Reverse current flow field structure for water electrolyzer with ceramic coating

Abstract

This invention provides a ceramic-coated water electrolyzer structure to resist reverse current flow field, relating to the field of hydrogen electrolysis technology. It includes an electrode plate with an inlet and an outlet, and a main channel between them. Both the inlet and outlet have a ceramic-coated upper surface. The main channel includes an inlet channel, an outlet channel, and an intermediate channel connecting the inlet and outlet channels. Both the inlet and outlet channels have at least one bend. Fins within the intermediate channel divide it into at least two parallel flow paths. Through this flow field structure design, it exhibits low pressure drop characteristics, effectively maintaining a uniform and constant fluid velocity, ensuring that reactants are fully transported through the flow field. This enables uniform development of the electrochemical reaction, enhances water and gas diffusion, and promotes a uniform current density distribution in the active region of the electrode plate.

Description

Technical Field

[0001] This utility model relates to the field of electrolytic hydrogen production technology, specifically to a water electrolysis cell structure with a ceramic coating that resists reverse current flow field. Background Technology

[0002] Hydrogen energy, as a clean energy carrier, boasts advantages such as zero carbon emissions, zero pollution, and high calorific value, and has attracted widespread attention due to its potential to replace traditional fossil fuels. Hydrogen can be obtained through various methods, among which water electrolysis technology, which can directly utilize renewable energy sources such as wind and solar power to produce green hydrogen, has become one of the main technological routes towards achieving dual-carbon goals and developing new types of productivity.

[0003] Water electrolyzers are devices used for hydrogen production through electrolysis, offering advantages such as high hydrogen purity, high conversion rate, and compact structure. Conversion rates can reach over 70% at high current densities, and based on fuel cell technology, they can be rapidly developed for market application and promotion. However, during hydrogen production using renewable energy, the start-up, shutdown, and fluctuations of the power supply can cause reverse current in the electrolyzer, leading to irreversible phase transitions in the catalyst on the electrode surface inside the cell. This ultimately affects the long-term stable and efficient operation of the electrolyzer.

[0004] Bipolar plates are one of the core components inside an electrolyzer, and their flow field structure design directly affects the uniform distribution of reactants and the efficient transport of gases, determining the electrochemical and hydrodynamic responses within the electrolyzer. An ideal flow field structure has the following characteristics: efficient mass transfer of reactants to the catalyst bed (CL), discharge of reaction products from the flow channel to the outside of the flow channel, suppression of reverse current, low voltage drop, low energy consumption, and effective thermal management.

[0005] For example, patent CN118970088A employs a symmetrical serpentine flow field with baffles. By placing air-blocking components on the inner sidewalls of the serpentine channel away from the ridge, the pressure drop within the channel is reduced, thus minimizing friction losses. Another example is patent CN119133503A, which optimizes the design of the serpentine channel to achieve a gradually decreasing number of channels. This enhances the drainage capacity of the flow field while appropriately controlling the pressure drop at the gas inlet and outlet. However, neither of these designs effectively solves the problem of electrolytic cell corrosion caused by reverse current, and there are areas for improvement. Utility Model Content

[0006] To address the shortcomings of existing technologies, the purpose of this invention is to provide a water electrolysis cell structure with a ceramic-coated layer that resists reverse current flow field.

[0007] According to the present invention, a ceramic-coated water electrolysis cell anti-reverse current flow field structure includes an electrode plate, an inlet and an outlet are provided on the electrode plate, and a main channel is provided between the inlet and the outlet. The upper surfaces of both the inlet and the outlet are coated with a ceramic layer. The main channel includes an inlet channel, an outlet channel, and an intermediate channel connecting the inlet channel and the outlet channel. Both the inlet channel and the outlet channel have at least one bend. The intermediate channel is provided with fins that divide the intermediate channel into at least two parallel flow channels.

[0008] Preferably, the connection between the water inlet channel and the intermediate channel is formed by a bend, and the connection between the water outlet channel and the intermediate channel is also formed by a bend.

[0009] Preferably, the included angle at any of the aforementioned bends is between 0 and 90 degrees.

[0010] Preferably, the water inlet channel includes at least two straight channels, the water outlet channel includes at least two straight channels, and the middle channel is a straight channel.

[0011] Preferably, the main channel has multiple channels between the inlet and the outlet, and the length of the intermediate channel of any one of the main channels is the same and they are parallel to each other, and the length of the fins inside any one of the intermediate channels is the same and they are parallel to each other.

