) 2 , (CH 2 OCO 2 Li) 2 , Li 2 S, Li x SO y , or a combination thereof, wherein X=F, Cl, I, or Br, R=a hydrocarbon group, 0<x≤1 and 1≤y≤4.

11. The particulate of claim 1 , wherein the ultra-high molecular weight polymer forms a mixture, blend, copolymer, or semi-interpenetrating network with a lithium ion-conducting polymer selected from poly(ethylene oxide) (PEO), polypropylene oxide (PPO), poly(acrylonitrile) (PAN), poly(methyl methacrylate) (PMMA), poly(vinylidene fluoride) (PVdF), poly bis-methoxy ethoxyethoxide-phosphazenex, polyvinyl chloride, polydimethylsiloxane, poly(vinylidene fluoride)-hexafluoropropylene (PVDF-HFP), a sulfonated derivative thereof, or a combination thereof.

12. The particulate of claim 1 , wherein said ultrahigh molecular weight polymer contains a lithium salt and/or a liquid solvent dispersed between chains of said ultrahigh molecular weight polymer.

13. The particulate of claim 12 , wherein said liquid solvent is selected from 1,3-dioxolane (DOL), 1,2-dimethoxyethane (DME), tetraethylene glycol dimethylether (TEGDME), poly(ethylene glycol) dimethyl ether (PEGDME), diethylene glycol dibutyl ether (DEGDBE), 2-ethoxyethyl ether (EEE), sulfone, sulfolane, ethylene carbonate (EC), propylene carbonate (PC), dimethyl carbonate (DMC), methylethyl carbonate (MEC), diethyl carbonate (DEC), ethyl propionate, methyl propionate, gamma-butyrolactone (γ-BL), acetonitrile (AN), ethyl acetate (EA), propyl formate (PF), methyl formate (MF), toluene, xylene, methyl acetate (MA), fluoroethylene carbonate (FEC), vinylene carbonate (VC), allyl ethyl carbonate (AEC), a hydrofluoroether, an ionic liquid solvent, and combinations thereof.

14. The particulate of claim 12 , wherein said lithium salt is selected from lithium perchlorate (LiClO 4 ), lithium hexafluorophosphate (LiPF 6 ), lithium borofluoride (LiBF 4 ), lithium hexafluoroarsenide (LiAsF 6 ), lithium trifluoro-methanesulfonate (LiCF 3 SO 3 ), bis-trifluoromethyl sulfonylimide lithium (LiN(CF 3 SO 2 ) 2 ), lithium bis(oxalato)borate (LiBOB), lithium oxalyldifluoroborate (LiBF 2 C 2 O 4 ), lithium nitrate (LiNO 3 ), Li-fluoroalkyl-phosphate, lithium bisperfluoro-ethysulfonylimide (LiBETI), lithium bis(trifluoromethanesulfonyl)imide, lithium bis(fluorosulfonyl)imide, lithium trifluoromethanesulfonimide (LiTFSI), an ionic liquid-based lithium salt, and combinations thereof.

15. The particulate of claim 1 , wherein said ultra-high molecular weight polymer is mixed with an electron-conducting polymer selected from polyaniline, polypyrrole, polyfuran, a bi-cyclic polymer, a sulfonated derivative thereof, or a combination thereof to form a blend, co-polymer, or semi-interpenetrating network.

16. The particulate of claim 1 , wherein said thin layer contains a conductive additive selected from graphite, graphene, or carbon material, or a combination thereof.

17. The particulate of claim 16 , wherein said graphite or carbon material is selected from polymeric carbon, amorphous carbon, chemical vapor deposition carbon, coal tar pitch, petroleum pitch, meso-phase pitch, carbon black, coke, acetylene black, activated carbon, fine expanded graphite particle with a dimension smaller than 100 nm, artificial graphite particle, natural graphite particle, or a combination thereof.

18. The particulate of claim 1 , wherein said ultrahigh molecular weight polymer contains an electrically conductive material dispersed therein.

19. The particulate of claim 18 , wherein said electrically conducting material is selected from an electron-conducting polymer, a metal particle or wire, a graphene sheet, a carbon fiber, a graphite fiber, a carbon nano-fiber, a graphite nano-fiber, a carbon nanotube, a graphite particle, an expanded graphite flake, an acetylene black particle, and combinations thereof.

20. The particulate of claim 19 , wherein said electrically conducting material has a thickness or diameter less than 100 nm.

21. The particulate of claim 1 , wherein one or a plurality of said particles is coated with a layer of carbon or graphene.

22. The particulate of claim 1 , wherein said positive electrode active material is in a form of nano particle, nano wire, nano fiber, nano tube, nano sheet, nano belt, nano ribbon, nano disc, nano platelet, or nano horn and wherein said positive electrode active nano material having a thickness or diameter from 0.5 nm to 100 nm.

23. The particulate of claim 22 , wherein said nano particle, nano wire, nano fiber, nano tube, nano sheet, nano belt, nano ribbon, nano disc, nano platelet, or nano horn is coated with or embraced by a conductive protective coating selected from a carbon material, graphene, electronically conductive polymer, conductive metal oxide, or conductive metal coating.

24. The particulate of claim 1 , wherein said positive electrode active material is selected from an inorganic material, an organic material, a polymeric material, or a combination thereof, and s

Assignees

• Nanotek Instruments Inc
• Global Graphene Group Inc

Inventors

• Zhamu Aruna
• Jang Bor Z

Classifications

• H01M2300/0091

  in the form of mixtures · CPC title

• H01M2300/0082

  Organic polymers · CPC title

• H01M4/602

  Polymers · CPC title

• C08K5/04

  Oxygen-containing compounds {(C08K5/0091 takes precedence)} · CPC title

• C08K3/38

  Boron-containing compounds · CPC title