Flow field structure of bipolar plate, bipolar plate and electrolytic bath
The proposed flow field structure with separate outlet-only and inlet-outlet channels addresses gas accumulation issues in bipolar plates, enhancing electrolysis efficiency and reducing costs by optimizing electrolyte circulation and discharge in electrolytic cells.
Patent Information
- Application Number
- CN202420024949.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-01-04
- Publication Date
- 2024-12-10
- Estimated Expiration
- 2034-01-04
AI Technical Summary
Existing flow field structures in bipolar plates for electrolyzers lead to gas accumulation when electrolyte circulation is limited to one side, hindering the rapid discharge of reaction products and affecting the performance and efficiency of the electrolytic cell.
A flow field structure with a first sub-field structure having only an outlet channel and a second sub-field structure with both inlet and outlet channels, allowing electrolyte circulation only through the latter, thereby preventing gas accumulation and facilitating rapid discharge of reaction products.
Improves the utilization rate of electrode active sites, enhances electrolysis efficiency, and reduces costs by avoiding gas accumulation, while maintaining a simpler design without unnecessary inlet channels.
Smart Images
Figure CN222139308U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of electrolysis, in particular to a flow field structure of a bipolar plate, a bipolar plate and an electrolytic cell. Background Art
[0002] Hydrogen plays an important role in the carbon neutrality path due to its advantages such as cleanness, high energy density, and storability and transportation. Hydrogen production by water electrolysis is currently the simplest and most effective way to obtain high-purity hydrogen. It can be combined with renewable energy power generation technologies, such as photovoltaic power generation, hydropower generation, and wind power generation, to produce green hydrogen and achieve zero carbon emissions in the hydrogen production process. For example, water electrolysis can be used as a large-scale hydrogen production technology, which has the advantages of environmental friendliness and high economic benefits, and has good application prospects. In the process of hydrogen production by electrolysis, the bipolar plate is an important component in the electrolyzer. Its main functions include providing mechanical support for the membrane electrode, transporting reactants or products, and conducting current. The flow field structure of the bipolar plate is a key factor affecting material transfer. An unreasonable flow field structure can easily lead to problems such as low mass transfer efficiency, uneven distribution of reactants or accumulation of products, which in turn affects the performance and life of the electrolyzer.
[0003] At present, there are few studies on the flow field structure with no electrolyte entering on one side. In this case, the traditional flow field structure is still used, but this flow field structure is prone to gas accumulation, which is not conducive to the discharge of reactants. Therefore, in the scenario where no electrolyte enters on one side, the use of such common flow field structure will not effectively meet the demand for the fastest discharge of reaction products. It is necessary to develop a new flow field structure to meet the demand for the fastest discharge of reaction products. Utility Model Content
[0004] The utility model provides a flow field structure of a bipolar plate, a bipolar plate and an electrolytic cell, aiming to solve the problem that in a scenario where no electrolyte enters one side, the existing flow field structure causes gas accumulation, which is not conducive to the rapid discharge of reactants.
[0005] In a first aspect of the utility model, a flow field structure of a bipolar plate is provided, comprising: a first sub-flow field structure and a second sub-flow field structure;
[0006] The first sub-flow field structure has only an outlet flow channel and is located on one side of the cathode side and the anode side of the bipolar plate body;
[0007] The second sub-flow field structure has an outlet flow channel and an inlet flow channel and is located on the other side of the cathode side and the anode side of the bipolar plate body.
[0008] In the embodiment of the utility model, the first sub-flow field structure is located on one side of the cathode side and the anode side of the bipolar plate body, and the second sub-flow field structure is located on the other side of the cathode side and the anode side of the bipolar plate body. The first sub-flow field structure has only an outlet flow channel, and the second sub-flow field structure has an outlet flow channel and an inlet flow channel. During the electrolysis process, the electrolyte can be circulated only in the second sub-flow field structure, but not in the first sub-flow field structure. Therefore, only the inlet flow channel and the outlet flow channel are set in the second sub-flow field structure, and only the outlet flow channel is set in the first sub-flow field structure, and the inlet flow channel is not required, so as to avoid the accumulation of reaction gas in the redundant inlet flow channel, so that the reaction gas can be quickly discharged from the outlet flow channel, thereby avoiding the accumulation of products in the flow channel and the electrode surface, thereby releasing more reaction active sites, improving the utilization rate of the active sites on the electrode surface, improving the performance of the electrolytic cell, and thus improving the electrolysis efficiency. Moreover, there is no inlet flow channel in the first sub-flow field structure without electrolyte circulation, and the first sub-flow field structure is simpler and can also reduce costs.
[0009] Optionally, the outlet flow channel includes: a main outlet, and multiple flow channels sequentially connected to the main outlet.
[0010] Optionally, in the extension direction of a flow channel, along the direction close to the main outlet, the width of the flow channel increases, and / or the depth increases.
[0011] Optionally, along the connection sequence close to the main outlet, the width of the flow channels of different stages increases, and / or the depth increases.
[0012] Optionally, in the extension direction of a flow channel: in the flow channel, the ratio of the maximum width to the minimum width is greater than 1 and less than or equal to 100, and / or, in the flow channel, the ratio of the maximum depth to the minimum depth is greater than 1 and less than or equal to 100.
[0013] Optionally, the multi-stage flow channel includes: a primary flow channel connected to the main outlet, and the outlet flow channel further includes: a support structure located between the main outlet and the primary flow channel.
[0014] A second aspect of the present invention provides a bipolar plate, comprising: a bipolar plate body, and any of the flow field structures of the aforementioned bipolar plates.
[0015] Optionally, the bipolar plate further comprises: a sub-ridge unit, wherein one sub-ridge unit is connected to at least two outlet flow channels.
[0016] The third aspect of the present invention provides an electrolytic cell, comprising: a plurality of stacked
[0017] The bipolar plate.
[0018] Optionally, each main outlet of each first sub-flow field structure of each bipolar plate is connected to form a first common outlet channel, and the first common outlet channel is connected to the first gas collecting port;
[0019] The main outlets of the second sub-flow field structures of the bipolar plates are connected to form a second common outlet channel, and the second common outlet channel is connected to the second gas collecting port.
[0020] Optionally, in the extension direction of the first common outlet channel, along the direction close to the first gas collecting port, the cross-sectional area of the first common outlet channel increases;
[0021] And / or, in the extension direction of the second common outlet channel, along the direction close to the second gas collecting port, the cross-sectional area of the second common outlet channel increases.
