Anode bipolar plate and hydrogen production system having the same

Abstract

The present invention relates to the field of new energy technology, and specifically to an anode bipolar plate and a hydrogen production system having the same. An anode bipolar plate comprises: a bipolar plate body, arranged along the flow direction of the flow field of the electrolyzer, provided with at least two flow channels, ribs formed between adjacent flow channels, liquid pure water flows in the flow channel in the flow field under the hydrogen production state, and the bottom surface of the rib is arranged in contact with the anode diffusion layer of the electrolyzer; a sub-flow channel structure, arranged in the rib, the sub-flow channel structure includes an inlet, an outlet, and a sub-flow channel connecting the inlet and the outlet, the inlet is arranged on the side of the rib, and the outlet is arranged on the bottom surface of the rib; in the hydrogen production state, liquid pure water enters from the inlet through the sub-flow channel to the outlet, and then reaches the anode diffusion layer at the bottom surface of the rib to avoid gas accumulation. The present invention solves the problem that the liquid pure water in the flow field cannot directly contact the porous layer below the rib, and there is a defect that gas is easily accumulated in the lower area of ​​the rib, which hinders the transmission of liquid pure water to the reaction area.

Description

Technical Field

[0001] The present invention relates to the field of new energy technology, and in particular to an anode bipolar plate and a hydrogen production system having the same. Background Art

[0002] At present, hydrogen energy is one of the most promising clean and sustainable energy carriers, with many advantages such as high energy density (140MJ / kg) and no carbon emissions during the reaction process. In the existing technology, water electrolysis is the most commonly used method for producing low-carbon hydrogen, among which proton exchange membrane water electrolysis technology is particularly promising, with advantages such as high efficiency, high hydrogen purity and no pollution.

[0003] In the proton exchange membrane water electrolysis technology, the proton exchange membrane electrolyzer (PEMEC) is the key, with the advantages of compact structure, high current density, and high hydrogen production efficiency. PEMEC consists of an anode bipolar plate, an anode diffusion layer, an anode catalyst layer, a proton exchange membrane, a cathode catalyst layer, a cathode diffusion layer, and a cathode bipolar plate. Among them, the flow field channel on the bipolar plate is the transmission channel for reactants and products, which has an important influence on the performance of PEMEC. On the anode side of PEMEC, the pure water supplied from the outside first enters the flow field, and then passes through the diffusion layer to reach the reaction area, that is, the catalyst layer. The oxygen and excess reactants produced by the reaction, such as liquid water, pass through the diffusion layer in the opposite direction into the flow channel. The gas in the flow channel is discharged to the flow field outlet under the action of water flow and collected. On the cathode side of PEMEC, since the cathode reaction does not require water consumption, the cathode flow field does not need to pass water, but passing water can enhance heat transfer, promote hydrogen discharge, and increase the water content of the membrane.

[0004] Among the various flow field structures of the electrolytic cell, since the liquid pure water in the flow field cannot directly contact the porous layer below the ribs (RIB) between two adjacent flow channels of the bipolar plate, gas is very likely to accumulate in the lower area of ​​the ribs, hindering the transmission of liquid pure water to the reaction area and easily leading to the formation of local hot spots, thereby affecting the electrolytic performance and component life. Summary of the invention

[0005] Therefore, the technical problem to be solved by the present invention is to overcome the defect that the liquid pure water in the flow field of the flow field structure in the prior art cannot directly contact the porous layer under the ribs, and the gas is easily accumulated in the lower area of ​​the ribs, hindering the transmission of liquid pure water to the reaction area, thereby providing an anode bipolar plate and a hydrogen production system having the same.

[0006] In order to solve the above problems, the present invention provides an anode bipolar plate, comprising:

[0007] A bipolar plate body, the bipolar plate body is arranged along the flow direction of the flow field of the electrolyzer, the bipolar plate body is provided with at least two flow channels, ribs are formed between adjacent flow channels, liquid pure water flows in the flow channels in the flow field in the hydrogen production state, and the bottom surface of the ribs is arranged in contact with the anode diffusion layer of the electrolyzer;

[0008] A sub-channel structure is arranged in the rib, and the sub-channel structure includes an inlet, an outlet, and a sub-channel connecting the inlet and the outlet, the inlet is arranged on the side of the rib, and the outlet is arranged on the bottom of the rib; in the hydrogen production state, the liquid pure water enters from the inlet through the sub-channel to the outlet, and then reaches the anode diffusion layer at the bottom of the rib to avoid gas accumulation.

