Graphene-enabled selenium cathode active material for an alkali metal-selenium secondary battery

1. A graphene-enabled hybrid particulate for use as a cathode active material of an alkali metal battery wherein said hybrid particulate comprises a single or a plurality of graphene sheets and a plurality of fine selenium particles or coatings, having a diameter or thickness from 0.5 nm to 10 μm, and the graphene sheets and the selenium particles or coatings are mutually bonded or agglomerated into said hybrid particulate containing an exterior graphene sheet or multiple exterior graphene sheets embracing said selenium particles or coatings, and wherein said graphene is in an amount of from 0.01% to 30% by weight based on the total weight of graphene and selenium combined, wherein said graphene-enabled hybrid particulate contains at least one interior graphene sheet.

2. The hybrid particulate of claim 1 , wherein said graphene sheets 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 20% 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.

3. The hybrid particulate of claim 2 , wherein said chemically functionalized graphene contains a functional group attached thereto to make the graphene sheets in a liquid medium exhibit a negative Zeta potential from −55 mV to −0.1 mV.

4. The hybrid particulate of claim 2 , wherein said chemically functionalized graphene comprises graphene sheets having a chemical functional group selected from alkyl or aryl silane, alkyl or aralkyl group, hydroxyl group, carboxyl group, carboxylic group, amine group, sulfonate group (—SO 3 H), aldehydic group, quinoidal, fluorocarbon, or a combination thereof.

5. The hybrid particulate of claim 2 , wherein said chemically functionalized graphene comprises graphene sheets having a chemical functional group selected from the group consisting of 2-azidoethanol, 3-azidopropan-1-amine, 4-(2-azidoethoxy)-4-oxobutanoic acid, 2-azidoethyl-2-bromo-2-methylpropanoate, chlorocarbonate, azidocarbonate, dichlorocarbene, carbene, aryne, nitrene, (R—)-oxycarbonyl nitrenes, where R =any one of the following groups,

and combinations thereof.

6. The hybrid particulate of claim 2 , wherein said chemically functionalized graphene comprises graphene sheets having a chemical functional group selected from an oxygenated group selected from the group consisting of hydroxyl, peroxide, ether, keto, and aldehyde.

7. The hybrid particulate of claim 2 , wherein said chemically functionalized graphene comprises graphene sheets having a chemical functional group selected from the group consisting of —SO 3 H, —COOH, —NH 2 , —OH, —R′CHOH, —CHO, —CN, —COCl, halide, —COSH, —SH, —COOR′, —SR′, —SiR′ 3 , —Si(—OR′—) y R′ 3 -y, —Si(—O—SiR′ 2 —)OR′, —R″, Li, AlR′ 2 , Hg—X, TlZ 2 and Mg—X; wherein y is an integer equal to or less than 3, R′ is hydrogen, alkyl, aryl, cycloalkyl, or aralkyl, cycloaryl, or poly(alkylether), R″ is fluoroalkyl, fluoroaryl, fluorocycloalkyl, fluoroaralkyl or cycloaryl, X is halide, and Z is carboxylate or trifluoroacetate, and combinations thereof.

8. The hybrid particulate of claim 2 , wherein said chemically functionalized graphene comprises graphene sheets having a chemical functional group selected from the group consisting of amidoamines, polyamides, aliphatic amines, modified aliphatic amines, cycloaliphatic amines, aromatic amines, anhydrides, ketimines, diethylenetriamine (DETA), triethylene-tetramine (TETA), tetraethylene-pentamine (TEPA), polyethylene polyamine, polyamine epoxy adduct, phenolic hardener, non-brominated curing agent, non-amine curatives, and combinations thereof.

9. The hybrid particulate of claim 2 , wherein said chemically functionalized graphene comprises graphene sheets having a chemical functional group selected from OY, NHY, O═C—OY, P═C—NR′Y, O═C—SY, O═C—Y, —CR′1-OY, N′Y or C′Y, and Y is a functional group of a protein, a peptide, an amino acid, an enzyme, an antibody, a nucleotide, an oligonucleotide, an antigen, or an enzyme substrate, enzyme inhibitor or the transition state analog of an enzyme substrate or is selected from R′—OH, R′—NR′ 2 , R′SH, R′CHO, R′CN, R′X, R′N + (R′) 3 X − , R′SiR′ 3 , R′Si(—OR′—) y R′ 3-y , R′Si(—O—SiR′ 2 —)OR′, R′—R″, R′—N—CO, (C 2 H 4 O—) w H, (—C 3 H 6 O—) w H, (—C 2 H 4 O) w —R′, (C 3 H 6 O) w —R′, R′, and w is an integer greater than one and less than 200.

10. The hybrid particulate of claim 1 , wherein said particulate further comprises a second element selected from Sn, Sb, Bi, S, Te, or a combination thereof and the weight of said second element is less than the weight of selenium.

11. The hybrid particulate of claim 1 , wherein said selenium coatings or particles have a thickness or diameter from 0.5 nm to 100 nm.

12. The hybrid particulate of claim 1 , having a diameter from 100 nm to 100 μm.

13. The hybrid particulate of claim 1 , having a diameter from 1.0 μm to 50 μm.

14. The hybrid particulate of claim 1 , having a substantially spherical or ellipsoidal shape.

15. The hybrid particulate of claim 1 , wherein said hybrid particulate further contains interior graphene sheets in physical contact with said selenium particles or coatings and with said exterior graphene sheet.

16. The hybrid particulate of claim 1 wherein the graphene amount is from 0.1% to 10% by weight of the total weight of graphene and selenium combined.

17. The hybrid particulate of claim 1 wherein said hybrid particulate has an electrical conductivity greater than 10 −4 S/cm.