[0022] Optionally, in the extension direction of the first common outlet channel: in the first common outlet channel, a ratio of an area of a maximum cross section to an area of a minimum cross section is greater than 1 and less than or equal to 100;
[0023] And / or, in the extension direction of the second common outlet channel: in the second common outlet channel, the ratio of the area of the maximum cross section to the area of the minimum cross section is greater than 1 and less than or equal to 100.
[0024] The flow field structure of the bipolar plate, the bipolar plate and the electrolytic cell mentioned above have the same or similar beneficial effects, and will not be described again here to avoid repetition. BRIEF DESCRIPTION OF THE DRAWINGS
[0025] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the description of the embodiments of the utility model will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.
[0026] Figure 1 A schematic diagram of a second sub-flow field structure in an embodiment of the utility model is shown;
[0027] Figure 2 A schematic diagram showing another second sub-flow field structure in an embodiment of the utility model is shown;
[0028] Figure 3 A partial structural schematic diagram of an electrolytic cell in an embodiment of the utility model is shown.
[0029] Description of the accompanying drawings:
[0030] 11-first sub-flow field structure, 1-main outlet, 2-primary flow channel, 3-secondary flow channel, 4-tertiary flow channel, 5-sub-ridge unit, 6-first gas collection port, 7-end pressure plate, 8-bipolar plate, 9-support structure. DETAILED DESCRIPTION
[0031] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.
[0032] The inventors discovered that during the electrolysis process, when the electrolyte circulates only on one side of the bipolar plate, the existing sub-flow field structures on both sides of the bipolar plate body will cause gas accumulation, which is not conducive to the discharge of reactants. The main reason is that during the electrolysis process, when the electrolyte circulates only on one side of the bipolar plate body, the inlet flow channel of the sub-flow field structure on the other side will not serve to allow substances to enter the sub-flow field structure, and it is redundant. The gas on the other side will stay and accumulate in the inlet flow channel of the sub-flow field structure on this side, which is not conducive to the discharge of reactants.
[0033] The utility model provides a flow field structure of a bipolar plate, the flow field structure comprising: a first sub-flow field structure 11 and a second sub-flow field structure, wherein the first sub-flow field structure 11 is located on the cathode side or the anode side, and the second sub-flow field structure is located on the other side of the cathode side or the anode side. The bipolar plate body refers to: the part of the bipolar plate other than the first sub-flow field structure 11 and the second sub-flow field structure.
[0034] The first sub-flow field structure 11 here has only an outlet flow channel, but no inlet flow channel, and the outlet flow channel is used to discharge substances from the first sub-flow field structure. In the process of electrolytic hydrogen production, the outlet flow channel is mainly used to discharge gas products, and may also discharge part of the liquid, which is not specifically limited.
[0035] The second sub-flow field structure here has an outlet flow channel and an inlet flow channel, the inlet flow channel is used to input substances into the second sub-flow field structure, and the outlet flow channel is used to discharge substances from the second sub-flow field structure. In the process of electrolytic hydrogen production, the outlet flow channel is mainly used to discharge gas products, and may also discharge part of the liquid, which is not specifically limited.
[0036] It should be noted that in the flow field structure, the inlet flow channel of the second sub-flow field structure can refer to the relevant technology. In the flow field structure, the outlet flow channel of the second sub-flow field structure can refer to the outlet flow channel of the first sub-flow field structure. Therefore, the first sub-flow field structure is mainly introduced in the whole article.
[0037] During the electrolysis process, the electrolyte can circulate only in the second sub-flow field structure, but not in the first sub-flow field structure 11. Therefore, only the inlet flow channel and the outlet flow channel are set in the second sub-flow field structure, and only the outlet flow channel needs to be set in the first sub-flow field structure 11, without the inlet flow channel, so as to avoid the accumulation of reaction gas in the redundant inlet flow channel, so that the reaction gas can be quickly discharged from the outlet flow channel, thereby avoiding the accumulation of products on the flow channel and the electrode surface, thereby releasing more reaction active sites, improving the utilization rate of the active sites on the electrode surface, improving the performance of the electrolytic cell, and thus improving the electrolysis efficiency. Moreover, there is no inlet flow channel in the first sub-flow field structure 11 without electrolyte circulation, and the first sub-flow field structure 11 is simpler and can also reduce costs.
[0038] More specifically, for AEM (Anion exchange membrane) electrolyzers, PEM (Proton exchange membrane) electrolyzers, and SOEC (solid oxide electrolysis) electrolyzers, there are usually three different electrolyte circulation modes during operation, namely, electrolyte circulation at both the cathode and cathode, electrolyte circulation only on the anode side, or electrolyte circulation only on the cathode side. For the case where electrolyte circulation is performed only on one side of the electrolyzer, that is, electrolyte flows into only the anode or only the cathode during the operation of the electrolyzer, the electrolyte can penetrate through the ion exchange membrane to the side without electrolyte circulation, thereby maintaining the wetting state of the ion exchange membrane or participating in the electrode reaction of the electrolysis process. When the electrolyzer is performing a single-sided electrolyte circulation operation, in the related art, a traditional sub-flow field structure with an inlet and outlet flow channel is usually still used on the side without electrolyte entry, but the sub-flow field structure has no electrolyte flowing into its inlet flow channel, and gas accumulation is easily formed in its liquid inlet channel, which is not conducive to the discharge of reactants. Therefore, in the utility model, on the side where no electrolyte enters, the inlet flow channel is not directly set, and the reaction gas will not stay or gather in the inlet flow channel, so that the reaction gas can be quickly discharged from the outlet flow channel, thereby avoiding the accumulation of products in the flow channel and the electrode surface, thereby releasing more reactive sites, improving the utilization rate of the active sites on the electrode surface, improving the performance of the electrolyzer, and then improving the electrolysis efficiency. Moreover, there is no inlet flow channel in the sub-flow field structure without electrolyte circulation, and the sub-flow field structure is simpler and can also reduce costs. AEM electrolysis hydrogen production, PEM electrolysis hydrogen production, and SOEC electrolysis hydrogen production also have the advantages of large operating current density, high purity of hydrogen produced (up to 99.999%), and fast response speed.
