Composite woven porous electrode and electrolytic cell, electrolysis device and method using the same

Abstract

The present invention discloses a composite woven porous electrode and an electrolytic cell, an electrolytic device and a method using the same. The composite woven porous electrode includes conductive hydrophilic filaments and alkali-resistant hydrophobic filaments, wherein: the conductive hydrophilic filaments and the alkali-resistant hydrophobic filaments are twisted into a "twisted" woven filament, and the woven filament is woven in an Ω shape to form a multi-scale void network structure, and woven peaks and woven valleys are formed; the multi-scale void network structure adopts a two-dimensional network stacking structure, and the stacking method is that the woven peaks and woven valleys in different stacking layers correspond to each other respectively to form a macroscopic flow channel; the composite woven porous electrode of the present invention reduces the presence of fine bubbles in the electrolyte, solves the separation difficulty caused by the small diameter of the fine bubbles, overcomes the problem of incomplete separation of the subsequent traditional gas-liquid separator, reduces the gas content rate in the electrolyte, improves the efficiency of alkaline water electrolysis for hydrogen production, and ensures the efficient and safe operation of the entire hydrogen production system.

Description

Technical Field

[0001] The present invention belongs to the technical field of hydrogen production by alkaline electrolyzed water, and particularly relates to a composite woven porous electrode, an electrolytic cell, an electrolysis device and a method using the same. Background Art

[0002] With the intensification of the global energy crisis and environmental pollution problems, hydrogen energy, as a clean and environmentally friendly energy form, has received extensive attention. One of the main methods for hydrogen production is electrolyzed water to produce hydrogen, especially the alkaline electrolyzed water hydrogen production technology. The alkaline electrolyzed water hydrogen production technology has the advantages of rich raw materials, low cost, simple operation, etc., and is a hydrogen production method with relatively wide industrial applications at present. However, although this technology has been relatively mature, in the process of high-efficiency electrolysis, the generation, attachment and separation of bubbles are still one of the key factors restricting the electrolysis efficiency.

[0003] During the electrolysis process, hydrogen and oxygen are respectively generated on the surfaces of the cathode and anode. The attachment of these bubbles on the electrode surface will not only reduce the effective reaction area of the electrode, but also increase the resistance in the electrolytic cell, resulting in a decrease in the electrolysis efficiency. The residence of bubbles on the electrode surface reduces the contact area between the reactants and the electrode, thus preventing the current density from being further increased. When the current density increases, the generated fine bubble group will increase the bubble burden of the system, forming a foaming phenomenon, which will not only lead to incomplete gas-liquid separation in the electrolytic cell, but also increase the electrolysis energy consumption and affect the stability of the entire electrolysis process.

[0004] In the prior art, the bubble problem is mainly alleviated by electrode surface modification and optimization of the gas-liquid separator. For example, CN116334679A discloses a gradient pore structure electrode, which accelerates bubble detachment through pore size gradient design, but its hydrophobic performance is insufficient and it is difficult to effectively capture fine bubbles; CN115799532A proposes a super-hydrophilic gas track structure to promote bubble coalescence, but the processing is complex and it is difficult to adapt to large-scale electrolytic cells. On the other hand, traditional gas-liquid separators rely on the combination of swirl and wire mesh for separation, but the separation efficiency for fine bubbles is limited and the device volume is large.

[0005] Therefore, developing an electrolytic cell device that can efficiently promote bubble coalescence, improve gas-liquid separation efficiency, and reduce electrolysis energy consumption has become the key to improving the efficiency of the electrolyzed water hydrogen production technology. Summary of the Invention

[0006] The object of the present invention is to propose a composite woven porous electrode, an electrolytic cell, an electrolysis device and a method using the same to improve the efficiency of alkaline electrolyzed water hydrogen production in view of the problems of increased electrolytic cell voltage, high electrolysis energy consumption and incomplete gas-liquid separation caused by fine bubble groups in the prior art during the electrolysis process.

