Multivalent metal ion battery having a cathode of recompressed graphite worms and manufacturing method

1. A multivalent metal-ion battery comprising an anode, a cathode, a porous separator electronically separating said anode and said cathode, and an electrolyte in ionic contact with said anode and said cathode to support reversible deposition and dissolution of a multivalent metal, multivalent selected from Ni, Zn, Be, Mg, Ca, Ba, La, Ti, Ta, Zr, Nb, Mn, V, Co, Fe, Cd, Cr, Ga, In, or a combination thereof, at said anode, wherein said anode contains said multivalent metal or its alloy as an anode active material and said cathode comprises a cathode layer of an exfoliated graphite or carbon material having inter-flake pores from 2 nm to 10 μm in pore size,

the cathode layer comprises an active layer of recompressed exfoliated graphite or carbon material comprising a physical density of 0.5 to 1.8 g/cm 3 and has a meso-scaled pores having a pore size of 2 nm to 50 nm.

2. The multivalent metal-ion battery of claim 1 , wherein said exfoliated carbon or graphite material in said cathode layer is selected from a thermally exfoliated product of meso-phase pitch, meso-phase carbon, meso carbon micro-beads (MCMB), coke particles, expanded graphite flakes, artificial graphite particles, natural graphite particles, highly oriented pyrolytic graphite, soft carbon particles, hard carbon particles, multi-walled carbon nanotubes, carbon nano-fibers, carbon fibers, graphite nano-fibers, graphite fibers, carbonized polymer fibers, or a combination thereof.

3. The multivalent metal-ion battery of claim 1 , wherein the active layer of recompressed exfoliated graphite or carbon material that is oriented in such a manner that said active layer has a graphite edge plane in direct contact with said electrolyte and facing or contacting said separator.

4. The multivalent metal-ion battery of claim 3 , wherein said active layer of recompressed exfoliated graphite or carbon material has a physical density from 1.1 to 1.8 g/cm 3 and has pores having a pore size from 2 nm to 5 nm.

5. The multivalent metal-ion battery of claim 3 , wherein said active layer of recompressed exfoliated graphite or carbon material has a specific surface area from 20 m 2/ g to 1,500 m 2/ g.

6. The multivalent metal-ion battery of claim 1 , further comprising an anode current collector supporting said multivalent metal or its alloy or further comprising a cathode current collector supporting said cathode layer of exfoliated graphite or carbon material.

7. The multivalent metal-ion battery of claim 6 , wherein said anode current collector contains an integrated nano-structure of electrically conductive nanometer-scaled filaments that are interconnected to form a porous network of electron-conducting paths comprising interconnected pores, wherein said filaments have a transverse dimension less than 500 nm.

8. The multivalent metal-ion battery of claim 7 , wherein said filaments comprise an electrically conductive material selected from the group consisting of electro-spun nano fibers, vapor-grown carbon or graphite nano fibers, carbon or graphite whiskers, carbon nano-tubes, nano-scaled graphene platelets, metal nano wires, and combinations thereof.

9. The multivalent metal-ion battery of claim 1 , wherein said electrolyte is selected from an aqueous electrolyte, organic electrolyte, polymer electrolyte, molten salt electrolyte, ionic liquid electrolyte, or a combination thereof.

10. The multivalent metal-ion battery of claim 1 , wherein said electrolyte contains NiSO 4 , ZnSO 4 , MgSO 4 , CaSO 4 , BaSO 4 , FeSO 4 , MnSO 4 , CoSO 4 , VSO 4 , TaSO 4 , CrSO 4 , CdSO 4 , GaSO 4 , Zr(SO 4 ) 2 , Nb 2 (SO 4 ) 3 , La 2 (SO 4 ) 3 , BeCl 2 , BaCl 2 , MgCl 2 , AlCl 3 , Be(ClO 4 ) 2 , Ca(ClO 4 ) 2 , Mg(ClO 4 ) 2 , Mg(BF 4 ) 2 , Ca(BF 4 ) 2 , Be(BF 4 ) 2 , Alkyl Grignard reagents, tri(3,5-dimethylphenyl borane, tris(pentafluorophenyl)borane, magnesium dibutyldiphenyl, Mg(BPh2Bu2)2, magnesium tributylphenyl Mg(BPhBu3)2), or a combination thereof.

11. The multivalent metal-ion battery of claim 1 , wherein the electrolyte comprises at least a metal ion salt selected from a transition metal sulphate, transition metal phosphate, transition metal nitrate, transition metal acetate, transition metal carboxylate, transition metal chloride, transition metal bromide, transition metal nitride, transition metal perchlorate, transition metal hexafluorophosphate, transition metal borofluoride, transition metal hexafluoroarsenide, or a combination thereof.

12. The multivalent metal-ion battery of claim 1 , wherein the electrolyte comprises at least a metal ion salt selected from a metal sulphate, phosphate, nitrate, acetate, carboxylate, nitride, chloride, bromide, or perchlorate of zinc, aluminum, titanium, magnesium, calcium, beryllium, manganese, cobalt, nickel, iron, vanadium, tantalum, gallium, chromium, cadmium, niobium, zirconium, lanthanum, or a combination thereof.

13. The multivalent metal-ion battery of claim 1 , wherein the electrolyte comprises an organic solvent selected from ethylene carbonate (EC), dimethyl carbonate (DMC), methylethyl carbonate (MEC), diethyl carbonate (DEC), methyl butyrate (MB), ethyl propionate, methyl propionate, propylene carbonate (PC), γ-butyrolactone (γ-BL), acetonitrile (AN), ethyl acetate (EA), propyl formate (PF), methyl formate (MF), tetrahydrofuran (THF), toluene, xylene, methyl acetate (MA), or a combination thereof.

14. The multivalent metal-ion battery of claim 1 , wherein the electrolyte also supports reversible intercalation and de-intercalation of ions at the cathode, wherein said ions include cations, anions, or both.

15. The multivalent metal-ion battery of claim 1 , wherein said cathode layer of exfoliated carbon or graphite material operates as a cathode current collector to collect electrons during a discharge of said multivalent metal-ion battery and wherein said battery contains no separate or additional cathode current collector.

16. The multivalent metal-ion battery of claim 1 , wherein said cathode layer of exfoliated carbon or graphite further comprises a binder material which bonds said exfoliated carbon or graphite material together to form a cathode electrode layer.

17. The multivalent metal-ion battery of claim 16 , wherein said binder material is an electrically conductive binder material selected from coal tar pitch, petroleum pitch, meso-phase pitch, a conducting polymer, a polymeric carbon, or a derivative thereof.

18. The multivalent metal-ion battery of claim 1 , wherein said battery has an average discharge voltage no less than 1.0 volt and a cathode specific capacity greater than 200 mAh/g based on a total cathode active layer weight.

19. The multivalent metal-ion battery of claim 1 , wherein said battery has an average discharge voltage no less than 1.0 volt and a cathode specific capacity greater than 300 mAh/g based on a total cathode active layer weight.

20. The multivalent metal-ion battery of claim 1 , wherein said battery has an average discharge voltage no less than 1.5 volts and a cathode specific capacity greater than 200 mAh/g based on a total cathode active layer weight.

21. The multivalent metal-ion battery of claim 1 , wherein said battery has an average discharge voltage no less than 1.5 volts and a cathode specific capacity greater than 300 mAh/g based on a total cathode active layer weight.