[0039] It should be noted that the relevant contents of the outlet flow channel recorded later in the full text are applicable to both the outlet flow channel in the first sub-flow field structure 11 and the outlet flow channel in the second sub-flow field structure. It may be applied only to the outlet flow channel in the first sub-flow field structure 11, or only to the outlet flow channel in the second sub-flow field structure, or simultaneously to the outlet flow channel in the first sub-flow field structure 11 and the outlet flow channel in the second sub-flow field structure, and there is no specific limitation on this.
[0040] Figure 1 A schematic diagram of a first sub-flow field structure in an embodiment of the utility model is shown. Figure 2 Schematic diagram of another first sub-flow field structure in the embodiment of the utility model is shown. In the utility model, the outlet flow channel of the second sub-flow field structure can also refer to Figure 1 and Figure 2 Provide explanation.
[0041] Optional, see Figure 1 , Figure 2 The outlet flow channel in the first sub-flow field structure 11 and / or the second sub-flow field structure may include: a main outlet 1, and multiple flow channels sequentially connected to the main outlet 1. The number of flow channels in the outlet flow channel is not specifically limited. For example, referring to Figure 1 , Figure 2 The outlet flow channel may include: a main outlet 1, a primary flow channel 2, which is connected to the main outlet 1, a secondary flow channel 3, which is connected to the primary flow channel 2, and a tertiary flow channel 4, which is connected to the secondary flow channel 3. The material flows from the tertiary flow channel 4 into the secondary flow channel 3, then into the primary flow channel 2, and finally discharged from the main outlet 1.
[0042] The extension direction of a flow channel can be the direction of its largest size. Along the direction close to the main outlet 1, the width of the flow channel increases, and / or the depth increases. Specifically, the direction of the width is perpendicular to the direction of the thickness. The closer to the main outlet 1, the larger the size of the flow channel, which can promote the gas in the flow channel to flow in the direction close to the main outlet 1, so that the reaction gas can be quickly discharged from the outlet flow channel, thereby avoiding the accumulation of products on the flow channel and the electrode surface, thereby releasing more reactive sites, improving the utilization rate of the active sites on the electrode surface, improving the performance of the electrolytic cell, and thus improving the electrolysis efficiency. It should be noted that the increase here can be a linear increase, an exponential increase, a multiple increase, etc., and the specific increase method is not limited. The multiple increase here can be a geometric increase, or an unequal ratio increase, etc., which is not specifically limited.
[0043] For example, the extension direction of a primary flow channel 2 may be the direction of its largest size. In the extension direction of a primary flow channel 2, along the direction close to the main outlet 1, the width of a primary flow channel 2 increases, and / or the depth increases. The direction of the width is perpendicular to the direction of the thickness, which can promote the gas in the primary flow channel 2 to flow in the direction close to the main outlet 1, so that the reaction gas can be quickly discharged from the outlet flow channel, thereby avoiding the accumulation of products on the flow channel and the electrode surface, thereby releasing more reaction active sites, improving the utilization rate of the active sites on the electrode surface, improving the performance of the electrolytic cell, and further improving the electrolysis efficiency. Figure 1 In the extension direction of the primary flow channel 2, along the direction close to the main outlet 1, that is, from the lower left corner to the upper right corner, Figure 1 In the example, in the extension direction of the primary flow channel 2, along the direction close to the main outlet 1, the width of the primary flow channel 2 increases, and the width d1 at the upper right corner reaches the maximum. Figure 2 In the extension direction of the primary flow channel 2, along the direction close to the main outlet 1, that is, the direction from the boundary of the first sub-flow field structure 11 to the main outlet 1, Figure 2 In the extension direction of the primary flow channel 2, along the direction close to the main outlet 1, the width of the primary flow channel 2 increases, and the width at the position closest to the main outlet 1 reaches the maximum.
[0044] It should be noted that when the number of primary flow channels 2 is greater than 1, Figure 2 , the width and / or the depth of each primary flow channel 2 may be in the above-mentioned pattern. Alternatively, the width and / or the depth of only one of the primary flow channels 2 may be in the above-mentioned pattern. Alternatively, the width and / or the depth of only part of the primary flow channels 2 may be in the above-mentioned pattern, which is not specifically limited.
[0045] For example, the extension direction of a secondary flow channel 3 may be the direction in which its dimension is largest. Figure 1 , Figure 2 In the extension direction of a secondary flow channel 3, along the direction close to a primary flow channel 2, the width of a secondary flow channel 3 increases, and / or the depth increases, which can promote the gas in the secondary flow channel 3 to flow in the direction close to the primary flow channel 2, so that the reaction gas can be quickly discharged from the outlet flow channel, thereby avoiding the accumulation of products on the flow channel and the electrode surface, thereby releasing more reaction active sites, improving the utilization rate of the active sites on the electrode surface, improving the performance of the electrolytic cell, and thus improving the electrolysis efficiency. It should be noted that when the number of secondary flow channels 3 is greater than 1, refer to Figure 1 and Figure 2, the width and / or the depth of each secondary flow channel 3 may be the above-mentioned rule. Alternatively, the width and / or the depth of only one of the secondary flow channels 3 may be the above-mentioned rule. Alternatively, the width and / or the depth of only some of the secondary flow channels 3 may be the above-mentioned rule, which is not specifically limited.
[0046] For example, the extending direction of a tertiary flow channel 4 may be the direction in which its dimension is the largest. Figure 2 In the extension direction of the tertiary flow channel 4, along the direction close to the secondary flow channel 3, the width of a tertiary flow channel 4 increases, and / or the depth increases, which can promote the gas in the tertiary flow channel 4 to flow in the direction close to the secondary flow channel 3, so that the reaction gas can be quickly discharged from the outlet flow channel, thereby avoiding the accumulation of products on the flow channel and the electrode surface, thereby releasing more reaction active sites, improving the utilization rate of the active sites on the electrode surface, improving the performance of the electrolytic cell, and thus improving the electrolysis efficiency. It should be noted that when the number of tertiary flow channels 4 is greater than 1, refer to Figure 2 , the width and / or depth of each tertiary flow channel 4 may be the above-mentioned rule. Alternatively, the width and / or depth of only one of the tertiary flow channels 4 may be the above-mentioned rule. Alternatively, the width and / or depth of only some of the tertiary flow channels 4 may be the above-mentioned rule, which is not specifically limited.