[0009] Optionally, the sub-channel is provided with a first sub-channel and a second sub-channel which are connected to each other, the first sub-channel is connected with an inlet, the second sub-channel is connected with an outlet, the central axis of the first sub-channel is arranged at an acute angle to the flow direction of liquid pure water, and the central axis of the second sub-channel is arranged perpendicular to the anode diffusion layer.

[0010] Optionally, the acute angle is 30° to 60°.

[0011] Optionally, a third sub-channel is provided between the first sub-channel and the second sub-channel, the third sub-channel is connected to the first sub-channel and the second sub-channel, and the cross-section of the third sub-channel is an arc shape.

[0012] Optionally, the ribs are integrally formed with the bipolar plate body.

[0013] Optionally, at least two spaced-apart sub-channel structures are provided on the same bipolar plate body.

[0014] A hydrogen production system comprises the above-mentioned anode bipolar plate, wherein the number of the bipolar plate bodies is at least two and the bipolar plate bodies are arranged at intervals.

[0015] Optionally, an electrolytic cell is further included, which includes an anode catalyst layer, a proton exchange membrane, a cathode catalyst layer, a cathode diffusion layer and a cathode bipolar plate stacked in sequence, wherein the anode diffusion layer is arranged in contact with the anode catalyst layer on one side away from the bipolar plate body.

[0016] The technical solution of the present invention has the following advantages:

[0017] 1. The anode bipolar plate provided by the present invention comprises: a bipolar plate body, which is arranged along the flow direction of the flow field of the electrolytic cell, and the bipolar plate body is provided with at least two flow channels, and ribs are formed between adjacent flow channels, and liquid pure water flows in the flow channels in the flow field under the hydrogen production state, and the bottom surface of the ribs is arranged in contact with the anode diffusion layer of the electrolytic cell; a sub-flow channel structure arranged in the ribs, which is provided with an inlet, an outlet, and a sub-flow channel connecting the inlet and the outlet, the inlet is arranged on the side of the rib, and the outlet is arranged on the bottom surface of the rib; in the hydrogen production state, after the liquid pure water enters from the inlet through the sub-flow channel to reach the outlet, it reaches the anode diffusion layer at the bottom surface of the rib to avoid gas accumulation. In the hydrogen production state, liquid pure water enters the anode diffusion layer through the sub-channel, and then to the anode catalyst layer and proton exchange membrane. Gas is generated during the hydrogen production process. The liquid pure water in the sub-channel is flushed to disperse the gas accumulated in the anode diffusion layer in the lower area of ​​the ribs. At the same time, the liquid pure water can also flow to the reaction area through the sub-channel so that there is no dead corner in the reaction area, so that the reactants and current density are evenly distributed, and the electrolysis performance is improved. In addition, the problem of bubbles in the sub-channel clogging the sub-channel can be avoided under the flow and flushing action of the above-mentioned liquid pure water.

[0018] 2. The anode bipolar plate provided by the present invention has a sub-channel with a first sub-channel and a second sub-channel connected to each other. The first sub-channel is connected to an inlet, and the second sub-channel is connected to an outlet. The central axis of the first sub-channel is set at an acute angle to the flow direction of the liquid pure water. Compared with the first sub-channel being set at a right angle to the liquid pure water, the acute angle allows the liquid pure water to naturally enter the inlet during the flow, and the acute angle of 30° to 60° is the preferred inflow angle. The central axis of the second sub-channel is set perpendicular to the anode diffusion layer, so that the liquid pure water naturally enters the anode diffusion layer under the pressure of the water, thereby driving the gas in the anode diffusion layer to move to other positions.

[0019] 3. The anode bipolar plate provided by the present invention has a third sub-channel between the first sub-channel and the second sub-channel, and the third sub-channel connects the first sub-channel and the second sub-channel. The cross-section of the third sub-channel is arc-shaped, and the arc-shaped sub-channel allows liquid pure water to reach the second sub-channel through the first sub-channel.

[0020] 4. The anode bipolar plate provided by the present invention has at least two spaced-apart sub-channel structures on the same bipolar plate body, so that liquid pure water can reach different positions of the anode diffusion layer through the sub-channel structures.

[0021] 5. In the anode bipolar plate provided by the present invention, the ribs are integrally formed with the bipolar plate body, that is, the ribs are part of the bipolar plate body, and the two are made of the same material for easy manufacturing.

[0022] 6. The hydrogen production system provided by the present invention has the advantages described in any of the above-mentioned anode bipolar plates due to the use of the anode bipolar plate described in any of the above-mentioned items. The number of bipolar plate bodies is at least two, and the arrangement of multiple bipolar plate bodies enables liquid pure water to reach different positions of the anode diffusion layer more quickly.

