Flow battery structure based on mesophyll tissue bionic electrode and use method thereof

Abstract

The invention provides a flow battery structure based on a mesophyll tissue bionic electrode and a use method of the flow battery structure, and belongs to the technical field of new energy batteries. The problems of low carbon dioxide electrochemical reduction efficiency, high electrode material cost, unreasonable structural design and the like in the prior art are solved. The device comprises a fixing device, a cover plate, an electrode body and an electrolytic cell wall, the cover plate is installed on the top of the electrolytic cell wall, the electrode body is located in the electrolytic cell wall, the electrode body is connected with the cover plate through the fixing device, the electrode body comprises a carbon aerogel electrode and a Zn electrode, the carbon aerogel electrode serves as a positive electrode, the Zn electrode serves as a negative electrode, and the Zn electrode serves as a negative electrode. The carbon aerogel electrode and the Zn electrode are connected through a fixed connecting piece, and an electrolyte inlet and an electrolyte outlet are formed in the two sides of the electrolytic cell wall respectively. The device is mainly used for energy storage and conversion and carbon capture and emission reduction in the industrial field.

Description

Technical Field

[0001] The present invention belongs to the technical field of new energy batteries, and particularly relates to a flow battery structure based on a biomimetic electrode of mesophyll tissue and a method for using the same. Background Art

[0002] In the industrial field, the development and utilization of carbon dioxide mainly focus on chemical synthesis, food processing, agricultural applications, and oilfield exploitation. However, these technologies have high costs, limited scales, and low comprehensive utilization rates, and fail to effectively directly reduce carbon dioxide emissions. Existing carbon capture technologies are costly and difficult to achieve resource utilization. Traditional treatment methods for recycled paper, such as incineration, have low economic benefits and also fail to be effectively combined with carbon dioxide conversion technologies. In addition, existing battery technologies have deficiencies in the electrochemical reduction efficiency of carbon dioxide, the cost of electrode materials, and structural design, resulting in low energy conversion efficiency and short cycle life.

[0003] In recent years, researchers have begun to explore "breathable" carbon dioxide batteries. This new type of battery can not only reduce dependence on traditional fossil fuels but also capture carbon dioxide, showing broad application prospects. However, existing technologies still have deficiencies in electrode materials, electrolyte performance, and structural design, resulting in low energy conversion efficiency and short cycle life. Summary of the Invention

[0004] In view of this, the present invention aims to provide a flow battery structure based on a biomimetic electrode of mesophyll tissue and a method for using the same to solve the problems of low electrochemical reduction efficiency of carbon dioxide, high cost of electrode materials, and unreasonable structural design in the prior art.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] A flow battery structure based on a biomimetic electrode of mesophyll tissue includes a fixing device, a cover plate, an electrode body, and an electrolytic cell wall. The cover plate is installed on the top of the electrolytic cell wall. The electrode body is located inside the electrolytic cell wall. The electrode body is connected to the cover plate through the fixing device. The electrode body includes a carbon aerogel electrode and a Zn electrode. The carbon aerogel electrode serves as the positive electrode, and the Zn electrode serves as the negative electrode. The carbon aerogel electrode and the Zn electrode are connected through a fixing connector. An electrolyte inlet and an electrolyte outlet are respectively provided on both sides of the electrolytic cell wall.

[0007] Furthermore, the electrolyte flowing through the electrolyte inlet and the electrolyte outlet adopts 1-ethyl-3-methylimidazolium tetrafluoroborate ionic liquid electrolyte.

[0008] Furthermore, an air inlet hole is provided at the bottom of the electrolytic cell wall, and an air outlet hole is provided above the cover plate.

[0009] Further, a foam ceramic is provided below the electrode body.

[0010] Further, the cover plate is fixed to the top of the electrolytic cell wall by a fixture.

[0011] Further, the electrode body is a three-dimensional porous electrode structure.

[0012] Further, both the cover plate and the electrolytic cell wall are made of acrylic plates.