[0047] Optionally, in the extension direction of a flow channel, along the direction close to the main outlet 1, the width of the flow channel 2 increases linearly, and / or the depth increases linearly. In the extension direction of a flow channel, along the direction close to the main outlet 1, the width and / or depth increase linearly, which can not only promote the gas in the flow channel, etc., to flow in the direction close to the main outlet 1, but also facilitate the reaction gas to be quickly discharged from the outlet flow channel, thereby avoiding the accumulation of products on the flow channel and the electrode surface, thereby releasing more reactive sites, improving the utilization rate of the active sites on the electrode surface, improving the performance of the electrolytic cell, and thus improving the electrolysis efficiency, and the appearance of the flow channel is beautiful and easy to prepare. The linear increase here means that in a flow channel, in its extension direction, the increase amplitude of each adjacent two sections of the sub-flow channel is equal. Here, the size of each section of the sub-flow channel in the extension direction of the flow channel is equal. That is, the linear increase in width means that in a flow channel, in its extension direction, the difference in the width of each adjacent two sections of the sub-flow channel is equal, and the closer to the main outlet 1, the greater the width of each section of the sub-flow channel. The linear increase in depth means that: in a flow channel, in the extension direction thereof, the difference in depth between each two adjacent sections of sub-flow channels is equal, and the closer to the main outlet 1, the greater the depth of each section of sub-flow channel.
[0048] For example, in the extension direction of a primary flow channel 2, along the direction close to the main outlet 1, the width of a primary flow channel 2 increases linearly, and / or the depth increases linearly. In the extension direction of a primary flow channel 2, along the direction close to the main outlet 1, the width and / or depth increases linearly, which can not only promote the gas in the primary flow channel 2 to flow in the direction close to the main outlet 1, but also facilitate the reaction gas to be quickly discharged from the outlet flow channel, thereby avoiding the accumulation of products on the flow channel and the electrode surface, thereby releasing more reaction active sites, improving the utilization rate of the active sites on the electrode surface, improving the performance of the electrolytic cell, and thus improving the electrolysis efficiency, but also the appearance of the primary flow channel 2 is beautiful and easy to prepare. Figure 1 In the extension direction of a primary flow channel 2, along the direction close to the main outlet 1, that is, from the lower left corner to the upper right corner, Figure 1 In the extension direction of a primary flow channel 2, the width of the primary flow channel 2 increases linearly along the direction close to the main outlet 1, and the width d1 at the upper right corner reaches the maximum. Figure 2 In the extension direction of a primary flow channel 2, along the direction close to the main outlet 1, that is, the direction from the boundary of the first sub-flow field structure 11 to the main outlet 1, Figure 2 In the extending direction of the primary flow channel 2, along the direction close to the main outlet 1, the width of a primary flow channel 2 increases linearly, and the width at the position closest to the main outlet 1 reaches the maximum. It should be noted that when the number of primary flow channels 2 is greater than 1, refer to Figure 2 , the width and / or depth of each primary flow channel 2 may increase linearly. Alternatively, the width and / or depth of only one of the primary flow channels 2 may increase linearly. Alternatively, the width and / or depth of only part of the primary flow channels 2 may increase linearly, which is not specifically limited. For example, Figure 1 , Figure 2 In the extension direction of a secondary flow channel 3, along the direction close to the primary flow channel 2, the width of a secondary flow channel 3 increases linearly, and / or the depth increases linearly, which can not only promote the gas in the secondary flow channel 3 to flow in the direction close to the primary flow channel 2, but also facilitate the reaction gas to be quickly discharged from the outlet flow channel, thereby avoiding the accumulation of products on the flow channel and the electrode surface, thereby releasing more reactive sites, improving the utilization rate of the active sites on the electrode surface, improving the performance of the electrolytic cell, and thus improving the electrolysis efficiency, and the secondary flow channel 3 has a beautiful appearance and is easy to prepare. It should be noted that when the number of secondary flow channels 3 is greater than 1, refer to Figure 1 , Figure 2 , the width and / or the depth of each secondary flow channel 3 may increase linearly. Alternatively, the width and / or the depth of only one of the secondary flow channels 3 may increase linearly. Alternatively, the width and / or the depth of only some of the secondary flow channels 3 may increase linearly, which is not specifically limited.
[0049] For example, Figure 2 In the extension direction of the tertiary flow channel 4, along the direction close to the secondary flow channel 3, the width of a tertiary flow channel 4 increases linearly, and / or the depth increases linearly, which can not only promote the gas in the tertiary flow channel 4 to flow in the direction close to the secondary flow channel 3, but also facilitate the reaction gas to be quickly discharged from the outlet flow channel, thereby avoiding the accumulation of products on the flow channel and the electrode surface, thereby releasing more reactive sites, improving the utilization rate of the active sites on the electrode surface, improving the performance of the electrolytic cell, and thus improving the electrolysis efficiency, and the tertiary flow channel 4 has a beautiful appearance and is easy to prepare. It should be noted that when the number of secondary flow channels 3 is greater than 1, refer to Figure 2 , the width and / or the depth of each tertiary flow channel 4 may increase linearly. Alternatively, the width and / or the depth of only one of the tertiary flow channels 4 may increase linearly. Alternatively, the width and / or the depth of only some of the tertiary flow channels 4 may increase linearly, which is not specifically limited.
[0050] Optionally, along the connection sequence close to the main outlet 1, the width of the flow channels of different levels increases, and / or the depth increases. That is, the closer the connection sequence of a certain level of flow channels is to the main outlet 1, the larger the width of the flow channels of this level, and / or the greater the depth, and the farther the connection sequence of a certain level of flow channels is from the main outlet 1, the smaller the width of the flow channels of this level, and / or the smaller the depth. Along the connection sequence close to the main outlet 1, the size of each level of flow channels is larger, and the gas output is smoother, which facilitates the reaction gas to be quickly discharged from the outlet flow channel, thereby avoiding the accumulation of products on the flow channel and the electrode surface, thereby releasing more reaction active sites, improving the utilization rate of the active sites on the electrode surface, improving the performance of the electrolytic cell, and then improving the electrolysis efficiency.
[0051] For example, refer to Figure 1 , Figure 2 , the order of connection along the main outlet 1 is: the tertiary flow channel 4 is farthest from the main outlet 1, the secondary flow channel 3 is next, and the primary flow channel 2 is closest to the main outlet 1. Then, the width and / or depth of the primary flow channel 2 is greater than the width and / or depth of the secondary flow channel 3, and the width and / or depth of the secondary flow channel 3 is greater than the width and / or depth of the tertiary flow channel 4.
