Electroswing adsorption cell with patterned electrodes for gas component separation.

Abstract

The present disclosure relates to a system and an electroswing adsorption cell having a patterned electrode. The patterned electrode includes a plurality of electrolyte regions, a plurality of gas regions, and a conductive scaffold. The conductive scaffold spans the plurality of electrolyte regions and contains electroactive species. Methods for fabricating the electrode, the electroswing adsorption cell, and a gas separation system including the electroswing adsorption cell are also described.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Patent Application No. 63 / 037,829, filed June 11, 2020, and U.S. Provisional Patent Application No. 63 / 128,358, filed December 21, 2020, the contents of both of which are incorporated by reference herein in their entireties. [Background technology]

[0002] The removal of target species from gas mixtures has been the subject of much research and development. For example, efforts are being made to mitigate global warming by curbing carbon dioxide emissions. To achieve this goal, several approaches have been explored, including traditional thermal methods, to capture carbon dioxide at different stages of its production. Other potential applications of target gas removal include the direct removal of target gases from air or ventilated air.

[0003] Electroswing adsorption (ESA) is an alternative method for capturing target gases from gas mixtures. While ESA is an effective process for removing target species from gas streams, the efficiency and productivity of this process can be limited by the speed at which gas species can diffuse to the sorbent electrode. In other words, the diffusion time constant of gas species to the electrode can be a limiting factor in ESA methods. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] US Patent Application Publication No. 2004 / 977797 [Patent Document 2] US Patent Application Publication No. 2007 / 0298267 [Patent Document 3] US Patent Application Publication No. 2002 / 0197519 [Patent Document 4] U.S. Patent No. 6,099,984 [Patent Document 5] US Patent Application Publication No. 2004 / 0209150 [Patent Document 6] US Patent Application Publication No. 2003 / 0203260 [Patent Document 7] US Patent Application Publication No. 2003 / 0022052 [Patent Document 8] US Patent Application Publication No. 2004 / 0151975 [Patent Document 9] US Patent Application Publication No. 2002 / 0081477 [Patent Document 10] U.S. Patent No. 6,309,773 [Patent Document 11] U.S. Patent No. 6,756,149 [Patent Document 12] U.S. Patent No. 6,159,629 [Patent Document 13] U.S. Patent No. 6,174,616 [Patent Document 14] U.S. Patent No. 5,486,430 [Patent Document 15] U.S. Patent No. 5,776,625 [Patent Document 16] U.S. Patent No. 6,017,648 [Patent Document 17] U.S. Patent No. 6,440,597 [Patent Document 18] US Patent Application Publication No. 2006 / 0073385 [Patent Document 19] US Patent Application Publication No. 2003 / 0031914 [Patent Document 20] US Patent Application Publication No. 2003 / 0072988 [Patent Document 21] US Patent Application Publication No. 2007 / 0231619 [Patent Document 22] US Patent Application Publication No. 2007 / 0042254 [Patent Document 23] US Patent Application Publication No. 2002 / 0172852 [Patent Document 24] U.S. Patent No. 6,261,711 [Patent Document 25] U.S. Patent No. 6,190,793 [Non-patent literature]

[0005] [Non-Patent Document 1] Ying Hou and Ruth E. Baltus, Ind, Eng, Chem, Res. 2007 Volume 46, No. 24, pages 8166-8175, "Experimental Measurement of the solubility and diffusivity of CO2 in room-temperature ionic liquids using a transient thin-liquid-film method" [Non-patent document 2] Javid Safarov, Rena Hamidova, Martin Stephan, Norbert Schmotz, Ismail Kul, Astan Shahverdiyev, and Egon Hassel, J Chem Therm 2013 Vol. 67, pp. 181-189, "Carbon dioxide solubility in 1-butyl-3-methylimidazolium-bis(trifluormethylsulfonyl)imide over a wide range of temperatures and pressures" Summary of the Invention [Problem to be solved by the invention]

[0006] Thus, there remains a need in the art for improved systems and electroswing adsorption cells for separating gas components. It would be particularly advantageous to provide an electroswing adsorption cell with patterned electrodes to address the technical limitations of the existing technology described above. [Means for solving the problem]

[0007] Provided herein is a patterned electrode for an electroswing adsorption cell, the patterned electrode comprising a plurality of electrolyte regions, a plurality of gas regions, and a conductive backbone, the conductive backbone spanning the plurality of electrolyte regions and comprising electroactive species capable of binding to a target gas when the electroactive species is in a reduced state and capable of releasing the target gas when the electroactive species is in an oxidized state.

[0008] An electroswing adsorption cell is also provided that includes a patterned electrode, a second electrode that includes a supplemental electroactive composite layer, and a separator between the patterned electrode and the second electrode.

