All-solid-state optical supercapacitor based on carbon-rich carbon nitride conjugated polymer and preparation method thereof

Abstract

This invention relates to an all-solid-state photovoltaic supercapacitor based on a carbon-nitride-rich conjugated polymer, belonging to the field of solar photovoltaic conversion and energy storage technology. It includes a first conductive glass and a second conductive glass; one side of the first conductive glass has a first titanium dioxide nanocrystalline mesoporous film; one side of the second conductive glass has a second titanium dioxide nanocrystalline mesoporous film; a carbon-nitride-rich conjugated polymer is disposed between the first and second titanium dioxide nanocrystalline mesoporous films; the outer surfaces of the first and second titanium dioxide nanocrystalline mesoporous films and the carbon-nitride-rich conjugated polymer are sealed with an insulating sealant. This invention also provides a method for preparing the all-solid-state photovoltaic supercapacitor.

Description

Technical Field

[0001] This invention belongs to the field of solar photovoltaic conversion and energy storage technology, and relates to an all-solid-state optical supercapacitor based on carbon-rich carbon nitride conjugated polymer and its preparation method. Background Technology

[0002] Photovoltaic supercapacitors are devices that induce and store photocharges under illumination, releasing the charge to generate current when needed. Existing technologies have the following problems:

[0003] (1) Low photogenerated charge storage capacity. Existing supercapacitors mainly consist of a photovoltaic electrode and an energy storage electrode sharing a single counter electrode. The photovoltaic material absorbs light to generate photogenerated charge, which is then input into the energy storage electrode material for charge storage. This mechanism requires a very close match between the voltage window and current magnitude between the photovoltaic electrode and the energy storage electrode; otherwise, significant internal electron losses will occur, reducing photoelectric conversion and charge storage efficiency, and severely affecting the photogenerated charge storage capacity.

[0004] (2) Problems arising from the use of electrolytes. Existing photoelectric supercapacitors all employ electrolytes to promote the separation of photogenerated charges or stabilize stored charges. Since supercapacitors utilize vast surfaces for charge storage, and the active surfaces originate from the nanoporous or mesoporous structures of the electrode materials, only liquid electrolytes can achieve good wetting effects. However, the organic solvents in liquid electrolytes are prone to combustion or explosion due to overheating, causing safety issues. If solid electrolytes are used, the smaller pores lead to poor contact between the electrolyte and electrode materials, significantly impacting surface activity and causing a severe decrease in storage capacity. Furthermore, because photoelectric supercapacitors require prolonged exposure to light, liquid electrolytes are prone to evaporation, increasing the difficulty of device packaging and reducing performance stability. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide an all-solid-state optical supercapacitor based on a carbon-rich carbon nitride conjugated polymer and a method for preparing the same, so as to prepare an all-solid-state optical supercapacitor without the use of an electrolyte with high photogenerated charge storage capacity.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A solid-state optical supercapacitor based on a carbon-nitride-rich carbon conjugated polymer includes a first conductive glass and a second conductive glass. The conductive surface of the first conductive glass is provided with a first titanium dioxide nanocrystalline mesoporous film. The conductive surface of the second conductive glass is provided with a second titanium dioxide nanocrystalline mesoporous film. A carbon-nitride-rich carbon conjugated polymer is disposed between the first and second titanium dioxide nanocrystalline mesoporous films. The outer surfaces of the first and second titanium dioxide nanocrystalline mesoporous films and the carbon-nitride-rich carbon conjugated polymer are sealed with an insulating sealant.

[0008] On the other hand, the present invention provides a method for preparing an all-solid-state optical supercapacitor based on a carbon-rich carbon nitride conjugated polymer, comprising the following steps:

[0009] S1: Preparation of carbon-rich carbon nitride conjugated polymers;

[0010] S2: Sinter titanium dioxide nanocrystalline mesoporous films on the conductive surfaces of two conductive glasses to obtain a conductive glass-TiO2 nanocrystalline mesoporous film composite electrode.

[0011] S3: A carbon-rich carbon nitride conjugated polymer is uniformly coated on the surface of the titanium dioxide nanocrystalline mesoporous film of the two composite electrodes.

[0012] S4: Two composite electrodes coated with carbon nitride conjugated polymer are bonded together using insulating sealant to obtain an all-solid-state optical supercapacitor.