[0052] Optionally, in the extension direction of a flow channel: in a flow channel, the ratio of the maximum width to the minimum width is greater than 1 and less than or equal to 100, and / or, in a flow channel, the ratio of the maximum depth to the minimum depth is greater than 1 and less than or equal to 100. In a flow channel, the ratio of the maximum width to the minimum width is more appropriate, which is conducive to the rapid discharge of the reaction gas, and the shape of the flow channel is more beautiful. In a flow channel, the ratio of the maximum depth to the minimum depth is more appropriate, which is conducive to the rapid discharge of the reaction gas, and the shape of the flow channel is more beautiful.
[0053] For example, in the extension direction of a flow channel, the ratio of the maximum width to the minimum width in the flow channel may be 1.1, or 2, or 5, or 20, or 33, or 50, or 70, or 80, or 100. In the extension direction of a flow channel, the ratio of the maximum depth to the minimum depth in the flow channel may be 1.1, or 7, or 10, or 30, or 40, or 51, or 69, or 86, or 100.
[0054] For example, in the extension direction of the primary flow channel 2: in one primary flow channel 2, the ratio of the maximum width d1 to the minimum width is greater than 1 and less than or equal to 100, in the extension direction of the primary flow channel 2: in one primary flow channel 2, the ratio of the maximum width d1 to the minimum width is more appropriate, which is conducive to the rapid discharge of the reaction gas, and the shape of the primary flow channel 2 is more beautiful. And / or, in one primary flow channel 2, the ratio of the maximum depth to the minimum depth is greater than 1 and less than or equal to 100, in the extension direction of the primary flow channel 2: in one primary flow channel 2, the ratio of the maximum depth to the minimum depth is more appropriate, which is conducive to the rapid discharge of the reaction gas, and the shape of the primary flow channel 2 is more beautiful.
[0055] For example, in the extension direction of the primary flow channel 2, the ratio of the maximum width d1 to the minimum width in one primary flow channel 2 may be 1.1, or 2, or 5, or 20, or 33, or 50, or 70, or 80, or 100. In the extension direction of the primary flow channel 2, the ratio of the maximum depth to the minimum depth in one primary flow channel 2 may be 1.1, or 7, or 10, or 30, or 40, or 51, or 69, or 86, or 100.
[0056] For example, in the extension direction of the secondary flow channel 3: in one secondary flow channel 3, the ratio of the maximum width d2 to the minimum width is greater than 1 and less than or equal to 100, in the extension direction of the secondary flow channel 3: in one secondary flow channel 3, the ratio of the maximum width d2 to the minimum width is more appropriate, which is conducive to the rapid discharge of the reaction gas, and the shape of the secondary flow channel 3 is more beautiful. And / or, in one secondary flow channel 3, the ratio of the maximum depth to the minimum depth is greater than 1 and less than or equal to 100, in the extension direction of the secondary flow channel 3: in one secondary flow channel 3, the ratio of the maximum depth to the minimum depth is more appropriate, which is conducive to the rapid discharge of the reaction gas, and the shape of the secondary flow channel 3 is more beautiful.
[0057] For example, in the extension direction of the secondary flow channel 3: in one secondary flow channel 3, the ratio of the maximum width d2 to the minimum width may be 1.1, or 3, or 5, or 20, or 40, or 50, or 70, or 80, or 100. In the extension direction of the secondary flow channel 3: in one secondary flow channel 3, the ratio of the maximum depth to the minimum depth may be 1.1, or 7, or 18, or 30, or 40, or 51, or 69, or 92, or 100.
[0058] For example, in the extension direction of the tertiary flow channel 4: in one tertiary flow channel 4, the ratio of the maximum width to the minimum width is greater than 1 and less than or equal to 100, in the extension direction of the tertiary flow channel 4: in one tertiary flow channel 4, the ratio of the maximum width to the minimum width is more appropriate, which is conducive to the rapid discharge of the reaction gas, and the shape of the tertiary flow channel 4 is more beautiful. And / or, in one tertiary flow channel 4, the ratio of the maximum depth to the minimum depth is greater than 1 and less than or equal to 100, in the extension direction of the tertiary flow channel 4: in one tertiary flow channel 4, the ratio of the maximum depth to the minimum depth is more appropriate, which is conducive to the rapid discharge of the reaction gas, and the shape of the tertiary flow channel 4 is more beautiful.
[0059] For example, in the extension direction of the tertiary flow channel 4, the ratio of the maximum width to the minimum width in a tertiary flow channel 4 may be 1.1, or 3, or 17, or 20, or 40, or 50, or 70, or 80, or 100. In the extension direction of the tertiary flow channel 4, the ratio of the maximum depth to the minimum depth in a tertiary flow channel 4 may be 1.1, or 7, or 21, or 30, or 40, or 51, or 69, or 88, or 100.
[0060] It should be noted that the linear increase in the width of the flow channel can effectively adjust the ratio between the flow field area and the contact area. When the flow field design is dense and the contact area is small, the width of the flow channel at the contact part between the flow channel and the membrane electrode can be made smaller than the width of the bottom of the flow channel, increasing the contact area between the bipolar plate and the membrane electrode, thereby reducing the contact resistance; when the flow field design is loose, the width of the flow channel at the contact part between the flow channel and the membrane electrode can be made larger than the width of the bottom of the flow channel, thereby reducing the contact area between the bipolar plate and the membrane electrode and reducing the product transmission and mass transfer resistance. Therefore, by linearly increasing the design of the flow channel structure, the flow channel area and the contact area can be effectively adjusted, thereby ensuring that the contact area between the bipolar plate and the membrane electrode remains within a reasonable range. In other words, in the process of designing the flow channel width, it is necessary to consider that the ridge-groove ratio is within a suitable range. When the ridge-groove ratio is within a suitable range, the width and depth can be designed in combination.
[0061] Optional, see Figure 1 , Figure 2Each primary flow channel 2 is connected by a quasi-parallel flow field, a point flow field, or a quasi-interdigitated flow field, namely, a secondary flow channel 3.
[0062] Optionally, in the outlet flow channel, the number of main outlets 1 may be 1 or more, for example, 1, 2, 3, etc. The number may be selected and optimized according to the shape and characteristics of the flow field structure. The shape of the main outlet 1 may be circular, triangular, quadrilateral, or polygonal, and its shape structure, etc., and the size of the main outlet 1 may be selected based on the characteristics of the flow field structure. When multiple main outlets 1 are provided in the outlet flow channel, they may also be provided in the axial direction to imitate the shape of leaf veins, and the main outlets 1 converge at the gas collection port to facilitate the connection of subsequent pipelines.