[0009] A method for fabricating an electroswing adsorption cell includes depositing a composite material on a separator, the composite material comprising a conductive scaffold coated with an electrolyte and an electroactive species, and forming a patterned electrode comprising a plurality of electrolyte regions and a plurality of gas regions, wherein forming the patterned electrode is by machining, lithography, etching, self-assembly, porogen removal, or a combination thereof.

[0010] A method for fabricating an electroswing adsorption cell includes depositing a composite material on a separator, the composite material including a conductive scaffold coated with an electrolyte and an electroactive species, forming a patterned first electrode including a plurality of electrolyte regions and a plurality of gas regions, and bonding a gas flow field and a second electrode to the patterned first electrode to obtain an electroswing adsorption cell.

[0011] A method of fabricating an electroswing adsorption cell includes providing a composite layer comprising a conductive scaffold coated with an electrolyte and a first electroactive species, providing a second conductive scaffold comprising gas-filled pores, pleating the composite layer with the second composite layer to obtain a patterned first electrode, and bonding a gas flow field and a second electrode to the patterned first electrode to obtain an electroswing adsorption cell.

[0012] The gas separation system includes a plurality of electroswing adsorption cells in fluid communication with a gas inlet and a gas outlet, each of the plurality of electroswing adsorption cells according to the present disclosure.

[0013] The above-described features and other features are exemplified by the following figures and detailed description. [Brief explanation of the drawings]

[0014] [Figure 1A] FIG. 1 is a schematic diagram of an asymmetric electrochemical swing adsorption cell with patterned electrodes. [Figure 1B] FIG. 1 is a schematic diagram of a symmetric electrochemical swing adsorption cell with patterned electrodes. [Figure 2A] 1 is a schematic diagram of an electrochemical swing adsorption cell with patterned electrodes. [Figure 2B] 1 is a schematic representation of a particle comprising a conductive skeleton. [Figure 2C] 2 is a schematic diagram of particles of a conductive scaffold 220 including small particles 224 disposed on larger fibers 222. FIG. [Figure 2D] 1 is a schematic diagram of a gas flow field. [Figure 2E] 1 is a schematic diagram of a gas flow field. [Figure 3] FIG. 1 is a side view of an electrochemical swing adsorption cell with patterned electrodes. [Figure 4] FIG. 2 is a front view of a patterned electrode. [Figure 5] FIG. 1 is a side view of an electrochemical swing adsorption cell with patterned electrodes. [Figure 6] FIG. 2 is a side view of a patterned electrode. [Figure 7] FIG. 1 is a side view of an electrochemical swing adsorption cell with patterned electrodes. [Figure 8] FIG. 2 is a front view of a patterned electrode. [Figure 9] FIG. 1 is a side view of an electrochemical swing adsorption cell with patterned electrodes. [Figure 10] FIG. 2 is a front view of a patterned electrode. [Figure 11] FIG. 1 is a perspective view of an electrochemical swing adsorption cell. [Figure 12] FIG. 1 is a side view of an electrochemical swing adsorption cell with patterned electrodes. [Figure 13] FIG. 1 is a side view of an electrochemical swing adsorption cell with a patterned electrode-separator assembly. [Figure 14] A method for forming an electrochemical swing adsorption cell is presented. [Figure 15] A method for forming an electrochemical swing adsorption cell is presented. [Figure 16] A method for forming an electrochemical swing adsorption cell is presented. [Figure 17] A method for forming an electrochemical swing adsorption cell is presented. [Figure 18] 1 shows simulated concentrations of Lewis acid gases in an electrochemical swing adsorption cell. [Figure 19] 1 shows simulated flow onto a patterned electrode at different electrode thicknesses (millimeters, mm), air flow rates, and gas region thicknesses. [Figure 20] 1 shows chemical schemes for the synthesis of polymeric ionic liquids according to synthesis examples 1 and 2. [Figure 21] 10 shows graphs of pressure drop and cell voltage versus time illustrating CO 2 capture of 10% CO 2 in N 2 in an electroswing adsorption cell according to Example 3. DETAILED DESCRIPTION OF THE INVENTION

[0015] A system and electroswing adsorption cell with patterned electrodes for the separation of gas components is described herein. Systems using the electroswing adsorption (ESA) process offer several potential advantages. ESA systems can remove carbon dioxide or other Lewis acids from air and deposit it at a different location (e.g., a greenhouse). ESA involves the application of a first potential (e.g., a cathodic potential) to an electroactive species (denoted below as "P"), resulting in the reduction of the electroactive species P. The reduced electroactive species P - can combine with a Lewis acid gas G dissolved in the adjacent electrolyte solution. + ”) is incorporated from the adjacent electrolyte solution to balance the charge of the electroactive species P.

[0016]

number

[0017] The ESA process can be reversed by application of a second potential (e.g., an anodic potential when the first potential is a cathodic potential). The interfacial contact area between the electroactive species P and the electrolyte can be increased by coating the electroactive species onto a porous, high-surface-area, electronically conductive scaffold (e.g., carbon fiber paper, carbon nanotube-coated carbon fiber). Examples of applications of ESA devices and methods for preparing same are described in U.S. Pat. No. 10,464,018, the entire disclosure of which is hereby incorporated by reference herein in its entirety for all purposes.

