Electrode frame, flow field plate assembly, and electrolytic cell

Abstract

The present application provides an electrode frame, a flow field plate assembly, and an electrolytic cell. The electrode frame is applied to the flow field plate assembly, and is provided with an accommodating cavity, a water inlet, a water outlet, and a first flow distribution channel, the accommodating cavity is configured to accommodate a plate mesh, and the water inlet is in communication with the accommodating cavity by means of the first flow distribution channel. The electrode frame further comprises flow distribution rows, each flow distribution row comprises at least two flow distribution members spaced apart, and the first flow distribution channel is internally provided with at least two flow distribution rows.

Description

Pole frame, flow field plate assembly and electrolytic cell

[0001] The present application claims priority to the Chinese patent application No. 202520067902.0, filed on January 10, 2025, the whole content of which is incorporated herein by reference. TECHNICAL FIELD

[0002] The present application relates to the technical field of batteries, in particular to a pole frame, a flow field plate assembly and an electrolytic cell. BACKGROUND

[0003] Under the background of the current world energy structure dominated by fossil fuels, hydrogen energy is widely regarded as a strong competitor to reverse the energy situation due to its high heat value and zero emissions. Among the various main preparation methods, water electrolysis is the focus of research in various countries due to its clean and efficient advantages. The water electrolysis technology at room temperature is mainly divided into alkaline water electrolysis AWE, proton exchange membrane water electrolysis PEM and anion exchange membrane water electrolysis AEM according to the type of electrolyte. SUMMARY

[0004] The pole plate is one of the core components inside the electrolytic cell, and the flow channel flow field structure on the pole plate has a key influence on the water electrolysis efficiency. The flow channel structure can determine the gas-liquid exchange efficiency of the electrolyte and the electrode, and can carry away the product bubbles generated on the electrode surface in time through the flow of the electrolyte, thereby improving the electrolysis efficiency of the electrolytic cell. The flow channel design in the related art is unreasonable, and bubbles are easily blocked.

[0005] The present application provides a pole frame applied to a flow field plate assembly, the pole frame is provided with a containing cavity, a water inlet, a water outlet and a first flow distribution groove, the containing cavity is configured to contain a plate net, the water inlet is connected to the containing cavity through the first flow distribution groove;

[0006] The pole frame further comprises a flow distribution row, the flow distribution row comprises at least two flow distribution pieces arranged at intervals, and the first flow distribution groove is provided with at least two rows of flow distribution rows.

[0007] The present application further provides a flow field plate assembly, comprising:

[0008] The pole frame described above; and

[0009] The plate net is contained in the containing cavity of the pole frame.

[0010] The present application further provides an electrolytic cell comprising the pole frame described above or the flow field plate assembly described above. ADVANTAGEOUS EFFECTS

[0011] In the application, by arranging multiple rows of shunt rows in the shunt groove of the polar frame, the fluid can flow through the shunt of at least two rows of shunt rows before flowing into the accommodation cavity, so that the fluid can flow more uniformly to the accommodation cavity, ensuring that each area in the accommodation cavity can be fully supplied with fluid, thereby improving the gas-liquid exchange inside the electrolytic cell, timely discharging the gas bubbles generated in the hydrogen production process, and improving the electrolysis efficiency of the electrolytic cell. BRIEF DESCRIPTION OF DRAWINGS

[0012] Fig. 1 is a structural schematic diagram of the polar frame provided by the embodiment of the application;

[0013] Fig. 2 is an enlarged view of A in Fig. 1;

[0014] Fig. 3 is a structural schematic diagram of the polar frame provided by the embodiment of the application;

[0015] Fig. 4 is an enlarged view of B in Fig. 3;

[0016] Fig. 5 is a structural schematic diagram of the flow field plate assembly provided by the embodiment of the application;

[0017] Fig. 6 is an enlarged view of C in Fig. 5.

