A morphology-reconfigurable structural supercapacitor and a preparation method thereof

Abstract

The present invention discloses a structural supercapacitor with reconfigurable morphology, comprising two carbon fiber electrodes and a diaphragm, an electrolyte and a filling matrix arranged between the two carbon fiber electrodes, wherein the electrolyte is a solid polymer electrolyte, the diaphragm is a fiber diaphragm, the solid polymer electrolyte and the fiber diaphragm are infiltrated to form a composite layer, and the filling matrix is ​​a thermoplastic sheet. The present invention adopts a structural supercapacitor with reconfigurable morphology of the above structure, which has structural bearing and energy storage performance and can be used to prepare various special components. The filled thermoplastic resin has the characteristic of being softened by heating, and the device can be reconfigured multiple times according to demand, and the material is economical and widely available, the preparation process is simple, the performance is stable, and it is easy to promote on a large scale.

Description

Technical Field

[0001] The present invention relates to a supercapacitor technology, and in particular to a supercapacitor with a reconfigurable morphology and a preparation method thereof. Background Art

[0002] Lightweight structural supercapacitors are mainly composed of multiple layers of carbon fiber and resin polymer, where carbon fiber is used as the electrode of the structural supercapacitor, and the blended polymer between the carbon fiber layers is used as the electrolyte of the supercapacitor. Through design, laying, impregnation, packaging and molding processes, composite materials that can replace traditional vehicle metal body sheet metal are made. This composite material has both structural bearing and energy storage functions, and can partially replace existing vehicle-mounted standard batteries, thereby minimizing vehicle weight, expanding vehicle space, and increasing vehicle endurance.

[0003] Prior art document US15 / 472,119 discloses a carbon fiber electrode combined with a carbon-based solid polymer electrolyte, using a multilayer honeycomb material (a honeycomb structure includes materials made of insulating materials, porous materials or conductive materials) sandwiched between electrodes to manufacture a supercapacitor with enhanced structural strength. The first disadvantage of this structural supercapacitor is that the material sandwiched between the electrodes is connected to the carbon fiber by bonding, and the bending strength is very weak; the second disadvantage is that liquid electrolyte is used, which is prone to leakage and poses safety risks. Summary of the invention

[0004] The purpose of the present invention is to provide a structural supercapacitor with reconfigurable morphology, which has structural bearing and energy storage performance, can be used to prepare various heterogeneous components, and the preparation method is simple, the performance is stable, and it is easy to promote on a large scale.

[0005] To achieve the above-mentioned purpose, the present invention provides a morphology-reconfigurable structural supercapacitor, comprising two carbon fiber electrodes and a diaphragm, an electrolyte and a filling matrix arranged between the two carbon fiber electrodes, the electrolyte is a solid polymer electrolyte, the diaphragm is a fiber diaphragm, and the solid polymer electrolyte and the fiber diaphragm are infiltrated to form a composite layer.

[0006] Preferably, the solid polymer electrolyte contains 15-60% high molecular polymer, 5-40% lithium salt and 5-80% ionic liquid.

[0007] Preferably, the polymer may be one of polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene, polyethylene oxide, polyvinyl alcohol, and any combination thereof.

[0008] Preferably, the lithium salt may be one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethylsulfonyl)imide, and any combination thereof.

[0009] Preferably, the ionic liquid may be one of 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide, 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, 1-ethyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium tetrafluoroborate, 1-butyl-2,3-dimethylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium iodide, and any combination thereof.

[0010] Preferably, the fiber diaphragm is a high-strength, high-toughness fiber membrane structure with a thickness of 50 to 300 μm.

[0011] Preferably, the fiber membrane may be glass fiber cloth, aramid cloth or non-woven nylon cloth.

[0012] Preferably, the filling matrix is ​​a thermoplastic resin.

[0013] Preferably, the thermoplastic resin includes but is not limited to one of polyethylene, polypropylene, ethylene-vinyl acetate resin, polyvinyl chloride, polystyrene, polyamide, polyoxymethylene, polycarbonate, polyphenylene ether, polysulfone and any combination thereof.

