System for performing electrochemical reactions

Abstract

Embodiments of the present invention relate to a system for performing an electrochemical reaction, the system comprising at least one electrochemical reaction subsystem wherein the electrochemical reaction subsystem comprises: a first electrode; a second electrode; the micro-channel unit is located between the first electrode and the second electrode and used for enabling electrolyte to circulate, the side wall, facing the first electrode and the second electrode, of the micro-channel unit is of a micropore structure, and the micro-channel unit is configured to have rigidity meeting preset conditions. Therefore, deformation of the micro-channel unit during electrochemical reaction is avoided. According to the system for performing the electrochemical reaction, provided by the invention, the micro-channel unit can be kept not to deform under the condition that the distance between the electrodes is relatively small, hydrogen and oxygen mixing is avoided, the air resistance phenomenon at the electrodes can be greatly reduced, and the hydrogen production efficiency is improved.

Description

Technical Field

[0001] Embodiments of the present invention generally relate to the field of electrochemistry, and more particularly to a system for performing electrochemical reactions. Background Art

[0002] Electrolytic water hydrogen production is an important means of producing hydrogen. When traditional systems for performing electrochemical reactions carry out water electrolysis, hydrogen and oxygen usually form in the form of bubbles on the corresponding electrode surfaces, which easily causes the phenomenon of gas blockage, thus hindering the occurrence of the water electrolysis reaction and resulting in low hydrogen production efficiency. Moreover, the generated hydrogen may pass through the diaphragm and mix with oxygen, posing a potential explosion risk.

[0003] In summary, when performing water electrolysis, the disadvantages of traditional systems for performing electrochemical reactions are as follows: gas blockage is likely to occur at the electrodes, the hydrogen production efficiency is low, and there is a risk of hydrogen-oxygen mixing. Summary of the Invention

[0004] In view of the above problems, the present invention provides a system for performing electrochemical reactions, which enables the microchannel unit to maintain its shape without deformation when the electrode spacing is small during water electrolysis, avoids the occurrence of hydrogen-oxygen mixing, and can significantly reduce the occurrence of gas blockage at the electrodes, thereby improving the hydrogen production efficiency.

[0005] According to a first aspect of the present invention, there is provided a system for performing electrochemical reactions, including at least one electrochemical reaction subsystem, wherein the electrochemical reaction subsystem includes: a first electrode; a second electrode; and a microchannel unit located between the first electrode and the second electrode for allowing an electrolyte to flow therethrough, wherein the side walls of the microchannel unit facing the first electrode and the second electrode have a microporous structure, and the microchannel unit is configured to have a rigidity that meets a predetermined condition to avoid deformation of the microchannel unit during the electrochemical reaction.

[0006] In some embodiments, the microchannel unit has a plurality of channels such that the electrolyte flowing into the microchannel unit from a first end thereof flows out of the microchannel unit from a second end thereof via the plurality of channels.

[0007] In some embodiments, the first end of the microchannel unit is located above the second end of the microchannel unit. In some embodiments, the channels are composed of at least one of the following materials: metal, ceramic, and rigid plastic.

[0008] In some embodiments, the microchannel unit includes: a fluid guiding plate; and a porous membrane covering the outer surface of the fluid guiding plate.

[0009] In some embodiments, the fluid guiding plate is made of metal foam or ceramic foam.

[0010] In some embodiments, the pore diameter of the fluid deflector is larger than that of the porous membrane. In some embodiments, the pore diameter of the fluid deflector is 10 - 2000 μm, preferably, the pore diameter of the fluid deflector is 50 - 200 μm. In some embodiments, the pore diameter of the porous membrane is not more than 100 μm, preferably, the pore diameter of the porous membrane is 1 - 20 μm.

[0011] In some embodiments, the system for performing an electrochemical reaction further includes: a flow splitting unit configured to be connected to the first end of the microchannel unit so that the electrolyte is evenly split into the microchannel unit via the flow splitting unit.

[0012] In some embodiments, the flow splitting unit includes: a flow splitting chamber and a dispersion array. In these embodiments, the flow splitting array is located between the flow splitting chamber and the microchannel unit.

[0013] In some embodiments, the flow splitting array includes a plurality of openings spaced apart from each other.