[0018] The pores of the electronically conductive framework can be filled with an electrolyte. The diffusion length L of the path that a Lewis acid gas G follows in an ESA cell to diffuse from the gas region through the electrolyte to the active site of an electroactive species P is D can affect the diffusion time constant of the Lewis acid gas G. In addition, the length L Iis the transport of cations C from the separator to the active sites of electroactive species P in the ESA cell. + is the migration distance. D A high L value can limit the diffusion rate of G and thereby the capture rate of the device. I The value can increase the internal resistance in the ESA cell.

[0019] In ESA configurations that include only electrolyte-filled regions in an electronically conductive framework, L D and L I are both equal to the thickness of the electrode material.

[0020] The amount of electroactive species P per unit area of ​​an electroswing adsorption cell is proportional to the thickness of the electrode material. The inventors unexpectedly discovered that by incorporating a gas-filled region into the electrode (e.g., by forming a patterned electrode), the gas-filled region can extend beyond the airflow field into the electrode material. In other words, L D can be measured from a point within the electrode (e.g., the distance between gas-filled regions) rather than from the interface between the gas flow field and the electrode. Gas diffusivity is higher through the gas phase than when the gas is dissolved in a liquid electrolyte. Therefore, it is advantageous for the Lewis acid gas G to travel as much as possible through the gas phase on its way to the active site of the electroactive species P. Incorporation of gas-filled regions into the electrode material therefore reduces L D This can effectively reduce the value of L I While maintaining or possibly increasing D Therefore, a shape that can reduce L is desirable. DReducing the diffusion time constant of the Lewis acid gas G can reduce the diffusion time constant of the Lewis acid gas G while increasing or maintaining the amount of electroactive species P per unit area of ​​the electroswing adsorption cell. In other words, modifying the physical structure of the electrode through which the gas species migrate can reduce the diffusion time constant of the gas species into the electrode. Reducing the diffusion time constant can improve the performance of the ESA system. Modifying the physical structure of the electrode can also increase the amount of electroactive species P per unit area of ​​the electroswing adsorption cell. A higher amount of electroactive species P per unit area can reduce the cost of implementing such an electroswing adsorption cell.

[0021] Thus, one aspect of the present disclosure is an electroswing adsorption cell including a first electrode comprising multiple electrolyte regions, multiple gas regions, and a conductive scaffold, where the conductive scaffold contains electroactive species extending into the multiple electrolyte regions. The electroswing adsorption cell of the present disclosure may also be referred to herein as an "electrochemical swing adsorption cell," an "electrochemical cell," or a "cell." For brevity, the first electrode comprising multiple electrolyte regions, multiple gas regions, and a conductive scaffold may also be referred to as a "patterned first electrode." The term "patterned," as used herein, may refer to a regular or irregular configuration of the gas regions of the electrode. The gas regions may be provided in an ordered, predictable, or regular configuration, or may be provided in an irregular, random, or unpredictable configuration. If the pattern is irregular, the first electrode may also be referred to as "heterogeneous," where the gas regions are unpredictably distributed throughout the electrode and can have any suitable size and shape. The arrangement and shape of the gas regions, and therefore the "pattern" of the first electrode, is described further herein.

[0022] The electroswing adsorption cell may further include a second electrode including a supplemental electroactive composite layer; and a separator between the patterned first electrode and the second electrode.

[0023] The patterned first electrode comprises a conductive scaffold and electroactive species. The conductive scaffold can comprise a carbonaceous material or a metal. In one embodiment, the conductive scaffold comprises a carbonaceous material. Exemplary carbonaceous materials can include, but are not limited to, carbon paper (treated, PTFE-treated, or untreated), carbon cloth, nonwoven carbon mats, carbon black, carbon fiber, carbon nanotubes (including multi-walled and single-walled carbon nanotubes), nonwoven carbon nanotube mats, graphite flakes, graphene, etc. (e.g., other nanostructured carbon materials), or combinations thereof.

[0024] In one aspect, the conductive scaffold can include a fibrous material, such as a fibrous carbonaceous material. When present, the fibers can have an ordered arrangement, such as in a woven material (e.g., the conductive scaffold can include fibers arranged parallel to each other along the x-axis, y-axis, or z-axis to form an ordered network). In one aspect, the fibers of the conductive scaffold can be dispersed throughout the patterned first electrode in a random configuration. In one aspect, the conductive scaffold can have an ordered arrangement in some portions of the patterned electrode and a random configuration in other portions of the patterned electrode.