[0012] Preferably, the channel depth of any one of the main channels is 1mm to 5mm.

[0013] Preferably, the ridge width between any two adjacent main channels is 0.5mm to 2mm; and the width of any one fin is 0.5mm to 2mm.

[0014] Preferably, the width of the intermediate channel is greater than the width of the inlet channel, and the width of the intermediate channel is greater than the width of the outlet channel.

[0015] Preferably, the liquid flows in the flow field structure as follows: the liquid enters the inlet channel from the inlet, and after passing through at least one bend in the inlet channel, it reaches the connection between the inlet channel and the intermediate channel. The liquid enters the intermediate channel and is divided into multiple parallel branches by the fins. The liquid that has been divided by the fins converges at the end of the intermediate channel and reaches the connection between the intermediate channel and the outlet channel. The liquid enters the outlet channel and reaches the outlet after passing through at least one bend in the outlet channel.

[0016] Preferably, the flow field structure is rectangular in shape on the surface of the electrode plate, the intermediate channel is located in the active region in the middle of the electrode plate, the inlet and outlet are located on two opposite sides of the rectangle, and the inlet and outlet are centrally symmetrical about the center point of the rectangle.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1. This utility model replaces the traditional 180-degree bend design of the serpentine flow field with multiple consecutive 90-degree bends. The turning angle is reduced by half, the influence of centrifugal force on fluid distribution is significantly weakened, the velocity gradient of the fluid at the bend is smaller, the difference in flow velocity between the outer and inner sides is greatly reduced, local eddies and flow dead zones are reduced, and the energy loss caused by them is reduced. This significantly reduces the resistance of the fluid during the turning process, thus having a lower pressure drop characteristic.

[0019] 2. This utility model uses fins to divide the widened central channel into multiple parallel branches, each of equal length and parallel to the others, which then converge back into the outlet channel. This design increases the channel width while maintaining the total normal cross-sectional area of ​​the fluid. The friction resistance and local resistance of all branches are consistent. According to the principle of resistance balance, the fluid will automatically achieve uniform distribution when branching, effectively maintaining a constant fluid velocity at the uniform point. This ensures that the fluid uniformly covers the active area of ​​the electrode, ensuring that the reactants are fully transported to the catalyst layer and forming a stable laminar flow state.

[0020] 3. This invention uses fins to divide the central channel into multiple parallel flow channels of equal width and length, ensuring that the fluid evenly covers the active area of ​​the electrode plate. This guarantees sufficient transfer of reactants to the catalyst layer, forming a stable laminar flow state. The 90-degree bend and stable flow velocity design ensure that the drag force of the fluid on the bubbles remains at a reasonable level, allowing the bubbles to be carried along the main flow towards the outlet in a timely manner. Compared with the traditional 180-degree bend, the 90-degree bend design significantly reduces the influence of centrifugal force when the fluid turns, reducing the phenomenon of excessive bubble aggregation on the outside of the bend due to centrifugal force. This makes the distribution of bubbles in the flow channel more uniform, avoiding the formation of gas blockage due to excessively high local bubble concentration. It ensures that the gas generated by the reaction can be smoothly transferred to the outlet with the fluid. The uniform distribution of reactants and the efficient discharge of products achieve uniform development of the electrochemical reaction, enhance the water and gas diffusion effect, and promote the uniform distribution of current density in the active area of ​​the electrode plate.

[0021] 4. This invention utilizes the inherent high resistance and chemical stability of ceramic materials to construct a key dielectric layer by covering the upper surfaces of the inlet and outlet with a ceramic-plated layer. During electrolytic cell operation, momentary voltage imbalances can occur, leading to a reverse potential difference between the electrodes. The electrodes, the conductive fluid within the flow channel, and the metal inlet and outlet constitute potential conductive paths. The ceramic-plated layer blocks these unnecessary conductive paths, reducing current leakage and thus energy loss. Especially in areas like the inlet and outlet where the fluid connects to external pipelines, a lack of insulation could lead to current leakage. The design protects the electrode interface from electrochemical corrosion by conducting the current to external devices. Simultaneously, during power fluctuations or start-up / shutdown conditions, the generation of reverse current is closely related to the potential difference and conductive path between the electrodes. Due to the insulating properties of the ceramic coating, the reverse current, which might otherwise flow through fluids or metal components, is significantly weakened by the high resistance of the ceramic coating. This prevents the reverse current from reaching a strength sufficient to trigger a catalyst phase change, thus avoiding irreversible phase changes in the catalyst on the electrode surface due to reverse current. This reduces problems such as catalyst dissolution and substrate corrosion, ensuring stable and safe operation of the system under complex electromagnetic conditions, extending the service life of the electrolyzer, and improving overall safety. Attached Figure Description

[0022] Other features, objects, and advantages of this invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0023] Figure 1 This is a schematic diagram illustrating the main flow field structure of this utility model;

[0024] Figure 2 This is a schematic diagram illustrating the flow field structure of the present invention without a ceramic coating.

