An electrochemical oxygen atmosphere regulating system and regulating method

Abstract

This invention belongs to the field of electrochemical deoxygenation technology, specifically relating to an electrochemical oxygen atmosphere control system and method. The system, from bottom to top, includes a porous bottom cover, a first hydrophobic and breathable membrane, an oxygen-consuming cathode, a liquid-conducting diaphragm, an oxygen-evolving anode, a second hydrophobic and breathable membrane, and a porous top cover. Each component layer forms a zero-gap contact through the clamping force of the outer shell, enabling the device to achieve an ultra-thin thickness. The liquid-conducting diaphragm has a transverse liquid-conducting groove extending to the external electrolyte chamber, utilizing capillary action to achieve rapid electrolyte replenishment and eliminate local hot spots. Through the coupling design between the hydrophobic and breathable membrane and the electrode interface, oxygen generated by the oxygen-evolving anode directly penetrates and overflows in the form of gas molecules, effectively suppressing bubble formation and accumulation in traditional electrolysis processes, and significantly reducing the ohmic resistance of the interface and operating energy consumption. This invention features an extremely thin structure, high reaction efficiency, and no bubble interference, making it suitable for precise oxygen concentration control in spaces such as refrigerators and precision storage environments.

Description

Technical Field

[0001] This invention belongs to the field of electrochemical deoxygenation technology, specifically relating to an electrochemical oxygen atmosphere control system and control method. Background Technology

[0002] Oxygen concentration is one of the core factors affecting the spoilage of organic matter, metal oxidation, and biological metabolic processes. In the field of food preservation, reducing the ambient oxygen concentration can effectively inhibit the respiration of fruits and vegetables and the reproduction of microorganisms, thereby significantly extending the shelf life. In biological experiments and precision industries, maintaining a low-oxygen or specific oxygen concentration environment is a necessary condition for experimental success and the lifespan of devices.

[0003] Currently, the main technical approaches to achieving a low-oxygen environment in confined spaces include:

[0004] Physical / chemical oxygen absorbers: These are disposable consumables that cannot be recycled and cannot achieve dynamic and precise control of oxygen concentration, resulting in high maintenance costs.

[0005] Physical vacuuming or nitrogen purging: This requires complex vacuum pumps, high-pressure nitrogen cylinders, or pressure swing adsorption (PSA) systems. Such devices are bulky, noisy, and energy-intensive, making them difficult to integrate into small household appliances such as refrigerators or portable food storage containers.

[0006] Traditional electrochemical oxygen pumps: Although they can achieve selective separation of oxygen, existing technologies have the following significant drawbacks:

[0007] Bulky structure: Traditional electrochemical systems typically include a separate electrolyte circulation pump, a storage tank, and a large flow field plate, resulting in a thick module that is difficult to meet the requirements of "ultra-thin" and "high integration" for consumer electronics products.

[0008] High internal resistance and low energy efficiency: If there is a gap between the anode and cathode and the membrane, it will result in a long ion transport path and a high polarization potential, which not only increases power consumption, but also makes it difficult to achieve a rapid reduction in the limiting oxygen concentration (such as below 1%).

[0009] Bubble buildup and corrosion issues: A large number of bubbles are generated during the oxygen evolution reaction (OER). These bubbles are prone to buildup and can lead to poor mass transfer, further increasing the energy consumption of the reaction. They can also cause local hot spots and corrosion, affecting the lifespan of the equipment.

[0010] To address the above problems, this invention is proposed. Summary of the Invention

[0011] This invention discloses an electrochemical oxygen atmosphere control system and method. The system employs a highly integrated layered structure, comprising, from bottom to top, a porous bottom cover, a first hydrophobic and breathable membrane, an oxygen-consuming cathode, a liquid-conducting diaphragm, an oxygen-evolving anode, a second hydrophobic and breathable membrane, and a porous top cover. Each component layer forms a zero-gap contact through the clamping force of the outer shell, enabling the system to achieve an ultra-thin thickness. The liquid-conducting diaphragm has transverse liquid-conducting channels extending to the external electrolyte chamber, utilizing capillary action to achieve rapid electrolyte replenishment and eliminate local hot spots. Through the coupling design between the hydrophobic and breathable membrane and the electrode interface, oxygen generated by the oxygen-evolving anode directly permeates and overflows in the form of gas molecules, effectively suppressing bubble formation and accumulation in traditional electrolysis processes, and significantly reducing the ohmic resistance of the interface and operating energy consumption. This invention features an extremely thin structure, high reaction efficiency, and no bubble interference, making it suitable for precise oxygen concentration control in spaces such as refrigerators and precision storage environments.

[0012] The first aspect of this application provides an electrochemical oxygen atmosphere control system, which includes: a porous bottom cover 7, a first hydrophobic and breathable membrane 1, an oxygen-consuming cathode 2, a liquid-conducting diaphragm 3, an oxygen-evolving anode 4, a second hydrophobic and breathable membrane 8, and a porous top cover 5 stacked sequentially from bottom to top.

[0013] The liquid-conducting diaphragm 3 is located between the oxygen-consuming cathode 2 and the oxygen-evolving anode 4, and is used to isolate the oxygen-consuming cathode 2 and the oxygen-evolving anode 4 and conduct ions;

[0014] The electrolyte chamber 52 is disposed on the porous top cover 5 or the porous bottom cover 7 and penetrates the porous top cover 5 or the porous bottom cover 7 so that the electrolyte in the electrolyte chamber 52 can contact the liquid-conducting diaphragm 3.

[0015] The area of ​​the liquid-conducting diaphragm 3 is larger than that of the oxygen-consuming cathode 2 or the oxygen-evolving anode 4, so that the extended portion of the liquid-conducting diaphragm 3 relative to the oxygen-consuming cathode 2 or the oxygen-evolving anode 4 can enter the interior of the electrolyte chamber 52 and come into contact with the electrolyte.

