Bipolar plate of alkaline electrolytic bath and electrolytic bath

Abstract

The invention relates to the technical field of hydrogen production, in particular to an alkaline electrolytic bath bipolar plate and an electrolytic bath, the alkaline electrolytic bath bipolar plate comprises a polar plate body, the polar plate body is provided with a first side face and a second side face which are oppositely arranged in the thickness direction of the polar plate body, and the first side face and the second side face are each provided with an electrolyte inlet and an electrolyte outlet; the pole plate body is provided with a third side face and a fourth side face which are oppositely arranged in the first direction, the electrolyte inlet is adjacent to the third side face, the electrolyte outlet is adjacent to the fourth side face, and the size of the pole plate body in the second direction is gradually increased in the direction from the third side face to the fourth side face; the polar plate body is provided with a fifth side face and a sixth side face which are oppositely arranged in the second direction, an included angle alpha is formed between each of the fifth side face and the sixth side face and the third side face, and alpha is larger than or equal to 60 degrees and smaller than or equal to 80 degrees.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrogen production, and in particular to an alkaline electrolyzer bipolar plate and an electrolyzer. Background Art

[0002] Hydrogen production by water electrolysis is an important way to obtain green hydrogen, which mainly includes alkaline water electrolysis, proton exchange membrane water electrolysis, solid oxide water electrolysis and anion exchange membrane water electrolysis. Among them, alkaline water electrolysis is the most mature and earliest industrialized water electrolysis hydrogen production technology, and the alkaline electrolyzer is the core structure of alkaline water electrolysis hydrogen production. The shape of the alkaline electrolyzer in the related technology is mainly cylindrical, and there is generally only one flow channel outlet at the top. Under high current density, the flow field distribution in the electrolysis chamber is uneven, the fluid flow resistance increases, and the energy consumption increases. Summary of the invention

[0003] The present invention aims to solve one of the technical problems in the related art at least to a certain extent. To this end, an embodiment of the present invention provides an alkaline electrolytic cell bipolar plate, which can improve the uniformity of the fluid flow field distribution in the small chamber.

[0004] The embodiment of the present invention also provides an alkaline electrolytic cell.

[0005] The alkaline electrolytic cell bipolar plate of the embodiment of the present invention includes a plate body, wherein the plate body has a first side surface and a second side surface arranged opposite to each other in the thickness direction thereof, the first side surface and the second side surface are both provided with an electrolyte inlet and an electrolyte outlet, the plate body has a third side surface and a fourth side surface arranged opposite to each other in the first direction, the first direction is orthogonal to the thickness direction of the plate body, the electrolyte inlet is arranged adjacent to the third side surface, the electrolyte outlet is arranged adjacent to the fourth side surface, the dimension of the plate body in the second direction gradually increases along the direction from the third side surface toward the fourth side surface, and the second direction is orthogonal to the first direction and the thickness direction of the plate body; the plate body has a fifth side surface and a sixth side surface arranged opposite to each other in the second direction, each of the fifth side surface and the sixth side surface has an angle α with the third side surface, and 60°≤α≤80°.

[0006] The alkaline electrolytic cell bipolar plate of the embodiment of the present invention can improve the uniformity of the fluid flow field distribution in the small chamber.

[0007] In some embodiments, the number of the electrolyte inlets on each of the first side and the second side is C, the size of the electrolyte inlet on the first side and the electrolyte inlet on the second side in the second direction is L1, and the shortest distance between the fifth side and the sixth side is L2, then C = [0.4 × (L2 / L1)], or, C = [0.6 × (L2 / L1)], where [] represents an integer.

[0008] In some embodiments, the number of the electrolyte outlets on the first side or the second side is D, D ≥ [1.5×C].

[0009] In some embodiments, the peripheral wall of the electrolyte inlet includes a first side wall and a second side wall arranged relative to each other in the second direction, and the spacing distance between the first side wall and the second side wall gradually increases along the direction from the third side surface toward the fourth side surface; and / or, the peripheral wall of the electrolyte outlet includes a third side wall and a fourth side wall arranged relative to each other in the second direction, and the spacing distance between the third side wall and the fourth side wall gradually increases along the direction from the fourth side surface toward the third side surface.

[0010] In some embodiments, the angle between the extension direction of the first side wall and the third side surface is the same as the angle between the fifth side surface and the third side surface; and / or the angle between the extension direction of the third side wall and the third side surface is the same as the angle between the fifth side surface and the third side surface.

