Method for patterning surface of proton ceramic electrolyte by adopting flexible material

Abstract

The invention discloses a method for patterning on the surface of a proton ceramic electrolyte by adopting a flexible material, and aims to solve the technical problems of low connection strength, few active reaction sites, poor electrochemical performance and the like in the interface of the existing PCFC electrolyte and a cathode. The method for patterning the surface of the proton ceramic electrolyte comprises the following steps: 1, preparing a patterning medium; 2, attaching and fixing the patterned medium and the surface of the proton ceramic electrolyte green body; 3, pressurizing treatment; 4, carrying out sintering treatment on the patterned proton ceramic electrolyte green body; and 5, coating the cathode material on the surface of the proton ceramic electrolyte with the patterned surface by using a silk-screen printing process, and carrying out heat treatment. According to the invention, the flexible patterned medium with periodic holes is adopted to realize lossless grooving of the electrolyte on the surface of the proton ceramic electrolyte, so that the peel strength and binding sites of an electrolyte / cathode interface are improved, the active reaction area is increased, the ohmic resistance and polarization resistance are reduced, and the cycling stability is improved.

Description

Technical Field

[0001] This invention belongs to the field of proton ceramic fuel cells, and specifically relates to a method for patterning the surface of a proton ceramic electrolyte to improve the electrochemical and mechanical properties of the electrolyte / cathode interface. Background Technology

[0002] Proton ceramic fuel cells (PCFCs) exhibit higher power density under intermediate temperature conditions (below 600 °C), alleviating challenges such as sealing problems, thermal expansion mismatch, material degradation, and long start-up times caused by higher operating temperatures, and are therefore considered a next-generation energy conversion technology. To improve the oxygen reduction reaction at the cathode, a three-phase conductive cathode with both high activity and chemical compatibility has been successfully developed, extending the three-phase boundary of ion, electron, and gas reactions from the electrolyte / electrode interface to the electrode bulk phase, effectively solving the problem of oxygen reduction reaction kinetic hysteresis. However, further research shows that even with a three-phase conductive electrode, the reactive region of the cathode is still mainly near the electrolyte / cathode interface, and the electrolyte / cathode interface resistance accounts for 70% to 80% of the total resistance (especially for thin-layer electrolytes). The root cause is poor interfacial connectivity, leading to limited effective contact sites and low mass transfer efficiency. Furthermore, the fragile mechanical interface is prone to delamination under external forces or high current density conditions, severely damaging the long-term stability, lifespan, and safety of the device. To promote the commercialization of PCFC stacks, the electrolyte / cathode interface connectivity problem has also been extensively studied by scholars both domestically and internationally.

[0003] Currently, two main techniques have been publicly reported for patterning the surface of PCFC ceramic electrolytes to improve the electrochemical and mechanical properties of the electrolyte / cathode interface. One technique is the picosecond laser ablation method proposed by Zhou et al. to precisely control the surface of BZCYYb ceramics (reference: ZHOU T, HUANG H, MENG Y, et al. Significantly Enhanced Performance of Protonic Ceramic Fuel Cells by Laser Engineering the Electrolyte / Cathode Interface[J / OL]. ACS Energy Letters, 2024: 4557-4563.), which removes the passivation layer and increases the micro-roughness to obtain a patterned surface with cross-grooves, thereby improving the electrochemical performance of the electrolyte / cathode interface. The second approach uses a PUA support plate as a micropattern template to achieve micropatterning of the electrolyte surface, increasing the effective reaction area and directly improving performance (Reference: LEEC, SHIN SS, KIM J, et al. Tailoring an interface microstructure for high-performance reversible protonic ceramic electrochemical cells via softlithography[J / OL]. ACS Applied Materials & Interfaces, 2022, 14(28): 32124-32133.). However, these methods still suffer from problems such as complex operation, high equipment requirements, limited processing area and shape, and low reproducibility. Therefore, in order to improve the physicochemical properties and long-term stability of the PCFC ceramic electrolyte-cathode interface, it is of great significance to develop a simple, scalable method for high-strength, low-interfacial-resistance electrolyte / cathode. Summary of the Invention

[0004] The purpose of this invention is to solve the technical problems of low connection strength, few active reaction sites, and poor electrochemical performance at the interface between the current PCFC electrolyte and cathode, and to provide a method for patterning the surface of a proton ceramic electrolyte using flexible materials.