[0025] Figure 3 This is a schematic diagram showing the structure of the inlet or outlet of the present invention.

[0026] Figure 4 This is a schematic diagram illustrating the flow channel structure of the middle channel, which is the main feature of this utility model.

[0027] Figure 5 The diagram mainly illustrates the reverse current suppression effect of this utility model;

[0028] Figure 6 This utility model mainly demonstrates the comparison of the flow field structure and the velocity in the middle of the parallel channel flow field and the serpentine channel flow field along the Y-axis.

[0029] As shown in the figure:

[0030] 1. Inlet; 2. Outlet; 3. Ceramic coating; 41. First straight segment; 42. Second straight segment; 43. Third straight segment; 44. Fourth straight segment; 45. Fifth straight segment; 5. Electrode plate; 6. Fin; 71. First bend; 72. Second bend; 73. Third bend; 74. Fourth bend. Detailed Implementation

[0031] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the present invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0032] Example 1

[0033] like Figure 1 , Figure 2 , Figure 3 , Figure 4 as well as Figure 5 As shown, the water electrolysis cell flow field structure for suppressing reverse current provided by this utility model includes an electrode plate 5, on which an inlet 1 and an outlet 2 are provided. A main channel is provided between the inlet 1 and the outlet 2. Both the inlet 1 and the outlet 2 have a ceramic-coated layer 3 on their upper surfaces. Each main channel includes an inlet channel, an outlet channel, and an intermediate channel connecting the inlet channel and the outlet channel. Both the inlet channel and the outlet channel have at least one bend. Fins 6 are provided in the intermediate channel to divide the intermediate channel into at least two parallel flow channels. Multiple main channels are provided between the inlet 1 and the outlet 2. Preferably, the multiple main channels have the same length; in a variation, the lengths of the multiple main channels may be different.

[0034] Furthermore, a bend is formed at the connection between the inlet channel and the intermediate channel, and a bend is formed at the connection between the outlet channel and the intermediate channel. The included angle at any bend is between 0 and 90 degrees. Preferably, the included angle at any bend is 90 degrees.

[0035] The flow direction of the liquid in the flow field structure is as follows: the liquid enters the inlet channel from the inlet 1, and after passing through at least one bend in the inlet channel, it reaches the connection between the inlet channel and the intermediate channel. The liquid enters the intermediate channel and is divided into multiple parallel branches by the fins 6. The liquid that has been divided by the fins 6 converges at the end of the intermediate channel and reaches the connection between the intermediate channel and the outlet channel. The liquid enters the outlet channel and reaches the outlet 2 after passing through at least one bend in the outlet channel.

[0036] Specifically, the inlet channel includes at least two straight channels, the outlet channel includes at least two straight channels, and the intermediate channel is a straight channel. The intermediate channels of any main channel are all of the same length and parallel to each other. The fins 6 inside any intermediate channel are all of the same length and parallel to each other. The channel depth of any main channel is 1mm to 5mm. The ridge width between any two adjacent main channels is 0.5mm to 2mm. The width of any fin 6 is 0.5mm to 2mm.

[0037] In one feasible implementation, preferably, the included angle at any bend is 90 degrees. Preferably, the width of the intermediate channel is greater than the width of the inlet channel and the width of the outlet channel. The width of any flow channel in the intermediate channel is 0.9 mm to 1.1 mm, and the width of the fins 6 between any two adjacent flow channels is 0.9 mm to 1.1 mm. While the width of the intermediate channel is greater than that of the inlet and outlet channels, the intermediate channel is separated by the fins 6, causing the liquid to first flow separately and then converge within the intermediate channel, forming active regions of multiple channels.

