Integrated in-situ construction method of flexible and stretchable supercapacitors

Abstract

The present invention proposes a new strategy for the integrated in-situ construction of a flexible and stretchable supercapacitor. First, an integrated flexible and stretchable precursor fiber membrane with a "sandwich" structure is spun layer by layer using electrospinning technology. Then, a conductive polymer is in-situ grown on the electrode precursor fibers containing an oxidant through a gas-phase polymerization method. Finally, an integrated flexible and stretchable supercapacitor is obtained after impregnating with an electrolyte and encapsulation. For the integrated flexible and stretchable supercapacitor constructed by the present invention, by utilizing the mechanical meshing and chemical bonding effects between nanofibers, a firm interfacial bonding and low interfacial impedance between the electrode / electrolyte are achieved, thereby endowing the supercapacitor with improved electrochemical stability during the deformation process.

Description

Technical Field

[0001] The present invention belongs to the technical field of new energy materials, and in particular relates to a method for constructing a novel integrated flexible stretchable supercapacitor. Background Art

[0002] Stretchable electronic devices such as electronic textiles, implantable sensors, and wearable health monitors are gradually becoming necessities to make people's lives more comfortable. The feasibility of stretchable electronic devices depends largely on the development and industrial production of stretchable energy storage systems. As one of the efficient energy storage and supply devices, stretchable supercapacitors have attracted widespread attention in the industry for their excellent power density, high cycle life, and outstanding mechanical properties.

[0003] The currently widely reported stretchable supercapacitors are stretchable supercapacitors assembled by adhering stretchable electrodes to both sides of a gel electrolyte. However, the undesirable interface structure and poor adhesion make it difficult for their electrochemical performance and mechanical deformation capabilities to adapt to the higher requirements of future wearable electronic devices. Therefore, in recent years, the construction concept of "integrated flexible stretchable supercapacitors" has been proposed, which transforms the original two-dimensional plane of the stretchable electrode / electrolyte interface on the device scale into a micro-nano three-dimensional structure, significantly reducing the interface impedance and effectively shortening the charge transfer path. In particular, the close combination of the components enables the integrated flexible supercapacitor to maintain structural stability during deformation, thus having better comprehensive electrochemical performance than traditional stretchable devices. The team of Qu Liangti of Tsinghua University and Zhang Zhipan of Beijing Institute of Technology used a cross-linked polyacrylamide gel electrolyte containing ethylene glycol / water / sulfuric acid as a raw material, and in situ grew polyaniline on its surface to prepare an integrated supercapacitor with antifreeze and high stretchability. In this design, no additional stretchable substrate or predefined stretchable structure is required (Energy Environ. Sci., 2021, 14, 3075-3085). Patent CN 113871214 A discloses the construction of an integrated flexible supercapacitor by in-situ deposition of a conductive polymer / graphene oxide composite electrode on both sides of an ammonium alginate-polyacrylic acid-polyacrylamide hydrogel electrolyte; Patent CN 107093520 A discloses the preparation of a three-layer integrated flexible thin film supercapacitor by using suction filtration to form a film and then reducing it with ultraviolet light. Although the stretchable electrodes / electrolytes prepared above have a certain degree of flexibility, the contact interface is still a smooth plane. Under long-term repeated deformation, delamination, shedding, or electrode breakage will occur, resulting in the attenuation of the electrochemical performance of the device during the cycle. In addition, due to many problems such as poor tensile deformation performance and complex assembly process, the large-scale production of the device is seriously restricted.

[0004] In view of this, evolving the overall structure of an integrated flexible and stretchable supercapacitor from a three-dimensional bulk to a two-dimensional thin film and transforming the contact interface from a two-dimensional plane to a micro-nano three-dimensional structure is one of the most effective strategies to synchronously improve the energy storage capacity and deformation ability of the device. Summary of the Invention

[0005] The purpose of the present invention is to propose a novel in-situ construction method for an integrated flexible and stretchable supercapacitor. First, an electrospinning technique is used to spin a "sandwich" structure integrated flexible and stretchable precursor fiber membrane layer by layer, and then a gas-phase polymerization method and electrolyte impregnation are combined to successfully construct an integrated flexible and stretchable supercapacitor, achieving true integration and effectively solving the problems of poor deformation ability and unstable dynamic electrochemical performance of supercapacitor devices.