[0005] This invention employs a method for patterning flexible materials on the surface of proton ceramic electrolytes, implemented according to the following steps:

[0006] Step 1: Process the flexible material with a specific pattern into the same shape and size as the electrolyte preform to be patterned, and then clean and dry the flexible material to obtain the patterned medium;

[0007] Step 2: The patterned medium from Step 1 is bonded and fixed to the surface of the proton ceramic electrolyte green body to obtain the tableting system;

[0008] Step 3: Pressurize and hold the pressure of the tableting system, then remove it and peel off the patterned medium attached to the surface of the proton ceramic electrolyte green body to obtain the patterned proton ceramic electrolyte green body.

[0009] Step 4: Place the patterned proton ceramic electrolyte green body into a muffle furnace and heat treat it at a temperature of 1350-1550 °C. Cool it to room temperature to obtain a surface-patterned proton ceramic electrolyte.

[0010] Step 5: Apply cathode material to the patterned proton ceramic electrolyte surface using screen printing, and treat at 900 ℃ ~ 1200 ℃ for 1 h ~ 3 h. After cooling, a full cell with a non-flat electrolyte / electrode interface is obtained.

[0011] In step one, the flexible material with a specific pattern is a nylon mesh, a lint-free cloth, or a high-temperature tape.

[0012] This invention proposes a method for patterning the surface of a proton ceramic electrolyte using a flexible material. By using a flexible medium with a specific pattern to pattern the surface of the proton ceramic electrolyte, mechanical interlocking is achieved at the electrolyte-cathode interface, improving the interfacial mechanical strength and cycle stability. Furthermore, by increasing the interface area between the electrolyte and the cathode, the active region is enlarged, thereby improving electrochemical performance.

[0013] The method of patterning the surface of a proton ceramic electrolyte using flexible materials, as described in this invention, has the following advantages:

[0014] By constructing regular grooves and protrusions on the surface of a proton-ceramic electrolyte using a flexible medium with a specific pattern, a mechanical interlocking effect is achieved at the electrolyte-cathode interface, increasing the interfacial mechanical strength to ~20 N and improving cycle stability. Furthermore, by increasing the electrolyte-cathode interface area, the oxygen reduction active region is increased, improving electrochemical performance and reducing interfacial resistance. In addition, the flexible material used in this invention is widely available, low-cost, and scalable. Compared to existing methods using PUA support plates as micro-pattern templates, this invention eliminates the need for specially formulated electrolyte and electrode coating slurries and temperature control during the patterning process. The operation is simple, and common electrolyte / half-cell green bodies can be used directly. It is not limited by the shape or size of the electrolyte / half-cell green body and can uniformly pattern large-area electrolyte surfaces such as flat plates or tubes. It is highly efficient and easy to implement, with broad application prospects and significant practical value. Attached Figure Description

[0015] Figure 1 The secondary electron micrograph of the surface microstructure of BZCYYb ceramic was obtained using a 500# nylon screen at 1400 ℃ / 10 h in Example 1.

[0016] Figure 2 The secondary electron image of the BZCYYb ceramic / PNC55 interface was obtained using a 500# nylon screen at 1400 ℃ for 10 h in Example 1.

[0017] Figure 3 The Nyquist plots are obtained at 650 °C and in humid air (3% H2O) for the PNC55 / BZCYYb / PNC55 symmetrical cells before and after patterning in Example 1. Detailed Implementation

[0018] Specific Implementation Method 1: This implementation method uses a flexible material to pattern the surface of a proton ceramic electrolyte and is achieved through the following steps:

[0019] Step 1: Process the flexible material with a specific pattern into the same shape and size as the electrolyte preform to be patterned, and then clean and dry the flexible material to obtain the patterned medium;

[0020] Step 2: The patterned medium from Step 1 is bonded and fixed to the surface of the proton ceramic electrolyte green body to obtain the tableting system;

[0021] Step 3: Pressurize and hold the pressure of the tableting system, then remove it and peel off the patterned medium attached to the surface of the proton ceramic electrolyte green body to obtain the patterned proton ceramic electrolyte green body.

[0022] Step 4: Place the patterned proton ceramic electrolyte green body into a muffle furnace and heat treat it at a temperature of 1350-1550 °C. Cool it to room temperature to obtain a surface-patterned proton ceramic electrolyte.

[0023] Step 5: Apply cathode material to the patterned proton ceramic electrolyte surface using screen printing, and treat at 900 ℃ ~ 1200 ℃ for 1 h ~ 3 h. After cooling, a full cell with a non-flat electrolyte / electrode interface is obtained.

