Solid electrolyte and solid oxide fuel cell with three-period extremely-small curved surface structure and preparation method of solid electrolyte and solid oxide fuel cell

Abstract

The invention discloses a solid electrolyte with a three-period minimum curved surface structure, a solid oxide fuel cell and a preparation method of the solid electrolyte and the solid oxide fuel cell, the solid electrolyte has the three-period minimum curved surface structure, and the three-period minimum curved surface structure is a P-cell structure, an IWP structure or a Neovius structure. According to the solid electrolyte provided by the invention, gas can more conveniently flow into the structure to generate electrochemical reaction, so that the interface contact area of the electrode-electrolyte can be greatly increased, more three-phase boundaries (TPB) can be provided, oxygen reduction (cathode) and fuel oxidation (anode) reactions can be promoted, the electrochemical activity per unit area is improved, and the polarization impedance is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of solid oxide fuel cells, and in particular to a solid electrolyte and a solid oxide fuel cell with a three-periodic minimal surface structure and a preparation method thereof. Background Art

[0002] A solid oxide fuel cell (SOFC) is a device that efficiently converts chemical energy into electrical energy. SOFCs can use various hydrocarbons as fuel, directly converting the chemical energy in the fuel into electricity without any intermediate combustion step. As a result, SOFCs offer the advantages of high energy density and low emissions, making them promising large-scale electrochemical devices.

[0003] The electrolyte, the core unit of a single SOFC cell, conducts oxide ions from the cathode to the anode and reacts with hydrocarbons to produce H2O and CO2, completing the entire electrochemical reaction. The advantages of electrolyte-supported SOFCs include superior mechanical properties (strong structural support), stable output performance (less susceptible to failure due to anode reoxidation), and low manufacturing costs (simple manufacturing process). SOFCs employing a three-periodic minimal surface (TPMS) structure increase the surface contact area by approximately 4.1 times that of a sheet-like SOFC electrolyte of the same size. Furthermore, the three-periodic minimal surface (TPMS) structure facilitates the flow of reactant gas on the anode side. This electrolyte enhances cell electrochemical performance by increasing the surface contact area. For example, patent publication number CN110845232A discloses a solid electrolyte-supported oxide fuel cell with a three-dimensional topology. However, the three-dimensional topology of the solid electrolyte in this oxide fuel cell adopts an enclosed design, making it difficult for gas to flow into the structure. Summary of the Invention

[0004] Based on this, the purpose of the present invention is to provide a solid electrolyte and solid oxide fuel cell with a three-periodic minimal surface structure and a preparation method thereof. The solid electrolyte can greatly increase the interface contact area between the electrode and the electrolyte, provide more three-phase boundaries (TPBs), promote oxygen reduction (cathode) and fuel oxidation (anode) reactions, enhance the electrochemical activity per unit area, and reduce polarization impedance.

[0005] To achieve the above object, the present invention adopts the following technical solutions: The present invention first provides a solid electrolyte with a three-periodic minimal surface structure, wherein the solid electrolyte has a three-periodic minimal surface structure, and the three-periodic minimal surface structure is a P-cell structure, an IWP structure, or a Neovius structure.

[0006] The present invention also provides a method for preparing the solid electrolyte having a three-periodic minimal surface structure as described above, which comprises the following steps: S11. creating a three-periodic minimal surface structure model, adjusting the created three-periodic minimal surface model, and saving it as an STL file; S12. Import the STL file into the slicing software for slicing; S13. Import the sliced ​​STL file into the light-curing 3D printer; S14. Adjust the printing parameters of the light-curing 3D printer, pour the solid electrolyte slurry into the 3D printer's material tank, start the 3D printer and start printing layer by layer; S15. Remove the printed green body, clean it, debind it and sinter it to obtain a solid electrolyte with a three-periodic minimal surface structure.

[0007] As a further improvement of the above solution of the present invention, in step S14, the solid electrolyte slurry is prepared from the following components in volume percentage: 25% to 60% photosensitive resin, 35% to 60% 8 mol yttria-stabilized zirconia ceramic powder, 2% to 6% dispersant, and 1% to 6% photoinitiator; The solid electrolyte slurry is prepared by adding a dispersant and 8 mol of yttria-stabilized zirconia ceramic powder to a stirred photosensitive resin, mixing the mixture, ball-milling the mixture at a speed of 100-120 r / min for 24 hours, adding a photoinitiator, and then continuing to ball-mill at a speed of 100-120 r / min for 120 minutes to obtain a solid electrolyte slurry.