[0007] To achieve the above object, the technical solutions adopted by the present invention are as follows:

[0008] In the first aspect of the present invention, a composite woven porous electrode is provided. The composite woven porous electrode includes conductive hydrophilic filaments and alkali-resistant hydrophobic filaments, wherein:

[0009] The conductive hydrophilic filaments and the alkali-resistant hydrophobic filaments are twisted into a "twisted" woven filament. The woven filament is woven in an Ω shape to form a multi-scale void network structure, and woven peaks and woven valleys are formed. The multi-scale void network structure adopts a two-dimensional network stacking structure, and the stacking method is that the woven peaks and woven valleys in different stacking layers correspond to each other respectively to form a macroscopic flow channel;

[0010] In the composite woven porous electrode, the volume ratio of the conductive hydrophilic filaments to the alkali-resistant hydrophobic filaments is 3:1 to 6:1; the aperture of the macroscopic flow channel is 1 to 5 mm, and the included angle θ between the direction of the macroscopic flow channel and the direction of the electrolyte flow is set to 25° 75°.

[0011] Furthermore, the distance between the conductive hydrophilic filaments or the alkali-resistant hydrophobic filaments in the composite woven porous electrode is 0.1 to 1 mm; the diameter of the conductive hydrophilic filaments or the alkali-resistant hydrophobic filaments is 100 to 200 μm; the weaving density is 50 to 200 mesh; the porosity of the composite woven porous electrode is 90% to 96%.

[0012] Furthermore, the material of the conductive hydrophilic filaments is selected from one or more of nickel, titanium, platinum, stainless steel, and carbon;

[0013] The material of the alkali-resistant hydrophobic filaments is selected from one or more of polytetrafluoroethylene, perfluoroethylene propylene copolymer, and polyvinylidene fluoride.

[0014] Furthermore, a hydrophilic surface catalyst is uniformly coated on the conductive hydrophilic filaments;

[0015] The hydrophilic surface catalyst is selected from one or more of nickel-based catalysts, cobalt-based catalysts, and Pt / C.

[0016] In the second aspect of the present invention, an electrolytic cell is provided. The electrolytic cell includes a plurality of electrolytic compartments connected in parallel. A single electrolytic compartment includes a cathode plate and an anode plate arranged oppositely, a diaphragm located between the two plates, and a cathode electrode and an anode electrode attached to both sides of the diaphragm. A cathode chamber is formed between the cathode plate and the cathode electrode, and an anode chamber is formed between the anode plate and the anode electrode;

[0017] The lower end of the electrolytic cell is provided with an electrolytic cell inlet communicating with the cathode chamber and the anode chamber, and its upper end is provided with an electrolytic cell outlet, including a first outlet communicating with the cathode chamber and a second outlet communicating with the anode chamber;

[0018] The cathode electrode and the anode electrode are the above-mentioned composite woven porous electrodes.

[0019] Further, the composite woven porous electrode and the electrode plate are installed inside the cathode chamber or the anode chamber through interference fit or transitional fit via a corrosion-resistant bracket, and are fixed by welding.

[0020] Further, the surface of the composite woven porous electrode close to the diaphragm is polished smoothly to prevent piercing the diaphragm; the composite woven porous electrode is subjected to edge sealing treatment.

[0021] The third aspect of the present invention is to provide an electrolysis device, including the above electrolytic cell, as well as two gas-liquid separators, two gas treatment devices, an alkali solution mixer and two alkali solution circulation pumps, wherein:

[0022] The mixed liquid inlets of the two gas-liquid separators are respectively connected to the first outlet and the second outlet of the electrolytic cell; their liquid phase outlets are connected to the alkali solution mixer via the corresponding alkali solution circulation pumps, and the alkali solution mixer is connected to the electrolytic cell inlet of the electrolytic cell to realize the circulation of the electrolyte; their gas phase outlets are connected to the corresponding gas treatment devices.

[0023] The fourth aspect of the present invention is to provide an electrolysis method using the above electrolysis device, including the following steps:

[0024] The electrolyte enters the electrolytic compartments from the electrolytic cell inlet at the bottom of the electrolytic cell and flows from bottom to top. During electrolysis, a large number of fine bubbles are generated on the cathode electrode and the anode electrode with a multi-scale void network structure. Among them, due to the low wetting property of the alkali-resistant and hydrophobic filaments at the microscopic level, high-density attachment points are provided for the fine bubbles generated by electrolysis, promoting their coalescence into millimeter-sized bubbles. The coalesced large bubbles move directionally along the macroscopic flow channels, detach from the electrode surface, and then enter the corresponding gas-liquid separators from the first outlet and the second outlet of the electrolytic cell. After gas-liquid separation, the electrolyte is pumped into the electrolytic cell for recycling, and the gas enters the corresponding gas treatment devices for drying and pressurizing treatment. The treated gas can be stored for use.

