Multi-channel microtubular copper hollow fiber membranes for sofc and methods of making the same

Abstract

This invention relates to a multi-channel microtubular copper hollow fiber membrane for use in SOFCs and its preparation method. The method involves: mixing copper powder, polyethylene glycol-30-dipolyhydroxystearate, N-methylpyrrolidone, and a binder in a certain proportion and then ball-milling to prepare a membrane liquid; or mixing copper powder, N-methylpyrrolidone, and a binder in a certain proportion and then ball-milling to prepare a membrane liquid; using the membrane liquid as the shell liquid and a coagulant as the core liquid, and extruding it into water through the spinning head of a spinning device to obtain a preform; sintering the preform in a hydrogen atmosphere to obtain a multi-channel microtubular copper hollow fiber membrane. The cross-section of the multi-channel microtubular copper hollow fiber membrane has densely packed finger-like pores, and several elliptical gas channels are formed within the membrane, with densely packed sponge-like pores formed on its inner wall. The copper hollow fiber membrane of this invention, as a support for SOFCs, has high strength and high thermal conductivity, improving gas transport rate and catalytic conversion rate.

Description

Technical Field

[0001] This invention relates to the field of SOFC technology, and in particular to a multi-channel microtubular copper hollow fiber membrane for SOFC and its preparation method. Background Technology

[0002] Solid oxide fuel cells (SOFCs) are all-solid-state structures that avoid the corrosion and encapsulation problems associated with acid-base or molten salt electrolytes in low- and medium-temperature fuel cells. They offer advantages such as a wide operating temperature range (700–1000℃), no need for precious metal catalysts in the electrocatalytic process, and a wide range of applicable fuels (H2, NH3, hydrocarbons, and oxygenated derivatives of hydrocarbons can all be used as SOFC fuels). Furthermore, the waste heat generated by SOFCs can be used for combined heat and power (CHP), thereby improving the efficiency of the power generation system. Traditional SOFCs are mostly all-ceramic structures. Among them, tubular SOFCs offer advantages such as high-temperature self-sealing, better thermal cycling resistance, and ease of scaling up to higher power outputs compared to planar SOFCs. However, ceramic SOFCs suffer from difficulties in welding and processing, leading to challenges in sealing and assembling the stack; lower mechanical properties resulting in poor thermal shock resistance; and low thermal conductivity leading to low start-up and shutdown rates. Therefore, the trend towards cryogenic manufacturing is driving a shift from traditional ceramic support structures—namely, anode, cathode, and electrolyte supports—to metal support structures. Using metal as the support not only combines the advantages of tubular SOFCs but also avoids the aforementioned problems associated with ceramic structures. Metal fiber membrane supported SOFCs (MS-SOFCs) possess mature welding and processing technology, good mechanical properties, and excellent thermal conductivity, resulting in a more compact stack. Furthermore, the price of metal materials is significantly lower than that of the ceramic materials used for the anode, cathode, and electrolyte, leading to lower manufacturing costs. Due to these advantages, MS-SOFCs hold the promise of replacing traditional electrode- or electrolyte-supported SOFCs.

[0003] Traditional metal supports are mostly single-channel or formed with pore-forming agents, which reduces the contact area of ​​fuel gas and increases the gas transport path. Patent CN200610118649.9 discloses a method for preparing a porous metal-supported low-temperature solid oxide fuel cell, using nickel oxide-scandium-doped zirconium oxide powder (NiO-ScSZ) (or gadolinium-doped cerium oxide powder (CGO)) as raw materials. This process is complex and difficult to manufacture. Patent CN202111274470.3 discloses a metal-supported solid oxide fuel cell and its preparation method. The method involves uniformly mixing metal oxide powder, solvent, dispersant, and pore-forming agent, ball milling for 24–28 hours, sequentially adding plasticizer, defoamer, and binder, and ball milling again for 24–28 hours to form a cast film liquid. After vacuum defoaming, the film is cast and dried to obtain a metal oxide support preform. However, this pore-forming agent-based method has poor flexibility in micropore adjustment, resulting in poor wear resistance and toughness of the support. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a multi-channel microtubular copper hollow fiber membrane for SOFCs and its preparation method, solving the problems of difficult sealing of flat SOFCs, difficult processing and welding of ceramic-structured tubular SOFCs and low mechanical properties, and low fuel gas contact area and long transmission path of single-channel or pore-forming metal supports.