[0006] To achieve the above purpose, the following technical solutions are adopted:

[0007] (1) Use electrospinning to spin and construct an integrated flexible and stretchable supercapacitor precursor fiber membrane with a "sandwich" structure

[0008] . Dissolve a polar polymer elastomer in a mixed organic solvent, and then add an oxidant and a crosslinking agent to the above solution. Control the content of the polar polymer elastomer to be 5wt% - 10wt%, the mass ratio of the polar polymer elastomer to the oxidant to be 1:(0.15 - 0.4), and the mass ratio of the polar polymer elastomer to the crosslinking agent to be 1:(0.02 - 0.06) to obtain a stretchable electrode precursor spinning solution A;

[0009] . Select the same polar polymer elastomer as in spinning solution A and dissolve it in an organic solvent. Control the content of the polar polymer elastomer to be 6wt% - 12wt%, then add 0.5wt% - 2wt% of the crosslinking agent, and control the mass ratio of the polar polymer elastomer to the crosslinking agent to be 1:(0.01 - 0.05) to obtain a stretchable quasi-solid electrolyte spinning solution B;

[0010] c. Use spinning solution A, with an aluminum foil as the receiver, and spin through an electrospinning machine to obtain a stretchable electrode precursor fiber membrane layer, with the membrane layer thickness controlled at 10 microns - 50 microns; then, use the stretchable electrode precursor fiber membrane as the receiver, and spin with spinning solution B through electrospinning to cover the stretchable electrode precursor fiber membrane layer, with the spun quasi-solid electrolyte precursor fiber membrane layer thickness controlled at 80 microns - 150 microns; finally, on the surface of the quasi-solid electrolyte precursor fiber membrane layer, use spinning solution A through electrospinning to cover the quasi-solid electrolyte precursor fiber membrane layer, and control the thickness of the stretchable electrode precursor fiber membrane layer at 10 microns - 50 microns. After removing the aluminum foil, an integrated flexible and stretchable supercapacitor precursor fiber membrane with a "sandwich" structure is obtained.

[0011] The polar polymer elastomer described above is one of fluororubber and polyacrylate rubber;

[0012] The oxidant in the spinning solution A described above is one of ferric trichloride, iron p-toluenesulfonate, and ammonium sulfate;

[0013] The crosslinking agent described above is one of hexamethylenediamine, triethylenetetramine, and tetraethylenetriamine;

[0014] The mixed organic solvent in the spinning solution A described above is a mixed solvent composed of acetone or butanone and N, N-dimethylformamide, N, N-dimethylacetamide, and N-methylpyrrolidone, and their volume ratio is 1:(1~4);

[0015] The organic solvent in the spinning solution B described above is one of butanone, N, N-dimethylformamide, and N, N-dimethylacetamide;

[0016] The spinning conditions described above are a voltage of 12~18 kV, a humidity of 10~30%, and a distance from the spinning needle to the receiver of 8~20 cm.

[0017] (2) In-situ growth of conductive polymers by gas-phase polymerization method to prepare an integrated flexible and stretchable supercapacitor fiber membrane

[0018] Put the above-mentioned "sandwich" structure integrated flexible and stretchable supercapacitor precursor fiber membrane into a vacuum-sealed container filled with conductive polymer monomers and hydrochloric acid, and carry out gas-phase polymerization for 2 hours to 12 hours at a temperature of 60°C to 130°C. After washing with water and ethanol, an integrated flexible and stretchable supercapacitor fiber membrane is prepared, and the surface loading of the conductive polymer active material is milligrams per centimeter -2 .

[0019] The conductive polymer monomer described above is one of aniline, thiophene, and pyrrole.

[0020] (3) Impregnate the electrolyte and encapsulate to construct an integrated flexible and stretchable supercapacitor

[0021] Immerse the integrated flexible and stretchable supercapacitor fiber membrane prepared in step (2) in a 1 mol / L 1-ethyl-3-methylimidazolium tetrafluoroborate or tetraethylammonium tetrafluoroborate / acetonitrile electrolyte for 10 minutes to 30 minutes, and encapsulate it with dimethyl silicone and a silicone-based binder to obtain an integrated flexible and stretchable supercapacitor.