[0025] Further, the flow rate of the electrolyte in the electrolytic cell is 0.2 - 2 m / s, the current density is 3000 - 8000 A / m², and the operating temperature of the electrolytic cell is 60 - 90 °C.

[0026] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0027] (1)The present invention combines and weaves a conductive hydrophilic material with an alkali-resistant hydrophobic material through a composite weaving process to form a composite woven porous electrode with a multi-scale pore network structure, including a microscopic hydrophobic adhesion layer and a macroscopic flow channel guiding layer. It induces the coalescence of bubbles generated by electrolysis under a high current density to form large bubbles and enables the rapid detachment of the large bubbles, which can effectively solve the problems of increased electrolytic cell voltage, high electrolysis energy consumption, and difficulty in further increasing the current density caused by a fine bubble group, reduce the gas holdup in the system, and effectively prevent the foaming of the two-phase flow in the electrolytic cell.

[0028] (2)The composite woven porous electrode provided by the present invention reduces the presence of fine bubbles in the electrolyte, solves the separation difficulty caused by the small diameter of the fine bubbles, overcomes the problem of incomplete separation of the subsequent traditional gas-liquid separator, reduces the gas holdup in the electrolyte, improves the efficiency of alkaline water electrolysis for hydrogen production, and ensures the efficient and safe operation of the entire hydrogen production system.

[0029] (3)The composite woven porous electrode designed by the present invention can not only be applied in a small electrolytic cell but also on large industrial equipment, showing great potential in industrial applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a schematic structural diagram of an electrolytic cell using a composite woven porous electrode.

[0031] Figure 2 is a schematic structural diagram of an electrolytic cell compartment.

[0032] Figure 3 is a schematic diagram of the Ω-shaped weaving process.

[0033] Figure 4 is a three-dimensional structural diagram of the composite woven porous electrode.

[0034] Figure 5 is a schematic diagram of the principle of coalescence induced by the composite woven porous electrode.

[0035] Figure 6 is a two-dimensional plane schematic diagram of the composite woven porous electrode.

[0036] Figure 7 is an electrolysis device using a composite woven porous electrode.

[0037] In the figure:

[0038] 10 - electrolytic cell; 11 - electrolytic cell compartment; 12 - cathode plate; 13 - anode plate; 14 - diaphragm; 15 - cathode electrode; 16 - anode electrode; 17 - electrolytic cell inlet; 18 - first outlet; 19 - second outlet;

[0039] 20 - Gas - liquid separator; 30 - Gas treatment equipment; 40 - Alkali solution mixer; 50 - Alkali solution circulation pump; 60 - Water replenishment and alkali preparation tank; 70 - Braided silk thread; 80 - Edge sealing. Detailed implementation manners

[0040] The technical solutions of the invention will be clearly and elaborately described below with reference to the accompanying drawings through specific embodiments. It should be understood that the following embodiments are only a part of the embodiments of the invention, rather than all embodiments. Based on the embodiments of the invention, other embodiments obtained by those of ordinary skill in the art without creative efforts all fall within the protection scope of the invention. Unless otherwise defined, all professional and scientific terms used herein have the same meaning as those familiar to those skilled in the art.

[0041] Embodiment 1: An electrolytic cell using a composite braided porous electrode

[0042] As Figure 1 and Figure 2 shown, the electrolytic cell 10 using a composite braided porous electrode in this embodiment includes: a plurality of electrolytic compartments 11 connected in parallel. A single electrolytic compartment 11 includes a cathode plate 12 and an anode plate 13 arranged oppositely, a diaphragm 14 located between the two plates, and cathode electrodes 15 and anode electrodes 16 adhered to both sides of the diaphragm 14. A cathode chamber is formed between the cathode plate 12 and the cathode electrode 15, and an anode chamber is formed between the anode plate 13 and the anode electrode 16.