[0005] The technical solution adopted in this invention is as follows:

[0006] This application provides a method for preparing a multi-channel microtubular copper hollow fiber membrane, comprising:

[0007] A film solution is prepared by ball milling a mixture of copper powder, polyethylene glycol-30-dipolyhydroxystearate, N-methylpyrrolidone, and binder in a specified ratio. Alternatively, a film solution is prepared by ball milling a mixture of copper powder, N-methylpyrrolidone, and binder in a specified ratio.

[0008] The membrane solution is subjected to vacuum degassing treatment;

[0009] The membrane liquid after vacuum degassing is used as the shell liquid, and the coagulant is used as the core liquid. At the same time, the membrane liquid is squeezed into water through the spinning head of the spinning equipment to obtain the preform.

[0010] The preform is sintered in a hydrogen atmosphere to obtain a multi-channel microtubular copper hollow fiber membrane. The cross-section of the multi-channel microtubular copper hollow fiber membrane has densely packed finger-shaped pores, and several elliptical gas channels are formed in the multi-channel microtubular copper hollow fiber membrane. The inner wall of the elliptical gas channels has densely packed sponge-like pores.

[0011] The further technical solution is as follows:

[0012] The mass ratio of copper powder, polyethylene glycol-30-dipolyhydroxystearate, N-methylpyrrolidone, and binder is (150-170):(0-2.5):(45-55):(10-20).

[0013] The coagulant is an aqueous solution of polyvinyl alcohol, and the mass ratio of polyvinyl alcohol to water is (1-3):14.

[0014] The adhesive is one or two of the following: polymethyl methacrylate, high-density polyethylene, polypropylene, polyethylene wax, polystyrene, ethylene-vinyl acetate copolymer, polymethyl methacrylate, polyvinyl butyral, and polyethyleneimine.

[0015] The extrusion speed of the coagulant is 9–30 mL / min, and the extrusion speed of the membrane liquid is 9–20 mL / min.

[0016] By adjusting the proportions of the components constituting the membrane solution, the concentration of the coagulant, and the ratio of the extrusion speed of the membrane solution and the coagulant, the ellipticity of the elliptical gas channel is controlled, resulting in a multi-channel microtubular copper hollow fiber membrane with a wall thickness of 40–800 μm and a diameter of 1–10 mm.

[0017] The sintering treatment is performed at a temperature of 300–1000℃, a heating rate of 1–5℃ / min, and a holding time of 4–10h.

[0018] The ball milling time is 12-30 hours, and the vacuum degassing treatment time is 30-120 minutes.

[0019] The elliptical gas channel is one of two, three, four, five, six, seven, nine, twelve, or nineteen channels.

[0020] The second aspect of this application provides a multi-channel microtubular copper hollow fiber membrane, prepared according to the aforementioned preparation method.

[0021] The beneficial effects of this invention are as follows:

[0022] The multi-channel microtubular copper hollow fiber membrane for SOFC prepared by this invention has high strength, high thermal conductivity, increased gas contact area, shortened gas diffusion path, and improved gas transport rate and catalytic conversion rate.

[0023] 1. Compared with traditional ceramic supports, which are brittle, have poor thermal conductivity, and low strength, the copper in this application has a face-centered cubic crystal structure and good plasticity. Copper has a thermal conductivity as high as 383.8 W·m-1·K-1 and a high strength of 110~128 GPa, which reduces the temperature gradient during heating, avoids cracking due to uneven temperature, and ensures the stability of the support during oxidation and reduction. At the same time, the high plasticity and high strength reduce the difficulty of encapsulation.