[0013] A method of using a flow battery structure based on a biomimetic electrode of mesophyll tissue, which includes the following steps:

[0014] Step 1: Cut the collected waste paper into pieces and soak it in deionized water for 3 days. Stir magnetically to form a uniform slurry, then freeze the slurry at -50°C for 36 hours and dry it in vacuum to form freeze-dried waste paper. Under the protection of an argon atmosphere, heat the freeze-dried waste paper to 400°C at a rate of 2°C / min and hold for 1 hour for pre-carbonization treatment. Then, heat it to 900°C at a heating rate of 5°C / min and hold for 1 hour for final carbonization treatment. Wait for it to cool naturally to room temperature to obtain black carbon aerogel. Grind the obtained carbon aerogel into powder, mix the cross-linking agent polytetrafluoroethylene and carbon nanotubes in a ratio of 1:0.2, and coat the mixture on the surface of a porous copper mesh to form a working electrode. After drying, obtain the positive electrode material of the device;

[0015] Step 2: Design a mold according to the battery size and arrangement structure. Cut zinc sheets into flakes as the negative electrode material, and use the carbon aerogel prepared in Step 1 as the positive electrode material. Connect the positive and negative electrodes through a fixed connector to form an electrode body;

[0016] Step 3: Open an electrolyte inlet and an electrolyte outlet on both sides of the electrolytic cell wall, open an air inlet at the bottom, and open an air outlet on the top of the cover plate. Install the cover plate and the electrolytic cell wall.

[0017] Step 4: Install the electrode body inside the electrolytic cell wall and fix it with a fixing device;

[0018] Step 5: Store the electrolyte in a storage tank, and then use an electric pump to realize electrolyte circulation through the electrolyte inlet and outlet on the side of the electrolytic cell wall to achieve countercurrent mixing of carbon dioxide gas flow and ionic electrolyte;

[0019] Step 6: Use an electrochemical workstation to test the electrode and reaction stability, and conduct charge-discharge tests and AC impedance tests on the electrode at different constant current density values;

[0020] Step 7: Test the voltage output characteristics using an electrochemical workstation. Inject carbon dioxide into the inner wall of the electrolytic cell through the air inlet to simulate the waste gas containing carbon dioxide in the factory. Through this battery structure, measure the voltage, current, and power output during the measurement using the electrochemical workstation.

[0021] Step 8: Test the carbon dioxide conversion efficiency using a gas spectrometer.

[0022] Furthermore, in Step 3, the hole diameters of the electrolyte inlet and the electrolyte outlet are 30 mm, and the hole diameters of the air outlet and the air inlet are 9 mm. The pipes of the electrolyte inlet and the electrolyte outlet are sealed with acrylic glue or epoxy resin to form a pipe with a length of 50 mm and an inner diameter of 30 mm, and the pipes of the air outlet and the air inlet are sealed with acrylic glue or epoxy resin to form a pipe with a length of 50 mm and an inner diameter of 9 mm.

[0023] Furthermore, in Step 8, collect the gas generated by the battery under the same conditions and conduct GC-MS joint measurement for gas composition analysis. The reaction converts carbon dioxide into methane.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0025] 1. The present invention prepares a novel carbon-based composite electrode material from waste paper. Its three-dimensional porous structure and relatively large specific surface area provide abundant active sites for the reaction. This design can effectively improve the battery reaction rate and energy conversion efficiency. The electrode material has high conductivity and good mechanical strength characteristics, achieving efficient CO2 capture and electrochemical energy storage while ensuring high-power output and long cycle life of the battery.

[0026] 2. The present invention draws on the collaborative mass transfer mechanism of the mesophyll tissue of plant leaves and constructs a three-dimensional porous electrode structure with the characteristics of "dense grid and sparse pores" through bionic design. It uses gas-liquid countercurrent to enhance mass transfer, reduce fluid flow resistance, and reduce energy loss; utilizes the natural convection effect driven by density difference to make the gas and liquid fully contact, maximize the reaction area, provide more reaction sites, and increase the battery capacity and output power; shortens the ion transport distance through the close arrangement between electrodes, improves the mass transfer efficiency, and accelerates the charging and discharging speed of the battery. The battery is innovative in structural design and has better comprehensive performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0028] Figure 1 is a schematic structural diagram of a flow battery structure based on a bionic electrode of mesophyll tissue according to the present invention;

[0029] Figure 2 Schematic structural diagram of the electrode body of the present invention;

[0030] Figure 3 Electrochemical impedance spectroscopy diagram of carbon aerogel electrodes with different masses of carbon nanotubes added;

[0031] Figure 4 Galvanostatic charge-discharge performance diagram of the carbon aerogel electrode battery with 0.2 g of carbon nanotubes added;

[0032] Figure 5 Electrical storage performance diagram of the carbon aerogel electrode with 0.2 g of carbon nanotubes added.