[0025] In one embodiment, the conductive scaffold can comprise carbon fibers having an average diameter of 0.1 to 20 μm. Within this range, the average diameter can be at least 0.1 μm, at least 0.2 μm, at least 0.3 μm, at least 0.4 μm, at least 0.5 μm, at least 0.6 μm, at least 0.7 μm, at least 0.8 μm, at least 0.9 μm, at least 1 μm, at least 2 μm, at least 3 μm, at least 4 μm, at least 5 μm, at least 6 μm, at least 7 μm, at least 8 μm, at least 9 μm, at least 10 μm, at least 11 μm, at least 12 μm, at least 13 μm, at least 14 μm, at least 15 μm, at least 16 μm, at least 17 μm, at least 18 μm, or at least 19 μm. Also within this range, the average diameter can be 20 μm or less, 19 μm or less, 19 μm or less, 18 μm or less, 17 μm or less, 16 μm or less, 15 μm or less, 14 μm or less, 13 μm or less, 12 μm or less, 11 μm or less, 10 μm or less, 9 μm or less, 8 μm or less, 7 μm or less, 6 μm or less, 5 μm or less, 4 μm or less, 3 μm or less, 2 μm or less, 1 μm or less, 0.9 μm or less, 0.8 μm or less, 0.7 μm or less, 0.6 μm or less, 0.5 μm or less, 0.4 μm or less, 0.3 μm or less, or 0.2 μm or less. Combinations of the average diameters referenced above for carbon fiber are also possible.

[0026] In one embodiment, the conductive backbone can comprise carbon nanotubes having an average diameter of 0.4 to 40 nm. Within this range, the carbon nanotubes can have an average diameter of at least 0.4 nm, at least 0.5 nm, at least 0.6 nm, at least 0.7 nm, at least 0.8 nm, at least 0.9 nm, at least 1 nm, at least 2 nm, at least 3 nm, at least 4 nm, at least 5 nm, at least 6 nm, at least 7 nm, at least 8 nm, at least 9 nm, at least 10 nm, at least 15 nm, at least 20 nm, at least 25 nm, at least 30 nm, or at least 35 nm. Also within this range, the carbon nanotubes can have an average diameter of 40 nm or less, 35 nm or less, 30 nm or less, 25 nm or less, 20 nm or less, 15 nm or less, 10 nm or less, 9 nm or less, 8 nm or less, 7 nm or less, 6 nm or less, 5 nm or less, 4 nm or less, 3 nm or less, 2 nm or less, 1 nm or less, 0.9 nm or less, 0.8 nm or less, 0.7 nm or less, 0.6 nm or less, or 0.5 nm or less. Combinations of the average diameters referenced above for the carbon nanotubes are also possible.

[0027] In one embodiment, the conductive backbone can comprise carbon nanotubes having an average length of 1 μm to 1 mm. Within this range, the carbon nanotubes can have an average length of at least 1 μm, at least 2 μm, at least 3 μm, at least 4 μm, at least 5 μm, at least 6 μm, at least 7 μm, at least 8 μm, at least 9 μm, at least 10 μm, at least 20 μm, at least 30 μm, at least 40 μm, at least 50 μm, at least 60 μm, at least 70 μm, at least 80 μm, at least 90 μm, at least 100 μm, at least 200 μm, at least 300 μm, at least 400 μm, at least 500 μm, at least 600 μm, at least 700 μm, at least 800 μm, at least 900 μm, or at least 1 mm. Also within this range, the carbon nanotubes can have an average length of 1 mm or less, 900 μm or less, 800 μm or less, 700 μm or less, 600 μm or less, 500 μm or less, 400 μm or less, 300 μm or less, 200 μm or less, 100 μm or less, 90 μm or less, 80 μm or less, 70 μm or less, 60 μm or less, 50 μm or less, 40 μm or less, 30 μm or less, 20 μm or less, 10 μm or less, 9 μm or less, 8 μm or less, 7 μm or less, 6 μm or less, or 5 μm or less. Combinations of the average lengths referenced above for the carbon nanotubes are also possible.

[0028] In one embodiment, the conductive scaffold can comprise vapor-grown carbon fibers having an average diameter of 100 to 200 nm. Within this range, the vapor-grown carbon fibers can have an average diameter of at least 100 nm, at least 110 nm, at least 120 nm, at least 130 nm, at least 140 nm, at least 150 nm, at least 160 nm, at least 170 nm, at least 180 nm, or at least 190 nm. Also within this range, the vapor-grown carbon fibers can have an average diameter of 200 nm or less, 190 nm or less, 180 nm or less, 170 nm or less, 160 nm or less, 150 nm or less, 140 nm or less, 130 nm or less, 120 nm or less, or 110 nm or less. Combinations of the average diameters referenced above for the vapor-grown carbon fibers are also possible.