[0011] In some embodiments, the number of the electrolyte inlets on each of the first side and the second side is multiple, and the multiple electrolyte inlets are evenly spaced in the second direction; and / or, the number of the electrolyte outlets on each of the first side and the second side is multiple, and the multiple electrolyte outlets are evenly spaced in the second direction.

[0012] In some embodiments, the alkaline electrolytic cell bipolar plate further comprises a plurality of concave-convex parts, the plurality of concave-convex parts are divided into a plurality of groups, the plurality of groups of concave-convex parts are arranged at intervals in the first direction, and each group of the concave-convex parts comprises protrusions and grooves arranged alternately in the second direction.

[0013] In some embodiments, an outer contour of the protrusion on a projection surface parallel to the first direction and the second direction is fan-shaped, and / or an outer contour of the groove on a projection surface parallel to the first direction and the second direction is fan-shaped.

[0014] In some embodiments, the arc of the sector protrudes in the direction toward the fourth side surface, the radius of the sector is R, the connection between the two radius edges of the sector is chamfered with a first chamfer radius, the first chamfer radius is 3 / 5R, and / or, the connection between the arc edge of the sector and the two radius edges is chamfered with a second chamfer radius, the second chamfer radius is 1 / 10R, and / or, the central angle of the sector is β, 40°≤β≤50°.

[0015] The alkaline electrolytic cell of the embodiment of the present invention comprises: a first bipolar plate and a second bipolar plate, both of which are the bipolar plates described in the above embodiment; an anode and a cathode, wherein the anode cooperates with the second bipolar plate, and the cathode cooperates with the first bipolar plate.

[0016] The alkaline electrolytic cell of the embodiment of the present invention can improve the electrolysis efficiency of the alkaline electrolytic cell and reduce energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Schematic diagram of an alkaline electrolytic cell according to an embodiment of the present invention.

[0018] Figure 2 Schematic diagram of a bipolar plate for an alkaline electrolytic cell according to an embodiment of the present invention.

[0019] Figure 3 yes Figure 2 A magnified schematic diagram of center A.

[0020] Figure 4 yes Figure 2 A magnified schematic diagram of point B in the middle.

[0021] Reference numerals:

[0022] Alkaline electrolytic cell 100, electrolytic chamber 110, first bipolar plate 1110, second bipolar plate 1120, anode 1130, cathode 1140, seal 1150, diaphragm 1160, end plate 120, screw 130,

[0023] Plate body 1, first side 11, second side 12, third side 13, fourth side 14, fifth side 15, sixth side 16, electrolyte inlet 2, first side wall 21, second side wall 22, electrolyte outlet 3, third side wall 31, fourth side wall 32, concave-convex part 4, protrusion 41, groove 42, arc edge 43, radius edge 44, pole frame 5. DETAILED DESCRIPTION

[0024] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0025] The bipolar plate of the alkaline electrolytic cell 100 of the embodiment of the present invention comprises a plate body 1, the plate body 1 has a thickness direction (such as Figure 1 The plate body 1 has a first side surface 11 and a second side surface 12 arranged opposite to each other in the front-to-back direction (as shown in FIG. 1 ), and the first side surface 11 and the second side surface 12 are both provided with an electrolyte inlet 2 and an electrolyte outlet 3. The plate body 1 has a first side surface 11 and a second side surface 12 arranged opposite to each other in the front-to-back direction (as shown in FIG. 1 ). Figure 2 The third side surface 13 and the fourth side surface 14 are arranged relatively in the vertical direction (as shown in the figure), the first direction is orthogonal to the thickness direction of the plate body 1, the electrolyte inlet 2 is arranged adjacent to the third side surface 13, the electrolyte outlet 3 is arranged adjacent to the fourth side surface 14, and the plate body 1 is arranged in the second direction (as shown in the figure) Figure 2 The dimension of the electrode body 1 (in the left-right direction shown in the figure) gradually increases from the third side surface 13 toward the fourth side surface 14, and the second direction is orthogonal to the first direction and the thickness direction of the electrode body 1. The electrode body 1 has a fifth side surface 15 and a sixth side surface 16 arranged opposite to each other in the second direction, and each of the fifth side surface 15 and the sixth side surface 16 has an angle α with the third side surface 13, and 60°≤α≤80°.

