CN114395773A

CN114395773A - Carbon dioxide electrolytic cell and carbon dioxide electrolysis electric pile device

Info

Publication number: CN114395773A
Application number: CN202111631131.6A
Authority: CN
Inventors: 陆奇; 徐冰君; 吴东欢
Original assignee: Tsinghua University; Peking University
Current assignee: Tsinghua University; Peking University
Priority date: 2021-12-28
Filing date: 2021-12-28
Publication date: 2022-04-26
Anticipated expiration: 2041-12-28
Also published as: CN114395773B

Abstract

The invention relates to the technical field of carbon dioxide electrolysis, in particular to a carbon dioxide electrolytic cell and a carbon dioxide electrolysis galvanic pile device. The carbon dioxide electrolytic cell comprises: a first electrode plate; the cathode electrode is arranged on one side of the first polar plate, and the cathode electrode and the first polar plate form a carbon dioxide gas chamber; the liquid flow plate is arranged on one side of the cathode electrode, which is far away from the first polar plate, and is provided with a pore passage for cathode electrolyte to pass through; the diaphragm is arranged on one side of the liquid flow plate, which is far away from the cathode electrode, and a cathode electrolyte chamber is formed between the diaphragm and the cathode electrode; the anode electrode is arranged on one side of the diaphragm, which is far away from the liquid flow plate; and the second polar plate is arranged on one side of the anode electrode, which is far away from the diaphragm, and an anolyte cavity is formed between the second polar plate and the diaphragm.

Description

Carbon dioxide electrolytic cell and carbon dioxide electrolysis electric pile device

Technical Field

The invention relates to the technical field of carbon dioxide electrolysis, in particular to a carbon dioxide electrolytic cell and a carbon dioxide electrolysis galvanic pile device.

Background

With the imperative development of efficient carbon dioxide emission reduction technology in China, among a plurality of technologies, carbon dioxide electrolysis is widely considered to have a wide prospect, and carbon dioxide can be efficiently converted into high-value-added chemicals such as formic acid and ethanol by using cheap renewable power. However, most of the carbon dioxide electrolysis researches are still in a laboratory research stage at present, the total reaction current is lower than 0.1A, and the total electrolysis power is lower than 0.5W; the only few carbon dioxide electrolytic amplification devices are based on single cell studies, with overall power still limited (<20W), and most employ a two-chamber membrane electrode configuration based on anionic membranes. The two-chamber electrolytic cell configuration only comprises a cathode gas chamber and an anolyte chamber, an anion membrane is in direct contact with a cathode electrode, the operation stability of the device mainly depends on the service life of the anion membrane under strong alkaline conditions, the device is limited by the low performance of the existing anion membrane, and the operation time of the carbon dioxide electrolytic cell with the configuration is generally less than 50 hours. Therefore, at present, a carbon dioxide electrolytic cell and a carbon dioxide electrolytic pile device which can keep the running time of more than 200 hours and the electrolytic power of more than 1kW are still lacked, and the industrial application of the carbon dioxide electrolysis is severely limited.

Disclosure of Invention

Based on the carbon dioxide electrolytic cell and the carbon dioxide electrolytic cell stack device, the carbon dioxide electrolytic cell and the carbon dioxide electrolytic cell stack device can stably operate for a long time, are low in energy consumption and are higher in electrolytic efficiency.

In one aspect of the present invention, there is provided a carbon dioxide electrolytic cell comprising:

a first electrode plate;

the cathode electrode is arranged on one side of the first polar plate, and the cathode electrode and the first polar plate form a carbon dioxide gas chamber;

the liquid flow plate is arranged on one side of the cathode electrode, which is far away from the first polar plate, and is provided with a pore passage for cathode electrolyte to pass through;

the diaphragm is arranged on one side of the liquid flow plate, which is far away from the cathode electrode, and a cathode electrolyte chamber is formed between the diaphragm and the cathode electrode;

the anode electrode is arranged on one side of the diaphragm, which is far away from the liquid flow plate; and

the second polar plate is arranged on one side of the anode electrode, which is far away from the diaphragm, and an anolyte cavity is formed between the second polar plate and the diaphragm;

the first electrode plate is provided with a first groove on one surface facing the cathode electrode, the second electrode plate is provided with a second groove on one surface facing the anode electrode, the first grooves and/or the second grooves extend to form a flow channel, and the flow channel is a multi-channel flow channel.