[0038] In a preferred embodiment, the overall flow field structure is rectangular. Both the inlet channel and the outlet channel include a bend with an included angle of 90 degrees. The inlet channel includes a first straight segment 41 and a second straight segment 42. The first straight segment 41 is connected to the inlet 1. The first straight segment 41 and the second straight segment 42 are perpendicular to each other and connected. The intermediate channel is a third straight segment 43. The third straight segment 43 is perpendicular to the second straight segment 42 and connected. The outlet channel includes a fourth straight segment 44 and a fifth straight segment 45. The fourth straight segment 44 is perpendicular to the third straight segment 43 and connected. The fifth straight segment 45 is perpendicular to the fourth straight segment 44 and connected, and the fifth straight segment 45 is connected to the outlet 2. Two parallel fins 6 are provided within the third straight segment 43. The length direction of both fins 6 is parallel to the length direction of the third straight segment 43. The two fins 6 divide the intermediate channel into three parallel flow channels. It should be noted that, in this embodiment, the first straight line segment 41 is perpendicular to the second straight line segment 42, the second straight line segment 42 is perpendicular to the third straight line segment 43, the third straight line segment 43 is perpendicular to the fourth straight line segment 44, and the fourth straight line segment 44 is perpendicular to the fifth straight line segment 45; the first straight line segment 41, the third straight line segment 43, and the fifth straight line segment 45 are parallel to each other; and the second straight line segment 42 and the fourth straight line segment 44 are parallel to each other.

[0039] In a more preferred embodiment, the three parallel flow channels have the same diameter. By setting the overall flow field structure as a rectangle, the main channel consists of multiple straight channels and multiple 90-degree bends. This improves space utilization and facilitates manufacturing due to the regular shape design, ensuring that each main channel has the same length. Furthermore, the technical solution of this application replaces the traditional 180-degree bend design of the serpentine flow field with multiple consecutive 90-degree bends, reducing the turning angle by half and significantly weakening the influence of centrifugal force on fluid distribution. At this time, the velocity gradient of the fluid at the bend is smaller, the velocity difference between the outer and inner sides is greatly reduced, local eddies and dead zones are reduced, and the energy loss caused by them is reduced. This significantly reduces the resistance of the fluid during the turning process, resulting in lower pressure drop characteristics.

[0040] Fin 6 divides the widened central channel into multiple parallel branches, each of equal length and parallel to the others, before converging back into the outlet channel. This design increases the channel width while maintaining a constant total cross-sectional area in the normal direction. All branches exhibit consistent friction and local resistance. Based on the principle of resistance balance, the fluid automatically achieves uniform distribution during branching, effectively maintaining a constant fluid velocity at the uniform point and ensuring that reactants are fully transported through the flow field.

[0041] In a more preferred embodiment, a ceramic-plated layer 3 is disposed on the upper surface of the inlet 1 and the upper surface of the outlet 2. This application's technical solution constructs a key dielectric layer by covering the upper surfaces of the inlet 1 and outlet 2 with a ceramic-plated layer 3, utilizing the inherent high resistivity and chemical stability of ceramic materials. The ceramic layer covers the upper surfaces of the metal inlet 1 and outlet 2. During electrolytic cell operation, the input voltage may experience momentary imbalances, leading to a reverse potential difference between the electrodes. The electrodes, the conductive fluid in the flow channel, the metal inlet 1, and the metal outlet 2 constitute potential conductive paths. The ceramic-plated layer 3 can block these unnecessary conductive paths, thereby reducing current leakage and energy loss. Especially in areas like the inlet 1 and outlet 2 where the fluid connects to external pipelines, a lack of insulation design could lead to current being conducted to external equipment through the fluid. This design not only protects the electrode plate 5 interface from electrochemical corrosion; simultaneously, during power fluctuations or start-up / shutdown conditions, the generation of reverse current is closely related to the potential difference between the electrodes and the conductive path. Due to the insulating properties of the ceramic coating layer 3, the reverse current that might have flowed through fluid or metal components is significantly weakened by the high resistance of the ceramic coating layer 3. This prevents the reverse current from reaching a strength sufficient to trigger a phase change in the catalyst, thus avoiding irreversible phase changes in the catalyst on the electrode surface due to the reverse current. This reduces problems such as catalyst dissolution and substrate corrosion, ensuring stable and safe operation of the system under complex electromagnetic conditions, extending the service life of the electrolyzer, and improving overall safety.

[0042] It should be noted that the technical solution of this application can change the position of the inlet and outlet 2 in the flow field, turning the original outlet 2 into the inlet 1 and the original inlet 1 into the outlet 2.