[0024] 2. The hollow fiber membrane prepared in this application has a finger-like pore and a sponge-like pore structure. The dense finger-like pores facilitate gas diffusion. The aqueous solution of polyvinyl alcohol can increase the proportion of finger-like pores as a coagulant. At the same time, the coagulant makes the membrane have higher wear resistance and toughness.

[0025] 3. Compared with traditional single-channel supports, multi-channel supports increase the internal surface area, thereby increasing the contact area with the gas and improving the catalytic conversion efficiency.

[0026] 4. Compared with traditional circular channels, the elliptical channel of this application can effectively shorten the gas diffusion path and improve the gas transmission rate under the combined effect of multiple channels and finger-shaped holes.

[0027] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. Attached Figure Description

[0028] Figure 1 This is a SEM image of the elliptical four-channel microtubular copper hollow fiber membrane prepared in Example 2 of the present invention.

[0029] Figure 2 The images show the IV and IP curves of the elliptical four-channel microtubular copper hollow fiber membranes prepared in Examples 1-3 of this invention. Detailed Implementation

[0030] The specific embodiments of the present invention are described below with reference to the accompanying drawings.

[0031] This application provides a method for preparing a multi-channel microtubular copper hollow fiber membrane, comprising:

[0032] A film solution is prepared by ball milling a mixture of copper powder, polyethylene glycol-30-dipolyhydroxystearate, N-methylpyrrolidone, and binder in a specified ratio. Alternatively, a film solution is prepared by ball milling a mixture of copper powder, N-methylpyrrolidone, and binder in a specified ratio.

[0033] The membrane solution is subjected to vacuum degassing treatment;

[0034] The membrane liquid after vacuum degassing is used as the shell liquid, and the coagulant is used as the core liquid. At the same time, the membrane liquid is squeezed into water through the spinning head of the spinning equipment to obtain the preform.

[0035] The preform is sintered in a hydrogen atmosphere to obtain a multi-channel microtubular copper hollow fiber membrane. The cross-section of the multi-channel microtubular copper hollow fiber membrane has densely packed finger-shaped pores, and several elliptical gas channels are formed in the multi-channel microtubular copper hollow fiber membrane. The inner wall of the elliptical gas channels has densely packed sponge-like pores.

[0036] The mass ratio of copper powder, polyethylene glycol-30-dipolyhydroxystearate, N-methylpyrrolidone, and binder is (150-170):(0-2.5):(45-55):(10-20).

[0037] The coagulant is an aqueous solution of polyvinyl alcohol, and the mass ratio of polyvinyl alcohol to water is (1-3):14.

[0038] The adhesive is one or two of the following: polymethyl methacrylate, high-density polyethylene, polypropylene, polyethylene wax, polystyrene, ethylene-vinyl acetate copolymer, polymethyl methacrylate, polyvinyl butyral, and polyethyleneimine.

[0039] The extrusion speed of the coagulant is 9–30 mL / min, and the extrusion speed of the membrane liquid is 9–20 mL / min.

[0040] Those skilled in the art know that the inner tube and shell side of the spinning head are mostly circular in cross-section. This application obtains an elliptical gas channel by adjusting the ratio of the components constituting the membrane liquid, the concentration of the coagulant, and the ratio of the extrusion speed of the membrane liquid and the coagulant. By changing the above-mentioned control parameters, the ellipticity of the elliptical gas channel is controlled to maximize the proportion of the thin-walled area. The resulting multi-channel microtubular copper hollow fiber membrane has a wall thickness of 40-800 μm and a diameter of 1-10 mm.

[0041] The preferred control parameters are: the mass ratio of copper powder, polyethylene glycol-30-dipolyhydroxystearate, N-methylpyrrolidone, and binder is 160:1:50:15; the mass ratio of polyvinyl alcohol and water is 1:14; and the extrusion speed ratio of film liquid and coagulant is 9:15.

[0042] The elliptical gas channel is one of two, three, four, five, six, seven, nine, twelve, or nineteen channels.