[0008] As a further improvement of the above solution of the present invention, the photosensitive resin is obtained by mixing 2-hydroxyethyl acrylate, 1,6-hexanediol diacrylate, and tripropylene glycol diacrylate in a volume ratio of 3:2:2.

[0009] As a further improvement of the above solution of the present invention, the dispersant is CPD01 and the photoinitiator is TPO.

[0010] As a further improvement of the above solution of the present invention, in step S14, the printing parameters of the 3D printer are: the exposure time of the bottom layer is 5~7s, the exposure time of the 4th layer and above is 4~6s, and the light intensity is 12~13mW / mm 2 , the printing layer thickness is 50μm, and the wavelength of the light curing light source is 350~450nm.

[0011] As a further improvement of the above scheme of the present invention, in step S15, the debinding sintering is first heated to 150°C at a heating rate of 1~2°C / min and kept warm for 2 hours, then heated to 350°C at a heating rate of 1~3°C / min and kept warm for 1.5 hours, then heated to 600°C at a heating rate of 2~4°C / min and kept warm for 6~7 hours, and finally heated to 1500°C at a heating rate of 5~7°C / min and kept warm for 2 hours, and then cooled naturally.

[0012] The present invention also provides a solid oxide fuel cell, which includes a solid electrolyte. The solid electrolyte is the solid electrolyte with a three-periodic minimal surface structure as described above.

[0013] The present invention also provides a method for preparing the solid oxide fuel cell as described above, which comprises the following steps: S21. The NiO-8YSZ slurry and terpineol were mixed in a mass ratio of 5:5 to obtain an anode slurry; S22. The anode slurry obtained in step S21 is injected into one side of the solid electrolyte having a three-periodic minimal surface structure, dried, and sintered; S23. The LSM-8YSZ slurry and terpineol were mixed to obtain a cathode slurry having a solid mass content of 25% to 45%; S24. Inject the cathode slurry obtained in step S23 into the other side of the solid electrolyte having the three-periodic minimal surface structure, dry it, and sinter it to obtain a solid oxide fuel cell.

[0014] The present invention prepares a high-density electrolyte support through photocuring printing technology and subsequent sintering and debinding, thereby improving the deformation and cracking problems of SOFC electrolyte 3D printed samples.

[0015] As a further improvement of the above solution of the present invention, in steps S22 and S24, the drying temperature is 100°C; in step S22, the sintering temperature is 1250-1400°C; in step S24, the sintering temperature is 850-1150°C.

[0016] Compared with the prior art, the present invention has the following beneficial effects: The present invention designs a solid electrolyte with a P-cell structure, an IWP structure, or a Neovius structure, which has a surface area 4.1 times higher than that of a planar electrolyte. It can significantly increase the electrode-electrolyte interface contact area and increase the active area for reacting with the reaction gas, thereby increasing the three-phase region and improving battery performance. It can provide more three-phase boundaries (TPBs), and gases can more easily flow into the structure to undergo electrochemical reactions, promote oxygen reduction (cathode) and fuel oxidation (anode) reactions, increase the electrochemical activity per unit area, and reduce polarization impedance. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a diagram of the P-cell structure model in Example 1; Figure 2 This is a physical picture of the solid electrolyte with a P-cell structure in Example 1; Figure 3 FIG1 is a diagram showing the combination of electrodes and electrolyte in a solid oxide fuel cell in Example 1; Figure 4 This is a physical picture of the solid electrolyte with an IWP structure in Example 4; Figure 5 This is a physical picture of the solid electrolyte with Neovius structure in Example 5. DETAILED DESCRIPTION

[0018] To facilitate understanding of the present invention, the present invention will be described more fully below in conjunction with specific embodiments. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to provide a more thorough and comprehensive understanding of the disclosure of the present invention.

[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0020] Example 1 This embodiment provides a solid oxide fuel cell supported by a solid electrolyte having a three-periodic minimal surface structure, and a preparation method thereof includes the following steps: Step 1: 2-Hydroxyethyl acrylate (Changxing Chemical Industry Co., Ltd.), 1,6-hexanediol diacrylate (Changxing Chemical Industry Co., Ltd.), and tripropylene glycol diacrylate (Changxing Chemical Industry Co., Ltd.) were mixed in a volume ratio of 3:2:2 to obtain a photosensitive resin. Dispersant CPD01 (Toagosei Co., Ltd., Japan) was added to the photosensitive resin and stirred thoroughly. Then, 8YSZ ceramic powder (Qingdao Tianyao Industrial Co., Ltd.) was added and ball milled using 3 mm diameter zirconia balls at a speed of 120 rpm. After 24 hours of ball milling, photoinitiator TPO (Guoyao Pharmaceutical Group Industrial Co., Ltd.) was added and ball milled again for 1 hour to obtain an 8YSZ ceramic slurry. The volume percentages of the components in the resulting 8YSZ ceramic slurry were: photosensitive resin 48%, 8YSZ ceramic powder 50%, dispersant CPD01 1%, and photoinitiator TPO 1%.

