Chemical-free production method of graphene-protected porous anode particles for lithium batteries

1. An impact-transfer method of producing multiple porous anode particulates for a lithium battery, said method comprising:

a) mixing multiple particles of a graphitic material, multiple polymer-coated primary anode active material particles, with or without the presence of externally added milling balls or beads, to form a mixture in an impacting chamber of an energy impacting apparatus, wherein at least one of said primary anode active material particles is porous, having a surface pore, an internal pore, or both surface and internal pores;

b) operating said energy impacting apparatus with a frequency and an intensity for a length of time sufficient for peeling off graphene sheets from said particles of graphitic material and transferring said peeled graphene sheets to surfaces of said polymer-coated anode active material particles and embrace or encapsulate said polymer-coated particles to produce particulates of graphene-embraced or graphene-encapsulated polymer-coated porous anode active material particles inside said impacting chamber;

c) recovering said particulates of graphene-embraced or graphene-encapsulated polymer-coated porous anode active material from said impacting chamber and separating said particles of ball-milling media from said particulates of graphene-embraced or graphene-encapsulated polymer-coated porous anode active material; and

d) thermally converting said polymer in said polymer-coated particles into a porous carbon matrix or carbon foam to obtain said multiple porous particulates, wherein at least one of said porous particulates comprises a core and a thin encapsulating layer that encapsulates or embraces said core, wherein said core comprises a single or a plurality of porous primary particles of an anode active material, having a pore volume Vpp and a solid volume Va, dispersed or embedded in a porous carbon matrix or carbon foam, wherein said porous carbon matrix or carbon foam contains pores having a pore volume Vp, and said thin encapsulating layer comprises graphene sheets and has 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 wherein a volume ratio Vp/Va is from 0.1/1.0 to 10/1.0 or a total pore volume ratio (Vp+Vpp)/Va is from 0.3/1.0 to 20/1.0, and the porous carbon matrix or carbon foam electronically and/or ionically connects the encapsulating layer to the primary particles of the anode active material.

2. An impact-transfer method of producing multiple porous particulates of graphene-encapsulated porous anode active material particles, said method comprising:

A) mixing multiple particles of a graphitic material, multiple porous primary anode active material particles, with or without the presence of externally added milling balls or beads, to form a mixture in an impacting chamber of an energy impacting apparatus, wherein said porous primary anode active material particles have a surface pore, an internal pore, or both surface and internal pores;

B) operating said energy impacting apparatus with a frequency and an intensity for a length of time sufficient for peeling off graphene sheets from said particles of graphitic material and transferring said peeled graphene sheets to surfaces of said porous primary anode active material particles and embrace or encapsulate said porous primary particles to produce particulates of graphene-embraced or graphene-encapsulated porous anode active material particles inside said impacting chamber; and

C) recovering said particulates of graphene-embraced or graphene-encapsulated porous primary anode active material from said impacting chamber and separating said particles of ball-milling media, if present, from said particulates of graphene-embraced or graphene-encapsulated porous primary anode active material particles.

3. The method of claim 1 , wherein said polymer contains a blowing agent, a reinforcement material, or both dispersed therein.

4. The method of claim 1 , where said multiple polymer-coated anode active material particles are produced by operating a procedure selected from pan-coating, air-suspension coating, centrifugal extrusion, vibration-nozzle encapsulation, spray-drying, coacervation-phase separation, interfacial polycondensation and interfacial cross-linking, in-situ polymerization, matrix polymerization, extrusion and pelletizing, or a combination thereof.

5. The method of claim 1 , wherein said particles of ball-milling media contain milling balls selected from ceramic particles, including ZrO 2 and non-ZrO 2 metal oxide particles, metal particles, glass particles, polymer particles, or a combination thereof.

6. The method of claim 1 , wherein said polymer-coated anode active material particles comprise a polymer selected from a thermoplastic, thermoset resin, rubber or elastomer, filled or reinforced polymer, interpenetrating polymer network, biopolymer, pitch, sugar, starch, or a combination thereof.

7. The method of claim 1 , further comprising a step of incorporating said particulate into a battery anode electrode.

8. The method of claim 1 , wherein said particles of anode active material contain prelithiated particles having 0.1% to 54.7% by weight of lithium ions preloaded into said particles prior to step (a) of mixing.

9. The method of claim 1 , wherein said particles of anode active material contain particles pre-coated with a layer of conductive material selected from a carbon, pitch, carbonized resin, conductive polymer, conductive organic material, metal coating, metal oxide shell, graphene, or a combination thereof.

10. The method of claim 1 , further comprising a step of exposing said multiple particulates to a liquid or vapor of a conductive material that is conductive to electrons and/or ions of lithium.