18. The hybrid particulate of claim 1 , wherein said selenium particles are in a nanowire, nanotube, nanodisc, nanoribbon, nanobelt, or nanoplatelet form having a diameter or thickness smaller than 100 nm.

19. The hybrid particulate of claim 1 , further comprising a carbon material in electronic contact with said selenium and a graphene sheet.

20. The hybrid particulate of claim 1 , further comprising a carbon material coated on at least one of said selenium particles or coatings, wherein said carbon material is selected from polymeric carbon, amorphous carbon, chemical vapor deposition carbon, carbon black, 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.

21. A powder mass containing a plurality of particulates as defined in claim 1 .

22. An alkali metal-selenium battery cathode containing the hybrid particulate of claim 1 as a cathode active material.

23. An alkali metal-selenium battery containing an anode, a cathode, an electrolyte in ionic contact with the cathode and the anode, wherein the cathode comprises the hybrid particulate of claim 1 .

24. The alkali metal-selenium battery of claim 23 , which contains a rechargeable lithium-selenium cell, sodium-selenium cell, potassium-selenium cell, lithium ion-selenium cell, sodium ion-selenium cell, or potassium ion-selenium cell.

25. The alkali metal-selenium battery of claim 23 , wherein said electrolyte is selected from polymer electrolyte, polymer gel electrolyte, composite electrolyte, ionic liquid electrolyte, non-aqueous liquid electrolyte, soft matter phase electrolyte, solid-state electrolyte, or a combination thereof.

26. A graphene-enabled hybrid particulate for use as an alkali metal battery cathode active material, wherein said hybrid particulate comprises a single or a plurality of graphene sheets and a single selenium particle, having a diameter or thickness from 0.5 nm to 30 μm, and the graphene sheet or plurality of graphene sheets encapsulate the selenium particle and wherein said graphene sheets 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 20% by weight of non-carbon elements, wherein said non-pristine graphene is not graphene oxide or reduced graphene oxide and is selected from 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 and wherein said graphene is in an amount of from 0.01% to 30% by weight based on the total weight of graphene and selenium combined, wherein said graphene-enabled hybrid particulate contains at least one interior graphene sheet.

27. The hybrid particulate of claim 26 , wherein said particulate further comprises a second element selected from Sn, Sb, Bi, S, Te, or a combination thereof and the weight of said second element is less than the weight of selenium.

28. The hybrid particulate of claim 26 , wherein said selenium particles are in a nanowire, nanotube, nanodisc, nanoribbon, nanobelt, or nanoplatelet form having a diameter or thickness smaller than 100 nm.

29. The hybrid particulate of claim 26 , further comprising a carbon material coated on said selenium particle, wherein said carbon material is selected from polymeric carbon, amorphous carbon, chemical vapor deposition carbon, carbon black, 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.

30. A powder mass containing a plurality of particulates as defined in claim 26 .

31. An alkali metal-selenium battery cathode containing the hybrid particulate of claim 26 as a cathode active material.

32. An alkali metal-selenium battery containing an anode, a cathode, an electrolyte in ionic contact with the cathode and the anode, wherein the cathode comprises the hybrid particulate of claim 26 .

33. The alkali metal-selenium battery of claim 32 , wherein said electrolyte contains an alkali salt selected from lithium perchlorate (LiClO 4 ), lithium hexafluorophosphate (LiPF 6 ), lithium borofluoride (LiBF 4 ), lithium hexafluoroarsenide (LiAsF 6 ), lithium trifluoro-metasulfonate (LiCF 3 SO 3 ), bis-trifluoromethyl sulfonylimide lithium (LiN(CF 3 SO 2 ) 2 , lithium bis(oxalato)borate (LiBOB), lithium oxalyldifluoroborate (LiBF 2 C 2 O 4 ), lithium oxalyldifluoroborate (LiBF 2 C 2 O 4 ), lithium nitrate (LiNO 3 ), Li-fluoroalkyl-phosphates (LiPF3(CF 2 CF 3 ) 3 ), lithium bisperfluoroethysulfonylimide (LiBETI), an ionic liquid salt, sodium perchlorate (NaClO 4 ), potassium perchlorate (KClO 4 ), sodium hexafluorophosphate (NaPF 6 ), potassium hexafluorophosphate (KPF 6 ), sodium borofluoride (NaBF 4 ), potassium borofluoride (KBF 4 ), sodium hexafluoroarsenide, potassium hexafluoroarsenide, sodium trifluoro-metasulfonate (NaCF 3 SO 3 ), potassium trifluoro-metasulfonate (KCF 3 SO 3 ), bis-trifluoromethyl sulfonylimide sodium (NaN(CF 3 SO 2 ) 2 ), sodium trifluoromethanesulfonimide (NaTFSI), bis-trifluoromethyl sulfonylimide potassium (KN(CF 3 SO 2 ) 2 ), or a combination thereof.

34. The alkali metal-selenium battery of claim 32 , wherein said solvent is selected from ethylene carbonate (EC), dimethyl carbonate (DMC), methylethyl carbonate (MEC), diethyl carbonate (DEC), ethyl propionate, methyl propionate, propylene carbonate (PC), gamma.-butyrolactone (γ-BL), acetonitrile (AN), ethyl acetate (EA), propyl formate (PF), methyl formate (MF), toluene, xylene or methyl acetate (MA), fluoroethylene carbonate (FEC), vinylene carbonate (VC), allyl ethyl carbonate (AEC), 1,3-dioxolane (DOL), 1,2-dimethoxyethane (DME), tetraethylene glycol dimethylether (TEGDME), poly(ethylene glycol) dimethyl ether (PEGDME), diethylene glycol dibutyl ether (DEGDBE), 2-ethoxyethyl ether (EEE), sulfone, sulfolane, room temperature ionic liquid, or a combination thereof.