[0029] In one embodiment, the conductive backbone carbon nanotubes are multi-walled nanotubes having an average diameter of 15 nm to 50 nm. Within this range, the multi-walled nanotubes can have an average diameter of at least 15 nm, at least 20 nm, at least 25 nm, at least 30 nm, at least 35 nm, at least 40 nm, or at least 45 nm. Also within this range, the multi-walled nanotubes can have an average diameter of 50 nm or less, 45 nm or less, 40 nm or less, 35 nm or less, 30 nm or less, 25 nm or less, or 20 nm or less. Combinations of the average diameters referenced above for the multi-walled nanotubes are also possible.

[0030] In one embodiment, the conductive backbone can comprise conductive carbon black. Examples of suitable materials include Ketjen black products available from Nouryon, Super P™ available from Imerys, or LITX™ products available from Cabot.

[0031] In one aspect, the conductive skeleton can include a metal or alloy, which can include, but is not limited to, iron, nickel, aluminum, titanium, zinc, magnesium, copper, alloys thereof, or combinations thereof.

[0032] In one embodiment, the conductive backbone can include metal nanowires, including, but not limited to, silver nanowires.

[0033] In one aspect, the conductive scaffold can be a composite material including a scaffold and a conductive polymer, e.g., the conductive polymer is disposed on at least a portion of the scaffold. The scaffold can include, for example, cellulose nanofibers. The cellulose nanofibers can optionally include various functional groups on the fiber surface, such as hydroxyl groups, carboxyl groups, (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO) groups, or combinations thereof. Examples of suitable conductive polymers include, but are not limited to, poly(thiophenes), poly(alkylthiophenes), poly(3,4-dialkoxythiophenes), poly(pyrroles), poly(anilines), and the like, or combinations thereof. In one aspect, the conductive polymer can include a blend of poly(3,4-ethylenedioxythiophene) and poly(styrenesulfonate) sodium salt (PEDOT-PSS). It should be understood that, when present, the above-mentioned conductive polymers can be doped (e.g., chemically oxidized or reduced) to achieve a desired conductivity. Suitable dopants and methods for doping conductive polymers can be readily determined by one skilled in the art.

[0034] In one embodiment, the conductive scaffold can comprise a mixture of any of the foregoing, for example, the conductive scaffold can comprise a mixture of at least two of carbon nanotubes, conductive carbon black, metal nanowires, or a composite comprising a structural scaffold and a conductive polymer.

[0035] The conductive backbone may have any suitable conductivity, for example, an electronic conductivity of 1×10 -3 ~1×10 4 S / cm, or 1 x 10 -2 ~1×10 3 The electrical conductivity may be determined at 20° C. according to ASTM B-193, "Standard Test Method for Resistivity of Electrical Conductor Materials."

[0036] The electroactive species can be disposed on the conductive framework. The electroactive species can be disposed on at least a portion of the surface of the conductive framework. In one embodiment, the conductive framework can be impregnated with the electroactive species. In one embodiment, one or more intervening layers can be disposed between the surface of the conductive framework and the electroactive species. In one embodiment, no intervening layers are present, and the electroactive species can be disposed directly on the surface of the conductive framework. The electroactive species can form a monolayer (e.g., a monolayer of molecules, oligomers, or polymers) on the surface of the conductive framework. Alternatively, the electroactive species can form a layer disposed on the surface of the conductive framework, for example, having a thickness of 0.5 to 100 nanometers. Within this range, the thickness of the layer of electroactive species can be at least 1 nanometer, or at least 5 nanometers, or at least 10 nanometers. Also within this range, the thickness of the electroactive species layer can be up to 90 nanometers, or up to 80 nanometers, or up to 70 nanometers, or up to 60 nanometers, or up to 50 nanometers, or up to 40 nanometers, or up to 30 nanometers, or up to 20 nanometers, or up to 10 nanometers.

[0037] The electroactive species may be referred to as being immobilized on the conductive framework such that the electroactive species cannot diffuse freely away from or dissociate from the conductive framework. The electroactive species can be immobilized on the conductive framework in various ways. For example, the electroactive species can be immobilized on the conductive framework by binding to the surface of the conductive framework (e.g., via covalent bonds, ionic bonds, or intramolecular interactions, such as electrostatic forces, van der Waals forces, hydrogen bonds, or a combination thereof). In one aspect, the electroactive species can be immobilized on the conductive framework by being adsorbed onto the surface of the conductive framework. In one aspect, the electroactive species can be immobilized on the conductive framework. Immobilizing the electroactive species can include, but is not limited to, grafting or polymerizing the electroactive species onto the surface of the conductive framework. "Grafting," as used herein, refers to a chemical or electrochemical process that creates a covalent bond between the electroactive species and the conductive framework. In one aspect, the electroactive species can be immobilized on the conductive framework by being included in a composition, such as a coating or composite layer, applied or deposited on the conductive framework. Immobilizing the electroactive species can also include electroplating, plasma deposition, vacuum infiltration, fusion coating, or any combination of the foregoing.