[0016] The porous bottom cover 7 has a through air intake hole 73, and the first hydrophobic and breathable membrane 1 covers the air intake hole 73 to allow air from the environment to enter the oxygen-consuming cathode 2 while preventing internal liquid from seeping out.

[0017] The porous top cover 5 has a through-hole gas evolution hole 51, and the second hydrophobic and breathable membrane 8 covers the gas evolution hole 51 to allow oxygen generated by the oxygen evolution anode 4 to overflow while preventing electrolyte loss.

[0018] More preferably, the porous top cover 5 is provided with gas evolution holes 51 in the area that overlaps with the oxygen evolution anode 4.

[0019] More preferably, an air intake hole 73 is provided on the area of ​​the porous bottom cover 7 that overlaps with the oxygen-consuming cathode 2.

[0020] Preferably, the porous bottom cover 7 and the porous top cover 5 are clamped together by external force to tightly press all the internal components of the porous bottom cover 7 and the porous top cover 5 together to form a zero-gap physical contact structure.

[0021] Preferably, the electrolyte chamber 52 is located at one end of the porous top cover 5 and extends through the porous top cover 5 so that the electrolyte in the electrolyte chamber 52 can contact the liquid-conducting diaphragm 3.

[0022] More preferably, the electrolyte chamber 52 is located in the area of ​​the porous top cover 5 where the gas separation holes 51 are not provided.

[0023] More preferably, a series of gas vents 51 are arrayed and spaced apart in a portion of the porous top cover 5. A series of gas intake vents 73 are arrayed and spaced apart in a portion of the porous bottom cover 7.

[0024] Preferably, the porous bottom cover 7 and / or the porous top cover 5 are provided with a sealing groove 72 on the inner side of the edge, and a sealing element is provided in the sealing groove 72 to achieve gas-liquid sealing at the edge.

[0025] Preferably, the surface of the oxygen-evolving anode 4 has a hydrophilic micro / nano structure. This structure, in conjunction with the zero-gap physical contact structure, allows the oxygen evolved on the oxygen-evolving anode 4 side to directly penetrate the second hydrophobic and breathable membrane 8 as gas molecules without accumulating into macroscopic bubbles, thereby reducing bubble accumulation and ohmic resistance on the oxygen-evolving anode 4 side.

[0026] The hydrophilic micro / nano structure is a catalyst layer supported on the surface of the porous conductive substrate.

[0027] Preferably, the liquid-conducting diaphragm 3 is provided with a transverse liquid-conducting groove 31 in the active area corresponding to the oxygen-consuming cathode 2 and the oxygen-evolving anode 4;

[0028] The transverse liquid guiding groove 31 is connected to the electrolyte tank 52 and is used to actively pump the electrolyte from the electrolyte tank 52 and distribute it evenly to the surface of the oxygen-consuming cathode 2 and the oxygen-evolving anode 4 through capillary force.

[0029] Preferably, the ends of the oxygen-consuming cathode 2 and the oxygen-evolving anode 4 are respectively provided with longitudinally extending conductive posts 54;

[0030] Both the porous top cover 5 and the liquid-conducting diaphragm 3 are provided with conductive post openings 53 that match the conductive posts 54. The conductive posts 54 pass through the conductive post openings 53 and extend to the outside of the system for connection to an external power source. The external power source supplies power to the oxygen-consuming cathode 2 and the oxygen-evolving anode 4 through the conductive posts 54.

[0031] Preferably, the conductive post 54 is integrally formed or connected with the oxygen-consuming cathode 2 or the oxygen-evolving anode 4.

[0032] Preferably, the liquid-conducting diaphragm 3 is a porous material selected from at least one of polyolefins, polyimide, polyethersulfone, polyvinylidene fluoride, ceramic composite diaphragms, or glass fiber diaphragms, and its thickness is 0.01 mm–5 mm.

[0033] Preferably, the porous bottom cover 7 and / or the porous top cover 5 are provided with a non-through longitudinal liquid guiding groove 71 near the edge;

[0034] One end of the longitudinal liquid guiding channel 71 extends to the electrolyte tank 52, and the other end intersects with multiple transverse liquid guiding channels 31 on the liquid guiding diaphragm 3 to form an orthogonal in-plane electrolyte distribution network for transporting and distributing electrolyte.

[0035] Preferably, the oxygen-consuming cathode 2 comprises a porous conductive substrate and an oxygen reduction electrocatalyst supported on its surface. The porous conductive substrate has a pore size of 100 nm–100 μm and is made of at least one material selected from carbon-based materials, metallic materials, or conductive polymer materials.

[0036] The oxygen reduction electrocatalyst includes at least one of noble metal catalysts, transition metal-nitrogen-carbon catalysts, transition metal oxides, transition metal hydroxides, transition metal sulfides, transition metal selenides, and transition metal phosphides.

[0037] The oxygen evolution anode 4 includes a porous conductive substrate and an oxygen evolution electrocatalyst supported on its surface;

[0038] The porous conductive substrate is made of at least one material selected from nickel foam, nickel felt, nickel mesh, titanium-based materials, stainless steel, or carbon-based materials.

[0039] Preferably, the oxygen evolution electrocatalyst comprises at least one of noble metal oxides, transition metal oxides, transition metal hydroxides, metal alloys, metal phosphides, metal sulfides, and metal nitrides.

[0040] The aforementioned conductive substrate can be manufactured in-house or purchased using existing technologies. The aforementioned catalyst can also be manufactured in-house or purchased using existing technologies.

[0041] Preferably, the electrolyte chamber 52 is located at one end of the porous top cover 5 and extends through the porous top cover 5 so that the electrolyte in the electrolyte chamber 52 can contact the liquid-conducting diaphragm 3;

[0042] The top of the electrolyte tank 52 is provided with a cover 6, which is used to seal the electrolyte tank 52 and prevent electrolyte leakage.