[0014] A method for preparing a morphology-reconfigurable structural supercapacitor comprises the following steps:

[0015] S1. Preparation of carbon fiber electrodes

[0016] S2. Preparation of solid polymer electrolyte / fiber diaphragm composite layer

[0017] S20, placing the solid polymer electrolyte into the acetonitrile solution and stirring and mixing thoroughly to obtain a polymer electrolyte slurry;

[0018] S21, cutting the fiber diaphragm into pieces;

[0019] S22, applying the polymer electrolyte slurry to the designed energy storage area of ​​the block fiber diaphragm, and drying for standby use;

[0020] S3, stacking

[0021] The carbon fiber electrode, the solid polymer electrolyte / fiber diaphragm composite layer, and the carbon fiber electrode are stacked in order to form an energy storage area; and a thermoplastic matrix is ​​laid on the upper and lower surfaces of the composite layer and the solid polymer electrolyte-free area between the carbon fiber electrodes to form a load-bearing area after hot pressing, and a laminate body is formed after composite stacking;

[0022] S30, hot pressing

[0023] The laminate is placed in a hot press, the thermoforming temperature is 75-250°C, the applied pressure is 1-5MPa, heated to melt and infiltrate, and pressure is applied to heat and soften, the softening treatment temperature is 70-180°C, and then cooled to obtain a structural supercapacitor;

[0024] S4, morphology remodeling

[0025] After heat treatment or local heating to soften, the morphology is reshaped, and after cooling, the morphology of the structural supercapacitor is reconstructed;

[0026] The softening method of morphology reshaping is completed by heating flat plate, hot oven, hot air gun and other equipment. The heated and softened structure supercapacitor is placed in another mold and reshaped under the action of force. The softening temperature is 70-180℃.

[0027] Therefore, the present invention adopts the structural supercapacitor with reconfigurable morphology of the above structure, which has both structural bearing and energy storage performance, can be used to prepare various special components, and the preparation method is simple, the performance is stable, and it is easy to promote on a large scale.

[0028] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A schematic cross-sectional view of a morphology-reconfigurable structural supercapacitor of the present invention;

[0030] Figure 2 The structural diagram of the electrolyte area and the resin matrix area on the fiber diaphragm of the present invention is designed and laid;

[0031] Figure 3 To cover Figure 2 A diagram of the carbon fiber layer structure on top of the layup;

[0032] Figure 4 To cover Figure 3 A resin matrix layer on top of the carbon fiber layer.

[0033] Among them: 1. Carbon fiber electrode; 2. Fiber diaphragm; 3. Electrolyte; 4. Matrix. DETAILED DESCRIPTION

[0034] The present invention will be further described below in conjunction with the accompanying drawings. It should be noted that this embodiment is based on the technical solution and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to this embodiment.

[0035] Figure 1 is a schematic cross-sectional view of a morphology-reconfigurable structural supercapacitor of the present invention, Figure 2 The structural diagram of the electrolyte area and the resin matrix area on the fiber diaphragm of the present invention is designed and laid; Figure 3 To cover Figure 2 A diagram of the carbon fiber layer structure on top of the layup; Figure 4 To cover Figure 3The resin matrix layer on top of the carbon fiber layer. Figure 1-Figure 4 As shown, the structure of the present invention includes two carbon fiber electrodes and a diaphragm, an electrolyte 3 and a filling matrix 4 arranged between the two carbon fiber electrodes. The electrolyte 3 is a solid polymer electrolyte, the diaphragm is a fiber diaphragm 2, and the solid polymer electrolyte is infiltrated with the fiber diaphragm 2 to form a composite layer.

[0036] Wherein, the solid polymer electrolyte contains 15-60% high molecular polymer, 5-40% lithium salt and 5-80% ionic liquid. Preferably, the polymer can be one of polyvinylidene fluoride (PVDF), polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP), polyethylene oxide (PEO), polyvinyl alcohol (PVA) and any combination thereof. Preferably, the lithium salt is one of lithium hexafluorophosphate (LiPO4F6), lithium tetrafluoroborate (LiBF4), lithium perchlorate (LiClO4), lithium bis(fluorosulfonyl) imide (LiFSI), lithium bis(trifluoromethylsulfonyl) imide (LiTFSI) and any combination thereof. Preferably, the ionic liquid is one of 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide (EMIMFSI), 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EMIMTFSI), 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIBF4), 1-butyl-3-methylimidazolium tetrafluoroborate (BMIMBF4), 1-butyl-2,3-dimethylimidazolium tetrafluoroborate (BMIMBF4), 1-butyl-3-methylimidazolium iodide (BMIMI) and any combination thereof.