[0021] Step 2: Use Magics 3D drawing software to draw a P-cell structure model with a high specific surface area: Use Magics to create a P-cell unit cell structure ( Figure 1 A) Use the array and cut functions to adjust the P-cell structure to 4 P-cells in length and width, and 1.5 P-cells in height. Figure 1 B is the side view of the P-cell structure. Figure 1 C is a three-dimensional diagram of the P-cell structure, Figure 1 D is another perspective of the P-cell structure; Solidworks software is then used to further improve and design the P-cell structure.

[0022] Step 3: Save the designed model as an STL file and import it into CHITUBOX software for slicing. Then upload the sliced ​​model to the DLP light-curing 3D printer.

[0023] Step 4: Pour the 8YSZ ceramic slurry prepared in step 1 above into the DLP light-curing 3D printer cylinder, and adjust the DLP light-curing 3D printer parameters: the exposure time for the bottom layer is 5s, the exposure time for the 4th layer and above is 4s, and the light intensity is 13mW / mm 2 The printing layer thickness is 50μm, the wavelength of the light curing light source is 350nm, and the cumulative molding is carried out layer by layer. After printing is completed, it is cleaned with industrial alcohol to obtain a solid electrolyte green body with a P-cell structure.

[0024] Step 5: Place the cleaned electrolyte green body into a muffle furnace for pressureless debinding and sintering: heat to 150°C at a heating rate of 1°C / min and keep warm for 2 hours, then heat to 350°C at a heating rate of 1°C / min and keep warm for 1.5 hours, then heat to 600°C at a heating rate of 2°C / min and keep warm for 6-7 hours, and finally heat to 1500°C at a heating rate of 5°C / min and keep warm for 2 hours. After debinding and sintering, take out the sample after natural cooling to obtain a solid oxide fuel cell electrolyte with a P-cell structure having a high specific surface area, such as Figure 2 shown. Figure 2 There are two sizes of solid electrolytes, and the specific sizes are reasonably designed according to actual conditions.

[0025] Step 6: Anode Preparation: NiO-8YSZ slurry (Jiaxing Raoji Technology Co., Ltd.) and terpineol were mixed in a 5:5 mass ratio to create a highly fluid anode slurry. This slurry was injected into one side of the electrolyte of a solid oxide fuel cell with a P-cell structure, dried at 100°C, and sintered at 1250°C.

[0026] Step 7: Cathode Preparation: LSM-8YSZ slurry (Jiaxing Raoji Technology Co., Ltd.) and terpineol were mixed to obtain a cathode slurry with a solid phase content of 25%. The resulting cathode slurry was injected into the other side of the solid oxide fuel cell electrolyte with a P-cell structure in Step 6. After drying at 100°C, it was sintered at 1150°C to obtain a solid oxide fuel cell. Figure 3 This is a diagram of the combination of electrodes and electrolyte in the solid oxide fuel cell in this embodiment. It can be seen that the electrode material is evenly attached to the electrolyte surface to form a thin layer with consistent thickness, without local peeling or agglomeration.

[0027] Example 2 The difference between this embodiment and embodiment 1 is that: In the 8YSZ ceramic slurry obtained in step 1 of this embodiment, the volume percentages of the components are: photosensitive resin 46%, 8YSZ ceramic powder 50%, dispersant CPD01 2%, and photoinitiator TPO 2%; In step 4 of this embodiment, the parameters of the DLP light-curing 3D printer are: the exposure time of the bottom layer is 6 seconds, the exposure time of the 4th layer and above is 5 seconds, and the light intensity is 12mW / mm 2 .

[0028] Example 3 The difference between this embodiment and embodiment 1 is that: In step 1 of this embodiment, when preparing 8YSZ ceramic slurry, the ball mill speed is 100 r / min. The volume percentage of each component in the final 8YSZ ceramic slurry is as follows: photosensitive resin 44%, 8YSZ ceramic powder 50%, dispersant CPD01 3%, photoinitiator TPO 3%; In step 4 of this embodiment, the parameters of the DLP light-curing 3D printer are: the exposure time for the bottom layer is 7 seconds, and the exposure time for the fourth layer and above is 6 seconds.

[0029] Example 4 The difference between this embodiment and embodiment 1 is that: in step 2 of this embodiment, the solid electrolyte model is an IWP structure; Figure 4 This is a physical picture of the solid electrolyte with an IWP structure in this embodiment.