[0013] Furthermore, the preparation steps of the carbon-rich carbon nitride conjugated polymer are as follows:

[0014] S11: Dicyandiamine, citric acid, and deionized water are mixed in a mass ratio of 1:1.9:60 to obtain the reactants;

[0015] S12: The reactants are introduced into a hydrothermal reactor and kept at 200°C for 3 hours to carry out a hydrothermal reaction to obtain the precursor.

[0016] S13: The precursor was sealed and stored in an ammonia atmosphere at room temperature for 3 to 14 months to carry out the aging reaction, and an aqueous solution of carbon-nitrogen conjugated polymer was obtained.

[0017] S14: The aqueous solution of carbon-rich carbon nitride conjugated polymer is freeze-dried at -80℃ and a vacuum degree below 30Pa to obtain a solid material of carbon-rich carbon nitride conjugated polymer.

[0018] Furthermore, the area of ​​the titanium dioxide nanocrystalline film is 3cm×3cm~9cm×9cm, and the thickness is 10~30μm.

[0019] Further, in step S3, 10-100 mg of carbon-rich carbon nitride conjugated polymer is mixed with 1-10 μl of deionized water to form a slurry; the slurry is then uniformly coated onto the TiO2 surface of two conductive glass-TiO2 nanocrystalline mesoporous film composite electrodes using a scraping method.

[0020] The beneficial effects of this invention are as follows: (1) Material properties. Existing technologies use two materials, namely photovoltaic materials and energy storage materials, to generate and store photogenerated charges. This invention uses one material, namely carbon-rich carbon nitride conjugated polymer with dual functions of light absorption and charge storage, to achieve the generation and storage of photogenerated charges. Its advantages are: it greatly simplifies the device structure, avoids the matching and synergy problem between the two materials, achieves a high level of synergy, effectively reduces internal electron loss and electron transmission loss between electrodes, and improves the photogenerated charge storage capacity. (2) Device structure. No electrolyte is used, which completely avoids a series of problems caused by electrolytes. For example, the performance instability caused by the volatilization and leakage of electrolytes; the safety of use caused by the flammability of electrolytes. All-solid-state devices are more conducive to long-term stability and safety of use, and the integration with other functional devices is also greatly improved. (3) Photogenerated charge storage performance. A single cell can achieve a value of not less than 170 mC cm⁻¹. -2 The photogenerated charge storage capacity; the operating voltage window is -2.5V to 2.5V; during the photocharging-discharging process, a significant color-changing effect occurs, exhibiting visual energy storage characteristics.

[0021] Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination, or may be learned from practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0022] To make the objectives, technical solutions, and advantages of the present invention clearer, the preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, wherein:

[0023] Figure 1 This is a schematic diagram of the structure of a supercapacitor.

[0024] Figure 2 Flowchart of the fabrication process for optical supercapacitors;

[0025] Figure 3 Typical cyclic current-voltage (CV) curves of an all-solid-state optical supercapacitor and its color changes at different potentials;

[0026] Figure 4 Typical charge-discharge curves for all-solid-state optical supercapacitors;

[0027] Figure 5 This is a diagram showing the band structure relationship between titanium dioxide (TiO2) and carbon-rich carbon nitride conjugated polymer (CPCN) in an all-solid-state optical supercapacitor. Detailed Implementation

[0028] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0029] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0030] In the following description, numerous details are explored to provide a more thorough explanation of embodiments of the invention. However, it will be apparent to those skilled in the art that embodiments of the invention may be practiced without these specific details. In other embodiments, well-known structures and devices are shown in block diagram form rather than in detail to avoid obscuring embodiments of the invention.

[0031] like Figure 1 As shown, this invention provides an all-solid-state optical supercapacitor based on a carbon-nitride conjugated polymer (CPCN). Conductive glass (FTO or ITO) serves as the conductive substrate and optical window; titanium dioxide nanocrystalline mesoporous film serves as the electron transport material and charge storage auxiliary material; and carbon-nitride conjugated polymer (CPCN) serves as the light absorption and photogenerated charge storage material. An insulating sealant is used as an insulating spacer between the two conductive glass layers. Thus, an all-solid-state photogenerated charge storage device is fabricated using a symmetrical capacitor structure without electrolyte: conductive glass / / TiO2 / / CPCN / / TiO2 / / conductive glass.

[0032] like Figure 2 As shown, the fabrication process of the optical supercapacitor is as follows:

[0033] ①Preparation of carbon-rich carbon nitride conjugated polymers.

