CN-122025440-A - Flexible paper-based supercapacitor and preparation method thereof

CN122025440ACN 122025440 ACN122025440 ACN 122025440ACN-122025440-A

Abstract

The invention relates to a flexible paper-based supercapacitor, which sequentially comprises a positive electrode, an electrolyte layer and a negative electrode from bottom to top, wherein the positive electrode sequentially comprises a carbon nanotube paper layer and a poly (benzodifurandione) -activated carbon composite layer from bottom to top, the negative electrode sequentially comprises a poly (benzodifurandione) -activated carbon composite layer and a carbon nanotube paper layer from bottom to top, the electrolyte layer comprises a water-based diaphragm, and the water-based diaphragm completely separates the electrolyte layer into an upper part and a lower part. According to the invention, the carbon nano tube is introduced into cellulose paper, so that the cellulose paper has higher conductivity and excellent mechanical flexibility, can be used as a substrate of a self-supporting electrode to load active substances, and PBFDO and Active Carbon (AC) are compounded to form an electric double layer-pseudo capacitance synergistic energy storage system, so that the electrochemical performance of the device is remarkably improved. The strategy breaks through the bottleneck of electrochemical performance and mechanical flexibility of the flexible super capacitor, and has wide prospect.

Inventors

HUANG FEI
ZHANG XINGDI
TANG HAORAN

Assignees

华南理工大学

Dates

Publication Date: 20260512
Application Date: 20260325

Claims (9)

1. The flexible paper-based supercapacitor is characterized by sequentially comprising a positive electrode, an electrolyte layer and a negative electrode from bottom to top; Wherein, the The positive electrode sequentially comprises a carbon nano tube paper layer and a poly (benzodifurandione) -activated carbon composite layer from bottom to top; the negative electrode sequentially comprises a poly (benzodifurandione) -activated carbon composite layer and a carbon nano tube paper layer from bottom to top; The electrolyte layer includes an aqueous separator that separates the electrolyte layer into upper and lower portions.
2. The flexible paper-based supercapacitor of claim 1, wherein the material of the electrolyte is selected from one or more of polyvinyl alcohol, neutral salts.
3. The flexible paper-based supercapacitor of claim 2, wherein the neutral salt is selected from one or more of sodium chloride, potassium chloride, sodium sulfate, potassium sulfate.
4. The flexible paper-based supercapacitor of claim 1, wherein the aqueous separator material is selected from one or more of cellulose paper, polypropylene, PAN/PVDF-HFP.
5. The method for manufacturing a flexible paper-based supercapacitor according to any one of claims 1 to 4, wherein the method for manufacturing a flexible paper-based supercapacitor comprises the steps of: S1-1, carrying out the papermaking processes of blending, pulping, papermaking, suction filtration and drying on carbon nano tubes and cellulose pulp to obtain carbon nano tube paper; S1-2, under an inert atmosphere, 2,3,5, 6-tetramethyl 1, 4-benzoquinone and 3, 7-dihydrobenzo [1,2-b:4,5-b ] difuran-2, 6-dione are mixed, heated and stirred for reaction to obtain a poly (benzodifuran dione) solution; S1-3, adding the activated carbon dispersion liquid into the poly (benzodifurandione) solution, and performing ultrasonic dispersion to obtain poly (benzodifurandione) -activated carbon slurry; S1-4, dripping the poly (benzodifurandione) -activated carbon slurry on the carbon nanotube paper to obtain a positive electrode and a negative electrode; S2, soaking the anode and the cathode in electrolyte solution; S3, placing a water-based diaphragm on the positive electrode, coating electrolyte solution, and obtaining an electrolyte layer after the electrolyte completely infiltrates the water-based diaphragm; and S4, placing a negative electrode on one side of the electrolyte layer, which is far away from the positive electrode, to obtain the flexible paper-based supercapacitor.
6. The method for manufacturing a flexible paper-based supercapacitor according to claim 5, wherein in the step S1-1, the mass ratio of the carbon nanotubes to the cellulose pulp is (1-3): 1-3.
7. The method of producing a flexible paper-based supercapacitor according to claim 5, wherein the poly (benzodifurandione) solution has a concentration of 8-12 mg/ml in step S1-2.
8. The method for producing a flexible paper-based supercapacitor according to claim 5, wherein in step S3, the concentration of polyvinyl alcohol in the electrolyte solution is 0.1 to 1 g/L.
9. The method for producing a flexible paper-based supercapacitor according to claim 5, wherein in step S3, the concentration of the neutral salt in the electrolyte solution is 1 to 5 mol/L.