[0023] 7. The hydrogen production system provided by the present invention also includes an electrolytic cell, which also includes an anode catalyst layer, a proton exchange membrane, a cathode catalyst layer, a cathode diffusion layer and a cathode bipolar plate stacked in sequence, wherein the anode diffusion layer is arranged in contact with the anode catalyst layer on the side away from the bipolar plate body, so that liquid pure water can reach the anode catalyst layer through the anode diffusion layer, and the electrolytic cell is arranged to achieve the production of hydrogen. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 A schematic diagram of the structure of an anode bipolar plate provided in an embodiment of the present invention;

[0026] Figure 2 It is a schematic diagram of the half-section structure of the anode bipolar plate provided in an embodiment of the present invention.

[0027] Explanation of the reference numerals: 1. inlet; 2. rib; 3. flow direction; 4. bottom surface; 5. side surface; 6. first sub-channel; 7. third sub-channel; 8. second sub-channel; 9. outlet. DETAILED DESCRIPTION

[0028] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0030] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0031] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0032] Example 1

[0033] An anode bipolar plate comprises: a bipolar plate body, which is arranged along the flow direction of a flow field of an electrolytic cell, the bipolar plate body is provided with at least two flow channels, ribs 2 are formed between adjacent flow channels, liquid pure water flows in the flow channels in the flow field in a hydrogen production state, and the bottom surface 4 of the rib 2 is arranged in contact with the anode diffusion layer of the electrolytic cell; a sub-flow channel structure arranged in the rib 2, which is provided with an inlet 1, an outlet 9, and a sub-flow channel connecting the inlet 1 and the outlet 9, the inlet 1 is arranged on the side of the rib 2, and the outlet 9 is arranged on the bottom surface of the rib; in the hydrogen production state, liquid pure water enters from the inlet 1 through the sub-flow channel to the outlet 9, and then reaches the anode diffusion layer at the bottom surface of the rib 2 to avoid gas accumulation.

[0034] In the hydrogen production state, liquid pure water enters the anode diffusion layer through the sub-channel, and then enters the anode catalyst layer and the proton exchange membrane. Gas is generated during the hydrogen production process. The gas accumulated in the anode diffusion layer in the lower area of ​​the rib 2 is dispersed by the flushing of the liquid pure water in the sub-channel. At the same time, the liquid pure water can also flow to the reaction area through the sub-channel so that there is no dead corner in the reaction area, so that the reactants and current density are evenly distributed, and the electrolysis performance is improved. In addition, under the flow and flushing of the above-mentioned liquid pure water, the problem of bubbles in the sub-channel blocking the sub-channel can be avoided.

[0035] Example 2

[0036] like Figure 1 - Figure 2 A specific embodiment of the anode bipolar plate shown includes: a long bipolar plate body, wherein the bipolar plate body is arranged along the flow direction 3 of the flow field of the electrolytic cell, wherein the bipolar plate body is provided with two flow channels, and a convex rib 2 is formed between adjacent flow channels, that is, the rib 2 is integrally formed with the bipolar plate body. In the hydrogen production state, liquid pure water with a certain pressure flows in the flow channel, and the bottom surface of the rib 2 is arranged in contact with the anode diffusion layer of the electrolytic cell, that is, the bottom surface of the rib 2 is flush with the bottom surface of the bipolar plate body.

[0037] In order to make the liquid pure water flow quickly to the anode diffusion layer of the bottom surface 4 of the rib 2, as Figure 1 , Figure 2 As shown, six sub-channel structures are provided in the rib 2, and the sub-channel structure includes an inlet 1, an outlet 9, and a sub-channel connecting the inlet 1 and the outlet 9, wherein the inlet 1 is provided on the side 5 of the rib 2, and the outlet 9 is provided on the bottom surface 4 of the rib 2, that is, the side of the rib 2 is the side of the channel. In order to allow the liquid pure water to flow naturally into the sub-channel structure, the sub-channel structure is provided with a first sub-channel 6, a second sub-channel 8, and a third sub-channel 7 that are connected to each other. The first sub-channel 6 is connected to the inlet 1, and the second sub-channel 8 is connected to the outlet 9. The central axis of the first sub-channel 6 is arranged at an acute angle to the flow direction 3 of the liquid pure water, and the acute angle is 30° to 60 degrees, preferably 45°. The central axis of the second sub-channel 8 is arranged perpendicular to the anode diffusion layer. In order to connect the first sub-channel 6 and the second sub-channel 8, as shown Figure 2 As shown, the third sub-channel 7 is located between the first sub-channel 6 and the second sub-channel 8, and the cross section of the third sub-channel 7 is an arc shape.