[0063] Optionally, the shape of any level of flow channel can be an arc-shaped vein structure, a pinnate vein structure, a forked vein structure, a longitudinal vein structure, a palmate vein structure, a lateral parallel vein structure, a reticular vein structure or an auxiliary reticular vein structure, etc.
[0064] For example, the shape of the primary flow channel 2 can be: an arc-shaped vein structure, a pinnate vein structure, a forked vein structure, a longitudinal vein structure, a palm-shaped vein structure, a lateral parallel vein structure, a reticular vein structure or an auxiliary reticular vein structure, etc.
[0065] For another example, the secondary flow channel 3 may be in the shape of an arc-shaped vein structure, a pinnate vein structure, a forked vein structure, a longitudinal vein structure, a palm-shaped vein structure, a lateral parallel vein structure, a reticular vein structure or an auxiliary reticular vein structure, etc. The secondary flow channel 3 may also be in the shape of a straight, wavy, diamond or other shapes, and may be arranged completely in parallel or arranged non-completely in parallel according to the spatial structure, etc.
[0066] For another example, the shape of the tertiary flow channel 4 can be: an arc-shaped vein structure, a pinnate vein structure, a forked vein structure, a longitudinal vein structure, a palm-shaped vein structure, a lateral parallel vein structure, a reticular vein structure or an auxiliary reticular vein structure, etc.
[0067] Optional, see Figure 2 The multi-stage flow channel includes: a primary flow channel 2 connected to the main outlet 1, and the outlet flow channel also includes: a support structure 9, located between the main outlet 1 and the primary flow channel 2. In addition to the function of diversion, the support structure 9 is mainly used to provide support for the membrane or electrode in contact with the sub-flow field structure, so as to firmly support the membrane or electrode in contact with the sub-flow field structure. There is no limitation on the specific shape of the support structure 9, for example, Figure 2 In the embodiment, the support structure 9 may be cylindrical in shape.
[0068] It should be noted that, refer to Figure 1 , Figure 2The first sub-flow field structure 11 and the second sub-flow field structure can both be bionic flow field structures based on leaf vein structures, which can make the flow field more evenly distributed in the active area and shorten the residence time of the reaction products in the flow channel as much as possible, so as to speed up the discharge of the reactants and improve the electrode reaction rate.
[0069] The utility model also provides a bipolar plate, including a bipolar plate body, and any of the aforementioned flow field structures. As mentioned above, the aforementioned first sub-flow field structure 11 and the second sub-flow field structure are respectively located on the cathode side and the anode side of the bipolar plate body. The bipolar plate has the same or similar beneficial effects as any of the aforementioned flow field structures, and the relevant parts can refer to the aforementioned loading, and in order to avoid repetition, they are not repeated here.
[0070] Optional, see Figure 1 , the bipolar plate also includes: a sub-ridge unit 5, which refers to a unit that generates gas. A sub-ridge unit 5 is connected to at least two outlet flow channels, so the gas generated by the sub-ridge unit 5 can be discharged from the at least two outlet flow channels, and there are at least two options for the discharge path of the gas generated by the sub-ridge unit 5. The discharge path of the gas generated by the sub-ridge unit 5 is more selective, and the gas generated by the sub-ridge unit 5 can be discharged as soon as possible from the shortest path or the fastest path, thereby avoiding the accumulation of products on the flow channel and the electrode surface, thereby releasing more reactive active sites, improving the utilization rate of the active sites on the electrode surface, and improving the performance of the electrolyzer. Here, on the basis of being greater than or equal to 2, the more outlet flow channels a sub-ridge unit 5 is connected to, the faster its gas discharge speed is, and the specific number of outlet flow channels connected is not specifically limited. For example, a sub-ridge unit 5 can be connected to two outlet flow channels, or a sub-ridge unit 5 can be connected to three outlet flow channels, or a sub-ridge unit 5 can be connected to four outlet flow channels, or a sub-ridge unit 5 can be connected to five outlet flow channels.
[0071] It should be noted that, for each sub-ridge unit, at least two outlet flow channels may be connected to each sub-ridge unit 5, or only one of the sub-ridge units 5 may be connected to the sub-ridge unit 5, or some of the sub-ridge units may be connected to each sub-ridge unit 5. For example, Figure 1 In the embodiment, for some sub-ridge units 5, one sub-ridge unit 5 is connected to four outlet flow channels. The types of these four outlet flow channels may be different according to their distribution locations. For example, Figure 1 In the figure, the four outlet flow channels connected to the sub-ridge unit marked with 5 are: two relatively distributed secondary flow channels 3 and two relatively distributed tertiary flow channels 4.
[0072] Figure 3The utility model also provides an electrolytic cell, referring to Figure 3 The electrolytic cell comprises: a plurality of bipolar plates 8 arranged in a stack.
[0073] Optionally, each main outlet 1 of each first sub-flow field structure 11 of each bipolar plate 8 is connected to form a first common outlet channel, and the first common outlet channel is connected to the first gas collection port 6. The reaction gas converges from the main outlet to the first common outlet channel, and then quickly discharges the bipolar plate through the first gas collection port 6. The main outlets of each second sub-flow field structure of each bipolar plate 8 are connected to form a second common outlet channel, and the second common outlet channel is connected to the second gas collection port. The reaction gas converges from the main outlet to the second common outlet channel, and then quickly discharges the bipolar plate through the second gas collection port.
[0074] Optionally, in the extension direction of the first common outlet channel, along the direction close to the first gas collection port 6, the cross-sectional area of the first common outlet channel is increased, which can promote the gas in each main outlet 1 to flow in the direction close to the first gas collection port 6, so that the reaction gas can be quickly discharged from the first gas collection port 6, thereby avoiding the accumulation of products on the flow channel and the electrode surface, thereby releasing more reaction active sites, improving the utilization rate of the active sites on the electrode surface, improving the performance of the electrolytic cell, and thus improving the electrolysis efficiency. And / or, in the extension direction of the second common outlet channel, along the direction close to the second gas collection port, the cross-sectional area of the second common outlet channel is increased, which can promote the gas in each main outlet, etc., to flow in the direction close to the second gas collection port, so that the reaction gas can be quickly discharged from the second gas collection port, thereby avoiding the accumulation of products on the flow channel and the electrode surface, thereby releasing more reaction active sites, improving the utilization rate of the active sites on the electrode surface, improving the performance of the electrolytic cell, and thus improving the electrolysis efficiency.