[0043] It should be emphasized that any flow field structure designed according to the technical solution of this application, regardless of the number and size of the flow channels, falls within the scope of protection of this utility model.

[0044] Example 2

[0045] According to the present invention, a flow field structure is disposed on the electrode plate 5, and the intermediate channel is located in the active region in the middle of the electrode plate 5.

[0046] Preferably, the flow field structure on the surface of the electrode plate 5 is rectangular, with the inlet 1 and outlet 2 located on opposite sides of the rectangle, and the inlet 1 and outlet 2 are centrally symmetrical about the center point of the rectangle.

[0047] After entering through inlet 1, the liquid first flows into the first straight section 41. The liquid receives initial guidance in the area of ​​inlet 1 covered by the ceramic coating layer 3. Then, the liquid passes through the first bend 71 at the connection between the first straight section 41 and the second straight section 42, and then flows along the second straight section 42 into the second bend 72 at the connection between the second straight section 42 and the third straight section 43. This 90-degree bend design effectively reduces the gas-liquid accumulation problem that easily occurs with traditional 180-degree bends, lowers local pressure drop, and keeps the water flow stable. The liquid then enters the third straight section 43 through the second bend 72 and is divided into multiple parallel direct currents by the fins 6. The channels of these parallel direct currents have the same width, ensuring uniform flow distribution while maintaining a constant normal cross-sectional area. The liquid diverted by fin 6 re-converges at the end of the third straight section 43. The liquid then sequentially passes through the third bend 73 at the connection between the third and fourth straight sections 43 and 44, the fourth straight section 44, the fourth bend 74 at the connection between the fourth and fifth straight sections 44 and 45, and the fifth straight section 45, adjusting its flow direction before finally being delivered to outlet 2. During this process, the liquid initially forms a stable flow pattern when passing through the first and second straight sections 41 and 42. After entering the third straight section 43, the separation effect of fin 6 ensures that the water flow evenly covers the active area in the middle of the electrode plate 5, significantly increasing the contact area with the electrode plate 5 and the catalyst layer, providing sufficient reactants for the electrolysis reaction. In the active area of ​​the electrode plate 5, water undergoes an electrolysis reaction under the influence of the electric field, and an oxidation reaction occurs at the anode: 4OH⁻ - →2H₂O + 4e - +O2↑, a reduction reaction occurs at the cathode: 4H2O + 4e - →2H₂↑+4OH⁻ -Water molecules decompose into hydrogen and oxygen on the catalyst layer surface. Due to the uniform flow field distribution brought about by the finned flow distribution structure of fin 6, the current density is uniformly distributed in the active area of ​​electrode 5, ensuring the uniformity of the electrochemical reaction and enhancing the diffusion and flow of water and gas. The gas generated by the reaction flows along the channel with the water flow. Due to the bending design of the main channel and the stable flow velocity, the stagnation and blockage of gas in the bending area are effectively avoided, ensuring the smooth transfer of products to outlet 2. At the same time, the ceramic layer 3, as a key dielectric layer, provides excellent electrical insulation performance. Combined with the uniform current density distribution, it effectively suppresses the reverse current caused by power fluctuations or start-up and shutdown conditions, avoiding irreversible phase transition of the catalyst on the electrode surface. Finally, the mixed fluid carrying a small amount of unreacted water and product gas is discharged from outlet 2, and the entire process ends.

[0048] The technical solution of this application divides the central channel into equal-width, equal-length, parallel sub-channels using fins 6, ensuring uniform fluid coverage of the active area of ​​the electrode plate 5. This guarantees sufficient transport of reactants to the catalyst layer, forming a stable laminar flow state. Furthermore, the 90-degree bend and stable flow velocity design maintain the drag force of the fluid on the bubbles at a reasonable level, allowing the bubbles to be carried along the main flow towards the outlet 2 in a timely manner. In addition, compared to the traditional 180-degree bend, the 90-degree bend significantly reduces the impact of centrifugal force during fluid turns, reducing the excessive aggregation of bubbles on the outside of the bend due to centrifugal action. This results in a more uniform distribution of bubbles within the flow channel, preventing localized high bubble concentrations and the formation of gas blockages. This ensures that the gas generated by the reaction can be smoothly transported to the outlet 2 with the fluid. The uniform distribution of reactants and the efficient discharge of products achieve uniform development of the electrochemical reaction, enhance water and gas diffusion, and promote a uniform current density distribution in the active area of ​​the electrode plate 5.