[0034] ② A titanium dioxide (TiO2) nanocrystalline mesoporous film of a certain thickness is sintered on conductive glass to obtain a conductive glass / TiO2 nanocrystalline mesoporous film composite electrode.

[0035] ③ Coat the TiO2 surfaces of the two composite electrodes uniformly with carbon-rich carbon nitride conjugated polymer (CPCN) for later use.

[0036] ④ Two composite electrodes loaded with CPCN are bonded together using insulating sealant to obtain an all-solid-state optical supercapacitor with the structure of “conductive glass / / TiO2 / / CPCN / / TiO2 / / conductive glass”.

[0037] like Figure 3 As shown, during cyclic voltammetry testing under illumination, the typical CV curve characteristics of the invented all-solid-state optical supercapacitor are as follows: two significant positive current peaks in the range of -0.6V to 0.6V, one low positive current peak in the range of 0.6V to 2.5V, one negative current peak in the range of 0.6V to 0V, and two negative current peaks in the range of 0V to -1.2V. The operating voltage window is -2.5V to 2.5V. With voltage changes, the device exhibits a reversible color change from blue to golden yellow and back to blue.

[0038] like Figure 4 As shown, during constant current charge-discharge (GCD) testing under illumination, the typical GCD curve characteristics of the invented all-solid-state optical supercapacitor are as follows: ① The charging voltage range is -0.6V to 2.5V, and the discharging voltage range is 0.6V to -2.5V. ② During charging, the GCD curve shows two linear segments where the voltage changes with the amount of stored charge; during discharging, the GCD curve shows one linear segment where the voltage changes with the amount of discharged charge. ③ The coulombic efficiency is greater than 100%.

[0039] like Figure 5 As shown, the band structure relationship between titanium dioxide and carbon-rich carbon nitride conjugated polymer used in this invention is as follows: the band gap value of titanium dioxide is 3.22 eV, and the band gap value of carbon-rich carbon nitride conjugated polymer is 1.74 eV; the conduction band bottom energy value of titanium dioxide is higher than the LUMO orbital energy value of carbon-rich carbon nitride conjugated polymer; the valence band top energy value of titanium dioxide is higher than the HOMO orbital energy value of carbon-rich carbon nitride conjugated polymer.

[0040] Example 1

[0041] A fully solid-state optical supercapacitor based on a carbon-nitride-rich carbon conjugated polymer, the manufacturing process of which includes the following steps:

[0042] (1) Preparation of carbon-rich carbon-nitride conjugated polymers

[0043] Dicyandiamine, citric acid, and deionized water were mixed at a mass ratio of 1:1.9:60 to obtain the reactants. The reactants were introduced into a hydrothermal reactor and subjected to a hydrothermal reaction at 200°C for 3 hours to obtain the precursor. The precursor was then sealed and stored at room temperature under an ammonia atmosphere for 8 months to undergo a aging reaction, yielding an aqueous solution of a carbon-nitrogen-rich carbon conjugated polymer. The aqueous solution of the carbon-nitrogen-rich carbon conjugated polymer was freeze-dried at -80°C and a vacuum degree below 30 Pa to obtain a solid material of the carbon-nitrogen-rich carbon conjugated polymer.

[0044] (2) Fabrication of conductive glass / TiO2 nanocrystalline mesoporous thin film composite electrode

[0045] Two FTO conductive glass plates were cleaned and set aside. Titanium dioxide nanocrystals were sintered onto the two FTO conductive glass plates respectively to obtain two conductive glass / TiO2 nanocrystal mesoporous film composite electrodes with the same area and thickness. The titanium dioxide nanocrystal film had an area of ​​3cm × 3cm and a thickness of 20μm.

[0046] (3) Assembly of all-solid-state optical supercapacitors based on carbon-nitride-rich carbon conjugated polymers

[0047] 10 mg of carbon-rich carbon nitride conjugated polymer was mixed with a small amount of deionized water (approximately 1 μl) to prepare a thick slurry. The slurry was then uniformly coated onto the TiO2 surface of two conductive glass / TiO2 nanocrystalline mesoporous film composite electrodes using a scraping method. A suitable amount of sealing insulating adhesive was then applied to the edges of the two electrodes coated with the carbon-rich carbon nitride conjugated polymer. The electrodes were then pressed together, and after the insulating adhesive solidified, an all-solid-state optical supercapacitor based on the carbon-rich carbon nitride conjugated polymer was obtained.