[0038] As used herein, "electroactive species" refers to an agent (e.g., a chemical entity) that undergoes oxidation or reduction upon exposure to an electric potential in an electroswing adsorption cell. A complex electroactive species can combine with or bind to a target gas when the electroactive species is in a particular oxidation state, e.g., a reduced state, and release the target gas when the electroactive species is in a second oxidation state, e.g., an oxidized state. As a non-limiting example, in one embodiment, the electroactive species can be reduced to a corresponding reduced state, thereby binding to the target gas to form a complex or adduct. Subsequent oxidation of the electroactive species can release the target gas. In particular, as a non-limiting example, if the electroactive species is benzoquinone, the neutral benzoquinone is considered the oxidized state, the semiquinone (e.g., the product of adding one electron to the neutral benzoquinone) is considered the first reduced state, and the benzoquinone dianion (the product of adding one electron to the semiquinone) is considered the second reduced state.

[0039] The electroactive species of the composite can be selected such that, in at least one oxidation state, the electroactive species has a strong affinity for the target gas. In one embodiment, in at least one oxidation state, the electroactive species has a high affinity for the target gas at room temperature (e.g., 23°C) of at least 10 1 liters / mole (M -1 ), or at least 10 2 M -1 , or at least 10 3 M -1 Within this range, the electroactive species can have a binding constant of 10 1 ~10 20 M -1 , 10 3 ~10 19 M -1 , 10 4 ~10 18 M -1 , 10 5 ~10 17 M -1 , 10 6 ~10 16 M -1 , or 10 7 ~10 15 M-1 In one embodiment, the binding constant with the target gas is 10 5 ~10 20 M -1 , or 10 10 ~10 15 M -1 In one embodiment, the target gas can be carbon dioxide (CO2), and the electroactive species (reduced state) is CO2 and 10 1 ~10 15 In one embodiment, the target gas can be sulfur dioxide (SO2), and the electroactive species (reduced state) can have a binding constant of 10 with SO2. 5 ~10 20 can have a coupling constant of

[0040] In one embodiment, the electroactive species can have at least two oxidation states. When the electroactive species is in a first oxidation state, it can be considered to be in an "active state," where it can have a high affinity for the target gas (e.g., the "active state" electroactive species can have a binding constant as defined above with the target gas). In a second oxidation state, the electroactive species can be considered to be in a "deactivated" state, where its affinity for the target gas is reduced compared to its affinity for the target gas in the "active" state. For example, the electroactive species can have a ratio of the binding constant of the deactivated state to the binding constant of the active state of 0.9:1 to 10. -20 :1, e.g., 0.9:1, 0.8:1, 0.5:1, 0.1:1, 10 -2 :1, 10 -3 :1, 10 -4 :1 or 10 -5 :1~10 -20 : 1. In one embodiment, the binding constant with the target gas in the deactivated state can be 0, i.e., the deactivated state is essentially inactive with respect to the target gas species.

[0041] The electroactive species can have at least one oxidation state in which a target gas can be released from the electroactive species. For example, in one embodiment, the electroactive species can have at least one oxidation state in which oxidation to the oxidized state can release the target gas from the electroactive species. In one embodiment, the binding constant of a reduced electroactive species can be greater than the binding constant of the corresponding oxidized electroactive species. Thus, in an advantageous feature, capture and release of the target gas can be achieved via redox cycling.

[0042] The electroactive species may be capable of binding the target gas on time scales on the order of minutes, seconds, milliseconds, or microseconds or slower.

[0043] In one embodiment, the electroactive species can have at least one oxidation state (e.g., a reduced state) in which the electroactive species is capable of binding with a target gas, but in which there is at least one temperature (e.g., in the ranges greater than or equal to 223 K, greater than or equal to 248 K, greater than or equal to 273 K, or greater than or equal to 298 K, and up to 323 K, 348 K, or 413 K, e.g., 298 K) at which it is thermodynamically unfavorable for the electroactive species to react with oxygen (O). In one embodiment, the electroactive species can have a reduced state in which the electroactive species is capable of binding with a target gas, but in which there is at least one temperature (e.g., 298 K) at which it is kinetically unfavorable for the electroactive species to react with oxygen (O). This is because the rate, e.g., the rate constant, for reaction with oxygen is too slow to cause the reaction to occur on a time scale commensurate with the capture of the target gas. Thus, the composite electroactive species effectively provides suitable specificity for the capture of the target gas.

[0044] The electroactive species of the composite can include an electroactive organic compound, an electroactive polymer, an electroactive oligomer, or a combination thereof. The electroactive species can include at least one functional group capable of binding to a target gas, for example, a carbonyl group.