[0014] In some embodiments, both the first electrode and the second electrode are gas diffusion electrodes. In some embodiments, the distance between the first electrode and the second electrode does not exceed 2 mm, preferably, the distance between the first electrode and the second electrode does not exceed 1 mm.

[0015] In some embodiments, the system provided according to the first aspect of the present invention is an electrolytic cell.

[0016] In some embodiments, the system provided according to the first aspect of the present invention is a fuel cell.

[0017] According to a second aspect of the present invention, there is provided a method for performing an electrochemical reaction using the system according to the first aspect of the present invention, the method including: providing an electrolyte so that the electrolyte is evenly introduced into the microchannel unit; and causing the electrolyte to seep out from the microporous structure on the side wall of the microchannel unit to contact the first electrode and the second electrode.

[0018] It should be understood that the content described in this part is not intended to identify the key or important features of the embodiments of the present invention, nor is it used to limit the scope of the present invention. Other features of the present invention will become readily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In combination with the accompanying drawings and with reference to the following detailed description, the above and other features, advantages, and aspects of the embodiments of the present invention will become more apparent. In the drawings, the same or similar reference numerals denote the same or similar elements.

[0020] Figure 1A A schematic diagram of a system for performing an electrochemical reaction is shown.

[0021] Figure 1BShows a schematic diagram of another system for performing an electrochemical reaction

[0022] Figure 2 Shows a schematic diagram of a system for performing an electrochemical reaction according to an embodiment of the present invention.

[0023] Figure 3A Shows a schematic diagram of an exemplary structure of a plurality of flow channels in a microchannel unit according to an embodiment of the present invention.

[0024] Figure 3B Shows a schematic diagram of another exemplary structure of a plurality of flow channels in a microchannel unit according to an embodiment of the present invention

[0025] Figure 4 Shows a schematic diagram of a microchannel unit according to an embodiment of the present invention.

[0026] Figure 5 Shows a schematic diagram of a shunt unit according to an embodiment of the present invention.

[0027] Figure 6 Shows a schematic diagram of a system for performing an electrochemical reaction according to another embodiment of the present invention. Detailed Description

[0028] The following describes exemplary embodiments of the present invention with reference to the accompanying drawings, including various details of the embodiments of the present invention to facilitate understanding, which should be considered merely exemplary. Therefore, those of ordinary skill in the art should recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of the present invention. Similarly, for the sake of clarity and conciseness, descriptions of well-known functions and structures are omitted below.

[0029] As used herein, the term "comprising" and its variations mean open inclusion, i.e., "including but not limited to". Unless otherwise stated, the term "or" means "and / or". The term "based on" means "at least partially based on". The terms "an example embodiment" and "an embodiment" mean "at least one example embodiment". The term "another embodiment" means "at least one additional embodiment". The terms "first", "second", etc. may refer to different or the same objects. There may be other explicit and implicit definitions below.

[0030] Electrolytic water hydrogen production is an important means for preparing hydrogen based on electrochemical reactions. Among them, alkaline water electrolysis is widely used in industry due to its low cost and high technical maturity. In traditional schemes for alkaline water electrolysis, a system (also called an alkaline electrolyzer) 100A for performing electrochemical reactions as shown in Figure 1A is usually adopted.

[0031] Figure 1A FIG. 1 shows a schematic diagram of a system 100A for performing an electrochemical reaction. As Figure 1A shown, the system 100A includes: a first electrode 110A, a second electrode 120A, and a diaphragm 130A, wherein the diaphragm 130A divides the system 100A into a first chamber 102A and a second chamber 104A. During the process of water electrolysis using the system 100A, an electrolyte (such as potassium hydroxide, sodium hydroxide, etc.) is introduced into the first chamber 102A and the second chamber 104A, and the first electrode 110A and the second electrode 120A are completely immersed in the electrolyte so that oxygen and hydrogen can be formed on the surfaces of the first electrode 110A and the second electrode 120A, respectively. Taking the first electrode 110A as the anode and the second electrode 120A as the cathode as an example, during the process of the electrochemical reaction of water electrolysis, an oxygen evolution reaction shown in the following formula (1) occurs at the first electrode 110A.

[0032] 4OH - → 2H2O + O2 + 4e - (1)

[0033] At the second electrode 120A, a hydrogen evolution reaction shown in the following formula (2) occurs.