[0024] In step one, the flexible material with a specific pattern is a nylon mesh, a lint-free cloth, or a high-temperature tape.

[0025] In this embodiment, the flexible material with a specific pattern is preferably a soft material with a periodic hole structure, such as nylon mesh.

[0026] This embodiment uses a soft material with periodic holes to achieve periodic patterning of the electrolyte surface, which effectively increases the interface area between the electrolyte and the cathode and improves the mechanical strength of the electrolyte / cathode interface.

[0027] Specific Implementation Method Two: This implementation method differs from Specific Implementation Method One in that, in step one, when the flexible material with a specific pattern is a nylon mesh, the mesh count of the nylon mesh is 300#~2000#.

[0028] Specific Implementation Method 3: This implementation method differs from Specific Implementation Method 1 or 2 in that the type of proton ceramic electrolyte embryo in step 2 is an independent electrolyte embryo or an anode-supported electrolyte embryo.

[0029] Specific Implementation Method Four: This implementation method differs from Specific Implementation Methods One to Three in that the pressure treatment method in step three is either isostatic pressing or roller pressing.

[0030] Specific Implementation Method 5: This implementation method differs from Specific Implementation Methods 1 to 4 in that the pressure applied in step 3 is 45MPa~200MPa, and the pressure is maintained for 1min~3min.

[0031] The pressure for pressurization in this embodiment is preferably 50MPa to 80MPa.

[0032] Specific Implementation Method Six: This implementation method differs from Specific Implementation Methods One to Five in that the heating rate of the heat treatment in step four is controlled to be 1~15℃ / min.

[0033] Specific Implementation Method Seven: This implementation method differs from Specific Implementation Methods One to Six in that the heat treatment time in step four is controlled to be 8h~12h.

[0034] Specific Implementation Method Eight: This implementation method differs from Specific Implementation Methods One to Seven in that step four involves heat treatment at a temperature of 1400–1500°C for 10–12 hours.

[0035] Specific Implementation Method Nine: This implementation method differs from Specific Implementation Methods One to Eight in that the surface microstructure of the proton ceramic electrolyte patterned in step four is a periodically distributed array of grooves, an array of protrusions, or a groove-protrusion composite structure.

[0036] Specific Implementation Method 10: This implementation method differs from Specific Implementation Methods 1 to 9 in that the height (or depth) of the microstructure patterned on the electrolyte surface in step four is 20~200 μm.

[0037] Specific Implementation Method Eleven: This implementation method differs from Specific Implementation Methods One through Ten in that step five is treated at a temperature of 900 ℃ ~ 1100 ℃ for 1 h ~ 1.5 h.

[0038] Example 1: This example uses a method of patterning flexible materials on the surface of a proton ceramic electrolyte, implemented according to the following steps:

[0039] Step 1: Process a 500# flexible nylon screen with periodic holes into the same shape and size as the BZCYYb electrolyte preform to be patterned, then clean and dry it to obtain the nylon screen patterned medium.

[0040] Step 2: The nylon screen patterned medium from Step 1 is bonded and fixed to the surface of the BZCYYb electrolyte green embryo to obtain the tableting system;

[0041] Step 3: Perform cold pressing on the system to be pressed in Step 2. Apply a pressure of 60 MPa and hold for 2 minutes. Then remove it and peel off the nylon screen patterned medium attached to the surface of the BZCYY electrolyte green body to obtain the patterned BZCYYb ceramic electrolyte green body.

[0042] Step 4: Place the patterned proton ceramic electrolyte green body from Step 3 into a muffle furnace, hold it at 1400℃ for 10 hours, and cool it to room temperature to obtain the surface-patterned BZCYYb ceramic electrolyte.

[0043] Step 5: The cathode is coated onto the patterned proton ceramic electrolyte surface using screen printing and treated at 1100℃ for 1 hour to obtain a full cell with a non-flat electrolyte / electrode interface.

[0044] pass Figure 1 It can be seen that using a 500# nylon screen with periodic holes to imprint periodic grooves and protrusions on the surface of BZCYYb did not cause cracks in the BZCYYb ceramic electrolyte. Figure 2 SEM images of the interface between the BZCYYb electrolyte and the PNC55 cathode show that BZCYYb and PNC55 form a good bond, and the number of interfacial bonding sites is increased. Figure 3 It can be seen that under a humid air (3% H2O) atmosphere at 650 ℃, the patterned PNC55|BZCYYb|PNC55 symmetric cell exhibits a lower polarization resistance (0.14). The unpatterned polarization resistance is 0.20. .