[0033] In the figure:

[0034] 1 - fixing appliance, 2 - cover plate, 3 - electrode body, 4 - electrolyte outlet, 5 - air inlet hole, 6 - foam ceramic, 7 - electrolyte inlet, 8 - electrolytic cell wall, 9 - clamp, 10 - air outlet hole, 11 - carbon aerogel electrode, 12 - Zn electrode, 13 - fixing connection part. Specific implementation manner

[0035] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings in the embodiments of the present invention. It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other. The described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments.

[0036] Specific implementation manner 1: Refer to Figures 1-5 Describing this implementation manner, a flow battery structure based on a mesophyll tissue bionic electrode, characterized in that: it includes a fixing appliance 1, a cover plate 2, an electrode body 3 and an electrolytic cell wall 8. The cover plate 2 is installed on the top of the electrolytic cell wall 8. The electrode body 3 is located inside the electrolytic cell wall 8. The electrode body 3 is connected to the cover plate 2 through the fixing appliance 1. The electrode body 3 includes a carbon aerogel electrode 11 and a Zn electrode 12. The carbon aerogel electrode 11 serves as the positive electrode, and the Zn electrode 12 serves as the negative electrode. The carbon aerogel electrode 11 and the Zn electrode 12 are connected through a fixing connection part 13. An electrolyte inlet 7 and an electrolyte outlet 4 are respectively arranged on both sides of the electrolytic cell wall 8. The electrolyte flowing through the electrolyte inlet 7 and the electrolyte outlet 4 is 1-ethyl-3-methylimidazolium tetrafluoroborate [EMIM][BF4] ionic liquid electrolyte.

[0037] The bottom of the electrolytic cell wall 8 is provided with an air inlet hole 5, the top of the cover plate 2 is provided with an air outlet hole 10, a foam ceramic 6 is arranged below the electrode body 3, the cover plate 2 is fixed to the top of the electrolytic cell wall 8 through a fixture 9, the electrode body 3 is a three-dimensional porous electrode structure, and both the cover plate 2 and the electrolytic cell wall 8 are made of acrylic plates.

[0038] The carbon aerogel electrode 11 is made from waste paper through processes such as soaking, crushing and pulping, freeze-drying, and high-temperature pyrolysis. It has the characteristics of a three-dimensional porous structure and a relatively large specific surface area. By adding a reasonably proportioned amount of carbon nanotubes and double-sided coating it on the surface of the Cu mesh to increase the reaction area and battery efficiency, the [EMIM][BF4] ionic liquid electrolyte, as the proton source for the CO2 reduction reaction, has high CO2 solubility and low viscosity. The three-dimensional porous electrode structure of the mesophyll tissue with the characteristic of "dense grid and sparse pores" and the countercurrent interactive electrolyte flow channel structure have the characteristic of low flow resistance. While maximizing the reaction area, the short electrode spacing improves the mass transfer efficiency, enabling the immediate power generation upon the introduction of carbon dioxide and achieving the efficient conversion of carbon dioxide.

[0039] Working principle: When the battery is working, zinc Zn at the anode undergoes an oxidation reaction, losing electrons and being converted into zinc hydroxide Zn(OH)2. The reaction formula is Zn + 2H2O → Zn(OH)2 + 2e - , and carbon dioxide at the cathode undergoes a reduction reaction. The [EMIM]+ cation layer adsorbed on the cathode interacts with the anion radical CO2 - to form a complex intermediate [EMIM–CO2], reducing the kinetic barrier of the CO2 molecule. Finally, methane fuel and water are generated. The reaction formula is CO2 + 8e - + 8H + → CH4 + 2H2O.