[0043] Specifically, the number of elliptical gas channels can be adjusted by changing different models of spinning heads.

[0044] After coating the anode, electrolyte, and cathode with the multi-channel microtubular copper hollow fiber membrane of this application, it can be assembled into SOFC.

[0045] Compared to ceramic and channelless or single-channel metal supports in SOFCs, the multi-channel microtubular structure not only provides stable support within the SOFC structure but also effectively increases the area occupied by the thin-walled region and the gas contact area, thereby enhancing the catalytic reaction rate. It also exhibits higher thermal conductivity and ductility, thus improving thermal shock resistance and reducing the internal temperature gradient of the battery, resulting in faster start-up. Copper, with its face-centered cubic crystal form, possesses good plasticity, and its thermal conductivity reaches as high as 383.8 W·m. -1 ·K -1 It also has a high strength of 110-128 GPa, which reduces the temperature gradient during heating, avoids cracking due to uneven temperature, ensures the stability of the support during oxidation and reduction, and reduces the difficulty of encapsulation due to its high plasticity and high strength.

[0046] Compared to traditional circular channels, the elliptical channels of this application can maximize the proportion of thin walls, with a wall thickness of 40 to 800 μm, thereby shortening the gas diffusion path and improving the gas transport rate through the combined effect of multiple channels and finger-shaped pores.

[0047] This application uses an aqueous solution of polyvinyl alcohol as a coagulant, which can increase the proportion of finger pores, and the addition of the coagulant makes the membrane have higher wear resistance and toughness.

[0048] The following specific embodiments further illustrate the preparation method and application of the multi-channel microtubular copper hollow fiber membrane of this application.

[0049] Example 1:

[0050] A method for preparing a four-channel microtubular copper hollow fiber membrane includes the following steps:

[0051] 1) Preparation of membrane solution: Dissolve 300g Cu powder in 90g N-methylpyrrolidone, mix and ball mill for 12h, then add 20g polymethyl methacrylate and mix and ball mill for 12h.

[0052] 2) The membrane solution obtained after ball milling is subjected to vacuum degassing treatment for 30 minutes;

[0053] 3) Prepare an aqueous solution of polyvinyl alcohol, with a mass ratio of polyvinyl alcohol to water of 1:14;

[0054] 4) Spinning: Adjust the extrusion speed of the membrane solution and coagulant to 9 mL / min, and simultaneously pressurize the membrane solution and coagulant so that they are extruded from the interlayer gap of the spinning head and the inner tube at the same time and enter the water to obtain an elliptical four-channel microtubular copper hollow fiber membrane preform with a wall thickness of 436 μm.

[0055] 5) The blank was sintered in a hydrogen atmosphere at a temperature of 300℃, a heating rate of 5℃ / min, and a holding time of 4h to obtain an elliptical four-channel microtubular copper hollow fiber membrane with a diameter of 5.2mm.

[0056] The prepared four-channel microtubular copper hollow fiber membrane was coated onto the anode, electrolyte, and cathode, and assembled into an elliptical four-channel microtubular copper hollow fiber membrane-supported single cell. Performance was measured, and the peak power density at 650℃ was 0.25 W·cm³. -2 .

[0057] Example 2:

[0058] A method for preparing a four-channel microtubular copper hollow fiber membrane includes the following steps:

[0059] 1) Preparation of membrane solution: Dissolve 320g Cu powder and 2g polyethylene glycol-30-dipolyhydroxy stearate in 100g N-methylpyrrolidone, mix and ball mill for 24h, then add 30g polymethyl methacrylate and mix and ball mill for 24h.

[0060] 2) The membrane solution obtained after ball milling is subjected to vacuum degassing treatment for 60 min;

[0061] 3) Prepare an aqueous solution of polyvinyl alcohol, with a mass ratio of polyvinyl alcohol to water of 1:14;

[0062] 4) Spinning: Adjust the extrusion speed of the membrane solution and the coagulant to 9 mL / min and 15 mL / min respectively, and simultaneously pressurize the membrane solution and the coagulant so that they are extruded from the interlayer gap of the spinning head and the inner tube at the same time and enter the water to obtain an elliptical four-channel microtubular copper hollow fiber membrane preform with a wall thickness of 290 μm.