11. The method of claim 1 , wherein said particles of anode active material are selected from the group consisting of:

(A) lithiated and un-lithiated 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) lithiated and un-lithiated alloys or intermetallic compounds of Si, Ge, Sn, Pb, Sb, Bi, Zn, Al, Ti, Ni, Co, or Cd with other elements;

(C) lithiated and un-lithiated oxides, carbides, nitrides, sulfides, phosphides, selenides, and tellurides of Si, Ge, Sn, Pb, Sb, Bi, Zn, Al, Ti, Fe, Ni, Co, or Cd, and their mixtures, composites, or lithium-containing composites;

(D) lithiated and un-lithiated salts and hydroxides of Sn;

(E) lithium titanate, lithium manganate, lithium aluminate, lithium-containing titanium oxide, lithium transition metal oxide;

and combinations thereof.

12. The method of claim 1 , wherein said anode active material particles include powder, flakes, beads, pellets, spheres, wires, fibers, filaments, discs, ribbons, or rods, having a diameter or thickness from 2 nm to 20 μm.

13. The method of claim 1 , wherein said graphitic material is selected from natural graphite, synthetic graphite, highly oriented pyrolytic graphite, graphite fiber, graphitic nanofiber, graphite fluoride, chemically modified graphite, mesocarbon microbead, partially crystalline graphite, or a combination thereof.

14. The method of claim 1 , wherein the energy impacting apparatus is a vibratory ball mill, planetary ball mill, high energy mill, basket mill, agitator ball mill, cryogenic ball mill, micro ball mill, tumbler ball mill, continuous ball mill, stirred ball mill, pressurized ball mill, attritor, plasma-assisted ball mill, freezer mill, vibratory sieve, bead mill, nanobead mill, ultrasonic homogenizer mill, centrifugal planetary mixer, vacuum ball mill, or resonant acoustic mixer.

15. The method of claim 1 , wherein said procedure of operating said energy impacting apparatus is conducted in a continuous manner using a continuous energy impacting device.

16. The method of claim 2 , wherein said particles of ball-milling media contain milling balls selected from ceramic particles, including ZrO 2 and non-ZrO 2 metal oxide particles, metal particles, glass particles, polymer particles, or a combination thereof.

17. The method of claim 2 , further comprising a step of incorporating said particulate into a battery anode electrode.

18. The method of claim 2 , wherein said particles of anode active material contain prelithiated particles having 0.1% to 54.7% by weight of lithium ions preloaded into said particles prior to step (a) of mixing.

19. The method of claim 2 , wherein said particles of anode active material contain particles pre-coated with a layer of conductive material selected from a carbon, pitch, carbonized resin, conductive polymer, conductive organic material, metal coating, metal oxide shell, graphene, or a combination thereof.

20. The method of claim 2 , wherein said particles of anode active material are selected from the group consisting of:

a) lithiated and un-lithiated 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) lithiated and un-lithiated alloys or intermetallic compounds of Si, Ge, Sn, Pb, Sb, Bi, Zn, Al, Ti, Ni, Co, or Cd with other elements;

c) lithiated and un-lithiated oxides, carbides, nitrides, sulfides, phosphides, selenides, and tellurides of Si, Ge, Sn, Pb, Sb, Bi, Zn, Al, Ti, Fe, Ni, Co, or Cd, and their mixtures, composites, or lithium-containing composites;

d) lithiated and un-lithiated salts and hydroxides of Sn;

e) lithium titanate, lithium manganate, lithium aluminate, lithium-containing titanium oxide, lithium transition metal oxide;

and combinations thereof.

21. The method of claim 2 , wherein said anode active material particles include powder, flakes, beads, pellets, spheres, wires, fibers, filaments, discs, ribbons, or rods, having a diameter or thickness from 2 nm to 20 μm.

22. The method of claim 2 , wherein said graphitic material is selected from natural graphite, synthetic graphite, highly oriented pyrolytic graphite, graphite fiber, graphitic nanofiber, graphite fluoride, chemically modified graphite, mesocarbon microbead, partially crystalline graphite, or a combination thereof.

23. The method of claim 2 , wherein the energy impacting apparatus is a vibratory ball mill, planetary ball mill, high energy mill, basket mill, agitator ball mill, cryogenic ball mill, micro ball mill, tumbler ball mill, continuous ball mill, stirred ball mill, pressurized ball mill, attritor, plasma-assisted ball mill, freezer mill, vibratory sieve, bead mill, nano bead mill, ultrasonic homogenizer mill, centrifugal planetary mixer, vacuum ball mill, or resonant acoustic mixer.

24. The method of claim 2 , wherein said procedure of operating said energy impacting apparatus is conducted in a continuous manner using a continuous energy impacting device.