[0026] Specifically, Figure 1 and Figure 2 As shown, the front end of the plate body 1 is the first side 11, the rear end of the plate body 1 is the second side 12, the lower end of the plate body 1 is the third side 13, the upper end of the plate body 1 is the fourth side 14, the left end of the plate body 1 is the fifth side 15, the right end of the plate body 1 is the sixth side 16, the left end of the third side 13 is connected to the lower end of the fifth side 15, the right end of the third side 13 is connected to the lower end of the sixth side 16, the left end of the fourth side 14 is connected to the upper end of the fifth side 15, and the right end of the fourth side 14 is connected to the upper end of the sixth side 16. The electrolyte inlet 2 is arranged adjacent to the lower end of the plate body 1, and the electrolyte outlet 3 is arranged adjacent to the upper end of the plate body 1. The size of the plate body 1 in the left-right direction gradually increases from bottom to top.

[0027] The outer contour of the plate body 1 is a trapezoid on the projection plane parallel to the up-down direction and the left-right direction, and the dimension of the third side 13 in the left-right direction is smaller than the dimension of the fourth side 14 in the left-right direction. The angle between the fifth side 15 and the third side 13 and the angle between the sixth side 16 and the third side 13 are both α. It can be understood that the angle between the fifth side 15 and the third side 13 and the angle between the sixth side 16 and the third side 13 both refer to the acute angles formed. That is, the angle between the fifth side 15 and the third side 13 is the angle between the extension line of the fifth side 15 and the third side 13, and the angle between the sixth side 16 and the third side 13 is the angle between the extension line of the sixth side 16 and the third side 13.

[0028] For example, the value of α is 60°, 62°, 65°, 73°, 74°, 77.5°, 78°, and 80°. When the value of α is less than 60°, the increased flow area of ​​the reaction area on the electrode body 1 is too large, which affects the uniformity of the fluid flow field and is not conducive to the rapid outflow of the mixed fluid of the electrolyte and the gas. When the value of α is greater than 80°, the increased flow area of ​​the reaction area on the electrode body 1 is small, and the improvement effect on the uniformity of the fluid flow field is small, so it has little effect on the rapid outflow of the mixed fluid of the electrolyte and the gas. The embodiment of the present invention does not specifically limit the value of α, which is subject to actual implementation.

[0029] At least one electrolyte inlet 2 is arranged at the lower end of the first side surface 11, at least one electrolyte outlet 3 is arranged at the upper end of the first side surface 11, at least one electrolyte inlet 2 is also arranged at the lower end of the second side surface 12, at least one electrolyte outlet 3 is also arranged at the upper end of the second side surface 12, and an electrolyte inlet at the lower end of the first side surface is adjacent to an electrolyte inlet at the lower end of the second side surface to form an electrolyte inlet group, and an electrolyte outlet 3 at the upper end of the first side surface 11 is adjacent to an electrolyte outlet at the upper end of the second side surface to form an electrolyte outlet group.

[0030] Optionally, the bipolar plate of the alkaline electrolytic cell 100 further includes a pole frame 5. On the projection plane parallel to the up-down direction and the left-right direction, the inner contour of the pole frame 5 is a trapezoid. The inner contour of the pole frame 5 is adapted to the outer contour of the pole plate body 1. The pole frame 5 and the pole plate body 1 can be connected by welding. Pole ears are respectively arranged on both sides of the pole frame 5 to facilitate positioning during the installation of the electrolytic cell. The bipolar plate of the alkaline electrolytic cell 100 further includes a pole plate body 1. The first side 11 and the second side 12 of the pole plate body 1 are both reaction areas. The bipolar plate is plate-shaped. Under the action of an external electric field, the bipolar plate forms an anode area on one side and a cathode area on the other side. The bipolar plates are located at both ends of the electrolytic chamber 110 structure and are separated by a diaphragm to form a chamber where alkali solution flows in the cathode area and the anode area, thereby preventing the mixing of hydrogen and oxygen produced by electrolysis and ensuring the safety of the operation of the electrolytic cell.

[0031] The alkaline electrolyte is KOH solution or NaOH solution. The working temperature of the alkaline electrolyte is 70-95℃ and the pressure is 0.1-0.5MPa. During the electrolysis of water, under the action of the hydrogen evolution cathode catalyst, water molecules undergo a reduction reaction at the cathode to precipitate hydrogen and OH. - Ions, the chemical reaction equation is as follows: 4H2O+4e - =2H2+4OH - , under the action of oxygen evolution anode catalyst, OH - The ions undergo oxidation reaction at the anode to release oxygen. The chemical reaction equation is as follows: 4OH- =O2+2H2O+4e - The overall reaction formula is: 2H2O=2H2+O2. Through the above reaction, water electrolysis can be used to produce hydrogen and oxygen.