[0063] 5) The blank was sintered in a hydrogen atmosphere at a temperature of 600℃, a heating rate of 3℃ / min, and a holding time of 6h to obtain an elliptical four-channel microtubular copper hollow fiber membrane with a diameter of 3.5mm.

[0064] The prepared four-channel microtubular copper hollow fiber membrane was coated onto the anode, electrolyte, and cathode, and assembled into an elliptical four-channel microtubular copper hollow fiber membrane-supported single cell. Performance was measured, and the peak power density at 700℃ was 0.46 W·cm³. -2 .

[0065] like Figure 1 As shown, this is a SEM image of the elliptical four-channel microtubular copper hollow fiber membrane prepared in Example 2. In the figure, (a) is the cross-section of the membrane, which has a large number of finger-like pores. In the figure, (b) is the microstructure of the inner wall of the elliptical gas channel, which has a large number of sponge-like pores.

[0066] Example 3:

[0067] A method for preparing a four-channel microtubular copper hollow fiber membrane includes the following steps:

[0068] 1) Preparation of membrane solution: 340g Cu powder and 5g polyethylene glycol-30-dipolyhydroxy stearate were dissolved in 110g N-methylpyrrolidone, mixed and ball-milled for 30h, and then 40g polymethyl methacrylate was added and ball-milled for 30h.

[0069] 2) The membrane solution obtained after ball milling was subjected to vacuum degassing for 120 min;

[0070] 3) Prepare an aqueous solution of polyvinyl alcohol, with a mass ratio of polyvinyl alcohol to water of 2:14;

[0071] 4) Spinning: Adjust the extrusion speed of the membrane solution and the coagulant to 15 mL / min and 20 mL / min respectively. Pressurize the membrane solution and the coagulant at the same time so that they are extruded from the interlayer gap of the spinning head and the inner tube at the same time and enter the water to obtain an elliptical four-channel microtubular copper hollow fiber membrane preform with a wall thickness of 271 μm.

[0072] 5) The preform was sintered in a hydrogen atmosphere at a temperature of 1000℃, a heating rate of 5℃ / min, and a holding time of 10h to obtain an elliptical multi-channel microtubular copper hollow fiber membrane with a diameter of 3.3mm.

[0073] The prepared four-channel microtubular copper hollow fiber membrane was coated onto the anode, electrolyte, and cathode, and assembled into an elliptical four-channel microtubular copper hollow fiber membrane-supported single cell. Performance was measured, and the peak power density at 750℃ was 0.79 W·cm³. -2 .

[0074] like Figure 2 The figure shows the IV (current-voltage) and IP (current-power) curves of the elliptical four-channel microtubular copper hollow fiber membranes prepared in Examples 1-3. As can be seen from the figure, the performance of the tubular copper hollow fiber membranes obtained in Examples 1-3 as metal supports for assembling single cells is increasing. This indicates that the larger the proportion of thin-walled area and the smaller the wall thickness of the elliptical four-channel microtubular copper hollow fiber membrane, the more conducive it is to the transmission of fuel gas.

[0075] Example 4:

[0076] A method for preparing a seven-channel microtubular copper hollow fiber membrane includes the following steps:

[0077] 1) Preparation of membrane solution: Dissolve 320g Cu powder and 2g polyethylene glycol-30-dipolyhydroxy stearate in 100g N-methylpyrrolidone, mix and ball mill for 30h, then add 30g polymethyl methacrylate and mix and ball mill for 30h.