[0049] Example 3

[0050] Based on Embodiment 1 or Embodiment 2, the present invention provides a water electrolysis cell flow field structure for suppressing reverse current, such as... Figure 6 The performance curves of water electrolysis using the flow field structure in Example 1 and the traditional parallel flow field and serpentine flow field structures are shown. The water electrolyzer temperature was set to 60℃, and liquid water with an average normal inflow velocity of 2.2 m / s was introduced at the inlet. By measuring and comparing the velocity along the Y-axis channel in the middle of the flow field, it can be seen that under the flow channel structure described in this application, the water velocity is maintained at about 2.1 m / s, while the velocities in the parallel flow field and serpentine flow field are both below 1.6 m / s. This invention exhibits small velocity attenuation, allowing more reactants to flow to the catalyst layer per unit time, thus improving the overall performance of the water electrolyzer.

[0051] In the description of this application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0052] The specific embodiments of this utility model have been described above. It should be understood that this utility model is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the substantive content of this utility model. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A water electrolysis cell structure resisting reverse current flow field with a ceramic-coated layer, characterized in that, Includes an electrode plate (5), on which an inlet (1) and an outlet (2) are provided, and a main channel is provided between the inlet (1) and the outlet (2), and both the inlet (1) and the outlet (2) are provided with a ceramic coating layer (3). The main channels include an inlet channel, an outlet channel, and an intermediate channel connecting the inlet channel and the outlet channel. Both the inlet channel and the outlet channel have at least one bend. The intermediate channel is provided with fins (6) that divide the intermediate channel into at least two parallel flow channels.

2. The water electrolysis cell structure resisting reverse current flow field with ceramic coating as described in claim 1, characterized in that, The connection between the water inlet channel and the intermediate channel forms a bend, and the connection between the water outlet channel and the intermediate channel also forms a bend.

3. The water electrolysis cell structure resisting reverse current flow field with ceramic coating as described in claim 2, characterized in that, The included angle at any of the aforementioned bends is between 0 and 90 degrees.

4. The water electrolysis cell structure resisting reverse current flow field with ceramic coating as described in claim 1, characterized in that, The water inlet channel includes at least two straight channels, the water outlet channel includes at least two straight channels, and the middle channel is a straight channel.

5. The water electrolysis cell structure resisting reverse current flow field with ceramic coating as described in claim 1, characterized in that, The main channel has multiple channels between the inlet (1) and the outlet (2), and the length of the middle channel of any one of the main channels is the same and they are parallel to each other. The length of the fins (6) inside any one of the middle channels is the same and they are parallel to each other.

6. The water electrolysis cell anti-reverse current flow field structure with ceramic coating as described in claim 1, characterized in that, The channel depth of any of the main channels is between 1 mm and 5 mm.

7. The water electrolysis cell structure resisting reverse current flow field with ceramic coating as described in claim 1, characterized in that, The ridge width between any two adjacent main channels in a set is 0.5 mm to 2 mm; The width of any one of the fins (6) is 0.5 mm to 2 mm.

8. The water electrolysis cell anti-reverse current flow field structure with ceramic coating as described in claim 1, characterized in that, The width of the intermediate channel is greater than the width of the inlet channel, and the width of the intermediate channel is greater than the width of the outlet channel.

9. The water electrolysis cell structure resisting reverse current flow field with ceramic coating as described in claim 1, characterized in that, The flow direction of the liquid in the flow field structure is as follows: the liquid enters the water inlet channel from the inlet (1), and after passing through at least one bend in the water inlet channel, it reaches the connection between the water inlet channel and the intermediate channel. The liquid enters the intermediate channel and is divided into multiple parallel branches by the fins (6). The liquid that has been divided by the fins (6) converges at the end of the intermediate channel and reaches the connection between the intermediate channel and the outlet channel. The liquid enters the outlet channel and reaches the outlet (2) after passing through at least one bend in the outlet channel.

10. The water electrolysis cell structure resisting reverse current flow field with ceramic coating as described in claim 1, characterized in that, The flow field structure is rectangular on the surface of the electrode plate (5). The intermediate channel is located in the active region in the middle of the electrode plate (5). The inlet (1) and outlet (2) are located on opposite sides of the rectangle, and the inlet (1) and outlet (2) are centrally symmetrical about the center point of the rectangle.

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