[0032] The following describes the flow process of the alkaline electrolyte by taking the first side 11 of the bipolar plate of the alkaline electrolytic cell 100 as the anode area as an example: the alkaline electrolyte enters the anode area of ​​the first side 11 of the electrode body 1 from the electrolyte inlet 2 of the first side 11, and the hydroxide ions generated in the cathode area enter the anode area through the diaphragm. The hydroxide ions in the electrolyte lose electrons on the anode surface and undergo an oxidation reaction to generate oxygen and water. As the cathode hydrogen evolution reaction and the anode oxygen evolution reaction proceed, the hydroxide ions in the electrolyte continuously enter the anode area from the cathode area through the diaphragm. In the process of the alkaline electrolyte flowing from bottom to top, a reaction occurs on the electrode surface to generate oxygen. The mixed fluid of oxygen and the anode electrolyte in the reaction area of ​​the first side 11 flows out from the electrolyte outlet 3 at the upper end of the first side 11.

[0033] The electrolytic cell bipolar plate of the embodiment of the present invention is set to gradually increase the size of the electrode body 1 in the left-right direction from the bottom to the top. Due to the continuous generation of hydrogen or oxygen during the electrolysis reaction, the volume of the fluid is continuously increased, and the flow resistance of the fluid is increased. This embodiment increases the flow area of ​​the fluid accordingly, so that the flow field distribution is more uniform, the flow resistance is reduced, and it is conducive to the rapid discharge of the gas. In specific implementation, by limiting the angle between the fifth side 15 and the third side 13 and the angle between the sixth side 16 and the third side 13, the increased volume of the fluid is associated with the gradually increased flow area of ​​the reaction area from the bottom to the top, thereby improving the uniformity of the flow field distribution of the fluid in the reaction area.

[0034] In some embodiments, the number of electrolyte inlets 2 on each of the first side 11 and the second side 12 is C, the size of the electrolyte inlet 2 on the first side 11 and the electrolyte inlet 2 on the second side 12 in the second direction is L1, and the shortest distance between the fifth side 15 and the sixth side 16 is L2, then C = [0.4×(L2 / L1)], or, C = [0.6×(L2 / L1)], where [] represents an integer.

[0035] Specifically, Figure 2As shown, the number of electrolyte inlets 2 on the first side 11 is the same as the number of electrolyte inlets 2 on the second side 12, and the size of the electrolyte inlet 2 on the first side 11 in the left-right direction is the same as the size of the electrolyte inlet 2 on the second side 12 in the left-right direction. The electrolyte inlet on the first side and the electrolyte inlet on the second side are arranged adjacent to each other in the left-right direction, that is, on a projection plane parallel to the left-right direction and the top and bottom, the electrolyte inlet on the first side and the electrolyte inlet on the second side are arranged at intervals, and the interval distance is about half of the size of a single electrolyte inlet in the left-right direction. The shortest distance between the fifth side 15 and the sixth side 16 refers to the size of the third side 13 in the left-right direction.

[0036] When the size of the third side surface 13 in the left-right direction is very small, only one electrolyte inlet 2 is provided to meet the liquid inlet requirements. When the size of the third side surface 13 in the left-right direction is very large, the number of electrolyte inlets 2 is determined according to the size of the third side surface 13 in the left-right direction and the size of the electrolyte inlet 2 in the left-right direction. Multiple electrolyte inlets 2 are provided to fill the liquid simultaneously, thereby improving the uniformity of the flow field distribution when the electrolyte just enters the reaction area in the small chamber.

[0037] In the embodiment of the present invention, the size of the third side surface 13 in the left-right direction is associated with the number of electrolyte inlets 2, so that the electrolyte can enter the reaction area from multiple positions at the lower end of the electrode plate at the same time, reducing the flow dead zone, and making the electrolyte fluid better cover all areas in the small chamber during the flow of the electrolyte from the inlet to the outlet, thereby improving the uniformity of the flow field distribution of the fluid in the reaction area.

[0038] In some embodiments, the number of electrolyte outlets 3 on the first side 11 or the second side 12 is D, where D≥[1.5×C].