[0078] 2) The membrane solution obtained after ball milling is subjected to vacuum degassing treatment for 60 min;

[0079] 3) Prepare an aqueous solution of polyvinyl alcohol, with a mass ratio of polyvinyl alcohol to water of 1:14;

[0080] 4) Spinning: Adjust the extrusion speed of the membrane solution and the coagulant to 20 mL / min and 20 mL / min respectively. Simultaneously pressurize the membrane solution and the coagulant so that they are extruded from the interlayer gap of the spinning head and the inner tube at the same time and enter the water to obtain an elliptical seven-channel microtubular copper hollow fiber membrane preform with a wall thickness of 234 μm.

[0081] 5) The preform was sintered in a hydrogen atmosphere at a temperature of 600℃, a heating rate of 1℃ / min, and a holding time of 6h to obtain an elliptical seven-channel microtubular copper hollow fiber membrane with a diameter of 4.0mm.

[0082] The prepared seven-channel microtubular copper hollow fiber membrane was coated onto the anode, electrolyte, and cathode, and assembled into an elliptical seven-channel microtubular copper hollow fiber membrane-supported single cell. Performance was measured, and the peak power density at 750℃ was 0.85 W·cm³. -2 .

[0083] Example 5:

[0084] A method for preparing a seven-channel microtubular copper hollow fiber membrane includes the following steps:

[0085] 1) Preparation of membrane solution: Dissolve 320g Cu powder and 2g polyethylene glycol-30-dipolyhydroxy stearate in 100g N-methylpyrrolidone, mix and ball mill for 30h, then add 30g polymethyl methacrylate and mix and ball mill for 30h.

[0086] 2) The membrane solution obtained after ball milling is subjected to vacuum degassing treatment for 60 min;

[0087] 3) Prepare an aqueous solution of polyvinyl alcohol, with a mass ratio of polyvinyl alcohol to water of 1:14;

[0088] 4) Spinning: Adjust the extrusion speed of the membrane solution and the coagulant to 9 mL / min and 15 mL / min respectively, and simultaneously pressurize the membrane solution and the coagulant so that they are extruded from the interlayer gap of the spinning head and the inner tube at the same time and enter the water to obtain an elliptical seven-channel microtubular copper hollow fiber membrane preform with a wall thickness of 248 μm.

[0089] 5) The preform was sintered in a hydrogen atmosphere at a temperature of 600℃, a heating rate of 5℃ / min, and a holding time of 6h to obtain an elliptical seven-channel microtubular copper hollow fiber membrane with a diameter of 3.9mm.

[0090] The prepared seven-channel microtubular copper hollow fiber membrane was coated onto the anode, electrolyte, and cathode. A single cell supported by an elliptical seven-channel microtubular copper hollow fiber membrane was assembled, and its performance was measured. The peak power density at 750℃ was 0.91 W·cm³. -2 .

[0091] Example 6

[0092] A method for preparing a nine-channel microtubular copper hollow fiber membrane includes the following steps:

[0093] 1) Preparation of membrane solution: Dissolve 320g Cu powder and 2g polyethylene glycol-30-dipolyhydroxy stearate in 100g N-methylpyrrolidone, mix and ball mill for 30h, then add 30g polymethyl methacrylate and mix and ball mill for 30h.

[0094] 2) The membrane solution obtained after ball milling is subjected to vacuum degassing treatment for 60 min;

[0095] 3) Prepare an aqueous solution of polyvinyl alcohol, with a mass ratio of polyvinyl alcohol to water of 1:14;

[0096] 4) Spinning: Adjust the extrusion speed of the membrane solution and the coagulant to 9 mL / min and 9 mL / min respectively. Simultaneously pressurize the membrane solution and the coagulant so that they are extruded from the interlayer gap of the spinning head and the inner tube at the same time and enter the water to obtain an elliptical nine-channel microtubular copper hollow fiber membrane preform with a wall thickness of 255 μm.

[0097] 5) The preform was sintered in a hydrogen atmosphere at a temperature of 600℃, a sintering rate of 5℃ / min, and a holding time of 6h to obtain an elliptical nine-channel microtubular copper hollow fiber membrane with a diameter of 4.5mm.

