Graphene-carbon hybrid foam-protected anode active material coating for lithium-ion batteries

1. A porous anode material structure for a lithium-ion battery, said structure comprising (A) an integral 3D graphene-carbon hybrid foam comprising multiple pores, having a pore volume Vp, and pore walls; and (B) coating of an anode active material, having a coating volume Vc, coated on surfaces of said pore walls; wherein said pore walls contain single-layer or few-layer graphene sheets chemically bonded by a carbon material having a carbon material-to-graphene weight ratio from 1/200 to 1/2, and wherein the volume ratio Vp/Vc is from 0.1/1.0 to 10/1.0, wherein said porous anode material structure includes porous particulates having multiple pores and pore walls coated with said coating, and said porous particulates have a diameter from 5 μm to 50 μm.

2. The porous anode material structure of claim 1 , wherein said few-layer graphene sheets have 2-10 layers of stacked graphene planes having an inter-plane spacing d 002 from 0.3354 nm to 0.40 nm as measured by X-ray diffraction and said single-layer or few-layer graphene sheets contain a pristine graphene material having essentially zero % of non-carbon elements, or a non-pristine graphene material having 0.001% to 25% 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, doped graphene, chemically functionalized graphene, or a combination thereof.

3. The porous anode material structure of claim 1 , wherein said volume ratio Vp/Vc is from 0.3/1.0 to 4.0/1.0.

4. The porous anode material structure of claim 1 , wherein said integral 3D graphene-carbon hybrid foam contains multiple pores that are interconnected to form open cells for accommodating an entry of said coating.

5. The porous anode material structure of claim 1 , wherein said pore walls contain a non-pristine graphene material and wherein said foam contains a content of non-carbon elements in the range from 0.01% to 20% by weight and said non-carbon elements include an element selected from oxygen, fluorine, chlorine, bromine, iodine, nitrogen, hydrogen, or boron.

6. The porous anode material structure of claim 1 , wherein said pore walls contain graphene fluoride and said 3D graphene-carbon hybrid foam contains a fluorine content from 0.01% to 15% by weight.

7. The porous anode material structure of claim 1 , wherein said pore walls contain graphene oxide and said 3D graphene-carbon hybrid foam contains an oxygen content from 0.01% to 20% by weight.

8. The porous anode material structure of claim 1 , wherein said pore walls contain a 3D network of interconnected graphene planes.

9. The porous anode material structure of claim 1 , wherein said anode active material coating 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 aluminate, lithium-containing titanium oxide, lithium transition metal oxide; (f) prelithiated versions thereof; (g) particles of Li, Li alloy, or surface-stabilized Li having at least 60% by weight of lithium element therein; and (h) combinations thereof.

10. The porous anode material structure of claim 9 , wherein said Li alloy contains from 0.1% to 10% by weight of a metal element selected from Zn, Ag, Au, Mg, Ni, Ti, Fe, Co, V, or a combination.

11. The porous anode material structure 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 , lithium titanate, or a combination thereof, wherein x=1 to 2.

12. The porous anode material structure of claim 1 , wherein said coating of anode active material is further coated with a layer of carbon or conducting polymer.