[0040] A new carbon-based composite electrode material was prepared from waste paper. Its three-dimensional porous structure and relatively large specific surface area provide abundant active sites for the reaction. This design can effectively improve the battery reaction rate and energy conversion efficiency. This electrode material has high conductivity and good mechanical strength characteristics, achieving the efficient capture of CO2 and electrochemical energy storage while ensuring high-power output and long cycle life of the battery. Drawing on the collaborative mass transfer mechanism of the mesophyll tissue of plant leaves, a three-dimensional porous electrode structure of the mesophyll tissue with the characteristic of "dense grid and sparse pores" was constructed through bionic design. The gas-liquid countercurrent was used to strengthen mass transfer, reduce the fluid flow resistance, and reduce energy loss; the natural convection effect driven by the density difference was utilized to make the gas-liquid fully contact, maximize the reaction area, provide more reaction sites, and improve the battery capacity and output power; the close arrangement between the electrodes can shorten the ion transport distance, improve the mass transfer efficiency, and accelerate the battery charge and discharge speed. This makes the battery unique in structural design and has better comprehensive performance.

[0041] Specific Embodiment 2: Refer to Figures 1-5 This embodiment describes a method of using a flow battery structure based on a biomimetic electrode of mesophyll tissue, which includes the following steps:

[0042] Step 1: Cut the collected waste paper into pieces and soak it in deionized water for 3 days. Stir magnetically to form a uniform slurry, then freeze the slurry at -50°C for 36 hours and dry it in vacuum to form freeze-dried waste paper. Under the protection of an argon atmosphere, heat the freeze-dried waste paper to 400°C at a rate of 2°C / min and hold for 1 hour for pre-carbonization treatment. Then, heat it to 900°C at a heating rate of 5°C / min and hold for 1 hour for final carbonization treatment. Wait for it to cool naturally to room temperature to obtain black carbon aerogel. Grind the obtained carbon aerogel into powder, mix cross-linking agent polytetrafluoroethylene and carbon nanotubes in a ratio of 1:0.2, and coat the mixture on the surface of a porous copper mesh to form a working electrode. After drying, obtain the positive electrode material of the device;

[0043] Step 2: Design a mold according to the battery size and arrangement structure. Cut zinc sheets into pieces as the negative electrode material. Use the carbon aerogel prepared in Step 1 as the positive electrode material, and connect the positive electrode and the negative electrode through a fixing connector 13 to form an electrode body 3. Press the positive electrode material into a rectangular sheet with geometric dimensions of 60 mm in length, 40 mm in width, and 1 mm in thickness. The positive electrode sheets are arranged alternately to form the main reaction area; the positive electrode and the negative electrode are connected by welding respectively;

[0044] Step 3: Open an electrolyte inlet 7 and an electrolyte outlet 4 on both sides of the electrolytic cell wall 8, open an air inlet hole 5 at the bottom, and open an air outlet hole 10 on the top of the cover plate 2, and install the cover plate 2 and the electrolytic cell wall 8.

[0045] Step 4: Install the electrode body 3 inside the electrolytic cell wall 8 and fix it with a fixing device 1;

[0046] Step 5: Store the electrolyte in a storage tank, and then use an electric pump to realize electrolyte circulation through the electrolyte inlet 7 and the electrolyte outlet 4 on the side of the electrolytic cell wall 8 to achieve the countercurrent mixing of carbon dioxide gas flow and ionic electrolyte, thereby improving the contact degree between carbon dioxide, electrolyte and the electrode, and finally achieving the purpose of improving the device performance and completing the assembly;

[0047] Step 6: Use an electrochemical workstation to test the electrode and reaction stability, and conduct charge-discharge tests and AC impedance tests on the electrode at different constant current density values. Under the constant current condition, the voltage of the electrode material rises and falls rapidly, and it can be used repeatedly. The internal resistance of the electrode and the reaction internal resistance are between 5 - 8 Ω;

[0048] Step 7: Test the voltage output characteristics using an electrochemical workstation. Inject carbon dioxide into the electrolytic cell wall 8 through the air inlet 5 to simulate the waste gas containing carbon dioxide in a factory. Through this battery structure, measure the voltage, current, and power output during the process using the electrochemical workstation. Under the condition of sufficient carbon dioxide input, the output voltage of the device is stable;

[0049] Step 8: Test the carbon dioxide conversion efficiency using a gas-phase spectrometer. Collect the gas generated by the battery under the same conditions and conduct GC-MS joint measurement for gas composition analysis. The reaction converts carbon dioxide into methane.