[0039] Specifically, Figure 2 As shown, the number of electrolyte outlets 3 on the first side 11 is the same as the number of electrolyte outlets 3 on the second side 12. Since the size of the fourth side 14 in the left-right direction is larger than the size of the third side 13 in the left-right direction, the number of electrolyte outlets 3 on the first side 11 and the second side 12 is associated with the number of electrolyte inlets 2 on the first side 11 and the second side 12, ensuring that the number of electrolyte outlets 3 is larger than the number of electrolyte inlets 2 while making the electrolyte outlets 3 proportional to the number of electrolyte inlets 2, thereby improving the uniformity of the flow field distribution of the mixed fluid of gas and electrolyte at the outlet.

[0040] In some embodiments, the peripheral wall of the electrolyte inlet 2 includes a first side wall 21 and a second side wall 22 arranged relative to each other in the second direction, and the spacing distance between the first side wall 21 and the second side wall 22 gradually increases along the direction from the third side surface 13 toward the fourth side surface 14; and / or, the peripheral wall of the electrolyte outlet 3 includes a third side wall 31 and a fourth side wall 32 arranged relative to each other in the second direction, and the spacing distance between the third side wall 31 and the fourth side wall 32 gradually increases along the direction from the fourth side surface 14 toward the third side surface 13.

[0041] Specifically, Figure 3 and Figure 4 As shown, the peripheral wall of the electrolyte inlet 2 at one end close to the interior of the chamber includes a first side wall 21 and a second side wall 22, the first side wall 21 is located on the left side, and the second side wall 22 is located on the right side, and the spacing distance between the first side wall 21 and the second side wall 22 in the left-right direction gradually increases from bottom to top, that is, the first side wall 21 and the second side wall 22 are on the projection surface parallel to the left-right direction and the up-down direction, the lower ends of the first side wall 21 and the second side wall 22 are close to each other, and the upper ends of the first side wall 21 and the second side wall 22 are far away from each other, so that the electrolyte inlet 2 is a gradually expanding shape, that is, the flow area of ​​the electrolyte inlet 2 gradually increases from bottom to top, which can have a better diversion effect on the flow of the electrolyte.

[0042] The surrounding wall of one end of the electrolyte outlet 3 close to the interior of the chamber includes a third side wall 31 and a fourth side wall 32, the third side wall 31 is located on the left, and the fourth side wall 32 is located on the right, and the spacing distance between the third side wall 31 and the fourth side wall 32 in the left-right direction gradually increases from top to bottom, that is, the third side wall 31 and the fourth side wall 32 are on the projection surface parallel to the left-right direction and the up-down direction, the upper ends of the third side wall 31 and the fourth side wall 32 are close to each other, and the lower ends of the third side wall 31 and the fourth side wall 32 are far away from each other, so that the electrolyte outlet 3 is a tapered shape, that is, the flow area of ​​the electrolyte outlet 3 gradually decreases from bottom to top, which can have a better diversion effect when the mixed fluid flows out.

[0043] In some embodiments, the angle between the extension direction of the first side wall 21 and the third side surface 13 is the same as the angle between the fifth side surface 15 and the third side surface 13; and / or the angle between the extension direction of the third side wall 31 and the third side surface 13 is the same as the angle between the fifth side surface 15 and the third side surface 13.

[0044] Specifically, Figure 3 and Figure 4As shown, the angle between the extension direction of the first side wall 21 and the third side surface 13 is the same as the angle between the extension direction of the third side wall 31 and the third side surface 13, and both are the same as the angle between the fifth side surface 15 and the third side surface 13. By setting the inlet expansion angle of the electrolyte inlet 2 and the contraction angle of the electrolyte outlet 3 to be the same as the angle between the fifth side surface 15 and the third side surface 13 of the plate body 1, it is convenient for the first side wall 21 and the second side wall 22 to better guide the electrolyte, and it is also convenient for the third side wall 31 and the fourth side wall 32 to better guide the outflow of the fluid, thereby improving the uniformity of the flow field distribution of the electrolyte entering the reaction area and the mixed fluid of the electrolyte and the gas flowing out of the reaction area.

[0045] In some embodiments, there are multiple electrolyte inlets 2 on each of the first side 11 and the second side 12, and the multiple electrolyte inlets 2 are evenly spaced in the second direction; and / or, there are multiple electrolyte outlets 3 on each of the first side 11 and the second side 12, and the multiple electrolyte outlets 3 are evenly spaced in the second direction.