In one embodiment, the flow channel is a multi-channel snake-shaped flow channel, the number of the channels is 3-8, the width of a single channel is 0.5-5 mm, and the depth is 0.1-3 mm.

In one embodiment, the anode electrode is a porous material formed of an anode catalyst or is composed of a porous substrate and a catalyst layer formed of an anode catalyst disposed on a surface of the porous substrate.

In one embodiment, the cathode electrode is a porous gas diffusion electrode comprising a gas diffusion layer and a cathode catalyst layer stacked, the gas diffusion layer being disposed toward the first plate side, and the cathode catalyst layer being disposed toward the flow plate side.

In one embodiment, the gas diffusion layer comprises at least one gas diffusion sublayer and the cathode catalyst layer comprises at least one cathode catalyst sublayer.

In one embodiment, the membrane is an anion exchange membrane or a cation exchange membrane.

In one embodiment, the first electrode plate and the second electrode plate are both made of conductive materials, and are respectively and independently selected from one or more of aluminum, titanium, stainless steel and graphite, and/or the flow plate is made of insulating resin.

In one embodiment, the carbon dioxide electrolytic cell further comprises a flow limiting channel, the flow limiting channel comprises a pipeline for transmitting the anolyte from the outside to the second polar plate, a pipeline for transmitting gas from the outside to the first polar plate and a pipeline for transmitting the catholyte from the outside to the flow plate, and the length of each section of pipeline is 5 cm-50 cm. .

In another aspect of the present invention, a carbon dioxide electrolysis cell stack apparatus is provided, which includes a plurality of carbon dioxide electrolysis cells stacked in series, wherein at least one of the carbon dioxide electrolysis cells is the carbon dioxide electrolysis cell.

In one embodiment, each of the carbon dioxide electrolysis cells is the carbon dioxide electrolysis cell as defined in any one of claims 1 to 7.

In one embodiment, at least two adjacent carbon dioxide electrolytic cells share a first plate of one carbon dioxide electrolytic cell and a second plate of the other carbon dioxide electrolytic cell, and one surface of the shared plate is provided with the first grooves, and the other surface of the shared plate is provided with the second grooves.

Compared with the prior art, the invention at least comprises the following beneficial effects:

on one hand, the carbon dioxide electrolytic cell provided by the invention has the advantages that the cathode electrolyte chamber is introduced into one side of the cathode on the basis of the two-chamber configuration, so that the carbon dioxide electrolytic cell forms a three-chamber structure of a carbon dioxide gas chamber, the cathode electrolyte chamber and an anode electrolyte chamber, the cathode electrolyte is positioned between the diaphragm and the cathode electrode and serves as a buffer layer, and the diaphragm is prevented from being directly contacted with the cathode electrode, so that the diaphragm can adopt an anion exchange membrane and also can use a cation exchange membrane, and compared with the anion exchange membrane, the cation exchange membrane can ensure the long-term stable operation of the electrolytic cell, and the operation life of the electrolytic cell is obviously prolonged; on the other hand, the grooves are arranged on the first polar plate, the second polar plate and the liquid flow plate to form a multi-channel flow channel, and the multi-channel flow channel regulates and controls the fluid resistance pressure drop in the flow channel and the resistance pressure drop in the current-limiting channel, so that the mass transfer rate is improved, the energy consumption is reduced, the reaction performance is not damaged in the process of amplifying the area of the reaction electrode, and the electrolysis efficiency of the electrolytic cell is improved.

The carbon dioxide electrolytic cell provided by the invention can realize the series connection of a plurality of electrolytic cells to form a carbon dioxide electrolytic galvanic pile device, efficiently enlarges the area of the reaction electrode, and even enlarges the total electrode area to 0.3m²And above, the electrolytic power can reach more than 1kW, and the reaction scale close to the industrial level and the stable operation time are realized.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 is a schematic diagram of a carbon dioxide electrolysis cell according to one embodiment;

FIG. 2 is a schematic structural diagram of a first plate according to an embodiment;

FIG. 3 is a schematic structural diagram of a cathode electrode according to an embodiment;

FIG. 4a is a schematic diagram of a schematic plan view of one embodiment of a fluid flow plate;

FIG. 4b is a schematic cross-sectional view of one embodiment of a fluid flow plate;

FIG. 5 is a schematic structural diagram of a second plate according to an embodiment;

FIG. 6 is a schematic structural view of a carbon dioxide electrolysis cell stack apparatus according to an embodiment;