[0034] 2H2O + 4e - → H2 + 2OH - (2)

[0035] However, as Figure 1A shown, hydrogen and oxygen are formed in the form of bubbles on the corresponding electrode surfaces, which easily causes a gas resistance phenomenon, thus hindering the occurrence of the electrochemical reaction and resulting in low hydrogen production efficiency. Secondly, although a diaphragm 130A (such as an asbestos diaphragm, a polyphenylene sulfide (PPS) diaphragm, a composite diaphragm, or other diaphragms) is provided in the system 100A to prevent the mixing of hydrogen and oxygen, in view of the production ratio of hydrogen and oxygen being 2:1, it is necessary to always maintain the pressure balance between the first chamber 102A and the second chamber 104A on both sides of the diaphragm 130A. Otherwise, once the pressures of the two chambers are unbalanced, too much hydrogen will pass through the diaphragm 130A and mix with oxygen, thereby causing an explosion risk.

[0036] Alternatively, in the prior art, porous capillaries can also be used to make the electrolyte contact the electrodes based on the capillary effect. Figure 1B FIG. 2 shows a schematic diagram of another system 100B for performing an electrochemical reaction.

[0037] As Figure 1BAs shown, system 100B includes: a first electrode 110B, a second electrode 120B, a porous capillary 130B, and an electrolyte container 140B. The porous capillary 130B is located between the first electrode 110B and the second electrode 120B, and the bottom end of the porous capillary 130B extends into the electrolyte container 140B. During the process of water electrolysis using system 100B, based on the capillary effect, the electrolyte in the electrolyte container 140B will spontaneously enter the porous capillary 130B and rise along the porous capillary 130B to a certain height to contact the first electrode 110B and the second electrode 120B, thereby generating oxygen and hydrogen accordingly.

[0038] However, the rising height of the electrolyte in the porous capillary 130B due to the capillary effect has limitations, thus also restricting the size of system 100B. In addition, as Figure 1B shown, since the porous capillary 130B is disposed between the first electrode 110B and the second electrode 120B, if the distance between the first electrode 110B and the second electrode 120B is small or they are relatively tightly arranged on both sides of the porous capillary 130B, it is easy to break the pores of the porous capillary 130B or cause the pores of the porous capillary 130B to be squeezed and deformed or even completely closed due to the difficulty of making the electrode surfaces completely flat, thereby affecting the occurrence of the capillary effect. Further, since the generated oxygen and hydrogen are actually isolated by the electrolyte in the porous capillary 130B, if the rise of the electrolyte in the porous capillary 130B is discontinuous, for example, the electrolyte fails to rise along the porous capillary 130B to a certain height or there are voids in the middle of the electrolyte in the porous capillary 130B, it will cause the risk of hydrogen-oxygen mixing.

[0039] In summary, the disadvantages of the above-mentioned existing systems for electrochemical reactions are as follows: the electrode spacing is large, air resistance is likely to occur at the electrodes, the hydrogen production efficiency is low, and there is a risk of hydrogen-oxygen mixing.

[0040] To at least partially solve one or more of the above problems and other potential problems, example embodiments of the present invention propose a system for electrochemical reactions. In at least one electrochemical reaction subsystem included in the system, by disposing a rigid microchannel unit for electrolyte flow that meets a predetermined condition between the first electrode and the second electrode to avoid deformation of the microchannel unit during the electrochemical reaction, the first electrode and the second electrode can be tightly arranged on opposite sides of the microchannel unit, thereby reducing the electrode spacing. At the same time, by fully filling the microchannel unit with the electrolyte to form a liquid partition, the occurrence of hydrogen-oxygen mixing is avoided. In addition, by allowing the electrolyte to seep out from the microporous structure on the side wall of the microchannel unit and contact the electrodes, the occurrence of air resistance at the electrodes can be significantly reduced, and the hydrogen production efficiency can be improved.

[0041] The following will be combined with Figures 2 to 6 Describe in detail a solution for performing an electrochemical reaction according to an embodiment of the present invention.

[0042] Figure 2 A schematic diagram of a system 200 for performing an electrochemical reaction according to an embodiment of the present invention is shown.