[0037] Preferably, the fiber membrane 2 is a high-strength, high-toughness fiber membrane structure with a thickness of 50 to 300 μm. Preferably, the fiber membrane can be glass fiber cloth, aramid cloth or non-woven nylon cloth.

[0038] Preferably, the filling matrix is ​​a thermoplastic resin, and the thermoplastic resin includes but is not limited to polyethylene (PE), polypropylene (PP), ethylene-vinyl acetate resin (EVA), polyvinyl chloride (PVC), polystyrene (PS), polyamide (PA), polyoxymethylene (POM), polycarbonate (PC), polyphenylene ether, polysulfone and any combination thereof.

[0039] A method for preparing a morphology-reconfigurable structural supercapacitor comprises the following steps:

[0040] S1. Preparation of carbon fiber electrodes

[0041] S2. Preparation of solid polymer electrolyte / fiber diaphragm composite layer

[0042] S20, placing the solid polymer electrolyte into the acetonitrile solution and stirring and mixing thoroughly to obtain a polymer electrolyte 3 slurry;

[0043] S21, cutting the fiber diaphragm 2 into blocks;

[0044] S22, applying the polymer electrolyte 3 slurry to the designed energy storage area of ​​the block fiber diaphragm 2, and drying for standby use;

[0045] S3, stacking

[0046] The carbon fiber electrode, the solid polymer electrolyte / fiber diaphragm composite layer, and the carbon fiber electrode are stacked in order to form an energy storage area; and a thermoplastic matrix is ​​laid in the area without solid polymer electrolyte between the upper and lower surfaces of the composite layer and the carbon fiber electrode to form a load-bearing area after hot pressing, and a laminate body is formed after composite stacking; in this embodiment, the ratio of the thermoplastic resin area (load-bearing area) is 5-95%, and the ratio of the solid electrolyte 3 area (energy storage area) is 5-95%;

[0047] S30, hot pressing

[0048] The laminate is placed in a hot press, the thermoforming temperature is 75-250°C, the applied pressure is 1-5MPa, heated to melt and infiltrate, and pressure is applied to heat and soften, the softening treatment temperature is 70-180°C, and then cooled to obtain a structural supercapacitor;

[0049] S4, morphology remodeling

[0050] After heat treatment or local heating to soften, the morphology is reshaped, and after cooling, the morphology of the structural supercapacitor is reconstructed;

[0051] The softening method of morphology reshaping is completed by heating a flat plate, a hot oven, a hot air gun and other equipment. The heated and softened structure supercapacitor is placed in another mold and reshaped under the action of force. The softening temperature is 70-180℃.

[0052] To further illustrate the present invention, the following embodiments are disclosed:

[0053] Example 1

[0054] The polyacrylonitrile carbon fiber cloth was washed with acetone, dried at 50℃ for 12h, cut into two 100*100mm carbon fiber squares, soaked with KOH solution, dried at 40℃ for 24h, treated at 800℃ in a tube furnace for 1h, and KOH modified the carbon fiber electrode. The solid polymer electrolyte non-woven nylon cloth composite membrane was prepared by fully stirring and mixing polyvinyl alcohol (PVA), lithium bis(trifluoromethylsulfonyl)imide (LiTFSI) and 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIBF4) in acetonitrile solution to obtain a polymer electrolyte slurry, cutting a 110*110mm non-woven nylon cloth, coating the 80*80mm area of ​​the non-woven nylon cloth with the solid polymer electrolyte solution, and drying at 50℃ for standby use. Polyethylene resin sheet / carbon fiber electrode / solid polymer electrolyte composite membrane / carbon fiber electrode / polyethylene resin sheet were used for layering, placed in a flat vulcanizer at 150℃, 5MPa for hot pressing for 0.5h, and cooled to obtain a structural supercapacitor. The product was placed in the special-shaped mold again, a force of 1 MPa was applied in a flat vulcanizer, and the temperature was maintained at 120°C for 1 hour. After cooling, a supercapacitor special component with a reconstructed morphology was obtained.

