CN115938814A - A kind of supercapacitor with reconfigurable structure and its preparation method - Google Patents

Abstract

The invention discloses a structural supercapacitor with reconfigurable morphology, which comprises two carbon fiber electrodes, a diaphragm arranged between the two carbon fiber electrodes, an electrolyte and a filling matrix, and the electrolyte is a solid polymer electrolyte. The separator is a fiber separator, the solid polymer electrolyte is infiltrated with the fiber separator to form a composite layer, and the filling matrix is a thermoplastic sheet. The present invention adopts the structural supercapacitor with reconfigurable structure of the above-mentioned structure, which has structural bearing and energy storage performance, and various different components can be prepared. The thermoplastic resin filled in it has the characteristics of heating and softening, which can realize multiple shape reconstruction of the device according to the demand, and the materials are economical and extensive, the preparation process is simple, the performance is stable, and it is easy to promote on a large scale.

Description

A kind of supercapacitor with reconfigurable structure and its preparation method

technical field

The invention relates to a supercapacitor technology, in particular to a structural supercapacitor with reconfigurable morphology and a preparation method thereof.

Background technique

Lightweight structural supercapacitors are mainly composed of multilayer carbon fibers and resin polymers, in which carbon fibers are used as electrodes of structural supercapacitors, and blended polymers between carbon fiber layers are used as electrolytes of supercapacitors. Through design, laying, impregnation, packaging and molding The process makes composite materials that can replace traditional vehicle metal body sheet metal. The composite material has both structural load-bearing and energy storage functions, and can partially replace the existing vehicle standard battery, reduce the weight of the vehicle body to the greatest extent, expand the vehicle space, and increase the vehicle's battery life.

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

Contents of the invention

The purpose of the present invention is to provide a structural supercapacitor with reconfigurable morphology, which has both structural load-bearing and energy storage properties, and various different components can be prepared. The preparation method is simple, the performance is stable, and it is easy to be promoted on a large scale.

To achieve the above object, the present invention provides 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, the electrolyte being a solid state The polymer electrolyte, the diaphragm is a fiber diaphragm, and the solid polymer electrolyte is infiltrated with the fiber diaphragm to form a composite layer.

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

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

Preferably, the lithium salt can be one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethylsulfonyl)imide and any of them combination.

Preferably, the ionic liquid can be 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 Salt, 1-butyl-3-methylimidazolium iodide and any combination thereof.

Preferably, the fiber separator is a high-strength, high-toughness fiber membrane structure with a thickness of 50-300 μm.

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

Preferably, the filling matrix is thermoplastic resin.

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

A method for preparing a structural supercapacitor with reconfigurable morphology, comprising the following steps:

S1. Preparation of carbon fiber electrodes

S2. Preparation of solid polymer electrolyte/fiber separator composite layer

S20, putting the solid polymer electrolyte into the acetonitrile solution and fully stirring and mixing to obtain a polymer electrolyte slurry;

S21, cutting the fiber membrane into pieces;

S22. Apply the polymer electrolyte slurry to the designed energy storage area of the bulk fiber diaphragm, and dry it for later use;

S3, stacking

Lay up carbon fiber electrodes, solid polymer electrolyte/fiber separator composite layers, and carbon fiber electrodes in sequence to form an energy storage area; and lay a thermoplastic matrix on the composite layer and the solid polymer electrolyte-free area between the carbon fiber electrodes to form a hot press The formed load-bearing area is laminated and laminated to form a laminated body;

S30, thermoforming

Place the laminated body in a hot press, thermoforming at a temperature of 75-250°C, applying a pressure of 1-5 MPa, heating to melt and infiltrate, applying pressure and heating to soften, softening at a temperature of 70-180°C, and then cooling to obtain a structure Super capacitor;

S4. Shape reconstruction

After heat treatment or partial heating and softening, the shape is reshaped, and the shape reconstruction of the structural supercapacitor is realized after cooling;

The softening method of shape remodeling is completed by heating plate, hot oven, hot air gun and other equipment. Put the heated and softened structural supercapacitor into another mold, and realize reshaping under the action of force. The softening temperature is 70-180°C.

Therefore, the present invention adopts the structural supercapacitor with reconfigurable structure of the above structure, which has both structural load-bearing and energy storage properties, and various different components can be prepared, and the preparation method is simple, stable in performance, and easy to scale up.

The technical solutions of the present invention will be described in further detail below with reference to the accompanying drawings and embodiments.