[0043] As Figure 2 shown, the system 200 includes an electrochemical reaction subsystem 210. Among them, the electrochemical reaction subsystem 210 may include: a first electrode 214, a second electrode 216, and a microchannel unit 212.

[0044] Regarding the first electrode 214 and the second electrode 216, they can be configured to be in contact with the electrolyte solution to facilitate the generation of corresponding gases. According to an embodiment of the present invention, the electrolyte solution can be, for example, a sodium hydroxide solution. If the first electrode 214 is the anode and the second electrode 216 is the cathode, then as described above, oxygen is generated at the first electrode 214, and hydrogen is generated at the second electrode 216.

[0045] In order to better diffuse and export the gases generated at the electrodes to avoid the phenomenon of gas resistance, according to an embodiment of the present invention, a gas diffusion layer can be provided on the side of the electrode away from the microchannel unit 212. As Figure 2 shown, a first gas diffusion layer 224 is provided on the side of the first electrode 214 away from the microchannel unit 212, and a second gas diffusion layer 226 is provided on the side of the second electrode 216 away from the microchannel unit 212. In this embodiment, the gas (such as oxygen) generated at the first electrode 214 can diffuse through the first gas diffusion layer 224 and be exported from the electrochemical reaction subsystem 210, for example, into an external pipeline (not shown) for transporting oxygen; similarly, the gas (such as hydrogen) generated at the second electrode 216 can diffuse through the second gas diffusion layer 226 and be exported from the electrochemical reaction subsystem 210, for example, into an external pipeline (not shown) for transporting hydrogen.

[0046] According to some other embodiments of the present invention, the electrodes can also be gas diffusion electrodes. For example, Figure 2 both the first electrode 214 and the second electrode 216 shown in

[0047] are gas diffusion electrodes, so that the gases formed at the electrodes can diffuse sufficiently through the gas diffusion electrodes.

[0048] In still other embodiments, when the electrode is a gas diffusion electrode and the thickness of the electrode is large enough, the electrode itself will have the function of a gas diffusion layer. In other words, the combination structure of the above-mentioned electrode and gas diffusion layer can be replaced by the electrode, so that in the structures of these embodiments, the gas diffusion layer can be excluded.

[0049] Regarding the microchannel unit 212, as Figure 2 shown, it is located between the first electrode 214 and the second electrode 216 for allowing the electrolyte to flow through. According to some embodiments of the present invention, the electrolyte can flow in from above the microchannel unit 212 and flow out from below the microchannel unit 212.

[0050] According to an embodiment of the present invention, the side walls of the microchannel unit 212 facing the first electrode 214 and the second electrode 216 have a microporous structure, so that the electrolyte flowing into the microchannel unit 212 can seep out through the microporous structure and contact the electrodes. In some embodiments, the pore diameter of the micropores on the side walls of the microchannel unit 212 can be 1 - 100 μm.

[0051] According to the inventive concept of the present invention, the microchannel unit 212 is further configured to have a rigidity that meets a predetermined condition to prevent the microchannel unit 212 from deforming during the electrochemical reaction.

[0052] Regarding having a rigidity that meets a predetermined condition, it means that the microchannel unit 212 maintains its shape unchanged during the process in which the electrolyte therein seeps out and undergoes an electrolysis reaction with the electrodes (i.e., the first electrode 214 and the second electrode 216), preventing the microchannel unit 212 from deforming excessively due to the pressure of the first electrode 214 and the second electrode 216. That is to say, preventing the local deformation of the microchannel unit 212 from being too large, so that the electrolyte cannot fill the microchannel unit 212, resulting in a local blank area in the microchannel unit 212 without electrolyte, and causing a risk of hydrogen and oxygen mixing with each other through this local blank area.

[0053] According to some embodiments of the present invention, the microchannel unit 212 can be provided with microchannels to support the shape of the microchannel unit 212, so that the microchannel unit 212 has a rigidity that meets a predetermined condition and prevents deformation. For example, in some embodiments, the microchannel unit 212 can have a plurality of channels, so that the electrolyte flowing into the microchannel unit 212 from the first end can flow out from the second end of the microchannel unit 212 through the plurality of channels. In still other embodiments, the electrolyte can also flow into the microchannel unit 212 from the first end and the second end of the microchannel unit 212 simultaneously.