[0048] The all-solid-state optical supercapacitor based on carbon-nitride conjugated polymer, manufactured through the above steps, achieves a temperature of 167 mC / cm² under AM1.5 simulated solar irradiation. -2 Photogenerated charge storage capacity.

[0049] Example 2

[0050] A fully solid-state optical supercapacitor based on a carbon-nitride-rich carbon conjugated polymer, the manufacturing process of which includes the following steps:

[0051] (1) Preparation of carbon-rich carbon-nitride conjugated polymers

[0052] Dicyandiamine, citric acid, and deionized water were mixed at a mass ratio of 1:1.9:60 to obtain the reactants. The reactants were introduced into a hydrothermal reactor and subjected to a hydrothermal reaction at 200°C for 3 hours to obtain the precursor. The precursor was then sealed and stored at room temperature under an ammonia atmosphere for 3 months to undergo a aging reaction, yielding an aqueous solution of a carbon-nitrogen-rich carbon conjugated polymer. The aqueous solution of the carbon-nitrogen-rich carbon conjugated polymer was freeze-dried at -80°C and a vacuum degree below 30 Pa to obtain a solid material of the carbon-nitrogen-rich carbon conjugated polymer.

[0053] (2) Fabrication of conductive glass / TiO2 nanocrystalline mesoporous thin film composite electrode

[0054] Two FTO conductive glass plates were cleaned and set aside. Titanium dioxide nanocrystals were sintered onto the two FTO conductive glass plates respectively to obtain two conductive glass / TiO2 nanocrystal mesoporous film composite electrodes with the same area and thickness. The titanium dioxide nanocrystal film had an area of ​​6cm × 6cm and a thickness of 30μm.

[0055] (3) Assembly of all-solid-state optical supercapacitors based on carbon-nitride-rich carbon conjugated polymers

[0056] 50 mg of carbon-rich carbon nitride conjugated polymer was mixed with a small amount of deionized water (approximately 5 μl) to prepare a thick slurry. The slurry was then uniformly coated onto the TiO2 surface of two conductive glass / TiO2 nanocrystalline mesoporous film composite electrodes using a scraping method. A suitable amount of sealing insulating adhesive was then applied to the edges of the two electrodes coated with the carbon-rich carbon nitride conjugated polymer. The electrodes were then pressed together, and after the insulating adhesive solidified, an all-solid-state optical supercapacitor based on the carbon-rich carbon nitride conjugated polymer was obtained.

[0057] The all-solid-state optical supercapacitor based on carbon-nitride conjugated polymer, manufactured through the above steps, achieves a temperature of 174 mC / cm² under AM1.5 simulated sunlight irradiation. -2 Photogenerated charge storage capacity.

[0058] Example 3

[0059] A fully solid-state optical supercapacitor based on a carbon-nitride-rich carbon conjugated polymer, the manufacturing process of which includes the following steps:

[0060] (1) Preparation of carbon-rich carbon-nitride conjugated polymers

[0061] Dicyandiamine, citric acid, and deionized water were mixed at a mass ratio of 1:1.9:60 to obtain the reactants. The reactants were introduced into a hydrothermal reactor and subjected to a hydrothermal reaction at 200°C for 3 hours to obtain the precursor. The precursor was then sealed and stored at room temperature under an ammonia atmosphere for 14 months to undergo a aging reaction, yielding an aqueous solution of a carbon-nitrogen-rich carbon conjugated polymer. The aqueous solution of the carbon-nitrogen-rich carbon conjugated polymer was freeze-dried at -80°C and a vacuum degree below 30 Pa to obtain a solid material of the carbon-nitrogen-rich carbon conjugated polymer.

[0062] (2) Fabrication of conductive glass / TiO2 nanocrystalline mesoporous thin film composite electrode

[0063] Two FTO conductive glass plates were cleaned and set aside. Titanium dioxide nanocrystals were sintered onto the two FTO conductive glass plates respectively to obtain two conductive glass / TiO2 nanocrystal mesoporous film composite electrodes with the same area and thickness. The titanium dioxide nanocrystal film had an area of ​​9cm × 9cm and a thickness of 10μm.