[0045] Exemplary electroactive organic compounds can include, but are not limited to, substituted or unsubstituted quinones or tetrones. In one aspect, the electroactive species includes a substituted or unsubstituted quinone (e.g., the quinone can include one or more functional groups or other moieties or linkages connecting the quinone). The selection of a substituent (e.g., functional group) on the substituted quinone can depend on various factors, including, but not limited to, its effect on the reducibility of the substituted quinone. One of skill in the art, with the benefit of this disclosure, will know how to determine which substituent or combination of substituents on the substituted quinone is appropriate for the first electroactive species, for example, based on synthetic feasibility and the resulting reducibility. Exemplary functional groups include, but are not limited to, halo (e.g., chloro, bromo, iodo), hydroxyl, carboxylate / carboxylic acid, sulfonate / sulfonic acid, alkylsulfonate / alkylsulfonic acid (e.g., C 1~18 alkyl sulfonates), phosphonates / phosphonic acids, alkyl phosphonates / alkyl phosphonic acids (e.g., C 1~18 alkylphosphonates), acyl (e.g., acetyl or ethyl esters), amino, amido, quaternary ammonium (e.g., tetraalkylamino), branched or unbranched alkyl (e.g., C 1~18 alkyl), heteroalkyl, alkoxy, glycoxy, polyalkylene glycoxy (e.g., polyethylene glycoxy), imino, polyimino, branched or unbranched alkenyl (e.g., C 2~18 alkenyl), branched or unbranched, C 2~18 Alkynyl, C 6~30 Aryl, C 4~20 Included may be heteroaryl, heterocyclyl, nitro, nitrile, thiyl, or carbonyl groups, any of which may be substituted or unsubstituted. Any suitable organic or inorganic counterion may be selected from the aforementioned charged species, such as alkali metals, alkaline earth metals, ammonium, or cations of the formula R4N + wherein each R is the same or different and independently represents a substituted ammonium group represented by the formula: 1~18hydrocarbyl, provided that at least one R is hydrocarbyl.

[0046] In one embodiment, the electroactive species comprises a substituted or unsubstituted quinone of structure (I) or (II):

[0047] [ka]

[0048] (In the formula, R 1 , R 2 , R 3 , and R 4 is independently at each occurrence hydrogen, halogen (e.g., chloro, bromo, iodo), hydroxyl, carboxylate / carboxylic acid, sulfonate / sulfonic acid, alkylsulfonate / alkylsulfonic acid (e.g., C 1~18 alkyl sulfonates), phosphonates / phosphonic acids, alkyl phosphonates / alkyl phosphonic acids (e.g., C 1~18 alkylphosphonates), acyl (e.g., acetyl or ethyl esters), amino, amido, quaternary ammonium (e.g., tetraalkylamino), branched or unbranched C 1~18 Alkyl, C 1~18 Heteroalkyl, C 1~18 Alkoxy, glycoxy, polyalkylene glycoxy (e.g., polyethylene glycoxy), imino, polyimino, branched or unbranched alkenyl, branched or unbranched C 2~18 Alkynyl, C 6~20 Aryl, C 4~20 heteroaryl, heterocyclyl, nitro, nitrile, thiyl, or carbonyl group, any of which may be substituted or unsubstituted, and any two adjacent R 1 ~R 4 The groups can optionally be linked together to form a cyclic group.

[0049] In one aspect, the electroactive organic compound can include a quinone, defined herein as a cyclic conjugated system having an even number of carbonyl groups that can be reduced to form the corresponding aromatic species in the manner shown below.

[0050] [ka]

[0051] These include derivatives of 1,4-benzoquinone, 1,2-benzoquinone, naphthoquinone, anthraquinone, phenanthrenequinone, benzanthraquinone, dibenzanthraquinone, 4,5,9,10-pyrenetetrone, or combinations thereof. Any of the foregoing may be optionally substituted as described above. In one aspect, the electroactive organic compound is a substituted or unsubstituted naphthoquinone. Other positional isomers of the foregoing non-limiting exemplary electroactive organic compounds can also be used (e.g., those with substituents at different positions of the quinone).

[0052] In one embodiment, the electroactive species comprises an electroactive polymer. As used herein, the term "polymer" refers to a structure having more than 10 repeating units. For example, the electroactive polymer can include repeating units comprising any of the aforementioned electroactive organic compounds. Suitable electroactive polymers can include, for example, those comprising repeating units derived from substituted or unsubstituted quinones. In one embodiment, at least a portion of the electroactive polymer comprises a polymer backbone with at least one electroactive organic compound covalently bonded to the polymer backbone. In one embodiment, the electroactive organic compound can form at least a portion of the polymer backbone.

[0053] In one embodiment, the electroactive polymer includes repeat units derived from quinones, which can include 1,4-benzoquinone, 1,2-benzoquinone, naphthoquinone, anthraquinone, phenanthrenequinone, benzanthraquinone, dibenzanthraquinone, 4,5,9,10-pyrenetetrone, or combinations thereof, as described above.

[0054] In one aspect, the electroactive polymer can include substituted or unsubstituted poly(anthraquinone). In one aspect, the electroactive polymer can include substituted or unsubstituted poly(vinylanthraquinone). In one aspect, the electroactive polymer can include substituted or unsubstituted poly(phenylnaphthoquinone).