[0038] A hydrogen production system comprises the above-mentioned two anode plates bipolar plates arranged at intervals and an electrolytic cell, wherein the electrolytic cell further comprises an anode catalyst layer, a proton exchange membrane, a cathode catalyst layer, a cathode diffusion layer and a cathode bipolar plate stacked in sequence, and the anode diffusion layer is arranged in contact with the anode catalyst layer on the side away from the bipolar plate body.

[0039] During the specific implementation process, when hydrogen is produced, liquid pure water flows along the flow direction 3 of the flow field, reaches the outlet 9 through the inlet 1, the first sub-channel 6, the third sub-channel 7, and the second sub-channel 8, and reaches the anode diffusion layer through the outlet 9. Under the action of water pressure, the liquid pure water will disperse the gas in the anode diffusion layer below the rib 2, and can also provide reactants there, so that the current density distribution is more uniform, thereby improving the electrolysis performance.

[0040] As an alternative implementation, the number of flow channels may be 3, 4 or even more.

[0041] As an alternative embodiment, the shape of the rib 2 may also be S-shaped, U-shaped or other structural forms.

[0042] As an alternative implementation, the number of sub-channel structures may be 2, 3, 4 or even more.

[0043] As an alternative embodiment, the cross-sectional shape of the third sub-channel 7 may also be other shapes such as a right-angle bend shape.

[0044] As an alternative embodiment, the acute angle may also be 30°, 35°, 40°, 50°, 60° or other angles.

[0045] Of course, this embodiment does not make any specific limitation on the angle between the central axis of the first sub-channel 6 and the flow direction 3 of the liquid pure water, and does not make any specific limitation on the angle between the central axis of the second sub-channel 8 and the anode diffusion layer. In this embodiment, the central axis of the first sub-channel 6 is set at an acute angle to the flow direction 3 of the liquid pure water; the central axis of the second sub-channel 8 and the anode diffusion layer can also be an acute angle or an obtuse angle.

[0046] Obviously, the above embodiments are merely examples for clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from them are still within the protection scope of the invention.

Claims

1. An anode bipolar plate, characterized in that: include: A bipolar plate body, the bipolar plate body being arranged along a flow direction (3) of a flow field of an electrolytic cell, the bipolar plate body being provided with at least two flow channels, a rib (2) being formed between adjacent flow channels, liquid pure water flowing in the flow channel in a hydrogen production state of the flow field, and a bottom surface (4) of the rib (2) being arranged in contact with an anode diffusion layer of the electrolytic cell; A sub-channel structure is arranged in the rib (2), the sub-channel structure comprises an inlet (1), an outlet (9), and a sub-channel connecting the inlet (1) and the outlet (9), the inlet (1) is arranged on the side surface (5) of the rib (2), and the outlet (9) is arranged on the bottom surface (4) of the rib (2); in the hydrogen production state, the liquid pure water enters from the inlet (1) through the sub-channel and reaches the outlet (9), and then reaches the anode diffusion layer at the bottom surface (4) of the rib (2), so as to avoid gas accumulation.

2. The anode bipolar plate according to claim 1, characterized in that: The sub-channel is provided with a first sub-channel (6) and a second sub-channel (8) which are connected to each other. The first sub-channel (6) is connected to an inlet (1), and the second sub-channel (8) is connected to an outlet (9). The central axis of the first sub-channel (6) is arranged at an acute angle to the flow direction (3) of the liquid pure water, and the central axis of the second sub-channel (8) is arranged perpendicular to the anode diffusion layer.

3. The anode bipolar plate according to claim 2, characterized in that: The acute angle is 30° to 60°.

4. The anode bipolar plate according to claim 2, characterized in that: A third sub-channel (7) is provided between the first sub-channel (6) and the second sub-channel (8), the third sub-channel (7) being connected to the first sub-channel (6) and the second sub-channel (8), and the cross section of the third sub-channel (7) is in the shape of an arc.

5. The anode bipolar plate according to claim 1, characterized in that: The ribs (2) are integrally formed with the bipolar plate body.

6. The anode bipolar plate according to any one of claims 1 to 5, characterized in that: At least two spaced-apart sub-channel structures are provided on the same bipolar plate body.

7. A hydrogen production system, characterized in that: The anode bipolar plate comprises the anode bipolar plate according to any one of claims 1 to 6, wherein the number of the bipolar plate bodies is at least two and the bipolar plate bodies are arranged at intervals.

8. The hydrogen production system according to claim 7, characterized in that: It also includes an electrolytic cell, which includes an anode catalyst layer, a proton exchange membrane, a cathode catalyst layer, a cathode diffusion layer and a cathode bipolar plate stacked in sequence, wherein the anode diffusion layer is arranged in contact with the anode catalyst layer on one side away from the bipolar plate body.

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