[0022] Compared with the prior art, the beneficial effects of the present invention are:

[0023] (1) The "sandwich" - structured integrated flexible and stretchable supercapacitor precursor fiber membrane prepared by the electrospinning technology of the present invention. Due to the mutual embedding of nanofibers, the mechanical meshing and chemical bonding between the electrode and the electrolyte layer are enhanced, realizing the true integration of the electrode / electrolyte layer interface, avoiding the slippage of the interface during the stretching process, shortening the ion transport path, and reducing the interface resistance.

[0024] (2) The gas - phase polymerization method of the present invention realizes the in - situ growth of conductive polymers on the integrated porous fiber membrane. By varying the addition amount of the oxidant, the content of active substances can be effectively regulated and key problems such as device short - circuit can be avoided.

[0025] (3) The strategy of combining the electrospinning layer - by - layer spinning technology and the gas - phase polymerization method proposed by the present invention to construct an integrated flexible and stretchable supercapacitor not only endows the flexible and stretchable supercapacitor with stable electrochemical performance during deformation, but also has the characteristics of simplicity in the construction process of the integrated stretchable device, large - scale production, and device editing. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a flow chart of the construction method of the integrated flexible and stretchable supercapacitor of the present invention;

[0027] Figure 2 is a field - emission scanning electron microscope cross - section photo of the integrated flexible and stretchable supercapacitor constructed in Example 1;

[0028] Figure 3 is the change of specific capacitance with the number of stretching - recovery cycles when the strain is 100% for the integrated flexible and stretchable supercapacitor constructed in Example 1. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] To more clearly illustrate the present invention, the following is a detailed description of the technology of the present invention in combination with specific embodiments. It should be understood that the following specific embodiments are only used to help those skilled in the art understand the present invention, rather than limiting the present invention.

[0030] Example 1

[0031] The construction method of the integrated flexible and stretchable supercapacitor is as Figure 1 shown, and the specific steps are as follows:

[0032] (1) Use electrospinning layer - by - layer spinning to construct a "sandwich" - structured integrated flexible and stretchable supercapacitor precursor fiber membrane

[0033] a. Dissolve fluororubber in a mixed organic solvent of acetone and N,N-dimethylformamide with a volume ratio of 1:2, then add ferric chloride and hexamethylenediamine to the above solution. Control the fluororubber content to be 6 wt%, the mass ratio of fluororubber to ferric chloride to be 1:0.25, and the mass ratio of fluororubber to hexamethylenediamine to be 1:0.03 to obtain a stretchable electrode precursor spinning solution A;

[0034] b. Selectively dissolve fluororubber in N,N-dimethylacetamide, then add hexamethylenediamine. Control the fluororubber content to be 8 wt% and the mass ratio of fluororubber to hexamethylenediamine to be 1:0.04 to obtain a spinning solution B of a stretchable quasi-solid electrolyte;

[0035] c. Use the spinning solution A, with aluminum foil as the receiver, and spin it through an electrospinning machine to obtain a stretchable electrode precursor fiber membrane layer, and control the membrane layer thickness to be 20 microns; then, use the stretchable electrode precursor fiber membrane as the receiver, and use the spinning solution B to electrospin to cover the stretchable electrode precursor fiber membrane layer, and control the fiber membrane layer thickness to be 100 microns; finally, on the surface of the quasi-solid electrolyte precursor fiber membrane layer, use the spinning solution A to electrospin to cover the quasi-solid electrolyte precursor fiber membrane layer, and control the thickness of the stretchable electrode precursor fiber membrane layer to be 20 microns. After removing the aluminum foil, a "sandwich" structure integrated flexible stretchable supercapacitor precursor fiber membrane is obtained. The above electrospinning conditions are: voltage is 14 kV, humidity is 10%, and the distance from the spinning needle to the receiver is 12 cm.

[0036] (2)In-situ growth of conductive polymers by gas-phase polymerization method to prepare an integrated flexible stretchable supercapacitor fiber membrane

[0037] Put the above "sandwich" structure integrated flexible stretchable supercapacitor precursor fiber membrane into a vacuum-sealed container filled with thiophene monomer and hydrochloric acid, and carry out gas-phase polymerization for 4 hours under the condition of a temperature of 100 °C. After washing with water and ethanol washing, an integrated flexible stretchable supercapacitor fiber membrane is prepared, and the surface loading of the conductive polymer active substance is 4 mg / cm -2 ,and through field emission cross-sectional scanning electron microscopy characterization as Figure 2 shown, it can be seen that the fibers of the electrode and the electrolyte layer are inter-embedded and adhered to each other, and this structure enhances the close contact between the electrode and the electrolyte interface, ensuring the stable output of electrochemical performance during the deformation process.

