Capillary electrolytic cell for producing hydrogen by electrolyzing water
By using anode capillary gas diffusion layer in PEM electrolytic hydrogen production equipment, the problem of oxygen bubble blockage is solved, the hydrogen production efficiency and the operationality of the equipment are improved, and it is suitable for industrial promotion.
Patent Information
- Application Number
- CN202421568875.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-04
- Publication Date
- 2025-06-10
- Estimated Expiration
- 2034-07-04
AI Technical Summary
During the PEM electrolysis of water hydrogen production, oxygen bubbles can easily block the porous channels of the anode gas diffusion layer, resulting in the liquid phase water transfer being blocked and the efficiency of the electrolytic cell is reduced.
The anode capillary gas diffusion layer is used to accelerate the gas diffusion rate through capillary phenomena, promote the circulation of water and the discharge of oxygen, and avoid bubble blockage.
It effectively improves the efficiency of hydrogen production by electrolyzing water, simplifies the flow path processing of the anode plate, reduces costs, and simplifies the installation process of the electrolytic cell.
Smart Images
Figure CN222961561U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of electrolytic water hydrogen production equipment, in particular to a capillary electrolytic cell for electrolytic water hydrogen production. Background Technique
[0002] Due to its short start-stop time, high hydrogen purity, environmental friendliness, easy response to the volatility of renewable energy, and the ability to convert electrical energy into hydrogen energy for storage, the PEM (Proton Exchange Membrane) electrolytic water hydrogen production technology is considered to be one of the ideal candidate technologies for large-scale hydrogen production and has developed rapidly in recent years.
[0003] The PEM electrolytic cell is the core part of the entire PEM electrolytic water hydrogen production system. By applying a certain voltage on both sides of the PEM electrolytic cell electrodes, water molecules will undergo an oxidation reaction at the anode to precipitate oxygen and a reduction reaction at the cathode to precipitate hydrogen, thereby realizing the decomposition of electrolytic water into oxygen and hydrogen.
[0004] The PEM electrolytic cell mainly consists of a proton exchange membrane, anode and cathode catalyst layers, anode and cathode gas diffusion layers, anode and cathode plates, and anode and cathode end plates from the inside to the outside. Among them, the proton exchange membrane, anode and cathode catalyst layers, and anode and cathode gas diffusion layers are also called the membrane electrode (MEA), which is the main place for mass transfer and electrochemical reactions during the entire water electrolysis process. The structure and performance of the membrane electrode directly affect the hydrogen production efficiency and lifespan of the PEM electrolytic cell. Among them, the main function of the proton exchange membrane is to achieve rapid proton conduction while blocking hydrogen and oxygen, with the characteristics of high proton conductivity, low gas permeability, and electron insulation. The most commonly used proton exchange membrane is the perfluorosulfonic acid membrane. The anode and cathode catalyst layers are mainly composed of precious metals. The cathode catalyst mainly uses Pt, Pd precious metals and their alloys, while the anode catalyst selects a few precious metals such as Ir, Ru or their oxides as catalyst materials. The anode and cathode diffusion layers mainly use porous materials as the transmission medium. The cathode gas diffusion layer mainly uses carbon paper to achieve hydrogen transmission. Since the anode gas diffusion layer is in an acidic environment and controls the transmission of water and oxygen at the same time, currently mainly porous titanium and titanium felt are used. During the electrolytic water process, the liquid water passes through the porous channels of the anode gas diffusion layer to the anode catalyst layer. As the electrochemical reaction proceeds, oxygen molecules nucleate and aggregate in the form of bubbles in the pore channels at the reaction sites and are difficult to exclude, which will cause pore blockage and hinder the transmission of liquid water, reducing the efficiency of the electrolytic cell. During the electrolytic water process, oxygen is continuously generated at the anode, and it is inevitable that the generated oxygen bubbles block the porous channels of the gas diffusion layer. Summary of the Invention
[0005] The purpose of the present utility model is to provide a capillary electrolytic cell for hydrogen production by electrolyzing water. By setting an anode capillary gas diffusion layer, the diffusion rate of gas is accelerated. Through capillary action, the circulation of water and the discharge of oxygen can be accelerated, solving the problem of oxygen bubbles blocking the porous channels, effectively improving the efficiency of hydrogen production by electrolyzing water. Through capillary action, the function of current collection can be achieved, and the corresponding anode plate does not need to be processed with flow channels, solving the difficulty of processing the flow channels of the anode plate, thereby reducing the cost of the anode plate. Moreover, the installation process of the electrolytic cell is simple, easy to operate, and the components are easily available, making it suitable for wide industrial promotion.