FIG. 7 is a schematic view of a carbon dioxide electrolysis cell stack device according to still another embodiment

Description of reference numerals:

100. a carbon dioxide electrolysis cell;

110. a first electrode plate; 120. a cathode electrode; 121. a gas diffusion layer; 122. a cathode catalyst layer; 130. A liquid flow plate; 140. a diaphragm; 150. an anode electrode; 160. a second polar plate;

200. a fixing plate;

300. screwing a fastener;

l1, anolyte distribution tube;

m1, an anolyte collecting tube;

l2, catholyte distribution tube;

m2, an anolyte collecting tube;

l3, gas distribution tube;

m3, gas gathering pipe.

Detailed Description

Reference will now be made in detail to embodiments of the invention, one or more examples of which are described below. Each example is provided by way of explanation, not limitation, of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment, can be used on another embodiment to yield a still further embodiment.

It is therefore intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. Other objects, features and aspects of the present invention are disclosed in or are apparent from the following detailed description. It is to be understood by one of ordinary skill in the art that the present discussion is a description of exemplary embodiments only, and is not intended as limiting the broader aspects of the present invention.

Other than as shown in the operating examples, or where otherwise indicated, all numbers expressing quantities of ingredients, physical and chemical properties, and so forth used in the specification and claims are to be understood as being modified in all instances by the term "about". For example, unless indicated to the contrary, the numerical parameters set forth in the foregoing specification and attached claims are approximations that can be suitably varied by those skilled in the art in seeking to obtain the desired properties utilizing the teachings disclosed herein. The use of numerical ranges by endpoints includes all numbers within that range and any range within that range, for example, 1 to 5 includes 1, 1.1, 1.3, 1.5, 2, 2.75, 3, 3.80, 4, and 5, and the like.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Referring to fig. 1, an embodiment of the invention provides a carbon dioxide electrolytic cell 100, which includes a first plate 110, a cathode 120, a flow plate 130, a diaphragm 140, an anode 150, and a second plate 160.

A surface of the first plate 110 facing the cathode electrode 120 is provided with a first groove a. Referring to fig. 2, the first groove a extends to form a flow channel having a plurality of channels. The flow channels may be serpentine, parallel or interdigitated, and in the specific example shown in fig. 2, the flow channels are serpentine.

In some preferred embodiments, the flow channel is a multi-channel serpentine flow channel, the number of the channels is 3 to 8, the width of a single channel is 0.5 to 5mm, and the depth is 0.1 to 3 mm. The design of the channel can control the ratio of the fluid resistance pressure drop in the flow channel to the resistance pressure drop in the flow limiting channel to be 10-100, can control the operating pressure of the fluid in a better range, further improves the mass transfer rate, reduces the energy consumption and improves the electrolysis efficiency of the electrolytic cell.

The material of the first electrode plate 110 may be independently selected from chemically stable conductive materials (e.g., aluminum, titanium, stainless steel, or graphite), so that the first electrode plate 110 may serve as a current collector. In some embodiments, the first electrode plate 110 is further provided with a current collecting connector, and the current collecting connector is communicated with an external circuit.

The cathode 120 is disposed on one side of the first plate 110, and the cathode 120 and the first plate 110 form a carbon dioxide gas chamber through which carbon dioxide gas can flow. A gas inlet (not shown) and a gas outlet (not shown) are connected to the first electrode plate 110, and carbon dioxide gas or a gas containing carbon dioxide is introduced and discharged by a flow controller (not shown) through the gas inlet and the gas outlet. Carbon dioxide gas or a gas containing carbon dioxide is circulated in the carbon dioxide gas chamber so as to contact the cathode electrode 120.

Generated at the cathode electrode 120 is carbon dioxide (CO)₂) To formic acid (HCOOH), carbon monoxide (CO) and methane (CH)₄) Acetic acid (CH)₃COOH), ethylene (C)₂H₄) Methanol (CH)₃OH), ethanol (C)₂H₅OH), n-propanol (C)₃H₇OH), and the like.

Referring to fig. 3, in some embodiments, the cathode electrode 120 has a gas diffusion layer 121 and a cathode catalyst layer 122 disposed on the gas diffusion layer 121. As shown in fig. 3, the gas diffusion layer 121 is disposed on the carbon dioxide gas flow path side, and is provided on the side facing the first electrode plate 110 in the carbon dioxide electrolytic cell. The cathode catalyst layer 122 is disposed on the cathode solution flow path side, and is provided on the side facing the flow plate 130 in the carbon dioxide electrolysis cell. Preferably, the cathode catalyst layer 122 has catalyst nanoparticles and catalyst nanostructures. The gas diffusion layer 111 is made of a porous carbon substrate such as carbon paper or carbon cloth, a metal mesh, a metal foam, a porous film, or the like.