[0038] (3)Impregnate the electrolyte and encapsulate to construct an integrated flexible stretchable supercapacitor

[0039] The integrated flexible and stretchable supercapacitor fiber membrane prepared in step (2) was immersed in 1 mol / L 1-ethyl-3-methylimidazolium tetrafluoroborate for 20 minutes and then encapsulated with dimethyl silicone and a silicon-based binder to obtain an integrated flexible and stretchable supercapacitor.

[0040] The applicant carried out electrochemical performance tests on the integrated stretchable supercapacitor constructed in this example under a stretched state. Figure 3 It can be seen that when the strain of the constructed integrated stretchable supercapacitor is 100%, after 500 stretching-recovery cycles, the specific capacitance retention rate is 93.6%, indicating that this construction strategy enhances the interfacial stability between the electrode and the electrolyte, thus contributing to the excellent and stable output characteristics of the electrochemical performance of the device.

[0041] Example 2

[0042] The integrated in-situ construction method of the flexible and stretchable supercapacitor includes the following steps:

[0043] (1) Use electrospinning to spin-layer by layer to construct a "sandwich" structure integrated flexible and stretchable supercapacitor precursor fiber membrane

[0044] a. Dissolve polyacrylate rubber in a mixed organic solvent of methyl ethyl ketone and N,N-dimethylacetamide with a volume ratio of 1:4, and then add ferric chloride and triethylenetetramine to the above solution. Control the content of polyacrylate rubber to be 7 wt%, the mass ratio of polyacrylate rubber to ferric chloride to be 1:0.3, and the mass ratio of polyacrylate rubber to triethylenetetramine to be 1:0.04 to obtain a stretchable electrode precursor spinning solution A;

[0045] . Dissolve polyacrylate rubber in N,N-dimethylformamide, and then add triethylenetetramine. Control the content of fluororubber to be 10 wt%, and the mass ratio of polyacrylate rubber to triethylenetetramine to be 1:0.03 to obtain a stretchable quasi-solid electrolyte spinning solution B;

[0046] . Similar to Example 1, an integrated flexible and stretchable supercapacitor precursor fiber membrane with a "sandwich" structure was prepared.

[0047] (2) In-situ grow conductive polymers by gas-phase polymerization method to prepare an integrated flexible and stretchable supercapacitor fiber membrane

[0048] Put the above "sandwich" structure integrated flexible and stretchable supercapacitor precursor fiber membrane into a vacuum-sealed container containing thiophene monomer and hydrochloric acid, and carry out gas-phase polymerization for 3 hours at a temperature of 110 °C. After washing with water and ethanol washing, an integrated flexible and stretchable supercapacitor fiber membrane was prepared, and the surface loading of the conductive polymer active substance was 4 mg / cm -2 .

[0049] (3) Impregnate with electrolyte and encapsulate to construct an integrated flexible and stretchable supercapacitor

[0050] Same as Example 1, encapsulated with dimethyl silicone and silicone-based binder to obtain an integrated flexible and stretchable supercapacitor.

[0051] Example 3

[0052] The integrated in-situ construction method of the flexible and stretchable supercapacitor includes the following steps:

[0053] (1) Use electrospinning to layer by layer fabricate a "sandwich" structure integrated flexible and stretchable supercapacitor precursor fiber membrane

[0054] . Dissolve fluororubber in a mixed organic solvent of acetone and N-methylpyrrolidone with a volume ratio of 1:3, then add iron p-toluenesulfonate and tetraethylenetriamine to the above solution, control the fluororubber content to be 8 wt%, the mass ratio of fluororubber to iron p-toluenesulfonate to be 1:0.4, and the mass ratio of fluororubber to tetraethylenetriamine to be 1:0.05 to obtain a stretchable electrode precursor spinning solution A;

[0055] . Select fluororubber dissolved in butanone, then add tetraethylenetriamine, control the fluororubber content to be 12 wt%, and the mass ratio of fluororubber to tetraethylenetriamine to be 1:0.05 to obtain a stretchable quasi-solid electrolyte spinning solution B;