[0043] An electrolytic cell inlet 17 communicating with the cathode chamber and the anode chamber is provided at the lower end of the electrolytic cell 10, and an electrolytic cell outlet is provided at its upper end, including a first outlet 18 communicating with the cathode chamber and a second outlet 19 communicating with the anode chamber, which are used to respectively output the gas - containing electrolytic solutions in the cathode chamber and the anode chamber. The electrolytic solution enters from the bottom of the electrolytic cell 10, flows from bottom to top, and the gas - containing electrolytic solution generated after electrolysis is discharged from the electrolytic cell outlet.

[0044] Both the above - mentioned cathode electrodes 15 and anode electrodes 16 are composite braided porous electrodes. The composite braided porous electrode includes: conductive hydrophilic silk threads and alkali - resistant hydrophobic silk threads, where:

[0045] As Figure 3 and Figure 4 shown, the conductive hydrophilic silk threads and the alkali - resistant hydrophobic silk threads are twisted into a "twisted" braided silk thread 70. The braided silk thread 70 is woven in a Ω - type to form a multi - scale void network structure, and braided wave peaks and braided wave valleys are formed. Specifically, the multi - scale void network structure adopts a two - dimensional network stacking structure, and the stacking method is that the braided wave peaks and braided wave valleys in different stacking layers correspond to each other to form a macroscopic flow channel.

[0046] In the composite braided porous electrode, the volume ratio of the conductive hydrophilic silk threads to the alkali - resistant hydrophobic silk threads is 3:1 to 6:1; AsFigure 5 As shown, the aperture of the macro flow channel is 1 - 5 mm, and the included angle θ between the direction of the macro flow channel and the direction of the electrolyte flow is set to 25° 75°.

[0047] The spacing between the conductive hydrophilic filaments or alkali - resistant hydrophobic filaments in the composite woven porous electrode is 0.1 - 1 mm; the diameter of the conductive hydrophilic filaments or alkali - resistant hydrophobic filaments is 100 - 200 μm; the weaving density is 50 - 200 mesh; the porosity of the composite woven porous electrode is 90% - 96%.

[0048] The material of the conductive hydrophilic filaments can be selected from most traditional electrode materials, such as materials like nickel, titanium, platinum, stainless steel, carbon, etc.;

[0049] The material of the alkali - resistant hydrophobic filaments is selected from one or more of polytetrafluoroethylene (PTFE), fluorinated ethylene propylene copolymer (FEP), and polyvinylidene fluoride (PVDF).

[0050] The conductive hydrophilic filaments are uniformly coated with a hydrophilic surface catalyst; the hydrophilic surface catalyst is selected from one or more of commonly used noble - metal - based catalysts such as nickel - based catalysts, cobalt - based catalysts, Pt / C, etc.

[0051] Back to Figure 5 through the composite weaving process, the multi - scale void network structure of the composite woven porous electrode includes a microscopic hydrophobic attachment layer and a macroscopic flow channel guiding layer; in the microscopic hydrophobic attachment layer, by utilizing the low - wetting property of the microscopic - level hydrophobic material, high - density attachment points are provided for the micro - bubbles generated by electrolysis, promoting their coalescence into millimeter - sized bubbles, facilitating their rapid detachment, reducing the gas holdup of the system while protecting the hydrophilic surface catalyst. In the macroscopic flow channel guiding layer, the macroscopic flow channels formed by this weaving process are directional flow channels, which can guide the coalesced bubbles to quickly detach from the electrode surface along the flow channels, preventing phenomena such as excessive pressure drop or blockage caused by bubble accumulation.

[0052] In addition, in the electrolytic cell, the composite woven porous electrode and the electrode plate are installed inside the cathode chamber or the anode chamber through interference fit or transition fit with a corrosion - resistant bracket and fixed by welding.

[0053] The side of the composite woven porous electrode close to the diaphragm 14 is polished smoothly to avoid piercing the diaphragm 14, and the edge - sealing treatment as shown in Figure 6 is carried out. The composite woven porous electrode includes a multi - scale void network structure formed by woven filaments 70 inside and an edge - sealing 80 outside.