Description of drawings

Fig. 1 is the cross-sectional schematic view of the structure supercapacitor with reconfigurable morphology of the present invention;

Fig. 2 is the design and laying structure diagram of the electrolyte region and the resin matrix region on the fiber diaphragm of the present invention;

Fig. 3 is a carbon fiber layer structure diagram covered on the layup of Fig. 2;

Fig. 4 is a resin matrix layer covered on the carbon fiber layer in Fig. 3 .

Among them: 1. Carbon fiber electrode; 2. Fiber diaphragm; 3. Electrolyte; 4. Matrix.

Detailed ways

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 detailed implementation and specific operation process, but the protection scope of the present invention is not limited to the present invention. Example.

Fig. 1 is a cross-sectional schematic view of the supercapacitor with reconfigurable morphology of the present invention, and Fig. 2 is a design and laying structure diagram of the electrolyte region and the resin matrix region on the fiber diaphragm of the present invention; The structural diagram of the carbon fiber layer above the layer; Fig. 4 is the resin matrix layer covering the carbon fiber layer in Fig. 3 . As shown in Figures 1-4, 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, so The membrane is a fiber membrane 2, and the solid polymer electrolyte is infiltrated with the fiber membrane 2 to form a composite layer.

Wherein, the solid polymer electrolyte contains 15-60% 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 lithium hexafluorophosphate (LiPO4F6), lithium tetrafluoroborate (LiBF4), lithium perchlorate (LiClO ₄ ), lithium bis(fluorosulfonyl)imide (LiFSI), bis(trifluoromethylsulfonyl One of lithium acyl imides (LiTFSI) and any combination thereof. Preferably, the ionic liquid is 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide (EMIMFSI), 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imine (EMIMTFSI), 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIBF ₄ ), 1-butyl-3-methylimidazolium tetrafluoroborate (BMIMBF ₄ ), 1-butyl - one of 2,3-dimethylimidazolium tetrafluoroborate (BMIMBF ₄ ), 1-butyl-3-methylimidazolium iodide (BMIMI), and any combination thereof.

Preferably, the fibrous separator 2 is a high-strength and high-toughness fibrous membrane structure with a thickness of 50-300 μm. Preferably, the fiber membrane may be glass fiber cloth, aramid fiber cloth or non-woven nylon cloth.

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), poly One of styrene (PS), polyamide (PA), polyoxymethylene (POM), polycarbonate (PC), polyphenylene ether, polysulfone and any combination thereof.

A method for preparing a structural supercapacitor with reconfigurable morphology, comprising the following steps:

S1. Preparation of carbon fiber electrodes

S2. Preparation of solid polymer electrolyte/fiber separator composite layer

S20, putting the solid polymer electrolyte into the acetonitrile solution and fully stirring and mixing to obtain the polymer electrolyte 3 slurry;

S21, cutting the fiber membrane 2 into pieces;

S22. Apply the slurry of the polymer electrolyte 3 to the designed energy storage area of the bulk fiber diaphragm 2, and dry it for later use;

S3, stacking

Lay up carbon fiber electrodes, solid polymer electrolyte/fiber separator composite layers, and carbon fiber electrodes in sequence to form an energy storage area; and lay a thermoplastic matrix on the composite layer and the solid polymer electrolyte-free area between the carbon fiber electrodes to form a hot press The bearing area after molding is laminated to make a laminate; in this embodiment, the ratio of the thermoplastic resin area (bearing area) is 5-95%, and the area of the solid electrolyte 3 (energy storage area) is 5-95%. ;

S30, thermoforming

Place the laminated body in a hot press, thermoforming at a temperature of 75-250°C, applying a pressure of 1-5 MPa, heating to melt and infiltrate, applying pressure and heating to soften, softening at a temperature of 70-180°C, and then cooling to obtain a structure Super capacitor;

S4. Shape reconstruction

After heat treatment or partial heating and softening, the shape is reshaped, and the shape reconstruction of the structural supercapacitor is realized after cooling;

The softening method of shape remodeling is completed by heating plate, hot oven, hot air gun and other equipment. Put the heated and softened structural supercapacitor into another mold, and realize reshaping under the action of force. The softening temperature is 70-180°C.

