ENERGY STORAGE DEVICE FOR HIGH TEMPERATURE APPLICATIONS

Abstract

An energy storage device, especially a super capacitor, useful for high temperature applications has current collector elements supporting a carbonaceous matrix modified or doped with pseudo-capacitive materials, including one or more transition metal dichalcogenides, transition metal oxides and mixtures thereof, in contact with a non-aqueous electrolyte composition whereby it is possible to exploit the faradic mechanism in addition to the electric double layer mechanism as an energy storage principle.

Claims

1. A device comprising current collector elements, each current collector element supporting a carbonaceous matrix, the carbonaceous matrix is modified or doped with pseudo-capacitive materials, and is in contact with a non-aqueous electrolyte composition.

2. The device of claim 1, wherein the non-aqueous electrolyte composition comprises cations and anions in a liquid medium selected from high boiling temperature solvents and ionic liquids.

3. The device of claim 1, wherein the non-aqueous electrolyte composition comprises one or more salts selected from the group consisting of organic salts and inorganic salts.

4. The device of claim 1 wherein the non-aqueous electrolyte composition comprises at least one quaternary ammonium salt.

5. The device of claim 1, wherein the non-aqueous electrolyte composition comprises at least one cation selected from the group consisting of tetrabutylammonium, 1-ethyl 3-methylimidazolium, 1-butyl-3 methylimidazolium, 1-(3-cyanopropyl)-3-methylimidazolium, 1,2-dimethyl-3-propylimidazolium, 1,3-bis(3-cyanopropyl)imidazolium, 1,3-diethoxyimidazolium, 1-butyl-1-methylpiperidinium, 1-butyl-2,3-dimethylimidazolium, 1-butyl-4-methylpyridinium, 1-butylpyridinium, 1-decyl-3-methylimidazolium, and 3-methyl-1-propylpyridinium.

6. The device of claim 1, wherein the non-aqueous electrolyte composition comprises at least one anion selected from the group consisting of ethylsulfate, methylsulfate, thiocyanate, acetate, chloride, methanesulfonate, tetrachloraluminate, tetrafluoroborate, hexafluorophosphate, trifluoromethanesulfonate, bis (pentafluoroethanesulfonate)imide, trifluoro(trifluoromethyl)borate, bis(trifluoromethanesulfonate)imide, tris(trifluoromethane 3 sulfonate)methide, and dicyanamide.

7. The device of claim 1, wherein the non-aqueous electrolyte composition comprises at least one of the following: glycerin, ethylene glycol, diethylene glycol, diethylene glycol dimethyl ether (diglyme), propylene carbonate, hexamethylphosphoramide (HMPA), N-methyl-2-pyrrolidinone (NMP), dimethyl sulfoxide (DMSO), dimethyl formamide (DMF), and hexamethylphosphorous triamide (HMPT).

8. The device of claim 1, wherein the carbonaceous matrix is modified or doped with pseudo-capacitive materials by a method selected from the group consisting of electrodeposition, chemical vapour deposition (CVD), sputtering, and atomic layer deposition.

9. The device of claim 1, wherein the carbonaceous matrix is modified or doped with a metal chalcogenide.

10. The device of claim 9, wherein the carbonaceous matrix is modified or doped with a metal oxide.

11. The device of claim 1, wherein the pseudo-capacitive materials comprise a transition metal.

12. The device of claim 11 wherein the pseudo-capacitive materials comprise at least one transition metal dichalcogenide, and at least one transition metal oxide.

13. The device of claim 12, wherein the pseudo-capacitive materials further comprise at least one component material selected from the group consisting of MoS.sub.2, MoSe.sub.2, WS.sub.2, WSe.sub.2, TeS.sub.2, TeSe.sub.2, TiS.sub.2, TaS.sub.2, ZrS.sub.2, Bi.sub.2S.sub.3, Bi.sub.2Se.sub.3, Bi.sub.2Te.sub.3, MoSe.sub.2, TaSe.sub.2, NbSe.sub.2, MoTe.sub.2, NiTe.sub.2, BiTe.sub.2, GeS.sub.2, GeSe.sub.2, GeTe Zn.sub.2, ZnSe, EuSe, Ag.sub.2S, Ag.sub.2Se, Ag.sub.2Te, FeS.sub.2, Fe.sub.7S.sub.8, Fe.sub.3S.sub.4, FeSe.sub.2, Fe.sub.3Se.sub.4, β-FeSe.sub.x, In.sub.2S.sub.3, SnS, SnS.sub.2, SnSe, SnTe, CuS, Cu.sub.2S, Cu.sub.2-xSe, Sb.sub.2S.sub.3, Sb.sub.2Te.sub.3, MnS, MnSe, CoS.sub.2, CoS.sub.3, CoTe, NiS, NiSe, NiTe, and VS.sub.2, and combinations thereof.

14. The device of claim 1 wherein the current collector elements comprise metallic components, supported upon plastics or ceramics, and configured as one form selected from the group consisting of a mesh, a foil, a foam, a sponge, a sheet, a scroll, a plate, a coil, and a rod.