In the cathode catalyst layer 122, catholyte, ions are supplied and discharged from the catholyte chamber, and in the gas diffusion layer 121, CO₂The gas is supplied from a carbon dioxide gas chamber. The gas diffusion layer 121 is a hydrophobic and gas permeable porous structure to ensure CO₂The gas may reach the cathode catalyst layer 122 through the gas diffusion layer 121. CO 2₂The reduction reaction of (a) occurs in the vicinity of the boundary between the gas diffusion layer 121 and the cathode catalyst layer 122, the gas-phase product is mainly discharged from the carbon dioxide gas chamber, and the liquid-phase product is mainly discharged from the catholyte chamber.

The cathode catalyst layer 122 is preferably made of a catalytic material (cathode catalytic material) that is capable of reducing carbon dioxide to produce a specific carbon-containing compound, and has a low overpotential and a high selectivity. As such a material, one or more of a carbon material, a transition metal material, a composite material of carbon and a transition metal oxide, an alloy of a noble metal and a transition metal, and a composite material of a noble metal and a transition metal oxide may be cited, wherein the transition metal may be selected from one or more of copper, tin, bismuth, lead, indium, cadmium, zinc, and nickel, and the noble metal may be selected from one or more of gold, silver, and a platinum group metal. The preparation method of the composite material can be one or more of electrodeposition, physical mixing, a hydrothermal method, a pyrolysis method, a ball milling method and a vapor deposition method. In the composite material, the mass percentage of the transition metal or the transition metal oxide can be 30-100%, and the mass percentage of the noble metal or the carbon is not more than 70%. The cathode catalyst layer 122 may be applied in various shapes such as a plate shape, a mesh shape, a line shape, a particle shape, a porous shape, a film shape, and an island shape.

A flow plate 130 is disposed on a side of the cathode electrode 120 facing away from the first plate 110. Referring to fig. 4a and 4b, a hollow hole c is formed on the flow plate 130 for the catholyte to pass through. The plurality of pore channels c extend to form a flow channel, similarly, the flow channel can also be a snake-shaped flow channel, a parallel flow channel or a cross comb-shaped flow channel, preferably a multi-channel snake-shaped flow channel, the number of the channels is 3-8, the width of a single channel is 0.5-5 mm, and the depth is 0.1-10 mm. The multi-channel snake-shaped flow channel is arranged on the liquid flow plate, so that the operating pressure of the fluid can be further reduced, the mass transfer rate is improved, the energy consumption is reduced, and the electrolysis efficiency of the electrolytic cell is improved. Note that the width of the hole c is the width of a single channel, and the depth of the hole c is the depth of a single channel. In some embodiments, a plurality of connecting ribs d are further disposed in the channel c of the flow plate 130, the connecting ribs d are disposed between two panels forming the channel c to enhance the mechanical strength of the flow channel, and the thickness of the connecting ribs d is 0.1mm to 8 mm.

The material of the flow plate 130 may be independently selected from chemically stable insulating materials, preferably an insulating resin material having high chemical stability and high mechanical strength, such as Polyetheretherketone (PEEK), chlorinated polyvinyl chloride (cpvc), and ABS plastic. .

The membrane 140 is disposed on a side of the flow plate 130 facing away from the cathode electrode 120. A catholyte chamber is formed between the membrane 140 and the cathode electrode 120, through which a catholyte may flow. The catholyte chamber is disposed between the cathode electrode 120 and the membrane 140 such that the catholyte is in contact with the cathode electrode 120 and the membrane 140. A catholyte introduction port (not shown) and a catholyte discharge port (not shown) are connected to the flow plate 130, through which the catholyte is introduced and discharged by a pump (not shown). The catholyte flows through the catholyte flow path (catholyte chamber) so as to contact the cathode 120 and the separator 140.