For further illustrating the present invention, disclose following embodiment:

Example 1

Clean polyacrylonitrile carbon fiber cloth with acetone, dry at 50°C for 12 hours, cut into two pieces of 100*100mm carbon fiber squares, soak the carbon fiber cloth with KOH solution, dry at 40°C for 24 hours, treat in a tube furnace at 800°C for 1 hour, change to KOH permanent carbon fiber electrodes. The solid polymer electrolyte non-woven nylon fabric composite membrane was prepared by polyvinyl alcohol (PVA), lithium bis(trifluoromethylsulfonyl)imide (LiTFSI) and 1-ethyl-3-methylimidazolium tetrafluoroboron Acid salt (EMIBF ₄ ) was fully stirred and mixed in acetonitrile solution to obtain polymer electrolyte slurry, cut out a 110*110mm non-woven nylon cloth, and coated the 80*80mm area of the non-woven nylon cloth with the solid polymer electrolyte solution, 50 °C drying for later use. Use polyethylene resin sheet/carbon fiber electrode/solid polymer electrolyte composite film/carbon fiber electrode/polyethylene resin sheet for lamination, put it in a flat vulcanizer at 150°C, press at 5MPa for 0.5h, and cool to obtain a structural supercapacitor . Put it into the special-shaped mold again, apply a force of 1 MPa in a flat vulcanizer, keep it at 120°C for 1 hour, and obtain the shape-reconstructed supercapacitor heterogeneous component after cooling.

Example 2

Clean the polyacrylonitrile carbon fiber cloth with acetone, dry it at 50°C for 12 hours, cut it into two pieces of 100*100mm carbon fiber squares, soak the carbon fiber cloth with KOH solution, dry it at 50°C for 24 hours, and treat it in a tube furnace at 1000°C for 1 hour to prepare KOH modified carbon fiber electrode. The solid polymer electrolyte glass fiber cloth composite membrane was prepared by polyvinylidene fluoride (PVDF), lithium hexafluorophosphate L (iPO4F ₆ ) and 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide (EMIMFSI) Thoroughly stir and mix in the acetonitrile solution to obtain the polymer electrolyte slurry, cut a 110*110mm non-woven nylon cloth, apply the solid polymer electrolyte solution to the 60*60mm area of the non-woven nylon cloth, and dry at 60°C stand-by. Polypropylene resin sheet/carbon fiber electrode/solid polymer electrolyte composite membrane/carbon fiber electrode/polypropylene resin sheet are used for lamination, put in a hot press at 170°C, 3MPa hot press for 0.5h, and cool to obtain a structural supercapacitor . Put it into the special-shaped mold again, put it into a hot oven, apply a heavy object with a force of 1MPa, keep it at 140°C for 1h, and obtain a structural supercapacitor heterogeneous component with a reconstructed morphology after cooling.

Example 3

Clean the polyacrylonitrile carbon fiber cloth with acetone, dry it at 50°C for 12 hours, cut it into two pieces of 100*100mm carbon fiber squares, soak the carbon fiber cloth with an aqueous solution of phenolic resin synthesized by formaldehyde and resorcinol, and dry it at 50°C for 24 hours. The carbon fiber electrode modified by carbon aerogel was prepared by treating in a type furnace at 1200℃ for 0.5h. The solid polymer electrolyte aramid cloth composite membrane is prepared by using polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP), lithium perchlorate (LiClO ₄ ) and 1-butyl-2,3-dimethylimidazole tetra Fluoroborate (BMIMBF ₄ ) is fully stirred and mixed in the acetonitrile solution to obtain a polymer electrolyte slurry, and a 110*110mm non-woven nylon cloth is cut, and the solid polymer electrolyte solution is coated on a 50*50mm non-woven nylon cloth area, dry for later use. Use polystyrene resin sheet/carbon fiber electrode/solid polymer electrolyte composite membrane/carbon fiber electrode/polystyrene resin sheet for lamination, put it in a flat vulcanizer at 90°C, press 3MPa for 0.5h, cool to obtain the structure Super capacitor. Put it into the special-shaped mold again, heat it with a heat gun to 80°C and keep it for 0.5h, place a 1MPa heavy object, and obtain the structural supercapacitor heterogeneous component with reconstructed morphology after cooling.

Example 4

Clean the polyacrylonitrile carbon fiber cloth with acetone, dry it at 50°C for 12 hours, cut it into two pieces of 100*100mm carbon fiber squares, soak the carbon fiber cloth with an aqueous solution of phenolic resin synthesized by formaldehyde and resorcinol, and dry it at 50°C for 36 hours. A carbon airgel modified carbon fiber electrode was prepared by treating at 1500 °C for 0.5 h in a formula furnace. The solid polymer electrolyte aramid cloth composite membrane was prepared by using polyethylene oxide (PEO), lithium tetrafluoroborate (LiBF ₄ ) and 1-butyl-3-methylimidazolium iodide (BMIMI) in acetone solution Thoroughly stir and mix to obtain the polymer electrolyte slurry, cut out a 110*110mm glass fiber cloth, apply the solid polymer electrolyte solution to the 40*60mm area of the glass fiber cloth, and dry it at 50°C for 24 hours for use. Use polycarbonate resin sheet/carbon fiber electrode/solid polymer electrolyte composite membrane/carbon fiber electrode/polycarbonate resin sheet for lamination, put it in a flat vulcanizer at 160°C, press 3MPa for 0.5h, cool to obtain the structure Put the supercapacitor into the special-shaped mold again, put it into a flat vulcanizer to apply a force of 1MPa, keep it at 140°C for 1h, and obtain a supercapacitor with a reconstructed structure after cooling.