[0098] The prepared nine-channel microtubular copper hollow fiber membrane was coated onto the anode, electrolyte, and cathode. A single cell supported by an elliptical nine-channel microtubular copper hollow fiber membrane was assembled, and its performance was measured. The peak power density at 650℃ was 0.68 W·cm³. -2 .

[0099] Example 7

[0100] A method for preparing a nine-channel microtubular copper hollow fiber membrane includes the following steps:

[0101] 1) Preparation of membrane solution: Dissolve 320g Cu powder and 2g polyethylene glycol-30-dipolyhydroxy stearate in 100g N-methylpyrrolidone, mix and ball mill for 30h, then add 30g polymethyl methacrylate and mix and ball mill for 30h.

[0102] 2) The membrane solution obtained after ball milling was subjected to vacuum degassing for 120 min;

[0103] 3) Prepare an aqueous solution of polyvinyl alcohol, with a mass ratio of polyvinyl alcohol to water of 3:14;

[0104] 4) Spinning: Adjust the extrusion speed of the membrane solution and the coagulant to 9 mL / min and 15 mL / min respectively, and simultaneously pressurize the membrane solution and the coagulant so that they are extruded from the interlayer gap of the spinning head and the inner tube at the same time and enter the water to obtain an elliptical nine-channel microtubular copper hollow fiber membrane preform with a wall thickness of 223 μm.

[0105] 5) The blank was sintered in a hydrogen atmosphere at a temperature of 600℃, a heating rate of 1℃ / min, and a holding time of 10h to obtain an elliptical nine-channel microtubular copper hollow fiber membrane with a diameter of 4.1mm.

[0106] The prepared nine-channel microtubular copper hollow fiber membrane was coated onto the anode, electrolyte, and cathode. A single cell supported by an elliptical nine-channel microtubular copper hollow fiber membrane was assembled, and its performance was measured. The peak power density at 750℃ was 0.71 W·cm³. -2 .

[0107] Example 8

[0108] A method for preparing a twelve-channel microtubular copper hollow fiber membrane includes the following steps:

[0109] 1) Preparation of membrane solution: 320g Cu powder and 2g polyethylene glycol (30) dihydroxy stearate are dissolved in 100g N-methylpyrrolidone, mixed and ball-milled for 30h, and then 30g polymethyl methacrylate is added and mixed and ball-milled for 30h.

[0110] 2) The membrane solution obtained after ball milling was subjected to vacuum degassing for 120 min;

[0111] 3) Prepare an aqueous solution of polyvinyl alcohol, with a mass ratio of polyvinyl alcohol to water of 1:14;

[0112] 4) Spinning: Adjust the extrusion speed of the membrane solution and the coagulant to 9 mL / min and 15 mL / min respectively, and simultaneously pressurize the membrane solution and the coagulant so that they are extruded from the interlayer gap of the spinning head and the inner tube at the same time and enter the water to obtain an elliptical twelve-channel microtubular copper hollow fiber membrane preform with a wall thickness of 241 μm.

[0113] 5) The preform was sintered in a hydrogen atmosphere at a temperature of 600℃, a sintering rate of 5℃ / min, and a holding time of 10h to obtain an elliptical twelve-channel microtubular copper hollow fiber membrane with a diameter of 3.9mm.

[0114] The prepared twelve-channel microtubular copper hollow fiber membrane was coated onto the anode, electrolyte, and cathode. A single cell supported by an elliptical twelve-channel microtubular copper hollow fiber membrane was assembled, and its performance was measured. The peak power density at 750℃ was 0.54 W·cm³. -2 .

[0115] Example 9

[0116] A method for preparing a 19-channel microtubular copper hollow fiber membrane includes the following steps:

[0117] 1) Preparation of membrane solution: 320g Cu powder and 2g polyethylene glycol (30) dihydroxy stearate are dissolved in 100g N-methylpyrrolidone, mixed and ball-milled for 30h, and then 30g polymethyl methacrylate is added and mixed and ball-milled for 30h.