[0075] It should be noted that Figure 3 In the extending direction of the first common outlet channel, the direction close to the first gas collecting port 6 may be roughly from right to left. Figure 3 In the embodiment, each main outlet 1 is stacked along the left-right direction to form a first common outlet channel, and the cross-sectional area of the first common outlet channel increases along the direction from right to left. Figure 3 In the figure, 7 is an end pressure plate.
[0076] Optionally, in the extension direction of the first common outlet channel, along the direction close to the first gas collecting port 6, the cross-sectional area of the first common outlet channel increases linearly, which can not only promote the gas in the first common outlet channel to flow in the direction of the first gas collecting port 6, but also facilitate the reaction gas to be quickly discharged from the outlet flow channel, thereby avoiding the accumulation of products on the flow channel and the electrode surface, thereby releasing more reaction active sites, improving the utilization rate of the active sites on the electrode surface, improving the performance of the electrolytic cell, and thus improving the electrolysis efficiency, but also the first common outlet channel has a beautiful appearance and is easy to prepare. Figure 3 In the embodiment, each main outlet 1 is stacked along the left-right direction to form a first common outlet channel, and the cross-sectional area of the first common outlet channel increases linearly from right to left.
[0077] Optionally, in the extension direction of the second common outlet channel, along the direction close to the second gas collecting port, the cross-sectional area of the second common outlet channel increases linearly, which can not only promote the gas in the second common outlet channel to flow in the direction of the second gas collecting port, but also facilitate the reaction gas to be quickly discharged from the outlet flow channel, thereby avoiding the accumulation of products in the flow channel and the electrode surface, thereby releasing more reaction active sites, improving the utilization rate of the active sites on the electrode surface, improving the performance of the electrolytic cell, and thus improving the electrolysis efficiency, but also the second common outlet channel has a beautiful appearance and is easy to prepare.
[0078] It should be noted that the linear increase here means: in a common outlet flow channel, in its extension direction, the increase amplitude of each adjacent two sections of the common outlet flow channel is equal. Here, the size of each section of the common outlet flow channel in the extension direction of the common outlet flow channel is equal. That is, the linear increase in width means: in a common outlet flow channel, in its extension direction, the difference in the cross-section of each adjacent two sections of the common outlet flow channel is equal, and the closer to the gas collection port, the larger the cross-sectional area of each section of the common outlet flow channel. A common outlet flow channel here refers to the first public outlet flow channel or the second common outlet flow channel, and the gas collection port corresponds to the common outlet flow channel.
[0079] Optionally, in the extension direction of the first common outlet channel: in the first common outlet channel, the ratio of the area of the maximum cross-section to the area of the minimum cross-section is greater than 1 and less than or equal to 100; in the extension direction of the first common outlet channel: in the first common outlet channel, the ratio of the area of the maximum cross-section to the area of the minimum cross-section is relatively appropriate, which is conducive to the rapid discharge of the reaction gas and the shape of the first common outlet channel is more beautiful.
[0080] For example, in the extension direction of the first common outlet channel, the ratio of the area of the maximum cross section to the area of the minimum cross section in the first common outlet channel can be: 1.1, or 2, or 5.
[0081] Or 20, or 33, or 50, or 70, or 80, or 100.
[0082] Optionally, in the extension direction of the second common outlet channel: in the second common outlet channel, the ratio of the area of the maximum cross-section to the area of the minimum cross-section is greater than 1 and less than or equal to 100; in the extension direction of the second common outlet channel: in the second common outlet channel, the ratio of the area of the maximum cross-section to the area of the minimum cross-section is relatively appropriate, which is conducive to the rapid discharge of the reaction gas and the shape of the second common outlet channel is more beautiful.
[0083] For example, in the extension direction of the second common outlet channel: in the second common outlet channel, the ratio of the area of the maximum cross-section to the area of the minimum cross-section can be: 1.1, or 2, or 16, or 20, or 33, or 51, or 70, or, 90, or 100.
[0084] The bipolar plate and the electrolytic cell have the same or similar beneficial effects as any of the aforementioned flow field structures, and the relevant parts of the three can be referenced to each other. In order to avoid repetition, they will not be described here.
[0085] The present application is further explained below in conjunction with specific embodiments.
[0086] Example 1
[0087] like Figure 1 As shown, the flow field structure of the bipolar plate is applied to a PEM electrolyzer, wherein the first sub-flow field structure 11 is applied to the cathode side, and the second sub-flow field structure is applied to the anode side. The first sub-flow field structure 11 is square, and its main outlet 1 is located on one side. Each primary flow channel 2 adopts a side parallel vein structure, and each primary flow channel 2 is connected by a non-completely parallel straight secondary flow channel 3. The first sub-flow field structure 11 is used as the cathode flow field, and the serpentine second sub-flow field structure is used as the anode flow field to assemble the PEM electrolyzer. The active area of the first sub-flow field structure 11 of the electrolyzer is 25cm 2 During the operation of the electrolytic cell, the anode was kept circulating with deionized water, the water inlet flow rate was 5 mL / min, the electrolytic cell operating temperature was 65 °C, and 1 A / cm was recorded after the electrolytic cell was running stably. 2 Operating point voltage.
[0088] As a comparative example, the other conditions remain unchanged, and the cathode sub-flow field structure adopts a serpentine flow field with an inlet flow channel and an outlet flow channel to assemble the electrolytic cell. The electrolytic cell is operated under the same operating conditions. After the electrolytic cell is running stably, the 1A / cm 2 Working point voltage. By comparison, it is found that the cathode sub-flow field adopts Figure 1The first sub-flow field structure 11 shown in the figure shows a better performance than the electrolytic cell in which the cathode sub-flow field is assembled with a serpentine sub-flow field having an inlet flow channel and an outlet flow channel at 1 A / cm 2 The voltage is 30mV (millivolts) lower at the operating point.
[0089] Example 2
[0090] like Figure 1 As shown, the structure and size of the electrolytic cell in Example 1 are the same. During the operation of the electrolytic cell, the anode is kept continuously circulating with deionized water, the water inlet flow rate is also 5 mL / min, the electrolytic cell operating temperature is 65°C, and 1 A / cm is recorded after the electrolytic cell runs stably. 2 Operating point voltage.