[0018] BRIEF DESCRIPTION OF DRAWINGS:

[0019] 1, polar frame; 11, accommodation cavity; 111, cavity side wall; 12, water inlet; 13, water outlet; 14, first shunt groove; 141, groove bottom wall; 1411, first side; 15, shunt row; 151, shunt member; 1511, first flow guide part; 1512, second flow guide part; 16, first shunt row; 161, first gap; 17, second shunt row; 18, second shunt groove; 2, flow field plate assembly; 21, plate mesh; 211, through hole; H1, extension direction of the first side. Embodiment of the application

[0020] Referring to Figs. 1-3, the first aspect of the application provides a polar frame 1 applied to a flow field plate assembly 2, the polar frame 1 is provided with an accommodation cavity 11, a water inlet 12, a water outlet 13 and a first shunt groove 14, the accommodation cavity 11 is configured to accommodate a plate mesh 21, the water inlet 12 is communicated to the accommodation cavity 11 through the first shunt groove 14; wherein the polar frame 1 further comprises multiple rows of shunt rows 15, the shunt row 15 comprises at least two shunt members 151 arranged at intervals, and the first shunt groove 14 is provided with at least two rows of shunt rows 15.

[0021] In the polar frame 1 of the present application, when the fluid enters the containing cavity 11 from the water inlet 12 through the first flow distribution groove 14, one row of flow distribution rows 15 first distributes the fluid, and because the flow distribution rows 15 contain flow distribution pieces 151 arranged at intervals, the fluid is divided into multiple small streams when flowing through the flow distribution pieces 151, and then another row of flow distribution rows 15 redistributes and reallocates the small streams that have been preliminarily adjusted, so that the fluid is more evenly distributed when entering the containing cavity 11. The containing cavity 11 is usually provided with a flow channel structure, and the fluid flows into the containing cavity 11 and then flows through the flow channel structure, thereby efficiently completing the hydrogen production process and flushing the bubbles accumulated in the containing cavity 11, and finally the fluid flows out of the water outlet 13.

[0022] The size and shape of the containing cavity 11 can be set according to design requirements. For example, the containing cavity 11 can be cylindrical, prismatic or irregularly shaped. The water outlet 13 and the water inlet 12 are usually centrally symmetrically arranged at the two ends of the polar frame 1, so that the fluid can flow through as many areas in the containing cavity 11 as possible. The first flow distribution groove 14 can be one, which alone communicates the water inlet 12 and the containing cavity 11; the first flow distribution groove 14 can also be provided with multiple, for example, two first flow distribution grooves 14 communicate the water inlet 12 and the containing cavity 11, and the two first flow distribution grooves 14 are arranged at intervals, so that the liquid is divided into two streams when entering the first flow distribution groove 14 from the water inlet 12, that is, the two first flow distribution grooves 14 arranged at intervals themselves have a certain flow distribution effect, so that the distribution of the liquid is more uniform.

[0023] The flow distribution pieces 151 arranged in the first flow distribution groove 14 can distribute the fluid, thereby adjusting the flow rate of the fluid entering the containing cavity 11, so that the flow of the fluid is more uniform. When the fluid enters the first flow distribution groove 14 from the water inlet 12, the distribution of flow rate and pressure is usually not uniform, and local turbulent flow is easy to occur. Therefore, the present application is provided with multiple rows of flow distribution rows 15 in the first flow distribution groove 14, one row of flow distribution rows 15 can preliminarily adjust the fluid, reduce the overall flow rate of the fluid, and make the flow of the fluid more orderly, and another row of flow distribution rows 15 can improve the uniformity of the fluid flow, so that the fluid flowing out of the first flow distribution groove 14 is closer to the laminar flow state, reducing the probability of generating bubbles when the liquid flows in the containing cavity 11 due to turbulent flow or collision with the flow field assembly; the fluid can be more evenly distributed in the containing cavity 11, improving the contact between the fluid and the flow field assembly, thereby ensuring efficient electrolysis reaction.

[0024] The arrangement of the flow distribution pieces 151 can also enhance the structural strength of the first flow distribution groove 14. In the embodiment of the present application, at least two rows of flow distribution rows 15 are arranged in the first flow distribution groove 14, and the flow distribution row 15 includes at least two flow distribution pieces 151 arranged at intervals. The flow distribution pieces 151 are more uniformly and densely distributed in the first flow distribution groove 14, thereby reducing the probability of fracture of the polar frame 1 at the first flow distribution groove 14 and improving the service life of the polar frame 1.