The diaphragm 140 is composed of an ion exchange membrane or the like that can move ions between the anode electrode 150 and the cathode electrode 120 and can separate the anode and the cathode of the electrolytic cell. As the ion exchange membrane, for example, cation exchange membranes such as Nafion and Flemion, and anion exchange membranes such as Neosepta and Selemion can be used. Preferably, the separator 140 is composed of a cation exchange membrane. However, in addition to the ion exchange membrane, a glass filter, a porous polymer membrane, a porous insulating material, or the like may be applied to the separator 140 as long as ions can be transferred between the anode 150 and the cathode 120.

An anode electrode 150 is disposed on a side of the membrane 140 facing away from the fluid flow plate 130. The anode electrode 150 is capable of reacting with water (H)₂O) to generate oxygen, hydrogen ions or to be able to react with hydroxyl ions (OH)^-) The catalyst is preferably mainly composed of a catalyst material (anode catalyst material) capable of reducing overvoltage of such a reaction to generate water and oxygen by oxidation. Examples of such a catalytic material include metals such as platinum (Pt), palladium (Pd) and nickel (Ni), alloys containing these metals, intermetallic compounds, binary metal oxides such as manganese oxide (Mn-O), iridium oxide (Ir-O), nickel oxide (Ni-O), cobalt oxide (Co-O), iron oxide (Fe-O), tin oxide (Sn-O), indium oxide (In-O), ruthenium oxide (Ru-O), lithium oxide (Li-O) and lanthanum oxide (La-O), Ni-Co-O, Ni-Fe-O, La-CTernary metal oxides such as O-O, Ni-La-O, Sr-Fe-O, quaternary metal oxides such as Pb-Ru-Ir-O, La-Sr-Co-O, Ru complexes, Fe complexes, and the like.

The anode 150 has a structure capable of moving the anolyte and ions between the separator and the anolyte chamber, and includes a base material having a porous structure such as a mesh material, a punched material, a porous body, and a metal fiber sintered body. The substrate may be made of a metal material such as a metal such as titanium (Ti), nickel (Ni), or iron (Fe), an alloy containing at least 1 of these metals (for example, stainless steel), or the anode catalytic material described above. When an oxide is used as the anode catalyst material, the anode catalyst material is preferably attached to or laminated on the surface of the substrate made of the metal material to form a catalyst layer. In terms of improving the oxidation reaction, the anode catalytic material preferably has nanoparticles, nanostructures, nanowires, or the like. The nanostructure is a structure in which nano-scale irregularities are formed on the surface of the catalyst material.

The second plate 160 is disposed on a side of the anode electrode 150 facing away from the separator 140. An anolyte chamber is formed between the second plate 160 and the diaphragm 140 in which anolyte may be circulated. The anolyte chamber is used to supply an anolyte to the anode electrode 150, and the second plate is provided with an anolyte introduction port (not shown) and an anolyte discharge port (not shown) through which the anolyte is introduced and discharged by a pump (not shown). The anolyte is circulated within the anolyte chamber in contact with the second plate 160.

Referring to fig. 5, a second groove b is formed on a surface of the second plate 160 facing the anode electrode 150. The second grooves b extend to form a flow channel with a plurality of channels, the flow channel formed by the second grooves b can also be a serpentine flow channel, a parallel flow channel or an interdigitated flow channel, and fig. 5 shows the serpentine flow channel.

The material of the second plate 160 can be independently selected from chemically stable conductive materials (such as aluminum, titanium, stainless steel, or graphite), so as to ensure that the second plate 160 can serve as a current collector. In some embodiments, the second plate 160 is further provided with a current collecting connector, and the current collecting connector is communicated with an external circuit.

As the anolyte and the catholyte of the carbon dioxide electrolysis cell of the present invention, it is preferable to contain at least water (H)₂O) solution. Carbon dioxide (CO)₂) Is derived from CO₂The gas chamber is supplied so that the catholyte may contain carbon dioxide (CO)₂) Or may not be contained. The anolyte and catholyte may be used in the same solution or in different solutions. As an anolyte and catholyte comprising H₂Examples of the solution of O include aqueous solutions containing any electrolyte. Examples of the aqueous solution containing an electrolyte include solutions containing hydroxide ions (OH) selected from the group consisting of^-) Hydrogen ion (H)⁺) Potassium ion (K)⁺) Sodium ion (Na)⁺) Lithium ion (Li)⁺) Cesium ion (Cs)⁺) Chloride ion (Cl)^-) Bromine ion (Br)^-) Iodide ion (I)^-) Nitrate ion (NO)₃ ^-) Sulfate ion (SO)₄ ^2-) Formate ion (HCOO)^-) Phosphate radical ion (PO)₄ ^3-) Borate ion (BO)₃ ^3-) And bicarbonate ion (HCO)₃ ^-) An aqueous solution of at least 1 kind of ion of (1). In order to reduce the resistance of the solution, it is preferable to use a solution in which an electrolyte such as potassium hydroxide, sodium hydroxide, or potassium hydrogen carbonate is dissolved at a high concentration as the anolyte and the catholyte.