[0054] Example 2: An electrolysis device using a composite woven porous electrode

[0055] As Figure 7As shown in the figure, the electrolysis device of this embodiment includes the electrolytic cell 10 of the above-mentioned Embodiment 1, two gas-liquid separators 20, two gas treatment devices 30, an alkali solution mixer 40, and two alkali solution circulation pumps 50, where:

[0056] The mixed liquid inlets of the two gas-liquid separators 20 are respectively connected to the first outlet 18 and the second outlet 19 of the electrolytic cell 10; their liquid phase outlets are connected to the alkali solution mixer 40 via the corresponding alkali solution circulation pumps 50, and the alkali solution mixer 40 is connected to the electrolytic cell inlet 17 of the electrolytic cell 10 to realize the circulation of the electrolyte; their gas phase outlets are connected to the corresponding gas treatment devices 30.

[0057] The above electrolysis device further includes a water replenishment and alkali preparation tank 60 connected to the alkali solution mixer 40 for timely water replenishment and alkali supplementation.

[0058] It should be noted that the above gas-liquid separators 20, gas treatment devices 30, alkali solution mixers 40, alkali solution circulation pumps 50, and water replenishment and alkali preparation tanks 60 are all conventional devices in the field and can be selected according to actual needs. Their specific structures will not be elaborated here.

[0059] Based on the above electrolysis method and principle of the electrolysis device using a composite woven porous electrode are as follows:

[0060] The electrolyte enters the electrolysis chamber 11 from the electrolytic cell inlet 17 at the bottom of the electrolytic cell 10 and flows upward. During electrolysis, a large number of fine bubbles are generated on the cathode electrode 15 and the anode electrode 16 with a multi-scale void network structure. Among them, due to the low wetting property of the alkali-resistant and hydrophobic filaments at the microscopic level, high-density attachment points are provided for the fine bubbles generated by electrolysis, promoting their coalescence into millimeter-sized bubbles. The coalesced large bubbles move directionally along the macroscopic flow channels, detach from the electrode surface, and then enter the corresponding gas-liquid separators 20 from the first outlet 18 and the second outlet 19 of the electrolytic cell 10. After gas-liquid separation, the electrolyte is pumped into the electrolytic cell 10 for recycling, and the gas enters the corresponding gas treatment device 30 for drying and pressurization treatment. The treated gas can then be stored for use.

[0061] During electrolysis, the flow rate of the electrolyte in the electrolytic cell 10 is 0.2 - 2 m / s, the current density is 3000 - 8000 A / m², and the operating temperature of the electrolytic cell 10 is 60 - 90 °C.

[0062] In addition, the volume of the electrolyte in the gas-liquid separator 20 is controlled to be 1 / 2 - 3 / 4 of the volume of the gas-liquid separator 20.

[0063] Embodiment 3

[0064] Using the electrolysis device of the above-mentioned Embodiment 2 to electrolyze the electrolyte of 30 wt% potassium hydroxide solution to generate hydrogen and oxygen, the flow rate of the electrolyte inlet is set to 0.5 m3 / h, the flow rate of the electrolyte is 0.5 m / s, the current density is 5000 A / m², and the operating temperature of the electrolytic cell is 60 °C;

[0065] In the composite woven porous electrode, the volume ratio of the conductive hydrophilic filaments to the alkali-resistant hydrophobic filaments is 4:1;

[0066] The spacing between the conductive hydrophilic filaments or the alkali-resistant hydrophobic filaments is 0.2 mm; the diameters of both the conductive hydrophilic filaments and the alkali-resistant hydrophobic filaments are 200 μm; the weaving density is 80 mesh; the porosity of the composite woven porous electrode is controlled at 95%;

[0067] The material of the conductive hydrophilic filaments is metallic nickel; the material of the alkali-resistant hydrophobic filaments is PTFE; the catalyst Pt / C is uniformly coated on the conductive hydrophilic filaments;

[0068] The angle θ between the direction of the macro flow channel and the direction of the electrolyte flow is 45°; the aperture of the macro flow channel is 5 mm.

[0069] Example 4

[0070] The electrolysis device and electrolysis conditions of this example are basically the same as those of Example 3, except that in the hydrophilic-hydrophobic composite woven porous electrode, the volume ratio of the conductive hydrophilic filaments to the alkali-resistant hydrophobic filaments is 3:1.