[0056] c. Use spinning solution A, with an aluminum foil as the receiver, spin through an electrospinning machine to obtain a stretchable electrode precursor fiber membrane layer, and control the membrane layer thickness to be 40 microns; then, use the stretchable electrode precursor fiber membrane as the receiver, use spinning solution B through electrospinning to cover the stretchable electrode precursor fiber membrane layer, and control the thickness of the spun quasi-solid electrolyte precursor fiber membrane layer to be 120 microns; finally, on the surface of the quasi-solid electrolyte precursor fiber membrane layer, use spinning solution A through electrospinning to cover the quasi-solid electrolyte precursor fiber membrane layer, and control the thickness of the stretchable electrode precursor fiber membrane layer to be 40 microns. After removing the aluminum foil, obtain a "sandwich" structure integrated flexible and stretchable supercapacitor precursor fiber membrane. The above electrospinning conditions: voltage is 16 kV, humidity is 20%, and the distance from the spinning needle to the receiver is 16 cm.

[0057] (2) In-situ grow conductive polymer by gas-phase polymerization method to prepare an integrated flexible and stretchable supercapacitor fiber membrane

[0058] Put the above-mentioned "sandwich"-structured integrated flexible and stretchable supercapacitor precursor fiber membrane into a vacuum-sealed container filled with thiophene monomer and hydrochloric acid, and carry out gas-phase polymerization for 2 hours at a temperature of 130 °C. After washing with water and ethanol, an integrated flexible and stretchable supercapacitor fiber membrane is prepared, and the areal loading of the conductive polymer active material is 6 mg / cm -2 .

[0059] (3)Impregnate with electrolyte and encapsulate to construct an integrated flexible and stretchable supercapacitor

[0060] Immerse the integrated flexible and stretchable supercapacitor fiber membrane prepared in step (2) in a 1 mol / L tetraethylammonium tetrafluoroborate / acetonitrile electrolyte for 30 minutes, and encapsulate it with dimethyl silicone and a silicone-based binder to obtain an integrated flexible and stretchable supercapacitor.

[0061] Example 4

[0062] The method for in-situ construction of an integrated flexible and stretchable supercapacitor includes the following steps:

[0063] (1)Construct a "sandwich"-structured integrated flexible and stretchable supercapacitor precursor fiber membrane by electrospinning layer by layer

[0064] . Dissolve fluororubber in a mixed organic solvent of methyl ethyl ketone and N,N-dimethylformamide with a volume ratio of 1:1, and then add ammonium persulfate and triethylenetetramine to the above solution. Control the fluororubber content to be 5 wt%, the mass ratio of fluororubber to ammonium persulfate to be 1:0.2, and the mass ratio of fluororubber to triethylenetetramine to be 1:0.01 to obtain a stretchable electrode precursor spinning solution A;

[0065] . Select to dissolve fluororubber in methyl ethyl ketone, and then add triethylenetetramine. Control the fluororubber content to be 6 wt%, and the mass ratio of fluororubber to triethylenetetramine to be 1:0.02 to obtain a spinning solution B of a stretchable quasi-solid electrolyte;

[0066] . Similar to Example 1, a "sandwich"-structured integrated flexible and stretchable supercapacitor precursor fiber membrane is prepared.

[0067] (2)In-situ growth of conductive polymer by gas-phase polymerization method to prepare an integrated flexible and stretchable supercapacitor fiber membrane

[0068] Put the above-mentioned "sandwich"-structured integrated flexible and stretchable supercapacitor precursor fiber membrane into a vacuum-sealed container filled with thiophene monomer and hydrochloric acid, and carry out gas-phase polymerization for 5 hours at a temperature of 60 °C. After washing with water and ethanol, an integrated flexible and stretchable supercapacitor fiber membrane is prepared, and the areal loading of the conductive polymer active material is 2 mg / cm -2 .

[0069] (3) Immerse in the electrolyte and encapsulate to construct an integrated flexible and stretchable supercapacitor

[0070] Same as Example 1, encapsulated with dimethyl silicone and silicone-based binder to obtain an integrated flexible and stretchable supercapacitor.