The catholyte may also be formed of BF and cations such as imidazolium ions and pyridinium ions₄ ^-、PF₆ ^-The salt of the anion may be an ionic liquid or an aqueous solution thereof which is in a liquid state over a wide temperature range. Examples of the other catholyte include amine solutions such as ethanolamine, imidazole, and pyridine, and aqueous solutions thereof. The amine may be any of primary, secondary and tertiary amines.

In some embodiments, the carbon dioxide electrolysis cell further comprises a flow restricting passage (not shown in the figures). The restricted flow path includes a pipe for transferring the anolyte from the outside to the second plate 160, a pipe for transferring the gas from the outside to the first plate 120, and a pipe for transferring the catholyte from the outside to the flow plate 130, and each section of the pipes has a length of 5cm to 50 cm.

Further, the invention also provides a carbon dioxide electrolysis galvanic pile device, which comprises a plurality of carbon dioxide electrolysis cells, wherein the plurality of carbon dioxide electrolysis cells are stacked in series, and at least one carbon dioxide electrolysis cell is the carbon dioxide electrolysis cell 100 in any embodiment.

Referring to fig. 6, in some embodiments, each carbon dioxide cell in the carbon dioxide electrolyzer unit is the carbon dioxide cell 100 described above. Two adjacent carbon dioxide electrolytic cells 100, wherein the first polar plate 110 of one carbon dioxide electrolytic cell 100 and the second polar plate 160 of the other carbon dioxide electrolytic cell 100 are shared, one surface of the shared polar plate is provided with a first groove a, and the other surface is provided with the second groove b.

In order to ensure good sealing performance of the carbon dioxide electrolysis cell stack device, in some embodiments, the first electrode plate 110, the flow plate 130 and the second electrode plate 160 are provided with positioning holes. Preferably, the number of fixing holes on each plate is 4, and more preferably, the fixing holes are evenly distributed around the plate. The positioning holes on the first plate 110, the flow plate 130 and the second plate 160 are in one-to-one correspondence.

Further, in some embodiments, the carbon dioxide electrolysis cell stack apparatus is further provided with a fixing assembly including two fixing plates 200 and a plurality of threaded fasteners 300. Regarding a plurality of carbon dioxide electrolysis cells stacked in series as a whole, as a device to be fixed, two fixing plates are respectively disposed on two opposite sides of the device to be fixed, and fixing holes are disposed on the fixing plate 200. Preferably, the number of the fixing holes on the fixing plate is 8, and more preferably, the fixing holes are uniformly distributed around the fixing plate. The fixing holes on the two fixing plates are respectively in one-to-one correspondence.

In some preferred embodiments, threaded fastener 300 is a spring screw fastener, including a threaded rod, a nut, and a coil spring. The sealing of the carbon dioxide electrolysis galvanic pile is realized by adopting the spring screw fastener, the problem of expansion with heat and contraction with cold when the carbon dioxide electrolysis galvanic pile operates at different temperatures can be solved, the device is prevented from being damaged, and the operation stability and the service life of the device are improved.

To further ensure the sealing performance of the carbon dioxide electrolysis cell stack, in some embodiments, a sealing assembly is further disposed between the first plate 110 and the flow plate 130, and/or between the second plate 160 and the flow plate 130, and/or between the flow plate 130 and the membrane 140.

In some embodiments, the seal assembly includes a seal ring disposed about a periphery of the desired sealing component and a gasket disposed between the seal ring and the desired sealing component.

Further, referring to fig. 7, the carbon dioxide electrolysis cell stack apparatus of the present invention further includes:

a power supply (not shown in the figure) that causes an electric current to flow between the anode portion and the cathode portion of each electrolytic cell of the carbon dioxide electrolysis cell stack;

a solution system for controlling the flow of a solution through the device; and

and the gas system is used for controlling the circulation of gas in the device.

The power supply is not limited to a general commercial power supply, a battery, or the like, and may be a power supply that supplies electric power generated by renewable energy sources such as a solar battery or wind power generation.