[0091] As a comparative example, the other conditions remain unchanged, and the cathode sub-flow field structure adopts a parallel flow field assembly electrolyzer with an inlet flow channel and an outlet flow channel. The electrolyzer is operated under the same operating conditions. After the electrolyzer is running stably, 1A / cm 2 Working point voltage. By comparison, it is found that the cathode sub-flow field adopts Figure 1 The first sub-flow field structure 11 shown in the figure has a lower performance than the electrolytic cell in which the cathode sub-flow field is assembled using a conventional parallel flow field with an inlet flow channel and an outlet flow channel at 1 A / cm 2 The voltage is 18mV lower at the operating point.
[0092] Example 3
[0093] like Figure 2 As shown, the flow field structure of the bipolar plate is applied to the cathode of the AEM electrolyzer, wherein the first sub-flow field structure 11 is applied to the cathode side, and the second sub-flow field structure is applied to the anode side. The flow field structure of the electrolyzer is circular, and its main outlet 1 is close to the edge. Each primary flow channel 2 adopts a palm-shaped vein structure, and each primary flow channel 2 is connected by a wavy non-completely parallel secondary flow channel 3 based on the spatial structure. The first sub-flow field structure 11 is used as the cathode flow field, and the point-shaped flow field structure is used as the second sub-flow field structure to assemble the AEM electrolyzer. The active area diameter of the first sub-flow field structure 11 of the electrolyzer is 6 cm. During the operation of the electrolyzer, the anode is kept continuously circulated with a 1M (1 mol / L, 1 mole per liter) KOH solution, the solution flow rate is 10 mL / min (milliliters per minute), the operating temperature of the electrolyzer is 55°C, and 0.8A / cm is recorded after the electrolyzer is running stably. 2 Operating point voltage.
[0094] As a comparative example, the other conditions remain unchanged, and the cathode sub-flow field structure adopts a point-shaped flow field with an inlet flow channel and an outlet flow channel to assemble the electrolytic cell. The electrolytic cell is operated under the same operating conditions. After the electrolytic cell is running stably, 0.8A / cm 2 Working point voltage. By comparison, it is found that the cathode sub-flow field adopts Figure 2 The first sub-flow field structure 11 shown in the figure has a better performance at 0.8 A / cm compared with the electrolytic cell in which the cathode sub-flow field is assembled using a traditional point-shaped flow field with an inlet flow channel and an outlet flow channel. 2 The voltage is 28mV lower at the operating point.
[0095] By comparing the above-mentioned Examples 1 to 3, it can be concluded that the electrolyzer formed by the flow field structure provided by the utility model has a lower voltage under the same working conditions. That is to say, under the same working conditions, the electrolyzer formed by the flow field structure provided by the present application has lower energy consumption than the electrolyzer formed by the flow field structure of the related art, which means that the gas discharge speed of the flow field structure provided by the present application is faster than that of the flow field structure of the related art, there is basically no product aggregation, or the product aggregation is less, and the electrolysis efficiency is higher.
[0096] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.
[0097] The embodiments of the utility model are described above in conjunction with the accompanying drawings, but the utility model is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the enlightenment of the utility model, ordinary technicians in this field can also make many forms without departing from the scope of protection of the utility model and the claims, which all fall within the protection of the utility model.
Claims
1. A flow field structure of a bipolar plate, characterized in that: include: a first sub-flow field structure and a second sub-flow field structure; The first sub-flow field structure has only an outlet flow channel and is located on one side of the cathode side and the anode side of the bipolar plate body; The second sub-flow field structure has an outlet flow channel and an inlet flow channel and is located on the other side of the cathode side and the anode side of the bipolar plate body.
2. The flow field structure of the bipolar plate according to claim 1, characterized in that: The outlet flow channel includes: a main outlet, and multiple flow channels sequentially connected to the main outlet.
3. The flow field structure of the bipolar plate according to claim 2, characterized in that: In the extension direction of a flow channel, along the direction approaching the main outlet, the width of the flow channel increases and / or the depth increases.
4. The flow field structure of the bipolar plate according to claim 2, characterized in that: Along the communication sequence close to the main outlet, the widths of the flow channels of different stages increase, and / or the depths increase.
5. The flow field structure of the bipolar plate according to claim 3, characterized in that: In the extension direction of a flow channel: in the flow channel, the ratio of the maximum width to the minimum width is greater than 1 and less than or equal to 100, and / or, in the flow channel, the ratio of the maximum depth to the minimum depth is greater than 1 and less than or equal to 100.
6. The flow field structure of the bipolar plate according to any one of claims 2 to 5, characterized in that: The multi-stage flow channel includes: a primary flow channel connected to the main outlet, and the outlet flow channel also includes: a support structure located between the main outlet and the primary flow channel.
7. A bipolar plate, characterized in that: include: A bipolar plate body, and a flow field structure of the bipolar plate as claimed in any one of claims 1 to 6.
8. The bipolar plate according to claim 7, characterized in that: Also includes: A sub-ridge unit, wherein one sub-ridge unit is connected to at least two outlet flow channels.
9. An electrolytic cell, characterized in that: include: A plurality of bipolar plates as claimed in claim 7 or 8 are stacked.
10. The electrolytic cell according to claim 9, characterized in that The main outlets of the first sub-flow field structures of the bipolar plates are connected to form a first common outlet channel, and the first common outlet channel is connected to the first gas collecting port; The main outlets of the second sub-flow field structures of the bipolar plates are connected to form a second common outlet channel, and the second common outlet channel is connected to the second gas collecting port.
11. The electrolytic cell according to claim 10, characterized in that In the extension direction of the first common outlet channel, along the direction close to the first gas collecting port, the cross-sectional area of the first common outlet channel increases; And / or, in the extension direction of the second common outlet channel, along the direction close to the second gas collecting port, the cross-sectional area of the second common outlet channel increases.
12. The electrolytic cell according to claim 10 or 11, characterized in that: In the extension direction of the first common outlet channel: in the first common outlet channel, the ratio of the area of the largest cross section to the area of the smallest cross section is greater than 1 and less than or equal to 100; And / or, in the extension direction of the second common outlet channel: in the second common outlet channel, the ratio of the area of the maximum cross section to the area of the minimum cross section is greater than 1 and less than or equal to 100.