[0054] Further, in some embodiments, an external force such as liquid gravity and / or hydraulic pressure brought by a pump valve can be used to make the electrolyte pass through the microchannel unit, so that the electrolyte fills the entire microchannel unit, thereby avoiding voids in the electrolyte in the microchannel unit. In this case, the first end of the microchannel unit can be located above the second end of the microchannel unit, so that the electrolyte can flow in from the upper port of the microchannel unit and flow out from the lower port of the microchannel unit via a plurality of channels.

[0055] Regarding the channel, it can refer to a fluid channel with a small thickness. According to an embodiment of the present invention, the thickness of the channel can be no more than 1 mm, preferably, the thickness of the channel can be no more than 0.5 mm, such as 0.2 mm or 0.02 mm. By making the electrolyte pass through the channels with a small thickness in the microchannel unit 212, the flow of the electrolyte can be made more controllable, and thus the exudation of the electrolyte from the microchannel unit to react with the electrode can also be better controlled. In other words, it helps to improve the controllability of the electrochemical reaction. And, since the channel thickness is small, the thickness of the microchannel unit 212 is correspondingly small, and the system 200 can have a small electrode spacing. In some embodiments, the channel can be a microfluidic channel, such that the electrolyte flowing through the microchannel unit 212 exhibits the properties of a microfluid.

[0056] According to some embodiments of the present invention, the structures of the plurality of channels in the microchannel unit 212 can be irregular. For example, the plurality of channels can be in a three-dimensional grid shape or a sponge shape. According to still other embodiments of the present invention, the structures of the plurality of channels in the microchannel unit 212 can be regular. For example, the plurality of channels are arranged in parallel. Figure 3A and Figure 3B Exemplarily shows the structures of the plurality of channels in the microchannel unit 212. Specifically, Figure 3A The plurality of channels shown in the microchannel unit have an irregular sponge-like structure; Figure 3B The plurality of channels shown in the microchannel unit have a regular structure arranged in parallel.

[0057] According to an embodiment of the present invention, the channel can be made of materials such as metal, ceramic, hard plastic, etc. or hard materials resistant to alkali that are suitable for making channels, so as to support the shape of the microchannel unit 212 and prevent the microchannel unit 212 from deforming.

[0058] According to still other embodiments of the present invention, the microchannel unit 212 can also have a "sandwich" structure as Figure 4 shown. This will be described in detail below and will not be elaborated here first. Figure 4

[0059] ​As described above, in the system 200 for performing an electrochemical reaction according to an embodiment of the present invention, since the microchannel unit 212 in the electrochemical reaction subsystem 210 has rigidity that meets a predetermined condition, the first electrode 214 and the second electrode 216 can be tightly arranged on both sides of the microchannel unit 212, and at the same time, the microchannel unit 212 will not undergo excessive deformation due to the extrusion of the first electrode 214 and the second electrode 216, thereby achieving a smaller electrode spacing.

[0060] According to an embodiment of the present invention, the distance between the first electrode 214 and the second electrode 216 can be, for example, no more than 2 mm. In some other embodiments, the distance between the first electrode 214 and the second electrode 216 can be no more than 1 mm, such as 0.8 mm, etc.

[0061] As Figure 2 shown, the electrochemical reaction subsystem 210 may further include: a first bipolar plate 234 and a second bipolar plate 236, where the first bipolar plate 234 is arranged outside the first gas diffusion layer 224, that is, on the side of the first gas diffusion layer 224 away from the first electrode 214; the second bipolar plate 236 is arranged outside the second gas diffusion layer 226, that is, on the side of the second gas diffusion layer 226 away from the second electrode 216. By using bipolar plates, multiple electrochemical reaction subsystems can be stacked to form a system for performing an electrochemical reaction including multiple electrochemical reaction subsystems, which will be described below in conjunction with Figure 6 description, and will not be elaborated here for the time being.

[0062] According to an embodiment of the present invention, metal bipolar plates can be used. For example, both the first bipolar plate 234 and the second bipolar plate 236 are metal bipolar plates.