[0043] The cover 6 is detachably connected to the electrolyte tank 52, or can be sealed and fixed.

[0044] The electrolyte is an aqueous solution selected from at least one of pure water, neutral electrolyte, weakly alkaline electrolyte, buffer solution, or strongly alkaline electrolyte.

[0045] The bottom of the electrolyte tank 52 is sealed by the plate surface of the oxygen-consuming cathode 2.

[0046] Preferably, the electrolyte tank 52 is integrally formed on the porous top cover 5. Specifically, the surrounding walls of the electrolyte tank 52 are integrally formed with the porous top cover 5. The porous top cover 5 forms a hollow structure in the central region surrounded by the tank walls of the electrolyte tank 52.

[0047] There is a conductive post opening 53 between the electrolyte tank 52 and the gas evolution hole 51.

[0048] Preferably, the control system further includes: an oxygen concentration detector 9 and a control system 10.

[0049] The oxygen-consuming cathode 2 side is a sealed environment for oxygen atmosphere regulation; the oxygen-evolving anode 4 side is isolated from the sealed environment for oxygen atmosphere regulation.

[0050] The oxygen concentration detector 9 is configured to detect the oxygen concentration in the sealed environment to be oxygen atmosphere regulated.

[0051] The control system is electrically connected to the oxygen-consuming cathode 2 and the oxygen-evolving anode 4, and is also electrically connected to the oxygen concentration detector 9;

[0052] The control system is configured to receive feedback signals from the oxygen concentration detector 9 and dynamically adjust the voltage or current applied across the oxygen-consuming cathode 2 and the oxygen-evolving anode 4 to achieve precise control of the ambient oxygen concentration on the side of the oxygen-consuming cathode 2.

[0053] Of course, the control system without oxygen concentration detector 9 and control system can also be called a control device.

[0054] The second aspect of this application provides a method for controlling an electrochemical oxygen atmosphere, wherein the control method is performed using the control system described in the first aspect;

[0055] The control method includes the following steps:

[0056] The oxygen concentration data of the environment on the side of the oxygen-consuming cathode 2 is obtained in real time through the oxygen concentration detector 9.

[0057] The control system compares the oxygen concentration data with a preset low-oxygen preservation concentration threshold.

[0058] When the oxygen concentration in the environment on the side of the oxygen-consuming cathode 2 is higher than a preset threshold, the control system outputs a working current to regulate the electrolyte inside the system to automatically wet the oxygen-evolving anode 4 and the oxygen-consuming cathode 2 through the transverse liquid guide tank 31. The oxygen-consuming cathode 2 undergoes an oxygen reduction reaction to absorb oxygen from the air, and the oxygen-evolving anode 4 undergoes an oxygen evolution reaction to discharge oxygen to the outside of the environment on the side of the oxygen-consuming cathode 2, thereby continuously reducing the ambient oxygen concentration.

[0059] When the oxygen concentration in the environment on the oxygen-consuming cathode side 2 reaches or falls below a preset threshold, the control system reduces its operating power or stops supplying power, causing the control system to enter a dormant state.

[0060] Compared with the prior art, this application has the following advantages:

[0061] 1. Sustainable and noiseless operation: This control system achieves directional oxygen migration through a reversible cycle of cathode oxygen reduction and anodic oxygen evolution. It does not consume chemical reagents, and the reaction process has no moving mechanical parts, making it extremely quiet and suitable for home use.

[0062] 2. Precise oxygen concentration control: With the oxygen concentration detector and control system, the current density can be dynamically adjusted according to real-time feedback to accurately maintain the oxygen concentration in the sealed space at the preset low oxygen threshold (e.g., adjustable from 0.1% to 10%), meeting the preservation needs of different fruits, vegetables or biological samples.

[0063] 3. Ultra-thin structure for easy installation: This application achieves an integrated design and clamping zero-gap process for a "seven-layer structure" consisting of a porous bottom cover 7, a first hydrophobic and breathable membrane 1, a second hydrophobic and breathable membrane 8, and a porous top cover 5. This is achieved through the design of a porous bottom cover 7, a first hydrophobic and breathable membrane 1, an oxygen-consuming cathode 2, a liquid-conducting diaphragm 3, an oxygen-evolving anode 4, a second hydrophobic and breathable membrane 8, and a porous top cover 5. This allows the thickness of the main body of the control system to be compressed to less than 6mm, greatly saving space and making it easy to embed in refrigerators, food storage containers, or other small sealed containers.

[0064] 4. Low energy consumption operation: The zero-gap structure shortens the ion transport path and significantly reduces the internal resistance of the control system; combined with a highly efficient catalyst, the control system requires only extremely low maintenance power when maintaining a low oxygen state.

[0065] 5. No bubble or hot spot risks: In the preferred technical solution, the catalyst layer of the oxygen evolution anode 4 in this application is a hydrophilic micro / nano structure. Through the micro / nano hydrophilic structure design on the anode surface, combined with the second hydrophobic and breathable membrane 8, a hydrophilic-hydrophobic Janus electrode is formed, allowing the generated oxygen to escape rapidly in molecular form, avoiding the problems of increased ohmic resistance and localized heating caused by the accumulation of macroscopic bubbles on the electrode surface. Simultaneously, the orthogonal electrolyte distribution network ensures uniform distribution and rapid replenishment of the electrolyte, effectively preventing localized drying and hot spot corrosion of the electrode, and extending the service life of the control system. Attached Figure Description

[0066] Figure 1 This is a schematic diagram of the overall explosion structure of the electrochemical oxygen atmosphere control system provided in an embodiment of the present invention.

[0067] Figure 2 This is a partial structural and assembly diagram of the fluid guiding system provided in an embodiment of the present invention.

[0068] Figure 3 This is a performance comparison diagram of the zero-gap structure and the non-zero-gap structure in the embodiments of the present invention.