[0064] (3) Assembly of all-solid-state optical supercapacitors based on carbon-nitride-rich carbon conjugated polymers

[0065] 100 mg of carbon-rich carbon nitride conjugated polymer was mixed evenly with a small amount of deionized water (approximately 10 μl) to prepare a thick slurry. The slurry was then uniformly coated onto the TiO2 surface of two conductive glass / TiO2 nanocrystalline mesoporous film composite electrodes using a scraping method. A suitable amount of sealing insulating adhesive was then applied to the edges of the two electrodes coated with the carbon-rich carbon nitride conjugated polymer, and the electrodes were pressed together. After the insulating adhesive solidified, an all-solid-state optical supercapacitor based on the carbon-rich carbon nitride conjugated polymer was obtained.

[0066] The all-solid-state optical supercapacitor based on carbon-rich carbon nitride conjugated polymer, manufactured through the above steps, achieves a temperature of 177 mC / cm² under AM1.5 simulated sunlight irradiation. -2 Photogenerated charge storage capacity.

[0067] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. An all-solid-state optical supercapacitor based on a carbon-rich carbon nitride conjugated polymer, characterized in that: The system does not use an electrolyte and includes a first conductive glass and a second conductive glass. The conductive surface of the first conductive glass is provided with a first titanium dioxide nanocrystalline mesoporous film. The conductive surface of the second conductive glass is provided with a second titanium dioxide nanocrystalline mesoporous film. A carbon-rich carbon nitride conjugated polymer is disposed between the first and second titanium dioxide nanocrystalline mesoporous films. The outer surfaces of the first and second titanium dioxide nanocrystalline mesoporous films and the carbon-rich carbon nitride conjugated polymer are sealed with an insulating sealant. The preparation steps of the carbon-rich carbon nitride conjugated polymer are as follows: S11: Dicyandiamine, citric acid, and deionized water are mixed in a mass ratio of 1:1.9:60 to obtain the reactants; S12: The reactants are introduced into a hydrothermal reactor and kept at 200°C for 3 hours to carry out a hydrothermal reaction to obtain the precursor. S13: The precursor is sealed and stored in an ammonia atmosphere at room temperature for 3 to 14 months to carry out the aging reaction, and an aqueous solution of carbon-nitrogen conjugated polymer is obtained. S14: The aqueous solution of carbon-rich carbon nitride conjugated polymer is freeze-dried at -80℃ and a vacuum degree below 30Pa to obtain a solid material of carbon-rich carbon nitride conjugated polymer.

2. A method for fabricating an all-solid-state optical supercapacitor based on a carbon-rich carbon nitride conjugated polymer, characterized in that: Includes the following steps: S1: Preparation of carbon-rich carbon nitride conjugated polymers; S2: Sinter titanium dioxide nanocrystalline mesoporous films on the conductive surfaces of two conductive glasses to obtain a conductive glass-TiO2 nanocrystalline mesoporous film composite electrode. S3: A carbon-rich carbon nitride conjugated polymer is uniformly coated on the surface of the titanium dioxide nanocrystalline mesoporous film of the two composite electrodes. S4: Two composite electrodes coated with carbon-rich carbon nitride conjugated polymer are bonded together using insulating sealant to obtain an all-solid-state optical supercapacitor that does not use an electrolyte. The preparation steps of the carbon-rich carbon nitride conjugated polymer are as follows: S11: Dicyandiamine, citric acid, and deionized water are mixed in a mass ratio of 1:1.9:60 to obtain the reactants; S12: The reactants are introduced into a hydrothermal reactor and kept at 200°C for 3 hours to carry out a hydrothermal reaction to obtain the precursor. S13: The precursor is sealed and stored in an ammonia atmosphere at room temperature for 3 to 14 months to carry out the aging reaction, and an aqueous solution of carbon-nitrogen conjugated polymer is obtained. S14: The aqueous solution of carbon-rich carbon nitride conjugated polymer is freeze-dried at -80℃ and a vacuum degree below 30Pa to obtain a solid material of carbon-rich carbon nitride conjugated polymer.

3. The method for preparing an all-solid-state optical supercapacitor based on a carbon-rich carbon nitride conjugated polymer according to claim 2, characterized in that: The titanium dioxide nanocrystalline film has an area of ​​3cm×3cm~9cm×9cm and a thickness of 10~30μm.

4. The method for preparing an all-solid-state optical supercapacitor based on a carbon-rich carbon nitride conjugated polymer according to claim 2, characterized in that: In step S3, 10-100 mg of carbon-rich carbon nitride conjugated polymer is mixed with 1-10 μl of deionized water to form a slurry. The slurry is then uniformly coated onto the TiO2 surface of two conductive glass-TiO2 nanocrystalline mesoporous film composite electrodes using a scraping method.

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