Porous graphene particulate-protected anode active materials for lithium batteries

Patent metadata

Field	Value
Publication number	US-2020127277-A1
Application number	US-201816163955-A
Country	US
Kind code	A1
Filing date	Oct 18, 2018
Priority date	Oct 18, 2018
Publication date	Apr 23, 2020
Grant date	—

Abstract

An anode for a lithium battery, comprising multiple porous graphene particulates, wherein at least one of the particulates comprises multiple pores (total volume Vpp), pore walls, and primary particles of an anode active material (total volume Va), disposed in the pores, wherein (a) the pore walls contain a graphene material; (b) the primary particles are in an amount from 0.5% to 95% by weight based on the total particulate weight; (c) the particulate is embraced or encapsulated by a thin encapsulating layer of electrically conducting material having a thickness from 1 nm to 10 μm, an electric conductivity from 10−6 S/cm to 20,000 S/cm and a lithium ion conductivity from 10−8 S/cm to 5×10−2 S/cm; and (d) the volume ratio Vpp/Va is from 1.3/1.0 to 5.0/1.0.

First claim

We claim:

1 . An anode or negative electrode layer for a lithium battery, said anode layer comprising multiple porous graphene particulates, wherein at least one of said porous graphene particulates comprises multiple pores, having a total volume Vpp, pore walls, and primary particles of an anode active material, having a total volume Va, disposed in said pores, wherein
a) said pore walls contain a graphene material selected from a pristine graphene, graphene oxide, reduced graphene oxide, graphene fluoride, graphene chloride, graphene bromide, graphene iodide, hydrogenated graphene, nitrogenated graphene, boron-doped graphene, nitrogen-doped graphene, chemically functionalized graphene, or a combination thereof; b) said primary particles of anode active material are in an amount from 0.5% to 95% by weight based on the total porous graphene particulate weight; c) said graphene particulate is embraced or encapsulated by a thin encapsulating layer of electrically conducting material having a thickness from 1 nm to 10 μm, an electric conductivity from 10 −6 S/cm to 20,000 S/cm and a lithium ion conductivity from 10 −8 S/cm to 5×10 −2 S/cm; and d) the volume ratio Vpp/Va is from 1.3/1.0 to 5.0/1.0 and said pores in said particulate have a sufficient amount of free space to accommodate a volume expansion of said primary particles of anode active material when said lithium battery is charged without inducing a volume expansion of said anode electrode by more than 20%.

3 . The anode layer of claim 1 , wherein said porous graphene particulate, excluding particles of anode active material, has a density from 0.1 to 1.5 g/cm 3 and a specific surface area from 50 to 2,000 m 2 /g.

4 . The anode layer of claim 1 , wherein said anode active material is selected from the group consisting of: (a) silicon (Si), germanium (Ge), tin (Sn), lead (Pb), antimony (Sb), bismuth (Bi), zinc (Zn), aluminum (Al), titanium (Ti), nickel (Ni), cobalt (Co), and cadmium (Cd); (b) alloys or intermetallic compounds of Si, Ge, Sn, Pb, Sb, Bi, Zn, Al, Ti, Ni, Co, or Cd with other elements; (c) oxides, carbides, nitrides, sulfides, phosphides, selenides, and tellurides of Si, Ge, Sn, Pb, Sb, Bi, Zn, Al, Ti, Fe, Ni, Co, V, or Cd, and their mixtures, composites, or lithium-containing composites; (d) salts and hydroxides of Sn; (e) lithium titanate, lithium manganate, lithium aluminate, lithium-containing titanium oxide, lithium transition metal oxide; (f) prelithiated versions thereof; (g) particles of Li, Li alloy, or surface-stabilized Li; and (h) combinations thereof.

5 . The anode layer of claim 1 , wherein said anode active material contains a prelithiated Si, prelithiated Ge, prelithiated Sn, prelithiated SnO x , prelithiated SiO x , prelithiated iron oxide, prelithiated VO 2 , prelithiated Co 3 O 4 , prelithiated Ni 3 O 4 , or a combination thereof, wherein x=1 to 2.

6 . The anode layer of claim 1 , wherein said primary particles of anode active material are in a form of nanoparticle, nanowire, nanofiber, nanotube, nanosheet, nanobelt, nanoribbon, or nanocoating having a thickness or diameter less than 100 nm.