[0006] To achieve the above object, the present utility model provides a capillary electrolytic cell for hydrogen production by electrolyzing water, including a proton exchange membrane. One side of the proton exchange membrane is provided with an anode unit, and the other side is provided with a cathode unit. An oxygen outlet hole and a water inlet hole are provided at the anode unit, and a hydrogen outlet hole is provided at the cathode unit. The anode unit, the proton exchange membrane, and the cathode unit are connected through a fixing screw passing through.
[0007] Preferably, the anode unit includes an anode end plate. An anode insulating plate is provided inside the anode end plate. An anode plate is provided inside the anode insulating plate. An anode capillary gas diffusion layer is provided inside the anode plate. An anode catalyst layer is provided inside the anode capillary gas diffusion layer. The anode capillary gas diffusion layer and the anode catalyst layer are sealed by an anode substrate. The anode catalyst layer is in contact with the proton exchange membrane.
[0008] Preferably, the cathode unit includes a cathode end plate. A cathode insulating plate is provided inside the cathode end plate. A cathode plate is provided inside the cathode insulating plate. A cathode gas diffusion layer is provided inside the cathode plate. A cathode catalyst layer is provided inside the cathode gas diffusion layer. The cathode gas diffusion layer and the cathode catalyst layer are sealed by a cathode substrate. The cathode catalyst layer is in contact with the proton exchange membrane.
[0009] Preferably, the cathode catalyst layer, the cathode gas diffusion layer, the anode capillary gas diffusion layer, the anode catalytic layer, and the proton exchange membrane are hot-pressed and formed by a hot press.
[0010] Preferably, the anode catalyst layer and the anode substrate are provided on one side of the proton exchange membrane, and the cathode catalyst layer and the cathode substrate are provided on the other side.
[0011] Preferably, the anode plate is one of a flow-channel anode plate or a non-flow-channel anode plate. Flow channels are provided on the flow-channel anode plate, and flow channels are provided on the cathode plate.
[0012] Preferably, the number of the fixing screws is eight. Fixing nuts are provided on the fixing screws, and gaskets are provided between the fixing nuts and the cathode end plate.
[0013] Therefore, the present utility model adopts the above-mentioned electrolytic water hydrogen production capillary electrolytic cell. By setting the anode capillary gas diffusion layer, the diffusion speed of gas is accelerated. Through the capillary phenomenon, the circulation of water and the discharge of oxygen can be accelerated, solving the problem of oxygen bubbles blocking the porous channels, effectively improving the efficiency of electrolytic water hydrogen production. Through the capillary phenomenon, the function of current collection can be realized, and the corresponding anode plate does not need to be processed with flow channels, solving the difficulty of processing the flow channels of the anode plate, thereby reducing the cost of the anode plate. Moreover, the installation process of the electrolytic cell is simple, easy to operate, and the components are easily available, which is suitable for wide industrial promotion.
[0014] The technical solution of the present utility model will be further described in detail below with reference to the drawings and embodiments. Description of the Drawings
[0015] Figure 1 is a reverse three-dimensional structural schematic diagram of an embodiment of the electrolytic water hydrogen production capillary electrolytic cell of the present utility model;
[0016] Figure 2 is a front three-dimensional structural schematic diagram of an embodiment of the electrolytic water hydrogen production capillary electrolytic cell of the present utility model;
[0017] Figure 3 is an internal sectional structural schematic diagram of an anode plate with flow channels in an embodiment of the electrolytic water hydrogen production capillary electrolytic cell of the present utility model;
[0018] Figure 4 is an internal sectional structural schematic diagram of an anode plate without flow channels in an embodiment of the electrolytic water hydrogen production capillary electrolytic cell of the present utility model.
[0019] Reference Numerals
[0020] 1. Anode end plate; 2. Anode insulating plate; 3. Anode plate with flow channels; 4. Anode substrate; 5. Anode capillary gas diffusion layer; 6. Anode catalyst layer; 7. Proton exchange membrane; 8. Cathode substrate; 9. Cathode catalyst layer; 10. Cathode gas diffusion layer; 11. Cathode plate; 12. Cathode insulating plate; 13. Cathode end plate; 14. Oxygen outlet hole; 15. Water inlet hole; 16. Hydrogen outlet hole; 17. Fixed screw; 18. Gasket; 19. Fixed nut; 20. Flow channel; 21. Anode plate without flow channels. Detailed Embodiments
[0021] The technical solution of the present utility model will be further described below with reference to the drawings and embodiments.
[0022] Unless otherwise defined, the technical terms or scientific terms used in this utility model shall have the ordinary meanings understood by those with ordinary skills in the field to which this utility model belongs. The "first", "second" and similar words used in this utility model do not denote any order, quantity or importance, but are only used to distinguish different components. Words such as "comprising" or "including" mean that the elements or objects appearing before this word cover the elements or objects listed after this word and their equivalents, without excluding other elements or objects. Words such as "connected" or "coupled" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Upper", "lower", "left", "right", etc. are only used to represent relative position relationships. When the absolute position of the object being described changes, the relative position relationship may also change accordingly.