[0069] Figure 4 This is a characteristic curve of the oxygen concentration decrease over time in a standard enclosed space according to an embodiment of the present invention.

[0070] Figure 5 This is a comparison curve of the long-term operational stability of Embodiment 1 of the present invention in bubble-free electrolysis mode and conventional bubble electrolysis mode.

[0071] Figure 6 The diagram shows the overall composition and connection principle of the electrochemical oxygen atmosphere control system provided in the embodiment of the present invention.

[0072] List of reference numerals in the attached diagram:

[0073] 1. First hydrophobic and breathable membrane; 2. Oxygen-consuming cathode; 3. Liquid-conducting diaphragm; 31. Transverse liquid-conducting groove; 4. Oxygen-evolving anode; 5. Porous top cover; 51. Gas evolution hole; 52. Electrolyte tank; 53. Conductive column opening; 54. Conductive column; 6. Cover; 7. Porous bottom cover; 71. Longitudinal liquid-conducting groove; 72. Sealing groove; 73. Air intake hole; 8. Second hydrophobic and breathable membrane; 9. Oxygen concentration detector; 10. Control system. Detailed Implementation

[0074] The present invention will be described below with reference to specific embodiments, but the implementation of the present invention is not limited thereto. Experimental methods not specifically described in the embodiments generally use conventional conditions and conditions described in the manual, or conditions recommended by the manufacturer. The general equipment, materials, reagents, etc., used are all commercially available unless otherwise specified. The raw materials used in the following embodiments and comparative examples are all commercially available.

[0075] The purpose of this invention is to provide an electrochemical oxygen atmosphere control system and its control method to solve the problems of large volume, high energy consumption, difficulty in precise control, and bubble accumulation during the electrolysis process in existing deoxygenation technologies.

[0076] To achieve the above objectives, the present invention adopts the following technical solution:

[0077] The present invention provides an electrochemical oxygen atmosphere control system, comprising: a porous bottom cover 7, a first hydrophobic and breathable membrane 1, an oxygen-consuming cathode 2, a liquid-conducting diaphragm 3, an oxygen-evolving anode 4, a second hydrophobic and breathable membrane 8, and a porous top cover 5 arranged sequentially from bottom to top.

[0078] The liquid-conducting diaphragm 3 is located between the oxygen-consuming cathode 2 and the oxygen-evolving anode 4, serving to isolate the anode and cathode and conduct ions. The porous bottom cover 7 and the porous top cover 5 are clamped together by external force to tightly press all internal components together, forming a zero-gap physical contact structure. The control system also integrates an electrolyte tank 52. The area of ​​the liquid-conducting diaphragm 3 is larger than that of the oxygen-consuming cathode 2 and the oxygen-evolving anode 4, and its extended portion enters the interior of the electrolyte tank 52 and comes into contact with the electrolyte.

[0079] Preferably, the porous bottom cover 7 has a through air intake hole 73, and the first hydrophobic and breathable membrane 1 covers the air intake hole 73, allowing air from the environment to enter the oxygen-consuming cathode 2 while preventing internal liquid from seeping out.

[0080] The porous top cover 5 has a through-hole gas evolution hole 51, and the second hydrophobic and breathable membrane 8 covers the gas evolution hole 51, allowing the oxygen generated by the oxygen evolution anode 4 to overflow while preventing the electrolyte from being lost.

[0081] The porous bottom cover 7 and / or the porous top cover 5 are provided with sealing grooves 72 on the inner side of their edges to achieve gas-liquid sealing at the edges.

[0082] Preferably, the ends of the oxygen-consuming cathode 2 and the oxygen-evolving anode 4 are integrally formed or connected with longitudinally extending conductive posts 54. The porous top cover 5 and / or the liquid-conducting diaphragm 3 are provided with conductive post openings 53 that match the conductive posts 54. The conductive posts 54 pass through the conductive post openings 53 and are led out to the outside of the control system for connection to an external power source.

[0083] Preferably, the liquid-conducting diaphragm 3 is a porous material selected from at least one of polyolefins, polyimide, polyethersulfone, polyvinylidene fluoride, ceramic composite diaphragms, or glass fiber diaphragms, and its thickness is 0.01 mm–5 mm.

[0084] The liquid-conducting diaphragm 3 has multiple parallel and spaced transverse liquid-conducting grooves 31 in the active areas corresponding to the oxygen-consuming cathode 2 and the oxygen-evolving anode 4. The transverse liquid-conducting grooves 31 are connected to the electrolyte tank 52 and are used to actively pump the electrolyte from the electrolyte tank 52 and distribute it evenly to the electrode working surface through capillary force to eliminate local hot spots.

[0085] The transverse liquid guiding groove 31 refers to the groove that extends along the width direction of the liquid guiding diaphragm 3.

[0086] Preferably, the surfaces of the porous bottom cover, the first hydrophobic and breathable membrane, the oxygen-consuming cathode, the liquid-conducting diaphragm, the oxygen-evolving anode, the second hydrophobic and breathable membrane, and the porous top cover are all basically rectangular.

[0087] Preferably, the porous bottom cover 7 and / or the porous top cover 5 are provided with non-through longitudinal liquid guiding grooves 71 near the edge. One end of the longitudinal liquid guiding groove 71 extends to the electrolyte tank 52, and the other end intersects with multiple transverse liquid guiding grooves 31 on the liquid guiding diaphragm 3, forming an orthogonal in-plane electrolyte distribution network. In this way, through the capillary action of the liquid guiding diaphragm 3 itself, and the rapid distribution effect of the transverse liquid guiding grooves 31 and the longitudinal liquid guiding grooves 71, the electrolyte can quickly and uniformly wet the liquid guiding diaphragm 3.

[0088] The longitudinal liquid guide groove 71 refers to the groove that extends along the length of the porous bottom cover 7 and / or the porous top cover 5.