[0050] In Step 3, the hole diameters of the electrolyte inlet 7 and the electrolyte outlet 4 are 30 mm, and the hole diameters of the air outlet 10 and the air inlet 5 are 9 mm. The pipes of the electrolyte inlet 7 and the electrolyte outlet 4 are sealed with acrylic glue or epoxy resin to form a pipe with a length of 50 mm and an inner diameter of 30 mm. The pipes of the air outlet 10 and the air inlet 5 are sealed with acrylic glue or epoxy resin to form a pipe with a length of 50 mm and an inner diameter of 9 mm

[0051] Specific Embodiment 3: Refer to Figures 1-5 To illustrate this embodiment, this example conducts an AC impedance performance experiment based on this structure. The CO2 flow battery uses 1-ethyl-3-methylimidazolium tetrafluoroborate [EMIM][BF4] as the electrolyte. The positive electrode of the battery is a carbon aerogel composite electrode, the negative electrode is a Zn sheet, the Cu mesh is the current collector with a thickness of 1 mm, the carbon dioxide flow rate is 1 ml / min, and the AC impedance performance of the electrode is as Figure 3 shown. As can be seen from the figure, the impedance curve of the carbon aerogel electrode with 0.2 g of carbon nanotubes added has a downward semi-circle in the high-frequency region, and the amplitude of the semi-circle is the smallest, indicating that its charge transfer internal resistance is the smallest and it has fast electron conduction and ion transport capabilities. The internal resistance of the carbon aerogel electrode without carbon nanotubes added is the largest.

[0052] Specific Embodiment 4: Refer to Figures 1-5 To illustrate this embodiment, this example conducts a galvanostatic charge-discharge performance experiment based on this structure. When the current densities are 4, 5, 10, 15, 20, 25, and 30 mA / g respectively, the galvanostatic charge-discharge (GCD) curves of the carbon aerogel electrode with 0.2 g of carbon nanotubes added to the sample are as Figure 4 shown. As can be seen from the figure, the GCD curves of the carbon aerogel electrode with 0.2 g of carbon nanotubes added to the sample are relatively symmetric isosceles triangles, indicating that the energy storage of the electrode material mainly relies on the double-layer mechanism and has good cyclicity. If the triangles deviate from symmetry at low current densities, it may be due to redox reactions occurring, and certain changes occur in the electrode material during the charge-discharge process, generating pseudocapacitance, and this process is not completely reversible.

[0053] Specific Embodiment 4: Refer to Figures 1-5 To illustrate this embodiment, based on this structure, an electricity storage performance experiment was conducted. The electricity storage performance of the carbon aerogel electrode with 0.2 g of carbon nanotubes added is as Figure 5 shown. As can be seen from the figure, when the current density is 4, 5, 10, 15, 20, 25, 30 mA·g -1 , the specific capacities of the corresponding electrodes of this patent are 2.4, 1.4, 0.9, 0.8, 0.65, 0.6, 0.62 mA·h·g -1 .

[0054] The specific embodiments of the present invention disclosed above are only used to help illustrate the present invention. The specific embodiments do not describe all the details in detail, nor do they limit the invention to the specific embodiments described. According to the content of this specification, many modifications and variations can be made. These embodiments are selected and specifically described in this specification to better explain the principle and practical application of the present invention, so that those skilled in the art can well understand and utilize the present invention.

Claims

1. A flow battery structure based on a biomimetic electrode of mesophyll tissue, characterized in that: It includes a fixing fixture (1), a cover plate (2), an electrode body (3) and an electrolytic cell wall (8). The cover plate (2) is installed on the top of the electrolytic cell wall (8). The electrode body (3) is located inside the electrolytic cell wall (8). The electrode body (3) is connected to the cover plate (2) through the fixing fixture (1). The electrode body (3) includes a carbon aerogel electrode (11) and a Zn electrode (12). The carbon aerogel electrode (11) serves as the positive electrode, and the Zn electrode (12) serves as the negative electrode. The carbon aerogel electrode (11) and the Zn electrode (12) are connected through a fixing connector (13). On both sides of the electrolytic cell wall (8), there are respectively an electrolyte inlet (7) and an electrolyte outlet (4).

2. The flow battery structure based on a biomimetic electrode of mesophyll tissue according to claim 1, wherein: The electrolyte flowing through the electrolyte inlet (7) and the electrolyte outlet (4) is 1-ethyl-3-methylimidazolium tetrafluoroborate ionic liquid electrolyte.

3. The flow battery structure based on a mesophyll tissue bionic electrode according to claim 1, wherein: At the bottom of the electrolytic cell wall (8), there is an air inlet hole (5), and above the cover plate (2), there is an air outlet hole (10).