The solution system comprises a 1 st solution system which is connected with the anolyte chamber and is provided with a pressure control part, an anolyte distributing pipe L1, a flow control part (pump) and an anolyte gathering pipe M1; and

a 2 nd solution system having a pressure control part, a catholyte distribution pipe L2, a flow control part (pump), and an anolyte convergence pipe M2 connected to the catholyte chamber.

The gas system includes a pressure control unit connected to the carbon dioxide gas chamber, a temperature adjustment unit, a gas distribution pipe L3, a flow control unit (flow controller), and a gas collecting pipe M3.

The solution flow rates and pressures of the anolyte and catholyte solutions are controlled by the solution system. The solution flow rates of the anolyte and catholyte were controlled at about 100mL/min and the pressure was controlled at 1bar to 5 bar. The carbon dioxide electrolysis electric pile device provided by the invention controls the ratio of the resistance pressure drop of the fluid in the flow channel to the resistance pressure drop in the flow limiting channel to be 10-100, wherein the ratio is higher than 10, so that the fluid can be uniformly distributed in each electrolytic cell, and the power consumption of a pump can be reduced and the energy efficiency can be improved when the ratio is lower than 100.

In a carbon dioxide electrolyser, the restricted flow paths include the line from anolyte distribution tube L1 to second plate 160, the line from gas distribution tube L31 to first plate 110, and the line from catholyte distribution tube L2 to flow plate 130.

The flow rate, pressure and temperature of the gas are controlled by the gas system. The gas flow rate is controlled to be 100-500 sccm (single electrolytic cell). If it is less than 100sccm, sufficient CO cannot be supplied₂Participating in the reaction; above 500sccm, the energy efficiency of the reaction is significantly reduced. The gas pressure was controlled at slightly above atmospheric pressure. The gas temperature is controlled between 0 ℃ and 100 ℃.

The following are specific examples. The present invention is intended to be further described in detail to assist those skilled in the art and researchers to further understand the present invention, and the technical conditions and the like do not limit the present invention. Any modification made within the scope of the claims of the present invention is within the scope of the claims of the present invention.

Example 1

The carbon dioxide electrolytic cell shown in fig. 7, a solution system and a gas system were connected and assembled to constitute an electrolytic cell stack device, and the carbon dioxide electrolysis performance was tested. The carbon dioxide electrolysis cell stack comprises 30 electrolytic cells, wherein a tin dioxide-loaded gas diffusion electrode (SiGeli Signal 39BC) is used as a cathode electrode, iridium dioxide-loaded titanium foam (0.8mm in thickness and 50 microns in pore diameter) is used as an anode electrode, DuPont Nafion 211 is used as an ion exchange membrane, and a potassium bicarbonate solution (with the concentration of 1mol/L) is used as an electrolyte. The polar plate is made of titanium, the liquid flow plate is made of chlorinated polyvinyl chloride resin, and a flow channel formed by the polar plate and the grooves in the liquid flow plate is a snake-shaped flow channel (shown in the figure).

In this electrolytic apparatus, the 1 st solution system including a pressure control unit (not shown), an anolyte distribution pipe L1, a flow control unit (pump), and an anolyte collecting pipe M1 is connected to the anolyte flow path.

The catholyte flow path is connected to a 2 nd solution system having a pressure control unit (not shown), a catholyte distribution line L2, a flow control unit (not shown), and an anolyte collecting line M2.

A pressure control unit (not shown), a temperature adjustment unit (not shown), a gas distribution pipe L3, a flow rate control unit (not shown), and a gas collecting pipe M3 are connected to the carbon dioxide gas flow path.

The humidified carbon dioxide raw material gas is divided into 30 air flows with the same flow velocity after passing through a gas distribution pipe L3, the air flows respectively flow into serpentine flow channels on the cathode side of the bipolar plates of 30 single electrolytic cells, then the air flows pass through a gas diffusion electrode and reach the surface of a cathode catalyst, the air is reduced into formate after rapid electron transfer occurs, and unreacted carbon dioxide flows out of the bipolar plates. The generated formate enters a liquid flow plate, flows out along with the electrolyte through a flow channel, is converged in an electrolyte converging pipe and then flows out of the galvanic pile, and a subsequent product separation process can be carried out. The gas flow rate in the cathode plate is controlled at 500sccm (single electrolytic cell) by a flow controller, the gas pressure is controlled at a little higher than normal pressure by a backpressure controller, and the gas temperature is controlled at 0 ℃ to 100 ℃.