[0089] The longitudinal liquid guiding groove 71 is located inside the sealing groove 72.

[0090] Preferably, the oxygen-consuming cathode 2 comprises a porous conductive substrate and an oxygen reduction electrocatalyst supported on its surface. The porous conductive substrate has a pore size of 100 nm–100 μm, and the material is selected from at least one of carbon-based materials, metallic materials, or conductive polymer materials. The oxygen reduction electrocatalyst comprises at least one of noble metal catalysts, transition metal-nitrogen-carbon catalysts, transition metal oxides, transition metal hydroxides, transition metal sulfides, transition metal selenides, and transition metal phosphides.

[0091] Preferably, the oxygen evolution anode 4 comprises a porous conductive substrate and an oxygen evolution electrocatalyst supported on its surface. The porous conductive substrate is selected from at least one of nickel foam, nickel felt, nickel mesh, titanium-based materials, stainless steel, or carbon-based materials. The oxygen evolution electrocatalyst comprises at least one of noble metal oxides, transition metal oxides, transition metal hydroxides, metal alloys, metal phosphides, metal sulfides, and metal nitrides.

[0092] Preferably, the surface of the oxygen evolution anode 4 has a hydrophilic micro / nano structure. This structure, in conjunction with the zero-gap physical contact structure, allows the oxygen evolved on the anode side to directly penetrate the second hydrophobic and breathable membrane 8 as gas molecules without accumulating into macroscopic bubbles, thereby reducing bubble accumulation and ohmic resistance on the OER side.

[0093] Preferably, the electrolyte chamber 52 is disposed on one side of the porous top cover 5, and the top of the electrolyte chamber 52 is equipped with a removable or sealed cover 6. The electrolyte is an aqueous solution selected from at least one of pure water, neutral electrolyte, weakly alkaline electrolyte, buffer solution, or strongly alkaline electrolyte.

[0094] Furthermore, the present invention also provides an electrochemical oxygen atmosphere control system, comprising:

[0095] Oxygen concentration detector 9 is used to detect the oxygen concentration in a confined space environment;

[0096] And a control system, which is electrically connected to the conductive post 54 and the oxygen concentration detector 9;

[0097] The control system is configured to receive feedback signals from the oxygen concentration detector 9 and dynamically adjust the voltage or current applied across the oxygen-consuming cathode 2 and the oxygen-evolving anode 4 to achieve precise control of the ambient oxygen concentration.

[0098] The present invention also provides a control method based on the above system, comprising:

[0099] The oxygen concentration detector 9 acquires ambient oxygen concentration data in real time.

[0100] The control system compares the oxygen concentration data with a preset low-oxygen preservation concentration threshold.

[0101] When the ambient oxygen concentration is higher than the preset threshold, the control system outputs the working current and regulates the electrolyte inside the system to automatically wet the electrode through the transverse liquid guide tank 31. The oxygen-consuming cathode 2 undergoes an oxygen reduction reaction to absorb oxygen from the air, and the oxygen-evolving anode 4 undergoes an oxygen evolution reaction to release oxygen, thereby continuously reducing the ambient oxygen concentration.

[0102] When the ambient oxygen concentration reaches or falls below a preset threshold, the control system reduces operating power or stops supplying power.

[0103] Example 1: An electrochemical oxygen atmosphere control system and its preparation method

[0104] This embodiment provides an ultrathin, bubble-free electrochemical oxygen atmosphere control system, such as... Figure 1 As shown, its main body consists of a porous bottom cover 7, a first hydrophobic and breathable membrane 1, an oxygen-consuming cathode 2, a liquid-conducting diaphragm 3, an oxygen-evolving anode 4, a second hydrophobic and breathable membrane 8, and a porous top cover 5 arranged sequentially from bottom to top.

[0105] 1. The specific parameters and manufacturing process of the core components are as follows:

[0106] The first hydrophobic and breathable membrane 1 and the second hydrophobic and breathable membrane 8 are both made of polytetrafluoroethylene (PTFE) porous membrane material, with a thickness of 20 μm and a porosity of 75%. These parameters ensure high-flux gas molecule penetration while utilizing the high surface tension of PTFE to perfectly block leakage of 1M potassium hydroxide (KOH) electrolyte. The PTFE porous membranes were purchased from Dongyue Group.

[0107] Oxygen-consuming cathode 2 (ORR electrode): Employs a composite bilayer structure. First, a hydrophobic gas diffusion layer is prepared: carbon black and PTFE binder are mixed at a mass ratio of 7:3, and ammonium chloride (NH4Cl) is added as a pore-forming material. The mixture is then pressed into a film using a hot roll forming method, followed by heat treatment at 200°C to sublimate the ammonium chloride, forming a hydrophobic layer with abundant micropores, serving as a hydrophobic porous conductive substrate. Subsequently, a catalyst layer is loaded onto the hydrophobic porous conductive substrate using a blade coating or spray coating method. The catalyst material is a Co-NC (cobalt-nitrogen-carbon) non-precious metal catalyst, mixed with an appropriate amount of PTFE binder. The catalyst loading is controlled at 1.5-2.5 mg / cm³. 2 Co-NC materials exhibit excellent oxygen reduction catalytic activity and are unaffected by high humidity environments.

[0108] Co-NC (cobalt-nitrogen-carbon) non-precious metal catalysts can be prepared using existing technologies. In this embodiment, the specific preparation steps for Co-NC are as follows: 2.91 g of cobalt nitrate and 6.56 g of 2-methylimidazole are dissolved in 150 mL of methanol, mixed, and stirred at 25°C for 6 hours. After washing and vacuum drying at 60°C, ZIF-67 is obtained. Subsequently, the mixture is pyrolyzed at 800°C for 2 hours under nitrogen atmosphere at a rate of 5°C / min. Finally, it is acid-washed with 0.5 M sulfuric acid at 80°C for 8 hours, and after washing and drying, the final product is obtained. The atomic percentages of the Co-NC catalyst are approximately 90.5% carbon, 8.2% nitrogen, and 1.3% cobalt.