[0071] Example 5

[0072] The electrolysis device and electrolysis conditions of this example are basically the same as those of Example 3, except that in the hydrophilic-hydrophobic composite woven porous electrode, the volume ratio of the conductive hydrophilic filaments to the alkali-resistant hydrophobic filaments is 6:1.

[0073] Example 6

[0074] The electrolysis device and electrolysis conditions of this example are basically the same as those of Example 3, except that the current density is 8000 A / m².

[0075] Comparative Example 1

[0076] The electrolysis device and electrolysis conditions of this comparative example are basically the same as those of Example 3, except that the electrode in the electrolysis device uses a traditional nickel mesh.

[0077] Comparative Example 2

[0078] The electrolysis device and electrolysis conditions of this comparative example are basically the same as those of Example 3, except that the composite woven porous electrode is made by cross-weaving the woven filaments and no macro flow channel is formed.

[0079] Comparative Example 3

[0080] This comparative example is basically the same as the electrolysis device and electrolysis conditions of Example 3, except that in the composite woven porous electrode, the volume ratio of the conductive hydrophilic filaments to the alkali-resistant hydrophobic filaments is 1:1.

[0081] Comparative Example 4

[0082] This comparative example is basically the same as the electrolysis device and electrolysis conditions of Example 3, except that in the composite woven porous electrode, the volume ratio of the conductive hydrophilic filaments to the alkali-resistant hydrophobic filaments is 8:1.

[0083] After high-current density electrolysis of the above Examples 3 to 6 and Comparative Examples 1 to 4, the bubble size, gas holdup, and bubble detachment velocity in the electrolyte at the top of the electrolytic cell are shown in Table 1 below.

[0084] Table 1

[0085]

[0086] From the results of Examples 3 to 6 and Comparative Examples 1 to 2 in Table 1 above, it can be seen that when the composite woven porous electrode of the present invention is used in the electrolysis device, it can play a role in regulating the coalescence of fine bubbles. At the same time, the formed macroscopic flow channels promote the rapid detachment of bubbles. The bubble size range in the electrolyte at the top of the electrolytic cell is 150 μm to 35 mm, the gas holdup is 11% to 29%, and the bubble detachment velocity is 29 to 49 cm / s, greatly reducing the number of fine bubbles in the electrolysis chamber, thereby reducing the voltage of the electrolysis chamber, improving the electrolysis efficiency, and helping to reduce the system operation risk, increasing the upper limit of the current density, and ensuring the efficient and safe operation of the entire hydrogen production system.

[0087] In addition, by comparing the test results of Examples 3 to 6, Comparative Example 3 and Comparative Example 4, it can be seen that when the ratio of the conductive hydrophilic filaments to the alkali-resistant hydrophobic filaments is too low, the conductivity will become poor, and the probability of bubble accumulation will increase, and the bubble detachment efficiency will decrease, resulting in an extended residence time of bubbles in the electrolytic cell and an increase in gas holdup. When the ratio is too high, it means that the attachment sites of small bubbles become fewer, resulting in a decrease in the probability of bubble coalescence in the electrolyte and a decrease in the overall bubble size. Therefore, it is necessary to select an appropriate volume ratio of the conductive hydrophilic filaments to the alkali-resistant hydrophobic filaments to make the prepared composite woven porous electrode have both excellent bubble coalescence effect and bubble detachment velocity.

[0088] This application has been described in detail, aiming to enable those skilled in the art to understand the content of this application and implement it. However, it should not be used to limit the protection scope of this application. Any equivalent changes or modifications made according to the spirit of this application should be covered within the protection scope of this application.