[0055] Example 2

[0056] The polyacrylonitrile carbon fiber cloth was cleaned with acetone, dried at 50℃ for 12h, cut into two 100*100mm carbon fiber squares, soaked with KOH solution, dried at 50℃ for 24h, and treated at 1000℃ in a tube furnace for 1h to prepare KOH modified carbon fiber electrode. The preparation of solid polymer electrolyte glass fiber cloth composite membrane is to mix polyvinylidene fluoride (PVDF), lithium hexafluorophosphate L (iPO4F6) and 1-ethyl-3-methylimidazolium bis (fluorosulfonyl) imide (EMIMFSI) in acetonitrile solution to obtain polymer electrolyte slurry, cut 110*110mm non-woven nylon cloth, apply solid polymer electrolyte solution to the 60*60mm area of ​​non-woven nylon cloth, and dry at 60℃ for standby use. Polypropylene resin sheet / carbon fiber electrode / solid polymer electrolyte composite membrane / carbon fiber electrode / polypropylene resin sheet are used for layering, put into a hot press at 170℃, 3MPa for 0.5h, and cool to obtain a structural supercapacitor. It is placed in the special-shaped mold again, placed in a hot oven, a weight with a force of 1 MPa is applied, and maintained at 140°C for 1 hour. After cooling, a supercapacitor special component with a reconstructed morphology is obtained.

[0057] Example 3

[0058] The polyacrylonitrile carbon fiber cloth was washed with acetone, dried at 50℃ for 12h, cut into two 100*100mm carbon fiber squares, impregnated with a phenolic resin aqueous solution synthesized from formaldehyde and resorcinol, dried at 50℃ for 24h, and treated in a tube furnace at 1200℃ for 0.5h to prepare a carbon aerogel-modified carbon fiber electrode. The solid polymer electrolyte aramid cloth composite membrane was prepared by fully stirring and mixing polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP), lithium perchlorate (LiClO4) and 1-butyl-2,3-dimethylimidazolium tetrafluoroborate (BMIMBF4) in an acetonitrile solution to obtain a polymer electrolyte slurry, cutting a 110*110mm non-woven nylon cloth, coating the solid polymer electrolyte solution on a 50*50mm area of ​​the non-woven nylon cloth, and drying for use. Polystyrene resin sheet / carbon fiber electrode / solid polymer electrolyte composite membrane / carbon fiber electrode / polystyrene resin sheet was layered, placed in a flat vulcanizer at 90°C, 3MPa for 0.5h, cooled, and a structural supercapacitor was obtained. It was placed in a special-shaped mold again, heated to 80°C with a hot air gun for 0.5h, a 1MPa weight was placed, and after cooling, a structural supercapacitor with a reconstructed morphology was obtained.

[0059] Example 4

[0060] The polyacrylonitrile carbon fiber cloth was cleaned with acetone, dried at 50℃ for 12h, cut into two 100*100mm carbon fiber squares, impregnated with a phenolic resin aqueous solution synthesized from formaldehyde and resorcinol, dried at 50℃ for 36h, and treated in a tube furnace at 1500℃ for 0.5h to prepare a carbon aerogel-modified carbon fiber electrode. The solid polymer electrolyte aramid cloth composite membrane was prepared by mixing polyethylene oxide (PEO), lithium tetrafluoroborate (LiBF4) and 1-butyl-3-methylimidazolium iodide (BMIMI) in an acetone solution to obtain a polymer electrolyte slurry, cutting a 110*110mm glass fiber cloth, coating the solid polymer electrolyte solution on the 40*60mm area of ​​the glass fiber cloth, and drying at 50℃ for 24h for standby use. Polycarbonate resin sheet / carbon fiber electrode / solid polymer electrolyte composite membrane / carbon fiber electrode / polycarbonate resin sheet were layered and placed in a flat vulcanizer at 160°C and 3MPa for hot pressing for 0.5h. The layer was cooled to obtain a structural supercapacitor. The layer was placed in a special-shaped mold again and placed in a flat vulcanizer to apply a force of 1MPa and maintain at 140°C for 1h. After cooling, a structural supercapacitor component with reconstructed morphology was obtained.