[0063] In the system 200 for performing an electrochemical reaction according to the above embodiment of the present invention, when the system 200 is used for water electrolysis, the electrolyte flowing into the microchannel unit 212 can slowly seep out from the microporous structures on both sides of the microchannel unit 212 and contact the first electrode 214 and the second electrode 216 on both sides of the microchannel unit 212 to generate hydrogen and oxygen respectively. Since the microchannel unit 212 enables the slowly permeating electrolyte to contact the electrodes, the gas generated at the electrodes can effectively contact the gas cavity in the cavity where the electrodes are located, reducing the possibility of gas resistance phenomenon occurring at the electrodes. And, since the microchannel unit 212 has rigidity that meets a predetermined condition, when the electrode spacing is small, the microchannel unit 212 can still keep the flow channels therein unobstructed so that the electrolyte can fully flow in the flow channels.

[0064] Figure 4 shows a schematic diagram of a microchannel unit 400 with a "sandwich" structure according to an embodiment of the present invention. AsFigure 4 As shown, the microchannel unit 400 may include: a fluid guide plate 410 and a porous membrane 420, where the porous membrane 420 covers the outer surface of the fluid guide plate 410.

[0065] Regarding the fluid guide plate 410, it may be a rigid fluid guide plate that meets predetermined conditions, so that the fluid guide plate 410 will not deform due to the pressure brought by the electrodes on both sides. According to an embodiment of the present invention, the fluid guide plate 410 may be made of a material that does not react with the electrolyte and is stable for a long time. For example, the fluid guide plate 410 may be made of metal foam (such as nickel foam) or ceramic foam. According to some embodiments of the present invention, the fluid guide plate 410 may also be a microfluidic guide plate.

[0066] Regarding the porous membrane 420, it may be a thin film with many small holes and stable chemical properties. For example, it may be a polymer membrane with a certain number of uniform small holes. According to an embodiment of the present invention, the porous membrane 420 may be a porous membrane with strong alkali resistance. In some embodiments, the porous membrane 420 may be, for example, a polyethersulfone (PES) porous membrane, a melamine porous membrane, or other suitable porous membranes.

[0067] Regarding the outer surface of the fluid guide plate 410, it refers to the outer surface of the side of the fluid guide plate 410. According to an embodiment of the present invention, the porous membrane 420 covers the outer surface of the fluid guide plate 410 facing the electrode.

[0068] According to the inventive concept of the present invention, in some embodiments, the pore size of the fluid guide plate 410 may be different from the pore size of the porous membrane 420. For example, the pore size of the fluid guide plate 410 may be larger than the pore size of the porous membrane 420, so that the electrolyte can fully flow in the fluid guide plate 410, while ensuring that the electrolyte in the fluid guide plate 410 slowly oozes out from the porous membrane 420 to contact the electrode. For example, the pore size of the fluid guide plate 410 may be 10 - 2000 μm, preferably, the pore size of the fluid guide plate 410 may be 50 - 200 μm, such as 100 μm. For example, the pore size of the porous membrane 420 may be no more than 100 μm, preferably, the pore size of the porous membrane 420 may be 1 - 20 μm, such as 5 μm.

[0069] According to the inventive concept of the present invention, the microchannel unit 400 may be integrally formed or separately formed, which is not limited here.

[0070] According to an embodiment of the present invention, the cross-section of the microchannel unit 400 may be rectangular.

[0071] Further, in order to enable the electrolyte to fully fill the microchannel unit to form a liquid partition, the system for performing an electrochemical reaction according to an embodiment of the present invention may further include a shunt unit, so that the electrolyte can first flow into the shunt unit and be further shunted to the microchannel unit via the shunt unit. Specifically, in some embodiments, the shunt unit may be configured to be connected to one end of the microchannel unit (e.g., Figure 2 the microchannel unit 212 or Figure 4 the microchannel unit 400) to evenly shunt the electrolyte to the microchannel unit via the shunt unit.

[0072] Figure 5 FIG. shows a schematic diagram of the shunt unit 500 according to an embodiment of the present invention, and the shunt unit 500 may be connected to one end of the microchannel unit 212 as shown in Figure 2 FIG.

[0073] As shown in Figure 5 FIG., the shunt unit 500 may include: a shunt chamber 510 and a dispersion array 520, wherein the dispersion array 520 may be located between the shunt chamber 510 and the microchannel unit 212.