[0109] Oxygen Evolution Anode 4 (OER Electrode): A woven nickel mesh with a three-dimensional porous structure is used as a substrate. A NiFe-LDH (nickel-iron layered double hydroxide) catalyst is grown in situ on its surface via hydrothermal synthesis. The specific steps are as follows: Nickel nitrate and ferric nitrate are dissolved in deionized water at a molar ratio of 3:1. Urea is added as a precipitant. The cleaned nickel mesh is placed in a reaction vessel, and a hydrothermal reaction is carried out at 120°C for 10-12 hours. After washing and drying, a hydrophilic catalyst layer with a micro / nanosheet structure is formed on the surface of the nickel mesh.

[0110] Liquid-conducting diaphragm 3: A porous glass fiber diaphragm with a thickness of 500 μm is selected. For example... Figure 2 As shown, the glass fiber diaphragm is pressed by a metal roller with a specific raised pattern to physically imprint multiple parallel transverse liquid guiding grooves 31 on a portion of the diaphragm surface using a rolling method.

[0111] 2. Assembly and integration of the control system:

[0112] Both the porous bottom cover 7 and the porous top cover 5 are made of alkali-resistant engineering plastics (such as ABS or PP materials) and are injection molded through three-dimensional modeling.

[0113] To extract internal electrical energy, holes are drilled in the inactive areas at the ends of the oxygen-consuming cathode 2 and the oxygen-evolving anode 4 (i.e., the areas extending beyond the transverse liquid-conducting groove 31 of the liquid-conducting diaphragm 3). Two corrosion-resistant 316L stainless steel bolts and nuts are used to pass through the holes and tighten them, forming conductive posts 54 that extend to the outside of the control system. Corresponding conductive post openings 53 are pre-drilled on the porous top cover 5. Corresponding conductive post openings 53 are also pre-drilled on the corresponding parts of the liquid-conducting diaphragm 3. Two 316L stainless steel bolts extend from the conductive post openings 53 to the outside of the control system for connecting the positive and negative terminals of the power supply, respectively.

[0114] The dimensions of the inner cavity of the liquid-conducting diaphragm 3, the porous bottom cover 7, and the porous top cover 5 are basically the same.

[0115] The oxygen-consuming cathode 2 body, the oxygen-evolving anode 4 body, the first hydrophobic and breathable membrane 1, the second hydrophobic and breathable membrane 8, the transverse liquid guiding groove 31 area of ​​the liquid guiding diaphragm 3, the gas evolution hole 51 area of ​​the porous bottom cover 7, and the air intake hole 73 area of ​​the porous top cover 5 have basically the same area and basically overlap vertically.

[0116] The seven-layer components are sequentially placed into the porous bottom cover 7, and compressed using the mechanical tolerances of the injection-molded shell. At this time, the side of the liquid-conducting diaphragm 3 extends into the electrolyte tank 52 integrally formed on one side of the porous top cover 5. After compression, alkali-resistant epoxy resin adhesive is injected into the joint between the porous bottom cover 7 and the porous top cover 5, as well as into the opening 53 of the conductive post, for bonding and sealing, forming an integral zero-gap module with a thickness of less than 6mm. At this time, the epoxy resin adhesive cures in the sealing groove 72 to form a seal.

[0117] Finally, open the cover 6 on top of the electrolyte tank 52 and inject an appropriate amount of 1M KOH aqueous solution. The electrolyte, relying on capillary force, quickly penetrates and evenly wets the entire anode and cathode interface along the transverse liquid guide groove 31 on the liquid guide diaphragm 3 and the longitudinal liquid guide groove 71 on the porous bottom cover 7. The control system can then enter the working preparation state.

[0118] Example 2: An electrochemical oxygen atmosphere control system and its working logic

[0119] like Figure 6 As shown, the electrochemical oxygen atmosphere control system also includes: an oxygen concentration detector 9 (electrochemical oxygen sensor) and a control system (including a microcontroller MCU and drive circuit).

[0120] Of course, the electrochemical oxygen atmosphere control system that does not include the oxygen concentration detector 9 (electrochemical oxygen sensor) and the control system (including the microcontroller MCU and drive circuit) can also be called an electrochemical oxygen atmosphere control device.

[0121] The electrochemical oxygen atmosphere control system is installed as follows: the environment on the side of the oxygen-consuming cathode 2 is a sealed environment where oxygen atmosphere control is to be performed, and the oxygen-evolving anode 4 is isolated from the sealed environment where oxygen atmosphere control is to be performed. For example, the electrochemical oxygen atmosphere control system is installed on the top wall of the sealed environment, so that the oxygen-consuming cathode 2 faces the sealed environment, and the oxygen-evolving anode 4 faces the external environment. The oxygen concentration detector 9 is configured to detect the oxygen concentration of the sealed environment where oxygen atmosphere control is to be performed.

[0122] Of course, the electrochemical oxygen atmosphere control system can also be installed sideways on the side wall of a sealed environment. When installed sideways, the cover 6 needs to seal the electrolyte tank 52 properly.

[0123] The control methods of the control system are as follows:

[0124] Users can set the target oxygen concentration (e.g., 11%) in the control system according to the preservation requirements of different fruits, vegetables or items.

[0125] The control system collects the oxygen concentration in the sealed container in real time through the oxygen concentration detector 9. When the detected concentration is higher than 15%, the control system outputs a DC operating current (e.g., applying a tank voltage of 1.2V-1.5V) to the conductive column 54 of the electrochemical oxygen atmosphere control device. At this time, the oxygen-consuming cathode 2 at the bottom reduces the oxygen in the incoming air to hydroxide ions; the hydroxide ions migrate through the liquid-conducting diaphragm 3 to the oxygen-evolving anode 4 at the top, undergo an oxygen evolution reaction to regenerate oxygen, and are discharged into the external environment through the gas evolution hole 51, thereby continuously reducing the oxygen concentration in the sealed space.