[0046] Specifically, the electrolyte inlet 2 on the first side 11 is the same as the electrolyte inlet 2 on the second side 12. When there are multiple electrolyte inlets 2, the multiple electrolyte inlets 2 are evenly spaced in the left and right directions to improve the flow uniformity of the electrolyte into the reaction area.

[0047] The number of the electrolyte outlets 3 on the second side 12 is the same as the number of the electrolyte outlets 3 on the second side 12. When the number of the electrolyte outlets 3 is multiple, the multiple electrolyte outlets 3 are evenly spaced in the left-right direction so that the mixed fluid of gas and electrolyte at different positions in the reaction area can flow out from each electrolyte outlet 3, facilitating the outflow of the mixed fluid.

[0048] In some embodiments, the bipolar plate of the alkaline electrolytic cell 100 further includes a plurality of concave-convex parts 4, the plurality of concave-convex parts 4 are divided into a plurality of groups, the plurality of groups of concave-convex parts 4 are arranged at intervals in the first direction, and each group of concave-convex parts 4 includes protrusions 41 and grooves 42 alternately arranged in the second direction.

[0049] Specifically, the plate body 1 is provided with a concave-convex component 4 in which protrusions 41 and grooves 42 are alternately arranged, and the concave-convex component 4 forms a flow path for the electrolyte in the small chamber. The multiple concave-convex components 4 are divided into multiple groups in the up and down direction, and are the first group of concave-convex components, the second group of concave-convex components, and the last group of concave-convex components from bottom to top. The first group of concave-convex components is adjacent to the electrolyte inlet 2, and the last group of concave-convex components is adjacent to the electrolyte outlet 3, and the number of at least one of the protrusions 41 and the grooves 42 in the last group of concave-convex components is greater than the number of the protrusions 41 and the grooves 42 in the first group of concave-convex components.

[0050] For example, the material of the bipolar plate includes but is not limited to cast iron metal plate, nickel plate, stainless steel metal plate, and carbon plate. A flat plate may be used and the surface may be processed into the flow channel of the concave-convex component 4 .

[0051] The embodiment of the present invention provides a plurality of grooves 42 and protrusions 41, and the curved gaps between the plurality of grooves 42 and protrusions 41 are helpful to reduce the electrolyte concentration difference at various locations in the flow channel, make the electrolyte distribution more uniform, reduce the electrolyte resistance, thereby reducing the energy consumption of the electrolytic equipment and improving its long-term operation stability.

[0052] In some embodiments, the outer contour of the protrusion 41 on the projection surface parallel to the first direction and the second direction is fan-shaped, and / or the outer contour of the groove 42 on the projection surface parallel to the first direction and the second direction is fan-shaped.

[0053] Specifically, the connection between the two radial edges 44 of the sector is located at the bottom, and the connection between the arc edge 43 of the sector and the two radial edges 44 is located at the top. After the electrolyte enters the reaction flow field through the electrolyte inlet 2, it needs to pass through multiple sector-shaped bodies that gradually widen from bottom to top for guidance, which can reduce eddy currents, enhance heat exchange, and reduce flow resistance, which is beneficial to the uniform distribution of the electrolyte in the flow field and increases the effective reaction area for electrolysis of water.

[0054] Under the guiding effect of multiple electrolyte inlets 2 and the first side wall 21 and the second side wall 22 of each electrolyte inlet 2, the electrode liquid quickly enters the reaction area of ​​the concave-convex part 4. Since bubbles are continuously generated during the electrolysis reaction, the fan-shaped setting of the concave-convex part 4 can reduce the aggregation of bubbles and reduce the flow resistance of the electrolyte. The electrolyte and gas continuously flow upward to the electrolyte outlet 3. The setting of multiple electrolyte outlets 3 can make the mixed fluid of electrode liquid and gas flow out through different electrolyte outlets 3, and effectively disperse the generated gas to be discharged through different outlets. Moreover, under the guiding effect of the third side wall 31 and the fourth side wall 32, the flow resistance is reduced, which facilitates the rapid outflow of the fluid.

[0055] In some embodiments, the arc of the sector bulges in the direction toward the fourth side surface 14, the radius of the sector is R, the connection between the two radial edges 44 of the sector is chamfered with a first chamfer radius, the first chamfer radius is 3 / 5R, and / or, the connection between the arc edge 43 of the sector and the two radial edges 44 is chamfered with a second chamfer radius, the second chamfer radius is 1 / 10R, and / or, the central angle of the sector is β, 40°≤β≤50°.