[0023] Embodiment 1
[0024] As Figures 1 to 2 shown, the present utility model provides an electrolytic water hydrogen production capillary electrolytic cell, which includes a proton exchange membrane 7. The proton exchange membrane 7 can only allow water and protons to pass through, while preventing the direct passage of electrons and other ions (such as OH - -). During the electrolysis process, when water molecules are oxidized at the anode to produce protons and oxygen, the protons can migrate from the anode side to the cathode side through the proton exchange membrane 7, while the electrons move through the external circuit, so as to recombine with the protons passing through the membrane at the cathode to generate hydrogen.
[0025] An anode unit is provided on one side of the proton exchange membrane 7, and a cathode unit is provided on the other side thereof. The anode unit is used to carry out an oxidation reaction to generate oxygen, and the cathode unit is used to carry out a reduction reaction to generate hydrogen. An oxygen outlet hole 14 and a water inlet hole 15 are provided at the anode unit. The oxygen generated by the anode unit is discharged through the oxygen outlet hole 14, and the water inlet hole 15 is used to input water into the electrolytic cell for electrolysis. A hydrogen outlet hole 16 is provided at the cathode unit. The hydrogen generated by the cathode unit is discharged and collected through the hydrogen outlet hole 16.
[0026] The anode unit, the proton exchange membrane 7 and the cathode unit are connected through the penetration of fixing screws 17. The number of the fixing screws 17 is eight. Fixing nuts 19 are provided on the fixing screws 17. A gasket 18 is provided between the fixing nuts 19 and the cathode end plate 13. The gasket 18 is used to protect the cathode end plate 13 from being damaged by the friction generated when the fixing nuts 19 are tightened. The fixing screws 17 pass through the anode unit, the proton exchange membrane 7 and the cathode unit in sequence and are tightened with the fixing nuts 19 to connect the three together.
[0027] The anode unit includes an anode end plate 1, which is used to fix the electrolytic cell components, provide mechanical strength, maintain close contact between components, and also play a role in supporting and protecting internal components from external pressure, ensuring the sealing of the electrolytic cell and preventing water leakage.
[0028] An anode insulating plate 2 is provided inside the anode end plate 1. The anode insulating plate 2 is used for electrical insulation to prevent current short - circuit, improve safety, and also play a certain role in thermal insulation, which helps to control the thermal management of the electrolytic cell and maintain an appropriate temperature of water.
[0029] An anode plate is provided inside the anode insulating plate 2. The anode plate is one of a flow - channel anode plate 3 or a non - flow - channel anode plate 21. Figure 3 In this case, the anode plate is a flow - channel anode plate 3. Figure 4 In this case, the anode plate is a non - flow - channel anode plate 21. The anode plate conducts the current from the external power supply into the anode unit and provides a path for the transmission of electrons. The flow - channel anode plate 3 is provided with a flow channel 20, which is used to evenly distribute water and oxygen, promote the discharge of gas, and at the same time ensure that the current is evenly distributed on the entire anode surface, improving the electrolysis efficiency.
[0030] An anode capillary gas diffusion layer 5 is provided inside the anode plate. An anode catalyst layer 6 is provided inside the anode capillary gas diffusion layer 5. The anode capillary gas diffusion layer 5 and the anode catalyst layer 6 are sealed by an anode substrate 4. The anode catalyst layer 6 is in contact with the proton exchange membrane 7. The anode substrate 4 is used to seal the anode capillary gas diffusion layer 5 and the anode catalyst layer 6 to prevent water and gas leakage. The anode capillary gas diffusion layer 5 has a porous structure, which can simultaneously allow the transmission of gas and the penetration of water, ensure that water is evenly delivered to the anode catalyst layer 6, and at the same time allow the oxygen and unreacted water generated during the electrolysis process to be discharged. In addition, it also plays a role in supporting the anode catalyst layer 6, enhancing its mechanical strength and stability.
[0031] The cathode unit includes a cathode end plate 13, whose function is the same as that of the anode end plate 1. A cathode insulating plate 12 is provided inside the cathode end plate 13. The cathode insulating plate 12 is used to prevent current short - circuit, ensure that the current only passes through the cathode plate 11 and will not be lost in other paths, which helps to maintain the electric field distribution inside the electrolytic cell and improve the electrolysis efficiency.