[0071] Example 5

[0072] The integrated in-situ construction method of the flexible and stretchable supercapacitor includes the following steps:

[0073] (1) Use electrospinning to spin layer by layer to construct a "sandwich" structure integrated flexible and stretchable supercapacitor precursor fiber membrane

[0074] . Dissolve fluororubber in a mixed organic solvent of acetone and N-methylpyrrolidone with a volume ratio of 1:4, then add ammonium persulfate and tetraethylenetriamine to the above solution, control the fluororubber content to be 10wt%, the mass ratio of fluororubber to ammonium persulfate is 1:0.4, and the mass ratio of fluororubber to tetraethylenetriamine is 1:0.06 to obtain a stretchable electrode precursor spinning solution A;

[0075] . Select to dissolve fluororubber in N,N-dimethylacetamide, then add tetraethylenetriamine, control the fluororubber content to be 12wt%, and the mass ratio of fluororubber to tetraethylenetriamine is 1:0.05 to obtain a spinning solution B of a stretchable quasi-solid electrolyte;

[0076] c. Use spinning solution A, with aluminum foil as the receiver, spin through an electrospinning machine to obtain a stretchable electrode precursor fiber membrane layer, and control the membrane layer thickness to be 50 microns; then, use the stretchable electrode precursor fiber membrane as the receiver, and use spinning solution B to spin through electrospinning to cover the stretchable electrode precursor fiber membrane layer, and control the thickness of the spun quasi-solid electrolyte precursor fiber membrane layer to be 140 microns; finally, on the surface of the quasi-solid electrolyte precursor fiber membrane layer, use spinning solution A to spin through electrospinning to cover the quasi-solid electrolyte precursor fiber membrane layer, and control the thickness of the stretchable electrode precursor fiber membrane layer to be 50 microns. After removing the aluminum foil, obtain a "sandwich" structure integrated flexible and stretchable supercapacitor precursor fiber membrane. The above electrospinning conditions: voltage is 18 kV, humidity is 30%, and the distance from the spinning needle to the receiver is 18 cm.

[0077] (2) In-situ growth of conductive polymers by gas-phase polymerization method to prepare an integrated flexible and stretchable supercapacitor fiber membrane

[0078] Put the above-mentioned "sandwich" - structured integrated flexible and stretchable supercapacitor precursor fiber membrane into a vacuum - sealed container filled with pyrrole monomer and hydrochloric acid, and carry out gas - phase polymerization for 6 hours at a temperature of 100 °C. After washing with water and ethanol, an integrated flexible and stretchable supercapacitor fiber membrane is prepared, and the areal loading of the conductive polymer active material is 3 mg / cm². -2 .

[0079] (3)Impregnate with electrolyte and encapsulate to construct an integrated flexible and stretchable supercapacitor

[0080] Place the integrated flexible and stretchable supercapacitor fiber membrane prepared in step (2) into 1 - ethyl - 3 - methylimidazolium tetrafluoroborate with a concentration of 1 mol / L and soak for 10 minutes. After encapsulation with dimethyl silicone and a silicone - based binder, an integrated flexible and stretchable supercapacitor is obtained.

[0081] Example 6

[0082] The method for in - situ construction of an integrated flexible and stretchable supercapacitor includes the following steps:

[0083] (1)Construct an "sandwich" - structured integrated flexible and stretchable supercapacitor precursor fiber membrane by electrospinning layer by layer

[0084] . Dissolve polyacrylate rubber in a mixed organic solvent of acetone and N, N - dimethylformamide with a volume ratio of 1:4, then add ferric p - toluenesulfonate and hexamethylenediamine to the above - mentioned solution. Control the content of polyacrylate rubber to be 7 wt%, the mass ratio of polyacrylate rubber to ferric p - toluenesulfonate to be 1:0.15, and the mass ratio of polyacrylate rubber to hexamethylenediamine to be 1:0.03 to obtain a stretchable electrode precursor spinning solution A;

[0085] . Select polyacrylate rubber dissolved in N, N - dimethylacetamide, and then add hexamethylenediamine. Control the content of fluororubber to be 8 wt%, and the mass ratio of polyacrylate rubber to hexamethylenediamine to be 1:0.02 to obtain a stretchable quasi - solid electrolyte spinning solution B;

[0086] c. Using spinning solution A, with an aluminum foil as the receiver, spin-spinning is carried out through an electrospinning machine to obtain a stretchable electrode precursor fiber membrane layer, and the thickness of the membrane layer is controlled to be 10 microns; then, using the stretchable electrode precursor fiber membrane as the receiver, spinning solution B is used for electrospinning to cover the stretchable electrode precursor fiber membrane layer, and the thickness of the spun quasi-solid electrolyte precursor fiber membrane layer is controlled at 80 microns; finally, on the surface of the quasi-solid electrolyte precursor fiber membrane layer, spinning solution A is used for electrospinning to cover the quasi-solid electrolyte precursor fiber membrane layer, and the thickness of the stretchable electrode precursor fiber membrane layer is controlled at 10 microns. After removing the aluminum foil, a "sandwich" structure integrated flexible stretchable supercapacitor precursor fiber membrane is obtained. The above electrospinning conditions are: voltage is 12 kV, humidity is 20%, and the distance from the spinning needle to the receiver is 20 cm.