[0061] Therefore, the present invention adopts the structural supercapacitor with reconfigurable morphology of the above structure, which has both structural bearing and energy storage performance, can be used to prepare various special components, and the preparation method is simple, the performance is stable, and it is easy to promote on a large scale.

[0062] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A morphology-reconfigurable structural supercapacitor, comprising two carbon fiber electrodes and a diaphragm, an electrolyte and a filling matrix disposed between the two carbon fiber electrodes, characterized in that: The electrolyte is a solid polymer electrolyte, the diaphragm is a fiber diaphragm, and the solid polymer electrolyte and the fiber diaphragm are infiltrated to form a composite layer; A method for preparing a morphology-reconfigurable structural supercapacitor comprises the following steps: S1. Preparation of carbon fiber electrodes S2. Preparation of solid polymer electrolyte / fiber diaphragm composite layer S20, placing the solid polymer electrolyte into the acetonitrile solution and stirring and mixing thoroughly to obtain a polymer electrolyte slurry; S21, cutting the fiber diaphragm into pieces; S22, applying the polymer electrolyte slurry to the designed energy storage area of ​​the block fiber diaphragm, and drying for standby use; S3, stacking The carbon fiber electrode, the solid polymer electrolyte / fiber diaphragm composite layer, and the carbon fiber electrode are stacked in order to form an energy storage area; and a thermoplastic matrix is ​​laid on the upper and lower surfaces of the composite layer and the solid polymer electrolyte-free area between the carbon fiber electrodes to form a load-bearing area after hot pressing, and a laminate body is formed after composite stacking; S30, hot pressing The laminate is placed in a hot press, the thermoforming temperature is 75-250°C, the applied pressure is 1-5MPa, heated to melt and infiltrate, and pressure is applied to heat and soften, the softening treatment temperature is 70-180°C, and then cooled to obtain a structural supercapacitor; S4, morphology remodeling After heat treatment or local heating to soften, the morphology is reshaped, and after cooling, the morphology of the structural supercapacitor is reconstructed; The softening method for morphological reshaping is completed through a heating plate, a hot oven, and a hot air gun. The heated and softened structural supercapacitor is placed in another mold and reshaped under the action of force. The softening temperature is 70 to 180°C.

2. The morphology-reconfigurable structural supercapacitor according to claim 1, characterized in that: The solid polymer electrolyte contains 15-60% high molecular polymer, 5-40% lithium salt and 5-80% ionic liquid.

3. The morphology-reconfigurable structural supercapacitor according to claim 2, characterized in that: The polymer is one of polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene, polyethylene oxide, polyvinyl alcohol and any combination thereof.

4. The morphology-reconfigurable structural supercapacitor according to claim 2, characterized in that: The lithium salt is one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethylsulfonyl)imide and any combination thereof.

5. The morphology-reconfigurable structural supercapacitor according to claim 2, characterized in that: The ionic liquid is one of 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide, 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, 1-ethyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium tetrafluoroborate, 1-butyl-2,3-dimethylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium iodide and any combination thereof.

6. The morphology-reconfigurable structural supercapacitor according to claim 1, characterized in that: The fiber diaphragm is a high-strength and high-toughness fiber membrane structure with a thickness of 50 to 300 μm.

7. The morphology-reconfigurable structural supercapacitor according to claim 6, characterized in that: The fiber membrane is glass fiber cloth, aramid cloth or non-woven nylon cloth.

8. The morphology-reconfigurable structural supercapacitor according to claim 1, characterized in that: The filling matrix is ​​thermoplastic resin.

9. The morphology-reconfigurable structural supercapacitor according to claim 8, characterized in that: The thermoplastic resin includes one of polyethylene, polypropylene, ethylene-vinyl acetate resin, polyvinyl chloride, polystyrene, polyamide, polyoxymethylene, polycarbonate, polyphenylene ether, polysulfone and any combination thereof.

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