[0056] Specifically, the embodiment of the present invention chamfers the connection between the two radial edges 44 of the fan and chamfers the connection between the arc edge 43 of the fan and the two radial edges 44, so that the fan is transformed into a fan-like structure with smoother edges, thereby reducing the flow resistance of the electrolyte.

[0057] Furthermore, by limiting the first chamfer angle and the second chamfer angle, it is possible to avoid the concave-convex component 4 from exerting excessive resistance on the fluid, thereby preventing the normal flow of the fluid from being affected.

[0058] When the central angle of the sector is greater than 50°, the arc edge 43 corresponding to the sector is too long, and the flow resistance caused by the upper end of the sector is too large. When the central angle of the sector is less than 40°, the arc edge 43 of the sector is too short and cannot fully reduce the effect of bubble aggregation. By limiting the angle of the central angle of the sector, it is ensured that the sector guides the fluid without generating a large flow resistance, thereby improving the uniformity of the flow field distribution of the fluid in the reaction area.

[0059] The alkaline electrolytic cell 100 of the embodiment of the present invention includes a first bipolar plate 1110, a second bipolar plate 1120, an anode 1130 and a cathode 1140. The first bipolar plate 1110 and the second bipolar plate 1120 are both bipolar plates of the above embodiment. The anode 1130 cooperates with the second bipolar plate 1120, and the cathode 1140 cooperates with the first bipolar plate 1110.

[0060] Specifically, Figure 1 As shown, the alkaline electrolytic cell 100 includes an end pressure plate 120 and a plurality of electrolytic chambers 110, wherein the end pressure plates 120 are arranged on both sides of the electrolytic chamber 110, and the plurality of electrolytic chambers 110 are pressed together by screws 130 to form an electrolytic cell, and each electrolytic chamber 110 includes a cathode 1140, an anode 1130, a sealing gasket 1150, a diaphragm 1160, a first bipolar plate 1110 and a second bipolar plate 1120, wherein the first bipolar plate 1110 and the second bipolar plate 1120 are located on both sides of the electrolytic chamber 110, the first bipolar plate 1110 is located on the left side, and the second bipolar plate 1120 is located on the right side, a sealing gasket 1150 is provided between the first bipolar plate 1110 and the cathode 1140, a sealing gasket 1150 is also provided between the second bipolar plate 1120 and the anode 1130, and a diaphragm 1160 is provided between the anode 1130 and the cathode 1140.

[0061] The outer contours of the anode 1130 and the cathode 1140 on the projection surface orthogonal to the up-down direction and the left-right direction are both trapezoidal. Correspondingly, the shape of the diaphragm 1160 matches the anode 1130 and the cathode 1140, and the sealing gasket 1150 matches the first bipolar plate 1110 and the second bipolar plate 1120, that is, the outer contours of the diaphragm 1160 and the sealing gasket 1150 on the projection surface orthogonal to the up-down direction and the left-right direction are both trapezoidal. The outer contour of the end pressure plate 120 on the projection surface orthogonal to the up-down direction and the left-right direction is also set to a trapezoid. The cathode 1140, the anode 1130, the first bipolar plate 1110 and the second bipolar plate 1120 in this embodiment are all set in a trapezoidal shape, which improves the utilization rate of the electrode and can further reduce the cost of hydrogen production.

[0062] For example, the anode 1130 and the cathode 1140 can both use pure nickel mesh or nickel foam as the substrate, and the anode catalyst and the cathode catalyst are coated respectively by spraying, rolling, chemical plating, etc. The diaphragm 1160 between the anode 1130 and the cathode 1140 prevents the hydrogen and oxygen generated by electrolysis from mixing. The diaphragm 1160 can be made of polyphenylene sulfide, polyetheretherketone, polysulfone diaphragm, or modified inorganic-organic composite diaphragm.

[0063] The alkaline electrolytic cell 100 of the embodiment of the present invention includes the bipolar plate of the above embodiment. As the fluid in the electrolysis chamber 110 flows from bottom to top, the flow area gradually increases. By setting the trapezoidal bipolar plate, the flow field distribution in the electrolysis chamber 110 is more uniform, and the flow resistance is reduced, which is conducive to the rapid discharge of the gas generated by electrolysis, reduces the electrolysis potential and energy consumption, improves the electrolysis efficiency, and reduces the hydrogen production cost.

[0064] Furthermore, since the gas generated by electrolysis can be discharged quickly, the gas content in the electrolysis chamber 110 is reduced, the resistance voltage drop is reduced, and the electrolysis potential and energy consumption are reduced, so that the electrolytic cell can operate safely at a high current density.