[0032] Inside the inner side of the cathode insulating plate 12, there is a cathode plate 11. A flow channel 20 is provided on the cathode plate 11. The cathode plate 11 is used to conduct electrons from an external power source to the cathode. Inside the cathode plate 11, there is a cathode gas diffusion layer 10. Inside the cathode gas diffusion layer 10, there is a cathode catalyst layer 9. The cathode gas diffusion layer 10 and the cathode catalyst layer 9 are sealed by a cathode substrate 8. The cathode substrate 8 plays a supporting role, which can not only provide mechanical stability but also play a sealing role. The cathode catalyst layer 9 is in contact with the proton exchange membrane 7. The cathode gas diffusion layer 10 is used to allow electrons to pass through and contact the catalyst surface for a reduction reaction; on the other hand, it also needs to have sufficient porosity to allow the generated hydrogen to effectively diffuse away from the catalyst surface, avoiding an increase in mass transfer resistance caused by the accumulation of hydrogen bubbles. The cathode catalyst layer 9 is used to accelerate the hydrogen evolution reaction and can improve the reaction rate.
[0033] The cathode catalyst layer 9, the cathode gas diffusion layer 10, the anode capillary gas diffusion layer 5, the anode catalyst layer 6, and the proton exchange membrane 7 are hot-pressed and formed by a hot press. On one side of the proton exchange membrane 7, there is an anode catalyst layer and an anode substrate 4, and on the other side, there is a cathode catalyst layer 9 and a cathode substrate 8.
[0034] When an electrolytic water hydrogen production capillary electrolytic cell provided by the present utility model is in use, first, water is transported to the inside through the water inlet hole 15, and then the power supply is connected to start electrolyzing water. During the electrolysis process, on the anode unit side, liquid water quickly passes through the anode capillary gas diffusion layer 5 under the action of capillary action, realizing full contact between water and the catalyst. At the same time, the oxygen generated by the anode unit quickly discharges through the anode capillary gas diffusion layer 5 under the action of capillary action, improving the efficiency of electrolytic water hydrogen production. The hydrogen generated at the cathode unit first passes through the flow channel 20 and then is discharged and collected through the hydrogen outlet hole 16.
[0035] Therefore, the present utility model adopts the above-mentioned electrolytic water hydrogen production capillary electrolytic cell. By setting the anode capillary gas diffusion layer, the diffusion speed of gas is increased. Through capillary action, the circulation of water and the discharge of oxygen can be accelerated, solving the problem of oxygen bubble blockage of the porous channel, effectively improving the efficiency of electrolytic water hydrogen production, and the installation process of the electrolytic cell is simple, easy to operate, and the components are easy to obtain, which is suitable for wide industrial promotion.
[0036] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present utility model and are not intended to limit them. Although the present utility model has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that they can still modify or equivalently replace the technical solutions of the present utility model, and these modifications or equivalent replacements cannot make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present utility model.
Claims
1. A capillary electrolyzer for producing hydrogen by electrolysis of water, characterized in that: It comprises a proton exchange membrane, one side of the proton exchange membrane is provided with an anode unit, the other side of the proton exchange membrane is provided with a cathode unit, the anode unit is provided with an oxygen outlet and a water inlet, the cathode unit is provided with a hydrogen outlet, and the anode unit, the proton exchange membrane and the cathode unit are connected through a fixing screw; The anode unit comprises an anode end plate, an anode insulating plate is provided inside the anode end plate, an anode plate is provided inside the anode insulating plate, an anode capillary gas diffusion layer is provided inside the anode plate, an anode catalyst layer is provided inside the anode capillary gas diffusion layer, the anode capillary gas diffusion layer and the anode catalyst layer are sealed by an anode substrate, and the anode catalyst layer is in contact with the proton exchange membrane; The cathode unit includes a cathode end plate, a cathode insulating plate is provided inside the cathode end plate, a cathode plate is provided inside the cathode insulating plate, a cathode gas diffusion layer is provided inside the cathode plate, a cathode catalyst layer is provided inside the cathode gas diffusion layer, the cathode gas diffusion layer and the cathode catalyst layer are sealed by a cathode substrate, and the cathode catalyst layer is in contact with the proton exchange membrane.
2. A capillary electrolyzer for producing hydrogen by electrolysis of water according to claim 1, characterized in that: The cathode catalyst layer, the cathode gas diffusion layer, the anode capillary gas diffusion layer, the anode catalyst layer and the proton exchange membrane are hot-pressed by a hot press.
3. A capillary electrolyzer for producing hydrogen by electrolysis of water according to claim 1, characterized in that: The anode catalyst layer and the anode substrate are disposed on one side of the proton exchange membrane, and the cathode catalyst layer and the cathode substrate are disposed on the other side thereof.
4. A capillary electrolyzer for producing hydrogen by electrolysis of water according to claim 1, characterized in that: The anode plate is one of an anode plate with flow channels or an anode plate without flow channels. The anode plate with flow channels is provided with flow channels, and the cathode plate is provided with flow channels.
5. A capillary electrolyzer for producing hydrogen by electrolysis of water according to claim 1, characterized in that: The number of the fixing screws is eight, and the fixing screws are provided with fixing nuts, and a gasket is provided between the fixing nuts and the cathode end plate.