Graphene foam-protected anode active materials for lithium batteries

Patent metadata

Field	Value
Publication number	US-2016043384-A1
Application number	US-201414121151-A
Country	US
Kind code	A1
Filing date	Aug 7, 2014
Priority date	Aug 7, 2014
Publication date	Feb 11, 2016
Grant date	—

Abstract

A lithium-ion battery anode layer, comprising an anode active material embedded in pores of a solid graphene foam composed of multiple pores and pore walls, wherein (a) the pore walls contain a pristine graphene material having essentially no (less than 0.01%) non-carbon elements or a non-pristine graphene material having 0.01% to 5% by weight of non-carbon elements; (b) the anode active material is in an amount from 0.5% to 95% by weight based on the total weight of the graphene foam and the anode active material combined, and (c) some of the multiple pores are lodged with particles of the anode active material and other pores are particle-free, and the graphene foam is sufficiently elastic to accommodate volume expansion and shrinkage of the particles of the anode active material during a battery charge-discharge cycle to avoid expansion of the anode layer. Preferably, the solid graphene foam has a density from 0.01 to 1.7 g/cm 3 , a specific surface area from 50 to 2,000 m 2 /g, a thermal conductivity of at least 100 W/mK per unit of specific gravity, and/or an electrical conductivity no less than 1,000 S/cm per unit of specific gravity.

First claim

We claim:

1 . An anode or negative electrode layer for a lithium battery, said anode layer comprising multiple particles of an anode active material and a solid graphene foam composed of multiple pores and pore walls, wherein
a. said pore walls contain a pristine graphene material having less than 0.01% by weight of non-carbon elements or a non-pristine graphene material having 0.01% to 5% by weight of non-carbon elements, wherein said non-pristine graphene is selected from 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 anode active material is in an amount from 0.5% to 95% by weight based on the total weight of said graphene foam and said anode active material combined; and c. some of said multiple pores are lodged with said particles of the anode active material and other pores are particle-free, and said graphene foam is sufficiently elastic to accommodate volume expansion and shrinkage of said particles of the anode active material during a battery charge-discharge cycle to avoid expansion of said anode layer.

2 . The anode layer of claim 1 , wherein said solid graphene foam has a density from 0.01 to 1.7 g/cm 3 , a specific surface area from 50 to 2,000 m 2 /g, a thermal conductivity of at least 100 W/mK per unit of specific gravity, and/or an electrical conductivity no less than 1,000 S/cm per unit of specific gravity.

3 . 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.

4 . 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.

5 . The anode layer of claim 1 , wherein said anode active material is in a form of nano particle, nano wire, nano fiber, nano tube, nano sheet, nano belt, nano ribbon, or nano coating having a thickness or diameter less than 100 nm.

6 . The anode layer of claim 5 , wherein said anode active material has a dimension less than 20 nm.

7 . The anode layer of claim 1 , further comprising a carbon or graphite material therein, wherein said carbon or graphite material is in electronic contact with or deposited onto said anode active material.

8 . 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, 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.

9 . The anode layer of claim 5 , further comprising a conductive protective coating, selected from a carbon material, electronically conductive polymer, conductive metal oxide, conductive metal coating, or a lithium-conducting material, which is deposited onto or wrapped around said nano particle, nano wire, nano fiber, nano tube, nano sheet, nano belt, nano ribbon, or nano coating.

10 . The anode layer of claim 9 , wherein said nano particle, nano wire, nano fiber, nano tube, nano sheet, nano belt, nano ribbon, or nano coating is prelithiated.

11 . The anode layer of claim 1 , further comprising a lithium-conducting coating deposited onto said anode active material.

12 . 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.

13 . The anode layer of claim 1 , wherein said pore walls contain a pristine graphene and said solid graphene foam has a density from 0.5 to 1.7 g/cm 3 or said pores have a pore size from 2 nm to 100 nm.

14 . The anode layer of claim 1 , wherein said non-pristine graphene material contains a content of non-carbon elements from 0.01% to 2.0% by weight.

15 . The anode layer of claim 1 , wherein said pore walls contain graphene fluoride and said solid graphene foam 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 solid graphene foam contains an oxygen content from 0.01% to 2.0% by weight.

17 . The anode layer of claim 1 , wherein said solid graphene foam has a specific surface area from 200 to 2,000 m 2 /g or a density from 0.1 to 1.5 g/cm 3 .

18 . The anode layer of claim 1 , wherein said non-carbon elements include an element selected from oxygen, fluorine, chlorine, bromine, iodine, nitrogen, hydrogen, or boron.

19 . The anode layer of claim 1 , which is in a continuous-length roll sheet form having a thickness no greater than 300 μm and a length of at least 2 meters and is produced by a roll-to-roll process.

20 . The anode layer of claim 1 , wherein said graphene foam 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, a thermal conductivity of at least 250 W/mK per unit of specific gravity, and/or an electrical conductivity no less than 2,500 S/cm per unit of specific gravity.

21 . The anode layer of claim 1 , wherein said graphene foam 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, a thermal conductivity of at least 300 W/mK per unit of specific gravity, and/or an electrical conductivity no less than 3,000 S/cm per unit of specific gravity.

22 . The anode layer of claim 1 , wherein said graphene foam 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, a mosaic spread value no greater than 0.7, a thermal conductivity of at least 350 W/mK per unit of specific gravity, and/or an electrical conductivity no less than 3,500 S/cm per unit of specific gravity.

23 . The anode layer of claim 1 , wherein said graphene foam has pore walls containing stacked graphene planes having an inter-graphene spacing less than 0.336 nm, a mosaic spread value no greater than 0.4, a thermal conductivity greater than 400 W/mK per unit of specific gravity, and/or an electrical conductivity greater than 4,000 S/cm per unit of specific gravity.

24 . The anode layer of claim 1 , wherein the pore walls conta

Assignees

• Zhamu Aruna
• Jang Bor Z

Inventors

• Zhamu Aruna
• Jang Bor Z

Classifications

• H01M4/587

  for inserting or intercalating light metals · CPC title

• H01M4/1393

  of electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx · CPC title

• H01M4/133 Primary

  Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx · CPC title

• H01M10/052

  Li-accumulators · CPC title

• H01M4/387

  Tin or alloys based on tin · CPC title