[0025] In the embodiment of the present application, the fluid flows through at least two rows of flow distribution rows 15 before flowing into the containing cavity 11, and at least two flow distribution pieces 151 are arranged in each row of flow distribution rows 15, so that the fluid can flow more uniformly to the containing cavity 11, ensuring that each area in the containing cavity 11 can be fully supplied with fluid, thereby improving the gas-liquid exchange inside the electrolytic cell and timely discharging the gas bubbles generated in the hydrogen production process, and further improving the electrolysis efficiency of the electrolytic cell.

[0026] In an embodiment, referring to FIG. 4, the flow distribution row 15 includes a first flow distribution row 16 and a second flow distribution row 17 arranged in the first flow distribution groove 14. The first gap 161 is formed between adjacent flow distribution pieces 151 in the first flow distribution row 16, and each first gap 161 is directed to one flow distribution piece 151 in the second flow distribution row 17.

[0027] Taking two rows of flow distribution rows 15 as an example, if the flow distribution pieces 151 in the two rows of flow distribution rows 15 are arranged one by one, the flow distribution pieces 151 form a neat array, and a straight channel is formed between each column of flow distribution pieces 151. After the fluid is distributed by the first flow distribution row 16, the fluid is likely to directly flow to the containing cavity 11 along the channel, so that the second flow distribution row 17 does not play a good distribution role.

[0028] Therefore, in the embodiment of the present application, the flow distribution piece 151 in the second flow distribution row 17 is arranged corresponding to the first gap between the first flow distribution row 16, so that after the fluid is distributed by the first flow distribution row 16, the fluid is divided into multiple streams and flows to the second flow distribution row 17 along the first gap. At this time, the flow distribution piece 151 in the second flow distribution row 17 can further distribute the multiple streams of fluid, and the fluid is again divided and redirected, thereby more effectively controlling the uniform flow of the fluid into the containing cavity 11.

[0029] In an embodiment, referring to FIG. 2, the surface of the flow distribution piece 151 away from the containing cavity 11 is convex in a direction away from the containing cavity 11 to form a first flow guide part 1511, and the first flow guide part 1511 is configured to guide the flow of the fluid when the fluid flows into the containing cavity 11.

[0030] The first flow guide part 1511 of the flow distribution member 151 is configured to guide the fluid when the fluid flows into the accommodation cavity 11, and the shape of the first flow guide part 1511 can be wedge-shaped, hemispherical, or the like. Taking the wedge-shaped first flow guide part 1511 as an example, the fluid is divided into two streams after hitting the tip of the wedge-shaped first flow guide part 1511 and flows along the two sides of the wedge-shaped first flow guide part 1511, and by controlling the angle of the tip of the wedge-shaped first flow guide part 1511, the flow direction of the two streams of fluid can be controlled, thereby better achieving the distribution of the fluid.

[0031] In an embodiment, referring to FIGS. 2 and 5, the polar frame 1 further includes a second flow distribution groove 18, and the water outlet 13 is connected to the accommodation cavity 11 through the second flow distribution groove 18. At least two rows of flow distribution rows 15 are arranged in the second flow distribution groove 18, and the second flow guide part 1512 is formed by protruding the side surface of the flow distribution member 151 towards the accommodation cavity 11. The second flow guide part 1512 is configured to guide the fluid when the fluid flows out of the accommodation cavity 11.

[0032] The second flow distribution groove 18 is configured to guide the fluid in the accommodation cavity 11 to the water outlet 13, so that the fluid can keep circulating and continuously carry the gas bubbles generated in the hydrogen production process out of the electrolytic cell. The flow distribution member 151 arranged in the second flow distribution groove 18 plays a certain strengthening role in the second flow distribution groove 18, thereby reducing the probability of breaking of the polar frame 1 at the second flow distribution groove 18. To prevent the flow distribution member 151 from affecting the smooth flow of the fluid from the accommodation cavity 11 to the water outlet 13, the second flow guide part 1512 is formed on the flow distribution member 151. After hitting the second flow guide part 1512, the fluid will automatically disperse and continue to flow towards the water outlet 13, thereby ensuring the circulation of the fluid in the electrolytic cell. The shape of the second flow guide part 1512 can be wedge-shaped, hemispherical, or the like, and the embodiments of the present application do not limit the shape of the second flow guide part 1512.