[0126] When the oxygen concentration reaches the set threshold of 15%, the control system cuts off the power supply or switches to a very small standby current, and the device stops pumping oxygen and enters a dormant state.

[0127] Example 3: Device Performance Verification and Comparative Experimental Analysis

[0128] To verify the superior performance of the electrochemical oxygen atmosphere control device of the present invention, the following comparative tests were conducted. The test results are combined with the appendix. Figures 3 to 5 Please provide an explanation.

[0129] 1. The effect of zero-gap structure on reducing ohmic internal resistance ( Figure 3 )

[0130] Figure 3 This is a comparison chart of the linear sweep voltammetry (LSV) performance of the "zero-gap structure" in this embodiment of the invention and the traditional "non-zero-gap structure".

[0131] The test conditions for the non-zero gap structure are as follows: remove the liquid-conducting diaphragm 3, immerse the anode directly in 1 MkOH solution, and maintain a physical distance of 6 mm between the anode and cathode. Other structures, including the anode and cathode structures, the first hydrophobic and breathable membrane, and the second hydrophobic and breathable membrane, remain unchanged. During installation, the cathode and anode are limited by adding snap-fit ​​groove structures to the edges of the cathode and anode. In specific operation, the porous bottom cover 7 and porous top cover 5 are printed using 3D printing. The cathode and anode are inserted into the grooves of the porous top cover 5 and porous bottom cover 7, and the edges are sealed with glue to achieve a 6 mm anode-cathode distance.

[0132] Depend on Figure 3 It is known that at extremely low currents, the initial potentials of the two structures are similar; however, in the high current range (e.g., when the current is greater than 1000mA), the advantages of the zero-gap structure are extremely obvious. This is because the clamping zero-gap structure of this invention compresses the ion transport distance to the thickness of the membrane (only 500μm), greatly reducing the ohmic voltage drop of the solution. Under the same set voltage (e.g., 1.3V), the current growth rate of the zero-gap structure is much greater than that of the non-zero-gap structure, exhibiting extremely high oxygen removal efficiency.

[0133] 2. Actual deoxygenation capacity test in a confined space ( Figure 4 )

[0134] The electrochemical oxygen atmosphere control system of Example 1 was installed on top of a standardized 10L sealed food storage container. The installation method was such that the oxygen-consuming cathode 2 faced the sealed environment, and the oxygen-evolving anode 4 faced the external environment. Initially, the environment of the sealed food storage container was ambient air (oxygen concentration approximately 21%). The electrochemical oxygen atmosphere control system was turned on and operated at constant power. Figure 4As shown, the oxygen concentration exhibits a nearly linear and stable decreasing trend over time. After approximately 80 minutes of operation, the oxygen concentration inside the sealed container successfully decreased from 21% to 11%. This curve demonstrates that the device of this invention possesses efficient and rapid atmosphere control capabilities in practical applications.

[0135] 3. Improved long-term stability due to the bubble-free double-layer hydrophobic membrane mode ( Figure 5 )

[0136] Traditional electrochemical deoxygenation or water electrolysis equipment generates a large number of oxygen bubbles on the anode side. These bubbles adhere to the electrode plates and diaphragm, causing a severe "bubble shielding effect" that leads to localized hot spots and corrosion.

[0137] This invention creates a "bubble-free working mode" by covering the oxygen-evolving anode 4 with a second hydrophobic and breathable membrane 8: the oxygen generated at the anode is directly discharged in the form of gas molecules through the PTFE micropores at the gas-liquid-solid three-phase interface, and the generation and aggregation of bubbles cannot be observed macroscopically.

[0138] To verify its effectiveness, Figure 5 A comparison of stability under long-term constant current operation was conducted. The test current was 3A constant current.

[0139] The conventional mode refers to modifying Example 1 under the conventional mode, specifically by removing the second hydrophobic and breathable membrane 8 while keeping the rest of the structure unchanged to achieve zero-gap assembly. This modification is achieved by using 3D printing technology combined with adhesives to fabricate a 2 cm high sealed hollow enclosure above the porous top cover 5, and then sealing the edges of the enclosure to the porous top cover 5 with adhesive. Subsequently, an electrolyte is filled inside the enclosure, directly exposing the oxygen-evolving anode 4 to the electrolyte, thereby generating bubbles in the electrolyte and driving the operation. The electrolyte also directly covers all the gas evolution pores 51.

[0140] The bubble-free operating mode is the operating mode of the electrochemical oxygen atmosphere control system of Example 1.

[0141] Depend on Figure 5 As can be seen, in the conventional bubble-filled mode, after approximately 700 hours of operation, the voltage fluctuates drastically or even spikes due to bubble accumulation causing localized drying and a sharp increase in internal resistance, leading to electrode failure. In contrast, the "bubble-free operating mode" of this invention maintains a highly stable voltage curve with no significant attenuation throughout a 2800-hour testing period, demonstrating a stability lifespan improvement of more than four times. This fully proves the scientific merit and long-term reliability of the stacked zero-gap structure combined with the liquid guiding groove design of this invention.