Claims

1. An electrolytic cell, characterized in that: The electrolytic cell comprises a plurality of electrolytic chambers connected in parallel, wherein each electrolytic chamber comprises a cathode plate and an anode plate arranged opposite to each other, a diaphragm located between the two plates, and a cathode electrode and an anode electrode attached to both sides of the diaphragm, a cathode chamber being formed between the cathode plate and the cathode electrode, and an anode chamber being formed between the anode plate and the anode electrode; The lower end of the electrolytic cell is provided with an electrolytic cell inlet communicating with the cathode chamber and the anode chamber, and the upper end is provided with an electrolytic cell outlet, including a first outlet communicating with the cathode chamber and a second outlet communicating with the anode chamber; The cathode electrode and the anode electrode are composite woven porous electrodes; The composite braided porous electrode comprises: a conductive hydrophilic thread and an alkali-resistant hydrophobic thread, wherein: The conductive hydrophilic thread and the alkali-resistant hydrophobic thread are twisted into a "twisted" braided thread, and the braided thread is braided in an Ω-shaped manner to form a multi-scale void network structure, and to form braided crests and braided troughs; the multi-scale void network structure adopts a two-dimensional mesh stacking structure, and the stacking method is that the braided crests and braided troughs in different stacking layers correspond to each other, forming a macro flow channel; In the composite woven porous electrode, the volume ratio of the conductive hydrophilic thread to the alkali-resistant hydrophobic thread is 3:1~6:1; the pore size of the macro flow channel is 1~5mm, and the angle θ between the macro flow channel direction and the electrolyte flow direction is set to 25° 75°.

2. The electrolytic cell according to claim 1, characterized in that The spacing between the conductive hydrophilic threads or alkali-resistant hydrophobic threads in the composite woven porous electrode is 0.1-1 mm; the diameter of the conductive hydrophilic threads or alkali-resistant hydrophobic threads is 100-200 μm; the weaving density is 50-200 meshes; and the porosity of the composite woven porous electrode is 90%-96%.

3. The electrolytic cell according to claim 1, characterized in that The material of the conductive hydrophilic wire is selected from one or more of nickel, titanium, platinum, stainless steel and carbon; The material of the alkali-resistant hydrophobic thread is selected from one or more of polytetrafluoroethylene, perfluoroethylene propylene copolymer, and polyvinylidene fluoride.

4. The electrolytic cell according to claim 1, characterized in that The conductive hydrophilic silk thread is evenly coated with a hydrophilic surface catalyst; The hydrophilic surface catalyst is selected from one or more of a nickel-based catalyst, a cobalt-based catalyst and Pt / C.

5. The electrolytic cell according to claim 1, characterized in that The composite braided porous electrode and the electrode plate are installed in the cathode chamber or the anode chamber through interference fit or transition fit of a corrosion-resistant bracket and fixed by welding.

6. The electrolytic cell according to claim 1, characterized in that The side of the composite braided porous electrode close to the diaphragm is polished to be smooth so as not to puncture the diaphragm; the composite braided porous electrode is edge-sealed.

7. An electrolysis device, characterized in that: The electrolysis device comprises the electrolytic cell according to any one of claims 1 to 6, as well as two gas-liquid separators, two gas treatment devices, an alkali liquid mixer and two alkali liquid circulation pumps, wherein: The mixed liquid inlets of the two gas-liquid separators are respectively connected to the first outlet and the second outlet of the electrolytic cell; their liquid phase outlets are connected to the alkali liquid mixer via the corresponding alkali liquid circulation pump, and the alkali liquid mixer is connected to the electrolytic cell inlet of the electrolytic cell to realize the circulation of the electrolyte; their gas phase outlets are connected to the corresponding gas processing equipment.

8. An electrolysis method, using the electrolysis device according to claim 7, characterized in that: The electrolysis method comprises the following steps: The electrolyte enters the electrolysis chamber from the electrolytic cell inlet at the bottom of the electrolytic cell and flows from bottom to top. During electrolysis, a large number of fine bubbles are generated on the cathode electrode and anode electrode with a multi-scale void network structure. Among them, due to the low wettability of the alkali-resistant hydrophobic silk thread at the microscopic level, a high-density attachment point is provided for the fine bubbles generated by electrolysis, which promotes their aggregation into millimeter-scale bubbles. The large bubbles after aggregation move directionally along the macroscopic flow channel, detach from the electrode surface, and then enter the corresponding gas-liquid separator from the first outlet and the second outlet of the electrolytic cell. After gas-liquid separation, the electrolyte is pumped to the electrolytic cell for recycling, and the gas enters the corresponding gas treatment equipment for drying and pressurization treatment. The treated gas can be stored and used.

9. The electrolysis method according to claim 8, characterized in that The flow rate of the electrolyte in the electrolytic cell is 0.2~2m / s, the current density is 3000~8000A / m², and the operating temperature of the electrolytic cell is 60~90℃.

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