[0033] In an embodiment, referring to FIG. 2, the flow distribution member 151 is prismatic. For example, the flow distribution member 151 can be a quadrangular prism, and at this time, the first flow guide part 1511 and the second flow guide part 1512 are both triangular prisms, and the two are spliced into a complete flow distribution member 151. Regardless of whether the fluid hits the first flow guide part 1511 or the second flow guide part 1512, the normal flow of the fluid will not be greatly affected. It can be understood that if the water inlet 12 and the water outlet 13 are arranged in a central symmetry, then at this time, the water inlet 12 and the water outlet 13 do not need to be distinguished. That is, when the polar frame 1 is installed, if the water outlet 13 of the polar frame 1 is connected to the water inlet pump, then the water outlet 13 at this time can be regarded as the water inlet 12, which does not affect the normal use of the polar frame 1, thereby simplifying the installation process of the polar frame 1 and reducing the difficulty of assembling the electrolytic cell.

[0034] In an embodiment, referring to FIGS. 2-4, the first diversion groove 14 has a groove bottom wall 141 including a first side 1411 facing the accommodating cavity 11, and a length of the first side 1411 along the extension direction H1 of the first side 1411 is between 1 / 10 and 1 / 6 of a length of the accommodating cavity 11; wherein a length of the water inlet 12 along the extension direction H1 of the first side 1411 is between 1 / 10 and 1 / 6 of the length of the accommodating cavity 11; and / or a length of the water outlet 13 along the extension direction H1 of the first side 1411 is between 1 / 10 and 1 / 6 of the length of the accommodating cavity 11.

[0035] If the length of the first side 1411 along the extension direction H1 of the first side 1411 is less than 1 / 10 of the length of the accommodating cavity 11, the opening of the first diversion groove 14 facing the accommodating cavity 11 is too narrow, and the flow rate of the fluid flowing out of the first accommodating cavity 11 is too high, so that the fluid directly hits the water outlet 13 and cannot better drive the circulation of the fluid in the entire electrolytic cell, resulting in that some fluid in the corner position cannot better participate in the electrolysis process, thereby reducing the hydrogen production efficiency. If the length of the first side 1411 along the extension direction H1 of the first side 1411 is greater than 1 / 6 of the length of the accommodating cavity 11, the opening of the first diversion groove 14 facing the accommodating cavity 11 is too wide, and the flow rate of the fluid flowing out of the first accommodating cavity 11 is too low, so that the gas bubbles generated in the hydrogen production process cannot be discharged in time, the gas-liquid exchange ability is reduced, and the first diversion groove 14 is too wide, which easily leads to that the structural strength of the polar frame 1 is low and the impact resistance is reduced, and the polar frame 1 is easily damaged. Therefore, the length of the first side 1411 along the extension direction H1 of the first side 1411 is set to be between 1 / 10 and 1 / 6 of the length of the accommodating cavity 11, for example, 1 / 10, 1 / 9, 1 / 8, 1 / 7, 1 / 6, etc., so that the polar frame 1 retains good mechanical strength, and the flow rate of the fluid flowing into the accommodating cavity 11 is also maintained in a moderate range, thereby improving the hydrogen production efficiency of the electrolytic cell.

[0036] If the length of the water inlet 12 is less than 1 / 10 of the length of the accommodating cavity 11, the flow rate of the fluid flowing out of the water inlet 12 is too fast, and gas bubbles are easily formed in the process of hitting the diversion member 151, and the stability of the fluid flow is affected. If the length of the water inlet 12 is greater than 1 / 6 of the length of the accommodating cavity 11, the structural strength of the polar frame 1 is easily reduced, and the polar frame 1 is easily damaged. Therefore, the length of the water inlet 12 is set to be between 1 / 10 and 1 / 6 of the length of the first accommodating cavity 11, for example, 1 / 10, 1 / 9, 8 / 8, 1 / 7, 1 / 6, etc., so that the probability of forming gas bubbles when the fluid hits the diversion member 151 is reduced, and the polar frame 1 retains good mechanical strength. The water outlet 13 is similar to the water inlet 12, and details are not repeated here.