[0074] Regarding the shunt chamber 510, one end thereof may be connected to a pipeline for conveying the electrolyte. When the electrolyte in the pipeline flows into the shunt chamber 510, the liquid flow cross-section of the electrolyte may be enlarged by the shunt chamber 510. According to an embodiment of the present invention, the cross-sectional area of the bottom end of the shunt chamber 510 may be the same as the cross-sectional area of the microchannel unit 212. In this case, the liquid flow cross-section of the electrolyte flowing into the shunt chamber 510 may be enlarged to be the same as the cross-sectional area of the microchannel unit 212.

[0075] Regarding the dispersion array 520, it may be used to balance the pressure of the electrolyte with an enlarged liquid flow cross-section and make the electrolyte flow into the microchannel unit 212 dispersedly, so as to achieve the purpose of filling the entire microchannel unit 212 with the electrolyte. Specifically, by using the dispersion array 520, a uniform flow field of the electrolyte can be better formed, so that the electrolyte flowing into the microchannel unit 212 flows uniformly through multiple channels in the microchannel unit 212, avoiding non-uniform internal resistance caused by non-uniform electrolyte concentration at different parts during the electrochemical reaction process. According to some embodiments of the present invention, the dispersion array 520 may include a plurality of openings spaced from each other.

[0076] It should be understood that Figure 5Only the structure of the flow splitting unit 500 is exemplarily shown. In some embodiments, the flow splitting chamber 510 and the dispersion array 520 in the flow splitting unit 500 may be arranged in a cross-section perpendicular to one end of the microchannel unit 212; in still other embodiments, the flow splitting chamber 510 and the dispersion array 520 in the flow splitting unit 500 may be arranged in a cross-section parallel to one end of the microchannel unit 212; in still other embodiments, either the flow splitting chamber 510 or the dispersion array 520 in the flow splitting unit 500 may be in a cross-section parallel to one end of the microchannel unit 212, while the other is arranged perpendicular to this cross-section. The present invention does not limit this.

[0077] In summary, through the above-described flow splitting unit, the electrolyte can quickly and completely and evenly fill the flow channels in the microchannel unit, that is, the electrolyte can fully fill the microchannel unit to form a liquid partition, realizing the liquid-phase isolation of hydrogen and oxygen and avoiding the occurrence of hydrogen-oxygen mixing.

[0078] Figure 6 The schematic diagram of a system 600 for performing an electrochemical reaction according to another embodiment of the present invention is shown.

[0079] As Figure 6 shown, the system 600 includes three electrochemical reaction subsystems, namely a first electrochemical reaction subsystem 610, a second electrochemical reaction subsystem 620, and a third electrochemical reaction subsystem 630, wherein the first electrochemical reaction subsystem 610 and the second electrochemical reaction subsystem 620 share a third bipolar plate 602, and the second electrochemical reaction subsystem 620 and the third electrochemical reaction subsystem 630 share a fourth bipolar plate 604.

[0080] Thus, the stacking of the electrochemical reaction subsystems can be realized through the bipolar plates, thereby realizing the industrial production of the system for performing an electrochemical reaction according to the embodiments of the present invention.

[0081] In summary, the system for performing an electrochemical reaction according to the embodiments of the present invention can safely and efficiently realize hydrogen production by electrolyzing water when the electrode spacing is small, and since the rigid microchannel unit that meets the predetermined conditions can completely isolate the oxygen and hydrogen generated by electrolyzing water and there is no risk of mutual mixing, the system provided by the present invention can be operated under normal pressure, reducing energy consumption.

[0082] According to another aspect of the present invention, the above-described system for performing an electrochemical reaction can also be used as a fuel cell. According to some embodiments of the present invention, it can be made as Figure 2The first electrode 214 and the second electrode 216 in the illustrated system 200 are catalytically active electrodes, such as any electrodes suitable for fuel cells, such as platinum-carbon (Pt / C) catalytic electrodes, iridium oxide (IrO2) catalytic electrodes, etc. By introducing hydrogen and oxygen into the first electrode 214 and the second electrode 216 respectively, corresponding electrochemical reactions occur at the first electrode 214 and the second electrode 216, and an electric current is formed.