[0030] Example 5 The difference between this embodiment and embodiment 1 is that: in step 2 of this embodiment, the solid electrolyte model is a Neovius structure; Figure 5 This is a physical picture of the solid electrolyte with Neovius structure in this embodiment.

[0031] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0032] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be determined by the appended claims.

Claims

1. A solid electrolyte having a three-periodic minimal surface structure, characterized in that: The solid electrolyte has a three-periodic minimal surface structure, and the three-periodic minimal surface structure is a P-cell structure, an IWP structure, or a Neovius structure.

2. A method for preparing a solid electrolyte having a three-periodic minimal surface structure as claimed in claim 1, characterized in that: It includes the following steps: S11. creating a three-periodic minimal surface structure model, adjusting the created three-periodic minimal surface model, and saving it as an STL file; S12. Import the STL file into the slicing software for slicing; S13. Import the sliced ​​STL file into the light-curing 3D printer; S14. Adjust the printing parameters of the light-curing 3D printer, pour the solid electrolyte slurry into the 3D printer's material tank, and start the 3D printer to begin layer-by-layer printing; S15. Remove the printed green body, clean it, debind it and sinter it to obtain a solid electrolyte with a three-periodic minimal surface structure.

3. The method for preparing a solid electrolyte having a three-periodic minimal surface structure according to claim 2, characterized in that: In step S14, the solid electrolyte slurry is prepared from the following components in volume percentage: 25% to 60% photosensitive resin, 35% to 60% 8 mol yttria-stabilized zirconia ceramic powder, 2% to 6% dispersant, and 1% to 6% photoinitiator; The solid electrolyte slurry is prepared by adding a dispersant and 8 mol of yttria-stabilized zirconia ceramic powder to a stirred photosensitive resin, mixing the mixture, ball-milling the mixture at a speed of 100-120 r / min for 24 hours, adding a photoinitiator, and then continuing to ball-mill at a speed of 100-120 r / min for 120 minutes to obtain a solid electrolyte slurry.

4. The method for preparing a solid electrolyte having a three-periodic minimal surface structure according to claim 3, characterized in that: The photosensitive resin is obtained by mixing 2-hydroxyethyl acrylate, 1,6-hexanediol diacrylate, and tripropylene glycol diacrylate in a volume ratio of 3:2:

2.

5. The method for preparing a solid electrolyte having a three-periodic minimal surface structure according to claim 3, characterized in that: The dispersant is CPD01, and the photoinitiator is TPO.

6. The method for preparing a solid electrolyte having a three-periodic minimal surface structure according to claim 2, characterized in that: In step S14, the printing parameters of the 3D printer are: exposure time for the bottom layer is 5-7s, exposure time for the 4th layer and above is 4-6s, and light intensity is 12-13mW / mm 2 , the printing layer thickness is 50μm, and the wavelength of the light curing light source is 350~450nm.

7. The method for preparing a solid electrolyte having a three-periodic minimal surface structure according to claim 2, characterized in that: In step S15, the debinding sintering is first heated to 150°C at a heating rate of 1~2°C / min and kept warm for 2 hours, then heated to 350°C at a heating rate of 1~3°C / min and kept warm for 1.5 hours, then heated to 600°C at a heating rate of 2~4°C / min and kept warm for 6~7 hours, and finally heated to 1500°C at a heating rate of 5~7°C / min and kept warm for 2 hours, and then cooled naturally.

8. A solid oxide fuel cell comprising a solid electrolyte, characterized in that: The solid electrolyte adopts the solid electrolyte with a three-periodic minimal surface structure as claimed in claim 1.

9. A method for preparing the solid oxide fuel cell according to claim 8, characterized in that: It includes the following steps: S21. The NiO-8YSZ slurry and terpineol were mixed in a mass ratio of 5:5 to obtain an anode slurry; S22. The anode slurry obtained in step S21 is injected into one side of the solid electrolyte having a three-periodic minimal surface structure, dried, and sintered; S23. The LSM-8YSZ slurry and terpineol were mixed to obtain a cathode slurry having a solid mass content of 25% to 45%; S24. Inject the cathode slurry obtained in step S23 into the other side of the solid electrolyte having the three-periodic minimal surface structure, dry it, and sinter it to obtain a solid oxide fuel cell.

10. The method for preparing a solid oxide fuel cell according to claim 9, characterized in that: In steps S22 and S24, the drying temperature is 100°C; in step S22, the sintering temperature is 1250-1400°C; in step S24, the sintering temperature is 850-1150°C.

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