The anolyte then flows through anolyte distribution pipe L1, and after dividing into 30 branches with the same flow rate, it flows into the serpentine flow channels on the anode side of bipolar plates of 30 single cells, and then reaches the anode catalyst surface through the pore channels of the foam electrode (anode electrode). The electrolyte is oxidized on the surface of the catalyst to generate oxygen, generated bubbles flow out of the polar plate along with the flowing electrolyte, flow out of the electric pile after being converged in the liquid converging pipe, and the generated oxygen can be discharged and then circularly flows into the electrolysis device again to participate in the reaction. The anolyte is delivered by a peristaltic pump and the flow rate of the single electrolytic cell is controlled at about 100mL/min, and the liquid pressure is controlled at 1bar to 5bar by a backpressure controller.

In the above electrolyzer, the ratio of the fluid resistance pressure drop in the serpentine flow channel to the resistance pressure drop in the restricted flow channel is controlled to be about 100.

The carbon dioxide electrolysis electric pile device has a total current of 10A (current density of 100 mA/cm)²) Under the condition (2), the total voltage of the electrolysis cell stack is 102.7V. The corresponding total power is 1027W, the power is always kept between 1020W and 1030W within 300 hours of operation time, the energy efficiency reaches 53 percent, and excellent performance is shown.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, so as to understand the technical solutions of the present invention specifically and in detail, but not to be understood as the limitation of the protection scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. It should be understood that the technical solutions provided by the present invention, which are obtained by logical analysis, reasoning or limited experiments, are within the scope of the appended claims. Therefore, the protection scope of the patent of the present invention shall be subject to the content of the appended claims, and the description and the attached drawings can be used for explaining the content of the claims.

Claims

1. A carbon dioxide electrolysis cell, comprising:

a first electrode plate;

the first electrode plate is provided with a first groove on one surface facing the cathode electrode, the second electrode plate is provided with a second groove on one surface facing the anode electrode, the first groove and/or the second groove extend to form a flow channel, and the flow channel is a multi-channel flow channel.

2. The carbon dioxide electrolysis cell according to claim 1, wherein the flow channel is a multi-channel serpentine flow channel, the number of the channels is 3 to 8, the width of a single channel is 0.5 to 5mm, and the depth is 0.1 to 3 mm.

3. The carbon dioxide electrolysis cell according to claim 1, wherein the anode electrode is a porous material formed of an anode catalyst or is composed of a porous substrate and an anode catalyst layer provided on a surface of the porous substrate.

4. The carbon dioxide electrolysis cell according to claim 1, wherein the cathode electrode comprises a gas diffusion layer and a cathode catalyst layer arranged in a stacked arrangement, the gas diffusion layer being arranged towards the first plate side and the cathode catalyst layer being arranged towards the flow plate side.

5. The carbon dioxide electrolysis cell according to claim 1, wherein the diaphragm is an anion exchange membrane or a cation exchange membrane.

6. A carbon dioxide electrolysis cell according to any one of claims 1 to 5, wherein the first plate and the second plate are both made of conductive materials, and are independently selected from one or more of aluminum, titanium, stainless steel and graphite, and/or the flow plate is made of insulating resin.

7. A carbon dioxide electrolysis cell according to any one of claims 1 to 5, further comprising a restricted flow passage comprising a conduit for transporting anolyte from the outside to the second plate, a conduit for transporting gas from the outside to the first plate, and a conduit for transporting catholyte from the outside to the flow plate, each length of conduit being in the range of 5cm to 50 cm.

8. A carbon dioxide electrolysis galvanic pile device, which is characterized by comprising a plurality of carbon dioxide electrolysis cells, wherein the plurality of carbon dioxide electrolysis cells are stacked in series, and at least one carbon dioxide electrolysis cell is the carbon dioxide electrolysis cell according to any one of claims 1 to 7.

9. The carbon dioxide electrolysis cell stack apparatus according to claim 8, wherein each of the carbon dioxide electrolysis cells is the carbon dioxide electrolysis cell according to any one of claims 1 to 7.

10. The carbon dioxide electrolysis cell stack apparatus according to claim 8 or 9, wherein at least two adjacent carbon dioxide electrolysis cells share a first plate of one of the carbon dioxide electrolysis cells and a second plate of the other carbon dioxide electrolysis cell, and one surface of the shared plate is provided with the first grooves and the other surface is provided with the second grooves.