[0083] Taking the first electrode 214 as the positive electrode and the second electrode 216 as the negative electrode as an example, when the system 200 is used as a fuel cell, oxygen is introduced into the first electrode 214 to perform an oxygen reduction reaction (ORR) at the first electrode 214, and hydrogen is introduced into the second electrode 216 to cause a hydrogen oxidation reaction (HOR) at the second electrode 216. The hydroxide ions generated at the first electrode 214 then move through the electrolyte in the microchannel unit 212 to the second electrode 214 to react with the hydrogen ions at the second electrode 214 to form water. Correspondingly, electrons flow out from the second electrode 216 and flow into the first electrode 214 through electrical conductors (such as the first gas diffusion layer 224, the first bipolar plate 234, the second gas diffusion layer 226, the second bipolar plate 236, etc. included in the system 200 and / or any electrical conductors disposed outside the system suitable for the present invention) to form an electric current. Figure 2 As shown, the first gas diffusion layer 224, the first bipolar plate 234, the second gas diffusion layer 226, the second bipolar plate 236, etc. The electrical conductors included in the system 200 and / or any electrical conductors disposed outside the system suitable for the present invention flow into the first electrode 214 to form an electric current.

[0084] The embodiments of the present disclosure have been described above. The above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations are obvious to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The choice of terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the technology in the market, or to enable other ordinary skill in the art to understand the embodiments disclosed herein.

[0085] The above are only optional embodiments of the present disclosure and are not used to limit the present disclosure. For those skilled in the art, the present disclosure can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present disclosure shall be included within the protection scope of the present disclosure.

Claims

1. A system for performing an electrochemical reaction, characterized in that, Comprising at least one electrochemical reaction subsystem, wherein the electrochemical reaction subsystem comprises: A first electrode; A second electrode; and A microchannel unit located between the first electrode and the second electrode for allowing an electrolyte to flow therethrough, wherein the side walls of the microchannel unit facing the first electrode and the second electrode have a microporous structure, and the microchannel unit is configured to have a rigidity that meets a predetermined condition to avoid deformation of the microchannel unit during the electrochemical reaction.

2. The system according to claim 1, wherein The microchannel unit has a plurality of channels such that the electrolyte flowing into the microchannel unit from a first end thereof flows out of the microchannel unit from a second end thereof via the plurality of channels.

3. The system according to claim 2, wherein The first end of the microchannel unit is located above the second end of the microchannel unit; and the channels are made of at least one of the following materials: metal, ceramic, and rigid plastic.

4. The system according to claim 1, wherein The microchannel unit comprises: A fluid flow guiding plate; and A porous membrane covering the outer surface of the fluid flow guiding plate.

5. The system according to claim 4, characterized in that, The fluid flow guiding plate is made of metal foam or ceramic foam.

6. The system according to claim 4, characterized in that, The pore size of the fluid flow guiding plate is larger than the pore size of the porous membrane, wherein the pore size of the fluid flow guiding plate is 10 - 2000 μm, preferably, the pore size of the fluid flow guiding plate is 50 - 200 μm, wherein the pore size of the porous membrane is not more than 100 μm, preferably, the pore size of the porous membrane is 1 - 20 μm.

7. The system according to claim 1, wherein Further comprising: A flow splitting unit configured to be connected to the first end of the microchannel unit so that the electrolyte is evenly split into the microchannel unit via the flow splitting unit.

8. The system according to claim 7, wherein The flow splitting unit comprises: a flow splitting chamber and a dispersion array, wherein the dispersion array is located between the flow splitting chamber and the microchannel unit, and the dispersion array comprises a plurality of openings spaced apart from each other.

9. The system according to claim 1, wherein Both the first electrode and the second electrode are gas diffusion electrodes, wherein the distance between the first electrode and the second electrode does not exceed 2 mm, preferably, the distance between the first electrode and the second electrode does not exceed 1 mm.

10. The system according to claim 1, wherein The system is an electrolytic cell.

11. The system according to claim 1, characterized in that, The system is a fuel cell.

12. A method for performing an electrochemical reaction using the system according to any one of claims 1 to 11, the method comprising: Providing an electrolyte such that the electrolyte is uniformly introduced into the microchannel unit; And Causing the electrolyte to ooze out from the microporous structure of the side wall of the microchannel unit to contact the first electrode and the second electrode.

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