[0065] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0066] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0067] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0068] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0069] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0070] It is to be understood that the above embodiments are exemplary and are not to be construed as limiting the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A bipolar plate for an alkaline electrolytic cell, characterized in that: include: A plate body, wherein the plate body has a first side surface and a second side surface arranged opposite to each other in the thickness direction thereof, the first side surface and the second side surface are both provided with an electrolyte inlet and an electrolyte outlet, the plate body has a third side surface and a fourth side surface arranged opposite to each other in the first direction, the first direction is orthogonal to the thickness direction of the plate body, the electrolyte inlet is arranged adjacent to the third side surface, the electrolyte outlet is arranged adjacent to the fourth side surface, the size of the plate body in the second direction gradually increases along the direction from the third side surface toward the fourth side surface, and the second direction is orthogonal to the first direction and the thickness direction of the plate body; The electrode body has a fifth side surface and a sixth side surface which are arranged opposite to each other in the second direction. Each of the fifth side surface and the sixth side surface has an angle α with the third side surface, and 60°≤α≤80°.

2. The alkaline electrolytic cell bipolar plate according to claim 1, characterized in that: The number of the electrolyte inlets on each of the first side surface and the second side surface is C, the size of the electrolyte inlet on the first side surface and the electrolyte inlet on the second side surface in the second direction is L1, and the shortest distance between the fifth side surface and the sixth side surface is L2, then C = [0.4 × (L2 / L1)], or, C = [0.6 × (L2 / L1)], where [] represents an integer.

3. The alkaline electrolytic cell bipolar plate according to claim 2, characterized in that: The number of the electrolyte outlets on the first side or the second side is D, and D≥[1.5×C].

4. The alkaline electrolytic cell bipolar plate according to claim 2, characterized in that: The peripheral wall of the electrolyte inlet comprises a first side wall and a second side wall arranged opposite to each other in the second direction, and a spacing distance between the first side wall and the second side wall gradually increases in a direction from the third side surface toward the fourth side surface; and / or, The peripheral wall of the electrolyte outlet includes a third side wall and a fourth side wall arranged opposite to each other in the second direction, and a spacing distance between the third side wall and the fourth side wall gradually increases in a direction from the fourth side wall toward the third side wall.

5. The alkaline electrolytic cell bipolar plate according to claim 4, characterized in that: The included angle between the extension direction of the first side wall and the third side surface is the same as the included angle between the fifth side surface and the third side surface; and / or, An included angle between an extension direction of the third side wall and the third side surface is the same as an included angle between the fifth side surface and the third side surface.

6. The alkaline electrolytic cell bipolar plate according to claim 2, characterized in that: There are multiple electrolyte inlets on each of the first side surface and the second side surface, and the multiple electrolyte inlets are evenly spaced in the second direction; And / or, there are multiple electrolyte outlets on each of the first side surface and the second side surface, and the multiple electrolyte outlets are evenly spaced apart in the second direction.

7. The alkaline electrolytic cell bipolar plate according to any one of claims 1 to 6, characterized in that: It also includes a plurality of concave-convex parts, which are divided into a plurality of groups. The plurality of groups of concave-convex parts are arranged at intervals in the first direction, and each group of the concave-convex parts includes protrusions and grooves alternately arranged in the second direction.

8. The alkaline electrolytic cell bipolar plate according to claim 7, characterized in that: The outer contour of the protrusion on the projection surface parallel to the first direction and the second direction is fan-shaped, and / or the outer contour of the groove on the projection surface parallel to the first direction and the second direction is fan-shaped.

9. The alkaline electrolytic cell bipolar plate according to claim 8, characterized in that: The arc of the sector is convex in the direction toward the fourth side surface, the radius of the sector is R, the connection between two radius edges of the sector is chamfered with a first chamfer radius, the first chamfer radius is 3 / 5R, and / or, The connection between the arc edge of the sector and the two radius edges is chamfered with a second chamfer radius, the second chamfer radius is 1 / 10R, and / or, The central angle of the sector is β, 40°≤β≤50°.

10. An alkaline electrolytic cell, characterized in that: include: A first bipolar plate and a second bipolar plate, wherein the first bipolar plate and the second bipolar plate are both bipolar plates as described in any one of claims 1 to 9; An anode and a cathode, wherein the anode cooperates with the second bipolar plate, and the cathode cooperates with the first bipolar plate.

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