[0087] (2) In-situ growth of conductive polymers by gas-phase polymerization method to prepare an integrated flexible stretchable supercapacitor fiber membrane

[0088] The above "sandwich" structure integrated flexible stretchable supercapacitor precursor fiber membrane is placed in a vacuum-sealed container containing aniline monomer and hydrochloric acid, and gas-phase polymerization is carried out for 12 hours at a temperature of 100 °C. After washing with water and ethanol washing, an integrated flexible stretchable supercapacitor fiber membrane is prepared, and the surface loading of the conductive polymer active material is 2 mg / cm -2 .

[0089] (3) Impregnating the electrolyte and encapsulating to construct an integrated flexible stretchable supercapacitor

[0090] The integrated flexible stretchable supercapacitor fiber membrane prepared in step (2) is immersed in 1 mol / L tetraethylammonium tetrafluoroborate / acetonitrile for 20 minutes, and is encapsulated with dimethyl silicone and a silicone-based binder to obtain an integrated flexible stretchable supercapacitor.

[0091] Comparative Example 1

[0092] The construction method of the flexible stretchable supercapacitor includes the following steps:

[0093] (1) Constructing a "sandwich" structure flexible stretchable supercapacitor precursor fiber membrane by using a hot press adhesion technique

[0094] . Similar to Example 1, obtain the stretchable electrode precursor spinning solution A;

[0095] . Similar to Example 1, obtain the spinning solution B of the stretchable quasi-solid electrolyte;

[0096] . Using spinning solution A, with an aluminum foil as the receiver, it is spun by an electrospinning machine to obtain a stretchable electrode precursor fiber membrane layer, and the membrane layer thickness is controlled to be 20 microns; then, with an aluminum foil as the receiver, spinning solution B is used for electrospinning to obtain a quasi-solid electrolyte precursor fiber membrane layer, and its membrane thickness is controlled to be 100 microns. The above electrospinning conditions are the same as those in Example 1.

[0097] Cut out 2 regular fiber membranes with a length * width of 8 * 6 cm from the above-prepared stretchable electrode precursor fiber membrane, and then cut out 1 regular fiber membrane with a length * width of 10 * 8 cm from the above-prepared quasi-solid electrolyte precursor fiber membrane. Then, the two stretchable electrode precursor fiber membranes are symmetrically adhered to both sides of the quasi-solid electrolyte precursor fiber membrane in a hot pressing form, so as to obtain an integrated flexible stretchable supercapacitor precursor fiber membrane with another interface contact mode of "sandwich" structure.

[0098] (2) In-situ growth of conductive polymer by gas-phase polymerization method to prepare an integrated flexible stretchable supercapacitor fiber membrane

[0099] Same as Example 1, an integrated flexible stretchable supercapacitor fiber membrane is obtained, and the surface loading amount of the conductive polymer active substance is 4 mg / cm -2 .

[0100] (3) Impregnating with electrolyte and encapsulating to construct an integrated flexible stretchable supercapacitor

[0101] Same as Example 1, an integrated flexible stretchable supercapacitor is obtained.

[0102] Table 1. Test results of the integrated flexible stretchable supercapacitors constructed in Examples 1 to 6 and Comparative Example 1

[0103]

[0104] Furthermore, the applicant conducted dynamic and static electrochemical performance output on the integrated flexible stretchable supercapacitors constructed in Examples 1 to 6 and Comparative Example 1, as shown in Table 1. It can be found that the fiber membranes spun from the fluororubber and hexamethylenediamine system are more conducive to the in-situ growth of conductive polymers, and a moderate surface loading amount of the conductive polymer helps to improve the specific capacitance retention rate of the entire device and enhance its electrochemical stability. Compared with Comparative Example 1, the electrospinning layer-by-layer spinning strategy can obtain a more closely contacted electrode / electrolyte interface than the hot pressing adhesion technology, so as to have a higher specific capacitance retention rate and more excellent electrochemical cycling performance during the dynamic stretching process.