4. A flow battery structure based on a mesophyll tissue bionic electrode according to claim 1, characterized in that: Below the electrode body (3), there is a foam ceramic (6).

5. A flow battery structure based on a biomimetic electrode of mesophyll tissue according to claim 1, characterized in that: The cover plate (2) is fixed on the top of the electrolytic cell wall (8) through a fixture (9).

6. The flow battery structure based on a biomimetic electrode of mesophyll tissue according to claim 1, characterized in that: The electrode body (3) is a three-dimensional porous electrode structure.

7. The structure of a flow battery based on a biomimetic electrode of mesophyll tissue according to claim 1, characterized in that: Both the cover plate (2) and the electrolytic cell wall (8) are made of acrylic plates.

8. A method for using a flow battery structure based on a mesophyll tissue bionic electrode as described in any one of claims 1-6, characterized in that: It includes the following steps: Step 1: Cut the collected waste paper into pieces and soak it in deionized water for 3 days. Stir magnetically to form a uniform slurry. Then freeze the slurry at -50 °C for 36 hours and vacuum dry it to form freeze-dried waste paper. Under the protection of an argon atmosphere, heat the freeze-dried waste paper to 400 °C at a rate of 2 °C / min and keep it warm for 1 hour for pre-carbonization treatment. Then, heat it to 900 °C at a heating rate of 5 °C / min and keep it warm for 1 hour for final carbonization treatment. Wait for it to cool naturally to room temperature to obtain black carbon aerogel. Grind the obtained carbon aerogel into powder. Mix the cross-linking agent polytetrafluoroethylene and carbon nanotubes in a ratio of 1:0.

2. Coat the mixture on the surface of a porous copper mesh to form a working electrode. After drying, obtain the positive electrode material of the device; Step 2: According to the battery size and arrangement structure, design a mold. Cut zinc sheets into pieces as the negative electrode material. Use the carbon aerogel made in Step 1 as the positive electrode material. Connect the positive electrode and the negative electrode through the fixing connector (13) to form the electrode body (3); Step 3: Open the electrolyte inlet (7) and the electrolyte outlet (4) on both sides of the electrolytic cell wall (8), open the air inlet hole (5) at the bottom, and open the air outlet hole (10) on the top of the cover plate (2). Install the cover plate (2) and the electrolytic cell wall (8). Step 4: Install the electrode body (3) inside the electrolytic cell wall (8) and fix it through the fixing fixture (1); Step 5: Store the electrolyte in a storage tank, and then use an electric pump to realize electrolyte circulation through the electrolyte inlet (7) and the electrolyte outlet (4) on the side of the electrolytic cell wall (8) to achieve countercurrent mixing of carbon dioxide gas flow and ionic electrolyte; Step 6: Use an electrochemical workstation to test the electrode and reaction stability, and conduct charge-discharge tests and AC impedance tests on the electrode at different constant current density values; Step 7: Test the voltage output characteristics using an electrochemical workstation. Inject carbon dioxide into the electrolytic cell wall (8) through the air inlet hole (5) to simulate the waste gas containing carbon dioxide in the factory. Through this battery structure, measure the voltage, current, and power output during the measurement using the electrochemical workstation. Step 8: Test the carbon dioxide conversion efficiency using a gas-phase spectrometer.

9. The usage method of a flow battery structure based on a mesophyll tissue bionic electrode according to claim 8, characterized in that: In Step 3, the hole diameters of the electrolyte inlet (7) and the electrolyte outlet (4) are 30 mm, and the hole diameters of the air outlet hole (10) and the air inlet hole (5) are 9 mm. The pipes of the electrolyte inlet (7) and the electrolyte outlet (4) are sealed with acrylic glue or epoxy resin to form a pipe with a length of 50 mm and an inner diameter of 30 mm. The pipes of the air outlet hole (10) and the air inlet hole (5) are sealed with acrylic glue or epoxy resin to form a pipe with a length of 50 mm and an inner diameter of 9 mm.

10. A method for using a flow battery structure based on a mesophyll tissue bionic electrode according to claim 8, characterized in that: In Step 8, collect the gas generated by the battery under the same conditions and conduct GC-MS joint measurement for gas composition analysis. The reaction converts carbon dioxide into methane.

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