[0118] 2) The membrane solution obtained after ball milling was subjected to vacuum degassing for 120 min;

[0119] 3) Prepare an aqueous solution of polyvinyl alcohol, with a mass ratio of polyvinyl alcohol to water of 1:14;

[0120] 4) Spinning: Adjust the extrusion speed of the membrane solution and the coagulant to 9 mL / min and 15 mL / min respectively, and simultaneously pressurize the membrane solution and the coagulant so that they are extruded from the interlayer gap of the spinning head and the inner tube at the same time and enter the water to obtain an elliptical nineteen-channel microtubular copper hollow fiber membrane preform with a wall thickness of 238 μm.

[0121] 5) The preform was sintered in a hydrogen atmosphere at a temperature of 600℃, a sintering rate of 5℃ / min, and a holding time of 10h to obtain an elliptical nineteen-channel microtubular copper hollow fiber membrane with a diameter of 4.6mm.

[0122] The prepared 19-channel microtubular copper hollow fiber membrane was coated onto the anode, electrolyte, and cathode. A single cell supported by an elliptical 19-channel microtubular copper hollow fiber membrane was assembled, and its performance was measured. The peak power density at 750℃ was 0.59 W·cm³. -2 .

[0123] It will be understood by those skilled in the art that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for producing a multi-channel microtubular copper hollow fiber membrane, characterized by, include: Copper powder, polyethylene glycol-30-dipolyhydroxystearate, N-methylpyrrolidone, and binder were mixed in proportion and then ball-milled to prepare a film solution. The membrane solution is subjected to vacuum degassing treatment; The membrane liquid after vacuum degassing is used as the shell liquid, and the coagulant is used as the core liquid. At the same time, the membrane liquid is squeezed into water through the spinning head of the spinning equipment to obtain the preform. The preform is sintered in a hydrogen atmosphere to obtain a multi-channel microtubular copper hollow fiber membrane. The cross-section of the multi-channel microtubular copper hollow fiber membrane has densely packed finger-shaped pores, and a number of elliptical gas channels are formed in the multi-channel microtubular copper hollow fiber membrane. The inner wall of the elliptical gas channels has densely packed sponge-like pores. The multi-channel microtubular copper hollow fiber membrane has a wall thickness of 40–800 μm and a diameter of 1–10 mm. The mass ratio of copper powder, polyethylene glycol-30-dipolyhydroxystearate, N-methylpyrrolidone, and binder is (150-170):(0-2.5):(45-55):(10-20), and the value of polyethylene glycol-30-dipolyhydroxystearate is not 0; The coagulant is an aqueous solution of polyvinyl alcohol, and the mass ratio of polyvinyl alcohol to water is (1-3): 14; The adhesive is one or two of the following: polymethyl methacrylate, high-density polyethylene, polypropylene, polyethylene wax, polystyrene, ethylene-vinyl acetate copolymer, polyvinyl butyral, and polyethyleneimine. The extrusion speed of the coagulant is 9–30 mL / min, and the extrusion speed of the membrane solution is 9–20 mL / min; The sintering treatment is performed at a temperature of 300–1000 °C, a heating rate of 1–5 °C / min, and a holding time of 4–10 h.

2. The method of producing a multi-channel microtubular copper hollow fiber membrane according to claim 1, characterized by, The ellipticity of the elliptical gas channel can be controlled by adjusting the proportions of the components constituting the membrane solution, the concentration of the coagulant, and the ratio of the extrusion speed of the membrane solution to that of the coagulant.

3. The method for preparing a multi-channel microtubular copper hollow fiber membrane according to claim 1, characterized in that, The ball milling time is 12–30 h, and the vacuum degassing treatment time is 30–120 min.

4. The method of claim 1, wherein the multi-channel microtubular copper hollow fiber membrane is prepared by the steps of: The elliptical gas channel is one of two, three, four, five, six, seven, nine, twelve, or nineteen channels.

5. A multi-pass microtubular copper hollow fiber membrane characterized in that, Prepared by the preparation method according to any one of claims 1-4.

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