Claims

1. An integrated in-situ construction method for flexible and stretchable supercapacitors, comprising the following steps: (1) Use electrospinning to layer by layer fabricate an integrated flexible and stretchable supercapacitor precursor fiber membrane with a "sandwich" structure a. Dissolve a polar polymer elastomer in a mixed organic solvent, then add an oxidant and a crosslinking agent to the above solution, control the content of the polar polymer elastomer to be 5wt% - 10wt%, the mass ratio of the polar polymer elastomer to the oxidant to be 1:(0.15 - 0.4), and the mass ratio of the polar polymer elastomer to the crosslinking agent to be 1:(0.02 - 0.06) to obtain a stretchable electrode precursor spinning solution A; Among them, the polar polymer elastomer is one of fluororubber and polyacrylate rubber; b. Select the same polar polymer elastomer as in spinning solution A and dissolve it in an organic solvent, control the content of the polar polymer elastomer to be 6wt% - 12wt%, then add 0.5wt% - 2wt% of the crosslinking agent, and control the mass ratio of the polar polymer elastomer to the crosslinking agent to be 1:(0.01 - 0.05) to obtain a quasi-solid electrolyte spinning solution B; c. Use spinning solution A, with an aluminum foil as the receiver, spin through an electrospinning machine to obtain a stretchable electrode precursor fiber membrane layer, and control the membrane layer thickness to be 10 microns - 50 microns; then, use the stretchable electrode precursor fiber membrane as the receiver, and use spinning solution B to electrospin to cover the stretchable electrode precursor fiber membrane layer, and control the thickness of the spun quasi-solid electrolyte precursor fiber membrane layer to be 80 microns - 150 microns; finally, on the surface of the quasi-solid electrolyte precursor fiber membrane layer, use spinning solution A to electrospin to cover the quasi-solid electrolyte precursor fiber membrane layer, and control the thickness of the stretchable electrode precursor fiber membrane layer to be 10 microns - 50 microns. After removing the aluminum foil, an integrated flexible and stretchable supercapacitor precursor fiber membrane with a "sandwich" structure is obtained. The electrospinning conditions are a voltage of 12 - 18 kV, a humidity of 10 - 30%, and a distance from the spinning needle to the receiver of 8 - 20 cm; (2) In-situ grow a conductive polymer by gas-phase polymerization method to prepare an integrated flexible and stretchable supercapacitor fiber membrane The above-mentioned "sandwich" structure integrated flexible and stretchable supercapacitor precursor fiber membrane is placed in a vacuum-sealed container containing a conductive polymer monomer and hydrochloric acid, and gas-phase polymerization is carried out for 2 to 12 hours under the condition of a temperature of 60 °C to 130 °C. After washing with water and ethanol washing, an integrated flexible and stretchable supercapacitor fiber membrane is prepared, and the surface loading of the conductive polymer active substance is 2 to 6 mg / cm -2 ; (3) Immerse in electrolyte and encapsulate to construct an integrated flexible and stretchable supercapacitor Immerse the integrated flexible and stretchable supercapacitor fiber membrane prepared in step (2) in a 1 mol / L 1-ethyl-3-methylimidazolium tetrafluoroborate or tetraethylammonium tetrafluoroborate / acetonitrile electrolyte for 10 minutes - 30 minutes, and encapsulate with dimethyl silicone and a silicone-based binder to obtain an integrated flexible and stretchable supercapacitor.

2. The construction method according to claim 1, characterized in that The oxidant in the spinning solution A is one of ferric chloride, iron p-toluenesulfonate, and ammonium persulfate.

3. The construction method according to claim 1, characterized in that, The crosslinking agent is one of hexamethylenediamine, triethylenetetramine, and tetraethylenetriamine.

4. The construction method according to claim 1, wherein The mixed organic solvent in the spinning solution A is a mixed solvent composed of acetone or butanone and N,N-dimethylformamide, N,N-dimethylacetamide, and N-methylpyrrolidone, and their volume ratio is 1:(1 - 4).

5. The construction method according to claim 1, characterized in that The organic solvent in the spinning solution B is one of methyl ethyl ketone, N, N-dimethylformamide, and N, N-dimethylacetamide.

6. The construction method according to claim 1, characterized in that The conductive polymer monomer is one of aniline, thiophene, and pyrrole.

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