[0037] According to a second aspect of the present application, a flow field plate assembly 2 is provided, referring to FIG. 5, comprising the polar frame 1 in the foregoing embodiments; and a plate mesh 21 accommodated in the accommodation cavity 11 of the polar frame 1. The flow field plate assembly 2 comprises the polar frame 1 described above, and thus has all the beneficial effects of the polar frame 1 described above, which will not be repeated here.

[0038] In an embodiment, the thickness of the plate mesh 21 is less than the thickness of the polar frame 1, and the difference between the thickness of the plate mesh 21 and the thickness of the polar frame 1 is in the range of 0.3mm to 0.6mm.

[0039] If the difference between the thickness of the plate mesh 21 and the thickness of the polar frame 1 is less than 0.3mm, the thickness of the plate mesh 21 is too small, and the strength of the plate mesh 21 is low, which is easy to be damaged, affecting the service life of the electrolytic cell; if the difference between the thickness of the plate mesh 21 and the thickness of the polar frame 1 is greater than 0.6mm, the thickness of the plate mesh 21 is too large, which is easy to occupy the space of other components in the electrolytic cell, reducing the stability of the electrolytic cell. Therefore, in the present application, the difference between the thickness of the plate mesh 21 and the thickness of the polar frame 1 is set to be in the range of 0.3mm to 0.6mm, for example, it can be 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm, 0.55mm, 0.6mm, so that the plate mesh 21 can maintain good strength while reducing the probability of affecting other components, improving the stability of the electrolytic cell.

[0040] In an embodiment, referring to FIG. 5 and FIG. 6, the plate mesh 21 is spaced apart from the cavity side wall 111, and the distance between the side of the plate mesh 21 and the adjacent cavity side wall 111 is in the range of 0.3mm to 0.75mm.

[0041] If the distance between the side of the plate mesh 21 and the adjacent cavity side wall 111 is less than 0.3mm, the distance is too small, and due to the error in the manufacturing process, it is easy to cause the plate mesh 21 to be unable to be assembled into the accommodation cavity 11; if the distance between the side of the plate mesh 21 and the adjacent cavity side wall 111 is greater than 0.75mm, the distance is too large, so that when the plate mesh 21 is assembled, the plate mesh 21 is easy to be deviated to one side of the accommodation cavity 11, the distance between the two sides of the plate mesh 21 and the cavity side wall 111 is too different, which affects the uniformity of fluid flow, and further affects the hydrogen production efficiency. Therefore, in the present application, the distance between the side of the plate mesh 21 and the adjacent cavity side wall 111 is set to be in the range of 0.3mm to 0.75mm, for example, it can be 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm, 0.55mm, 0.6mm, 0.65mm, 0.7mm, 0.75mm, so that the plate mesh 21 can be installed into the accommodation cavity 11, and the distance between the two sides of the plate mesh 21 and the adjacent cavity side wall 111 is within an appropriate range.

[0042] In an embodiment, referring to FIG. 5 and FIG. 6, the plate mesh 21 comprises a plurality of through holes 211, and the through holes 211 are quadrilaterals. By arranging a plurality of quadrilateral through holes 211 on the plate mesh 21, when fluid is input into the accommodating cavity 11 of the pole frame 1, the fluid can be uniformly distributed in each through hole 211, facilitating the uniform flow of the fluid, and further facilitating the discharge of the bubbles generated by the fluid. In addition, the mesh flow field is used instead of a complete plate, which reduces the regional flow resistance of the fluid and reduces the probability of regional accumulation of bubbles and regional increase of heat.

[0043] In an embodiment, the length of the longer diagonal of the through hole 211 ranges from 8 mm to 11 mm; and / or,

[0044] The length of the shorter diagonal of the through hole 211 ranges from 5 mm to 7 mm.