7 . The anode layer of claim 5 , wherein said primary particles of anode active material have a dimension less than 20 nm.

8 . The anode layer of claim 1 , wherein said porous graphene particulate further comprises a carbon or graphite material therein, wherein said carbon or graphite material is in electronic contact with or deposited onto said primary particles of anode active material.

9 . The anode layer of 7 , wherein said carbon or graphite material is selected from polymeric carbon, amorphous carbon, chemical vapor deposition carbon, coal tar pitch, petroleum pitch, mesophase 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.

10 . The anode layer of claim 1 , wherein said porous graphene particulate further comprises a carbon material that chemically bonds sheets of said graphene together to form an integral 3D network of electron-conducting pathways interposed between pores inside said particulate.

11 . The anode layer of claim 1 , wherein said thin encapsulating layer comprises a material selected from a carbon nanotube, carbon nanofiber, nanocarbon particle, metal nanoparticle, metal nanowire, electron-conducting polymer, graphene, conductive metal oxide, amorphous carbon, polymeric carbon, CVD carbon, or a combination thereof, wherein said graphene is selected from pristine graphene, graphene oxide, reduced graphene oxide, graphene fluoride, graphene chloride, nitrogenated graphene, hydrogenated graphene, doped graphene, functionalized graphene, or a combination thereof and said graphene comprise single-layer graphene or few-layer graphene, wherein said few-layer graphene is defined as a graphene platelet formed of less than 10 graphene planes.

12 . The anode layer of claim 10 , wherein said electron-conducting polymer is selected from polyaniline, polypyrrole, polythiophene, polyfuran, a bi-cyclic polymer, a sulfonated derivative thereof, or a combination thereof.

13 . The anode layer of claim 1 , wherein said pore walls contain stacked graphene planes having an inter-plane spacing d 002 from 0.3354 nm to 0.36 nm as measured by X-ray diffraction.

14 . The anode layer of claim 1 , wherein said pore walls contain a pristine graphene and said solid porous graphene particulate has a density from 0.5 to 1.5 g/cm 3 , excluding said primary particles of anode active material.

15 . The anode layer of claim 1 , wherein said pore walls contain graphene fluoride and said porous graphene particulate contains a fluorine content from 0.01% to 2.0% by weight.

16 . The anode layer of claim 1 , wherein said pore walls contain graphene oxide and said porous graphene particulate contains an oxygen content from 0.01% to 2.0% by weight.

17 . The anode layer of claim 1 , wherein said porous graphene particulate has an oxygen content or non-carbon content less than 1% by weight, and said pore walls have an inter-graphene spacing less than 0.35 nm.

18 . The anode layer of claim 1 , wherein said porous graphene particulate has an oxygen content or non-carbon content less than 0.01% by weight and said pore walls contain stacked graphene planes having an inter-graphene spacing less than 0.34 nm.

19 . The anode layer of claim 1 , wherein said porous graphene particulate has an oxygen content or non-carbon content no greater than 0.01% by weight and said pore walls contain stacked graphene planes having an inter-graphene spacing less than 0.336 nm, and a mosaic spread value no greater than 0.7.

20 . The anode layer of claim 1 , wherein said porous graphene particulate has pore walls containing stacked graphene planes having an inter-graphene spacing less than 0.336 nm and a mosaic spread value no greater than 0.4.

21 . The anode layer of claim 1 , wherein the pore walls contain stacked graphene planes having an inter-graphene spacing less than 0.337 nm and a mosaic spread value less than 1.0.

22 . The anode layer of claim 1 , wherein said pore walls contain a 3D network of interconnected graphene planes.

23 . A powder mass of an anode active material comprising multiple porous graphene particulates, wherein at least one of said porous graphene particulates comprises multiple pores, having a total volume Vpp, pore walls, and prima

Assignees

• Nanotek Instruments Inc

Inventors

• Lu Sheng-Yi
• Chiu Wen Y
• Jang Bor Z

Classifications

• H01M4/523

  for non-aqueous cells (H01M4/525 takes precedence) · CPC title

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• H01M4/366

  as layered products · CPC title

• H01M10/052

  Li-accumulators · CPC title

• H01M4/387

  Tin or alloys based on tin · CPC title