Description

Flexible paper-based supercapacitor and preparation method thereof Technical Field The invention relates to the technical field of capacitors, in particular to a flexible paper-based supercapacitor and a preparation method thereof. Background With the rapid rise of emerging fields such as wearable electronics, flexible robots, intelligent medical equipment and the like, the application field of energy storage devices is changing from traditional fixed type to flexible portable type and wearable type, and the performance requirements of the market on the energy storage devices are not limited to single electrochemical indexes any more, but are evolving towards the dual targets of high electrochemical performance and excellent mechanical flexibility. The flexible super capacitor is used as an energy storage device with the characteristics of high power density of the traditional capacitor and high energy density of the secondary battery, and has the outstanding advantages of high charge and discharge speed (completed in a few seconds), long cycle life (the cycle number reaches 10 4-106 times), high mechanical compatibility and the like, and becomes a core energy storage component of flexible electronic equipment, and the performance of the flexible super capacitor is directly dependent on the structural design and material selection of electrode materials, so that the development of high-performance flexible electrode materials has become a key for promoting the application of the flexible super capacitor. The flexible electrode is used as the core of the flexible super capacitor, and the dual performance requirements are required to be met at the same time. In electrochemical aspect, the polymer has high specific surface area, excellent electron conductivity and ion transmission efficiency, and abundant charge storage sites, and in mechanical aspect, the polymer has flexible characteristics such as light weight, repeated bending, self-supporting and the like. The traditional flexible electrode is often prepared by adopting an active material-conductive agent-binder ternary composite system, and is loaded on the surface of the metal foil current collector through coating, knife coating or printing and other processes. However, the technical route has a plurality of inherent defects that (1) the binder is easy to block the pore structure of the active material, reduces the utilization rate of active sites and increases the charge transmission resistance in the electrode, (2) the addition of the conductive agent increases the loading performance and cost of the process, and the compatibility of part of the conductive agent, the active material and the binder is poor, so that the problem of interface separation is easy to occur, and (3) the metal current collector has excellent conductivity, but the flexibility improvement and the energy density optimization of the device are seriously affected by the rigid characteristic and the higher mass ratio. In addition, the interlayer binding force of the traditional electrode is generally weak, active materials are easy to fall off from a current collector in the repeated mechanical deformation process, the performance of the device is caused to decay rapidly, and the requirement of the application scene of wearable electronic equipment and the like on the long-term service stability of the energy storage device is difficult to meet. The cellulose paper is used as a natural polymer material which has rich sources, low cost, biodegradability and excellent mechanical flexibility, and the porous structure formed by interweaving the fibers provides a new thought for the structural innovation of the flexible electrode. However, the insulating property of pure cellulose paper severely limits its application as electrode material directly, and the electrochemical performance requirements must be met by conducting modification treatment. The existing conductive modification strategies mainly comprise carbon material (graphene, carbon nano tube, active carbon and the like) compounding, metal nano particle deposition, conductive polymer in-situ polymerization and the like, wherein the carbon material compounding modification is the most commonly used method due to low cost and remarkable conductive improvement effect. However, the traditional composite process such as solution soaking, chemical vapor deposition, in-situ reduction and the like has a plurality of defects that the solution soaking method is easy to cause partial agglomeration of carbon materials to cause uneven construction of a conductive network, the chemical vapor deposition method needs harsh reaction conditions such as high temperature, vacuum and the like, the preparation process is complex, and impurity ions can be introduced in the in-situ reduction method to influence the electrochemical stability of an electrode. Meanwhile, the traditional carbon material modified paper-based electrode depends on a single