Therefore, the present invention adopts the structural supercapacitor with reconfigurable structure of the above structure, which has both structural load-bearing and energy storage properties, and various different components can be prepared, and the preparation method is simple, stable in performance, and easy to scale up.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that: it still Modifications or equivalent replacements can be made to the technical solutions of the present invention, and these modifications or equivalent replacements cannot make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present invention.

Claims (10)

1. A structural supercapacitor with reconfigurable morphology, comprising two carbon fiber electrodes and a diaphragm, electrolyte and filling matrix arranged between the two carbon fiber electrodes, characterized in that: the electrolyte is a solid polymer electrolyte , the separator is a fiber separator, and the solid polymer electrolyte is infiltrated with the fiber separator to form a composite layer. 2. The supercapacitor with reconfigurable morphology according to claim 1, characterized in that: the solid polymer electrolyte contains 15-60% polymer, 5-40% lithium salt and 5-80% ionic liquid . 3. The supercapacitor with reconfigurable morphology according to claim 2, characterized in that: the polymer can be polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene, polyethylene oxide, polyethylene One of the alcohols and any combination thereof. 4. The supercapacitor with reconfigurable morphology according to claim 2, characterized in that: the lithium salt can be lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium bis(fluorosulfonyl)imide , one of lithium bis(trifluoromethylsulfonyl)imide and any combination thereof. 5. The supercapacitor with reconfigurable morphology according to claim 2, characterized in that: the ionic liquid can be 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide, 1 -Ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, 1-ethyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium tetrafluoroboron One of salt, 1-butyl-2,3-dimethylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium iodide and any combination thereof. 6 . The supercapacitor with reconfigurable morphology according to claim 1 , wherein the fiber separator is a high-strength and high-toughness fiber membrane structure with a thickness of 50-300 μm. 7 . The supercapacitor with reconfigurable morphology according to claim 6 , wherein the fiber membrane can be glass fiber cloth, aramid fiber cloth or non-woven nylon cloth. 8 . The supercapacitor with reconfigurable morphology according to claim 1 , wherein the filling matrix is a thermoplastic resin. 9. The supercapacitor with a reconfigurable structure according to claim 8, wherein the thermoplastic resin includes but is not limited to polyethylene, polypropylene, ethylene-vinyl acetate resin, polyvinyl chloride, polyvinyl chloride One of styrene, polyamide, polyoxymethylene, polycarbonate, polyphenylene ether, polysulfone and any combination thereof. 10. A method for preparing a supercapacitor with a reconfigurable structure, characterized in that: comprising the following steps: S1. Preparation of carbon fiber electrodes S2. Preparation of solid polymer electrolyte/fiber separator composite layer S20, putting the solid polymer electrolyte into the acetonitrile solution and fully stirring and mixing to obtain a polymer electrolyte slurry; S21, cutting the fiber membrane into pieces; S22. Apply the polymer electrolyte slurry to the designed energy storage area of the bulk fiber diaphragm, and dry it for later use; S3, stacking Lay up carbon fiber electrodes, solid polymer electrolyte/fiber separator composite layers, and carbon fiber electrodes in sequence to form an energy storage area; and lay a thermoplastic matrix on the composite layer and the solid polymer electrolyte-free area between the carbon fiber electrodes to form a hot press The formed load-bearing area is laminated and laminated to form a laminated body; S30, thermoforming Place the laminated body in a hot press, thermoforming at a temperature of 75-250°C, applying a pressure of 1-5 MPa, heating to melt and infiltrate, applying pressure and heating to soften, softening at a temperature of 70-180°C, and then cooling to obtain a structure Super capacitor; S4. Shape reconstruction After heat treatment or partial heating and softening, the shape is reshaped, and the shape reconstruction of the structural supercapacitor is realized after cooling; The softening method of shape remodeling is completed by heating plate, hot oven, hot air gun and other equipment. Put the heated and softened structural supercapacitor into another mold, and realize reshaping under the action of force. The softening temperature is 70-180°C.

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