Claims

1. An electrochemical oxygen atmosphere control system, characterized in that, The control system includes: a porous bottom cover (7), a first hydrophobic and breathable membrane (1), an oxygen-consuming cathode (2), a liquid-conducting diaphragm (3), an oxygen-evolving anode (4), a second hydrophobic and breathable membrane (8), and a porous top cover (5) stacked from bottom to top. The liquid-conducting diaphragm (3) is located between the oxygen-consuming cathode (2) and the oxygen-evolving anode (4) to isolate the oxygen-consuming cathode (2) and the oxygen-evolving anode (4) and to conduct ions; The electrolyte chamber (52) is disposed on the porous top cover (5) or the porous bottom cover (7) and penetrates the porous top cover (5) or the porous bottom cover (7) so that the electrolyte in the electrolyte chamber (52) can contact the liquid-conducting diaphragm (3); The area of ​​the liquid-conducting diaphragm (3) is larger than that of the oxygen-consuming cathode (2) or the oxygen-evolving anode (4) so ​​that the extension of the liquid-conducting diaphragm (3) relative to the oxygen-consuming cathode (2) or the oxygen-evolving anode (4) can enter the interior of the electrolyte tank (52) and come into contact with the electrolyte. The porous bottom cover (7) has a through air intake hole (73), and the first hydrophobic and breathable membrane (1) covers the air intake hole (73) to allow air from the environment to enter the oxygen-consuming cathode (2) while preventing internal liquid from seeping out. The porous top cover (5) has through-holes (51) for gas evolution. The second hydrophobic and breathable membrane (8) covers the gas evolution holes (51) to allow oxygen generated by the oxygen evolution anode (4) to overflow while preventing electrolyte loss.

2. The electrochemical oxygen atmosphere control system according to claim 1, characterized in that, The porous bottom cover (7) and the porous top cover (5) are clamped together by external force to tightly press all the internal components of the porous bottom cover (7) and the porous top cover (5) together to form a zero-gap physical contact structure.

3. The electrochemical oxygen atmosphere control system according to claim 1, characterized in that, The electrolyte chamber (52) is located at one end of the porous top cover (5) and extends through the porous top cover (5) so that the electrolyte in the electrolyte chamber (52) can contact the liquid-conducting diaphragm (3).

4. The electrochemical oxygen atmosphere control system according to claim 1, characterized in that, The porous bottom cover (7) and / or the porous top cover (5) are provided with a sealing groove (72) on the inner side of the edge, and a sealing element is provided in the sealing groove (72) to achieve gas-liquid sealing at the edge.

5. The electrochemical oxygen atmosphere control system according to claim 1, characterized in that, The surface of the oxygen evolution anode (4) has a hydrophilic micro / nano structure.

6. The electrochemical oxygen atmosphere control system according to claim 1, characterized in that, The liquid-conducting diaphragm (3) has a transverse liquid-conducting groove (31) in the active area corresponding to the oxygen-consuming cathode (2) and the oxygen-evolving anode (4). The transverse liquid guide groove (31) is connected to the electrolyte tank (52) and is used to actively pump the electrolyte from the electrolyte tank (52) and distribute it evenly to the surface of the oxygen-consuming cathode (2) and the oxygen-evolving anode (4) by capillary force.

7. The electrochemical oxygen atmosphere control system according to claim 6, characterized in that, The porous bottom cover (7) and / or the porous top cover (5) are provided with non-through longitudinal liquid guiding grooves (71). One end of the longitudinal liquid guiding channel (71) extends to the electrolyte tank (52), and the other end intersects with multiple transverse liquid guiding channels (31) on the liquid guiding diaphragm (3) to transport and distribute the electrolyte.

8. The electrochemical oxygen atmosphere control system according to claim 1, characterized in that, The oxygen-consuming cathode (2) includes a porous conductive substrate and an oxygen reduction electrocatalyst supported on its surface; The oxygen reduction electrocatalyst includes at least one of noble metal catalysts, transition metal-nitrogen-carbon catalysts, transition metal oxides, transition metal hydroxides, transition metal sulfides, transition metal selenides, and transition metal phosphides. The oxygen evolution anode (4) includes a porous conductive substrate and an oxygen evolution electrocatalyst supported on its surface; The oxygen evolution electrocatalyst includes at least one of noble metal oxides, transition metal oxides, transition metal hydroxides, metal alloys, metal phosphides, metal sulfides, and metal nitrides.

9. The electrochemical oxygen atmosphere control system according to claim 1, characterized in that, The control system also includes: an oxygen concentration detector (9) and a control system. The oxygen-consuming cathode (2) side environment is a sealed environment for oxygen atmosphere regulation, and the oxygen-evolving anode (4) side is isolated from the sealed environment for oxygen atmosphere regulation. The oxygen concentration detector (9) is configured to detect the oxygen concentration of the sealed environment to be oxygen atmosphere regulated. The control system is electrically connected to the oxygen-consuming cathode (2) and the oxygen-evolving anode (4), and is also electrically connected to the oxygen concentration detector (9); The control system is configured to receive feedback signals from the oxygen concentration detector (9) and dynamically adjust the voltage or current applied across the oxygen-consuming cathode (2) and the oxygen-evolving anode (4) to achieve precise control of the ambient oxygen concentration on the side of the oxygen-consuming cathode (2).

10. A method for controlling an electrochemical oxygen atmosphere, characterized in that, The control method is performed using the control system described in claim 9; The control method includes the following steps: The oxygen concentration data of the environment on the oxygen-consuming cathode (2) side is obtained in real time through the oxygen concentration detector (9); The control system compares the oxygen concentration data with a preset low-oxygen preservation concentration threshold. When the oxygen concentration in the environment on the side of the oxygen-consuming cathode (2) is higher than the preset threshold, the control system outputs the working current, and the electrolyte inside the device automatically wets the oxygen-evolving anode (4) and the oxygen-consuming cathode (2) through the transverse liquid guide tank (31). The oxygen-consuming cathode (2) undergoes an oxygen reduction reaction to absorb oxygen from the air, and the oxygen-evolving anode (4) undergoes an oxygen evolution reaction to discharge oxygen to the outside of the environment on the side of the oxygen-consuming cathode (2), thereby continuously reducing the ambient oxygen concentration. When the oxygen concentration in the environment on the oxygen-consuming cathode (2) side reaches or falls below a preset threshold, the control system reduces the operating power or stops supplying power, causing the device to enter a dormant state.

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