[0045] In this embodiment, the BZCYYb ceramic surface patterning is obtained using a 500# nylon screen. Compared with existing methods for increasing the interfacial bonding area, this method is more flexible and less expensive. The flexible patterned material has virtually no limitations on the shape and size of the electrolyte and does not damage the electrolyte surface. Furthermore, the improvement effect is significant, with the BZCYYb / PNC55 interface strength increased to 20N, and the ohmic resistance and polarization resistance of the symmetrical cell both reduced. This indicates that the method of this invention can effectively improve the physicochemical properties of the interface between the BZCYYb ceramic electrolyte and the PNC55 cathode.

[0046] Example 2: The difference between this example and Example 1 is that the flexible printing medium is a 1500# flexible nylon screen plate with periodic holes, which is then pressurized.

[0047] The joint obtained in this embodiment has a room temperature shear strength of 19 N.

[0048] Example 3: This example differs from Example 1 or 2 in that the printing method uses a roller with a 1500# flexible nylon screen with periodic holes for pressure.

[0049] The electrolyte surface area growth rate obtained in this embodiment is 18%.

Claims

1. A method for patterning the surface of a proton ceramic electrolyte using a flexible material, characterized in that... The method of patterning the surface of a proton ceramic electrolyte using flexible materials is implemented according to the following steps: Step 1: Process the flexible material with a specific pattern into the same shape and size as the electrolyte preform to be patterned, and then clean and dry the flexible material to obtain the patterned medium; Step 2: The patterned medium from Step 1 is bonded and fixed to the surface of the proton ceramic electrolyte green body to obtain the tableting system; Step 3: Pressurize and hold the pressure of the tableting system, then remove it and peel off the patterned medium attached to the surface of the proton ceramic electrolyte green body to obtain the patterned proton ceramic electrolyte green body. Step 4: Place the patterned proton ceramic electrolyte green body into a muffle furnace and heat treat it at a temperature of 1350-1550 °C. Cool it to room temperature to obtain a surface-patterned proton ceramic electrolyte. Step 5: Apply cathode material to the patterned proton ceramic electrolyte surface using screen printing, and treat at 900 ℃ ~ 1200 ℃ for 1 h ~ 3 h. After cooling, a full cell with a non-flat electrolyte / electrode interface is obtained. In step one, the flexible material with a specific pattern is a nylon mesh, a lint-free cloth, or a high-temperature tape.

2. The method for patterning the surface of a proton ceramic electrolyte using a flexible material according to claim 1, characterized in that... In step one, when the flexible material with a specific pattern is nylon mesh, the mesh count of the nylon mesh is 300#~2000#.

3. The method for patterning the surface of a proton ceramic electrolyte using a flexible material according to claim 1, characterized in that... In step three, the pressure treatment method is either isostatic pressing or roller pressing.

4. The method for patterning the surface of a proton ceramic electrolyte using a flexible material according to claim 1, characterized in that... In step three, the pressure applied is 45MPa to 200MPa, and the pressure is maintained for 1 to 3 minutes.

5. The method for patterning the surface of a proton ceramic electrolyte using a flexible material according to claim 1, characterized in that... In step four, the heating rate of the heat treatment is controlled to be 1~15℃ / min.

6. The method for patterning the surface of a proton ceramic electrolyte using a flexible material according to claim 1, characterized in that... In step four, the heat treatment time is controlled to be 8 to 12 hours.

7. The method for patterning the surface of a proton ceramic electrolyte using a flexible material according to claim 1, characterized in that... In step four, heat treatment is carried out at a temperature of 1400-1500℃ for 10-12 hours.

8. The method for patterning the surface of a proton ceramic electrolyte using a flexible material according to claim 1, characterized in that... Step four: The surface microstructure of the proton ceramic electrolyte with surface patterning is a periodically distributed array of grooves, an array of protrusions, or a groove-protrusion composite structure.

9. The method for patterning the surface of a proton ceramic electrolyte using a flexible material according to claim 1, characterized in that... The height of the microstructure patterned on the electrolyte surface in step four is 20~200 μm.

10. The method for patterning the surface of a proton ceramic electrolyte using a flexible material according to claim 1, characterized in that... Step 5: Treat at 900 ℃ ~ 1100 ℃ for 1 h ~ 1.5 h.

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