15. The device of claim 1, wherein the carbonaceous matrix comprises one form selected from the group consisting of graphene, activated carbon, carbon fibres, rayon, viscose, carbon nanotubes, carbon aerogel, carbon fabric, cloth, and tape.

16. The device of claim 1, wherein the carbonaceous matrix comprises a graphene aerogel, and the pseudo-capacitive materials comprise molybdenum disulphide.

17. The device of claim 1 configured as a supercapacitor and comprising a plurality of current collector elements serving as positive electrodes and negative electrodes, with electrical conductor elements for connecting the plurality of current collector elements to an external electrical circuit, the plurality of current collector elements each being in contact with the non-aqueous electrolyte composition confined within the device, and having a separator positioned between the current collector elements so that the positives, and negative electrodes are separated.

18. The device of claim 17, wherein the separator comprises a thermally stable polymer, or a ceramic, or a glass, and the separator is porous.

19. The device of claim 17 wherein the device is configured as a multilayer structure, filled with electrolyte and sealed with a polymer or resin that may be assembled into a “coin” cell or a pouch cell.

20. The device of claim 19, wherein the device is sealed using a photo-curable resin.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0054] The accompanying drawings, which will be referred to hereinafter for the purpose of further illustrating the disclosure by way of example, include.

[0055] FIG. 1 shows a graphical representation of cyclic voltammetries recorded between 30° C. and 200° C. at 30 mV/s of scan rate for a device containing the materials reduced graphene oxide doped with MoS.sub.2.

[0056] FIG. 2 shows a graphical representation of a thermal analysis (TGA and DSC) to assess the optimal thermal stability of the disclosed graphene oxide doped with MoS.sub.2 up to 220° C.

[0057] FIG. 3 illustrates schematically an assembly of a supercapacitor device.

DETAILED DESCRIPTION

[0058] Referring to the accompanying FIG. 1, a comparison of materials discussed in Shen, Baoshou, et al. Journal of Materials Chemistry A 4.21 (2016): 8316-8327, and Borges, Raquel S., et al. Scientific reports 3 (2013), with an embodiment made in accordance with this disclosure, reveals that the embodiment disclosed here, exhibits capacitance values up to 210 F/g (corresponding to 365 mF/cm.sup.2) @ 200° C. with a voltage windows equal to 2.1 V. These values are superior in terms of specific capacitance (both in gravimetric and areal density). The specific capacitance values recorded at the different temperatures are collected in Table 1 below.

TABLE-US-00002 TABLE 1 Capacitance values recorded at the different temperatures Temp (° C.) C.sub.s (F/g) C.sub.s (mF/cm.sup.2) 30 174.9 306.2 50 202.1 353.7 100 209.3 366.1 150 190.8 333.9 200 208.5 364.6

[0059] A device may be assembled according to the following illustrative procedure, representing one possible embodiment of one possible assembly method without limitation, and referring to FIG. 3, wherein in a first stage, a metallic current collector element 1 is formed by cutting or stamping from sheet metal to a desired shape, optionally with a projecting electrical conducting connector 2. An active material in the form of a slurry, gel, or paste as described hereinbefore, and comprising a carbonaceous matrix modified or doped with pseudo-capacitive materials together with a polymeric binder can be applied to the current collector element 1 in a controlled manner, for example using a doctor blade, to form a deposit 3 covering a selected surface area on at least one surface of the current collector element 1 to provide a first electrode 4. The electrode can be mounted upon a flexible support substrate 5. The same procedure is repeatable to provide a second electrode 8. The electrodes 4, 8 may be thermally processed under reduced pressure to remove solvent sufficiently and minimise moisture presence before any subsequent assembly steps. The electrodes 3, 8 are oriented and juxtaposed in a confronting spaced relationship and a porous polymeric sheet separator 6 of appropriate thermal stability is introduced between the electrodes 4, 8 to form a laminar assembly.

[0060] Optionally the laminar assembly may be scrolled into a generally cylindrical body 9. The scrolled cylindrical body 9 can be introduced to an electrolyte solution, for example by immersion in a bath of electrolyte, and subjected to a reduced pressure to facilitate separator 6 infiltration with the electrolyte solution and air evacuation. After electrolyte filling, the cylindrical body 9 can be coated with a layer of photo-curable resin and UV-irradiated to sufficiently polymerize the resin, thereby providing a sealed device. The resin coating step may be repeated and other finishing steps may be optionally carried out to provide a sealed device with a continuous and uniform polymeric film surface.

[0061] Advantages of the disclosed methods, materials and device include the ability to realise a device that is capable of operating at the working temperature required for subterranean, for example a downhole application (up to 200° C. or above) exploiting electrolytes at lower viscosity and higher ionic mobility with respect to the known products, combined with composite electrodes (for example a 3D graphene network including pseudocapacitive materials) able to deliver capacitance values which are higher than the values attainable by the exploitation of carbon allotropes alone.