[0045] If the length of the longer diagonal of the through hole 211 is less than 8 mm, the through hole 211 is too small, which is difficult to process, resulting in high production cost. If the length of the longer diagonal of the through hole 211 is greater than 11 mm, the through hole 211 is too large, and the porosity of the plate mesh 21 is large, so that the structural strength of the plate mesh 21 itself is low and cannot work in a high-pressure environment. Therefore, the length of the longer diagonal of the through hole 211 ranges from 8 mm to 11 mm in the embodiment of the application, which can be 8 mm, 8.5 mm, 9 mm, 9.5 mm, 10 mm, 10.5 mm, or 11 mm, so that the plate mesh 21 can maintain a high structural strength while the through hole 211 is relatively easy to process. The shorter diagonal of the through hole 211 is set similarly, which is not described here.

[0046] According to a third aspect of the present application, an electrolytic cell is provided, comprising the pole frame 1 in the foregoing embodiments or the flow field plate assembly 2 in the foregoing embodiments. The electrolytic cell comprises the pole frame 1 described above, so the electrolytic cell has all the beneficial effects of the pole frame 1 described above, which are not described here in the embodiment of the present application. The electrolytic cell can be an AEM (anion exchange membrane) electrolytic cell.

Claims

1. A pole frame for use in a flow field plate assembly, the pole frame having a receiving cavity, an inlet, an outlet, and a first diversion groove, the receiving cavity being configured to receive a plate mesh, and the inlet being connected to the receiving cavity through the first diversion groove; in, The pole frame also includes a flow divider, which includes at least two spaced-apart flow dividers, and the first flow divider slot has at least two rows of the flow dividers.

2. The pole frame according to claim 1, wherein the flow divider includes a first flow divider and a second flow divider located within the first flow divider groove, wherein a first gap is formed between adjacent flow dividers in the first flow divider, and each of the first gaps faces one of the flow dividers in the second flow divider.

3. The pole frame according to claim 2, wherein the side surface of the diverter facing away from the receiving cavity protrudes in a direction away from the receiving cavity to form a first flow guide, the first flow guide being configured to guide fluid as it flows into the receiving cavity.

4. The pole frame according to claim 3, wherein the pole frame further includes a second diversion groove, the outlet is connected to the receiving cavity through the second diversion groove, at least two rows of diversion rows are provided in the second diversion groove, and the surface of the diversion member facing the receiving cavity protrudes in a direction close to the receiving cavity to form a second flow guide, the second flow guide being configured to guide the fluid when it flows out of the receiving cavity.

5. The pole frame according to claim 4, wherein the shunt element is prismatic.

6. The pole frame according to any one of claims 1 to 5, wherein the bottom wall of the first diversion channel includes a first side facing the receiving cavity, and along the extending direction of the first side, the ratio of the length of the first side to the length of the receiving cavity is between 1 / 10 and 1 / 6; wherein, Along the extending direction of the first side, the ratio of the length of the inlet to the length of the receiving cavity is between 1 / 10 and 1 / 6; and / or, Along the extending direction of the first side, the ratio of the length of the outlet to the length of the receiving cavity is between 1 / 10 and 1 / 6.

7. A flow field plate assembly, comprising: The polar frame as described in any one of claims 1 to 6; and, A mesh plate, which is housed within the receiving cavity of the pole frame.

8. The flow field plate assembly according to claim 7, wherein the thickness of the plate mesh is less than the thickness of the pole frame, and the thickness difference between the plate mesh and the pole frame is in the range of 0.3 mm to 0.6 mm.

9. The flow field plate assembly according to claim 7 or 8, wherein the plate mesh is spaced apart from the cavity sidewall of the receiving cavity, and the distance between the side edge of the plate mesh and the adjacent cavity sidewall is between 0.3 mm and 0.75 mm.

10. The flow field plate assembly according to any one of claims 7 to 9, wherein the plate mesh includes a plurality of through holes, the through holes being quadrilateral.

11. The flow field plate assembly according to claim 10, wherein the length of the longer diagonal of the through hole ranges from 8 mm to 11 mm; and / or, The shorter diagonal of the through hole ranges in length from 5 mm to 7 mm.

12. An electrolytic cell comprising an electrode frame as claimed in any one of claims 1 to 6 or a flow field plate assembly as claimed in any one of claims 7 to 11.

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