[0055] In one embodiment, the electroactive species comprises an electroactive oligomer. As used herein, the term "oligomer" refers to a structure having 2 to 10 repeating units. Thus, an electroactive oligomer can have any of the structures described for electroactive polymers, provided that it is limited to 10 or fewer repeating units. For example, suitable electroactive oligomers can include oligomers containing repeating units derived from substituted or unsubstituted quinones, preferably 1,4-benzoquinone, 1,2-benzoquinone, naphthoquinone, anthraquinone, phenanthrenequinone, benzanthraquinone, dibenzanthraquinone, 4,5,9,10-pyrenetetrone, or combinations thereof. In one embodiment, the electroactive oligomer can comprise an oligo(anthraquinone). In one embodiment, the electroactive oligomer can comprise an oligo(vinylanthraquinone). In one embodiment, the electroactive oligomer can comprise a substituted or unsubstituted oligo(phenylnaphthoquinone).

[0056] When the electroactive species comprises an electroactive polymer or oligomer, the electroactive polymer or oligomer may optionally be crosslinked. Crosslinking can be accomplished by a variety of methods known in the art. Those of skill in the art will be able to determine an appropriate crosslinking chemistry based on the selection of the electroactive species, with the benefit of this disclosure.

[0057] The thickness of the electroactive species on the surface of the conductive scaffold can be, for example, 0.1 to 20 nanometers, or 0.2 to 15 nanometers, or 0.5 to 10 nanometers. The thickness of the electroactive species on the surface of the conductive scaffold can depend on the mode of deposition.

[0058] The electroactive species can be present in an amount of 10 to 90 weight percent, based on the weight of the electroactive species and conductive scaffold of the patterned first electrode. Within this range, the electroactive species can be present in an amount of at least 20 weight percent, or at least 25 weight percent, or at least 30 weight percent, or a minimum of 40 weight percent, or at least 50 weight percent, based on the weight of the electroactive species and conductive scaffold of the first electrode. Also within this range, the electroactive species can be present in an amount of up to 80 weight percent, or up to 70 weight percent, or up to 60 weight percent, or up to 50 weight percent, or up to 45 weight percent, or up to 40 weight percent. For example, the electroactive species can be present in an amount of 10 to 75 weight percent, or 10 to 60 weight percent, or 15 to 60 weight percent, or 20 to 55 weight percent, or 25 to 55 weight percent, or 30 to 50 weight percent, based on the weight of the electroactive species and conductive scaffold of the patterned first electrode.

[0059] The electroactive species and the conductive backbone may be present in a weight ratio of 1:10 to 10:1, or 1:5 to 5:1, or 1:10 to 1:1.

[0060] The electroactive species is reactive with a target gas. The target gas is an electrophilic molecule. In one embodiment, the target gas is a Lewis acid gas. The target gas can form a complex or adduct with the electroactive species when the electroactive species is in a reduced state, for example, by binding to the electroactive species in its reduced state. The target gas can be carbon dioxide (CO), sulfur oxide species, such as sulfur dioxide (SO) or sulfur trioxide (SO), organosulfates (RSO, where each R is independently hydrogen, C, 1~12 Alkyl or C 6~20 aryl), such as dimethyl sulfate, nitrogen oxide species such as nitrogen dioxide (NO) or dinitrogen trioxide (NO), phosphate esters (RPO, where each R is independently hydrogen, C 1~12 Alkyl or C 6~20 aryl), such as trimethyl phosphate, esters (RCOOR′, where each R is independently hydrogen, C 1~12 Alkyl or C 6~20 aryl, and each R' is independently C 1~12 Alkyl or C 6~20 aryl), such as methyl formate or methyl acrylate, aldehydes (RCHO, where each R is independently hydrogen, C 1~12 Alkyl or C 6~20 aryl), such as formaldehyde or acrolein, ketones (RCO, where each R is independently hydrogen, C 1~12 Alkyl or C 6~20 aryl), e.g., acetone, isocyanate (RNCO, where each R is independently hydrogen, C 1~12 Alkyl or C 6~20 aryl, and each R' is independently C 1~12 Alkyl or C 6~20 aryl), e.g., methyl isocyanate, isothiocyanate (RNCS, where each R is independently hydrogen, C 1~12 Alkyl or C 6~20 aryl, and each R' is independently C 1~12 Alkyl or C 6~20 aryl), borane (BR, where each R is independently hydrogen, C1~12 Alkyl or C 6~20 aryl), such as trimethylborane, or borates (RBO, where each R is independently hydrogen, C 1~12 Alkyl or C 6~20 aryl), for example, trimethyl borate. The target gas can optionally include any combination of the aforementioned target gas species.

[0061] The patterned first electrode includes a plurality of gas regions and a plurality of electrolyte regions (i.e., including an electrolyte). The electrolyte region includes at least a portion of a conductive scaffold having an electrolyte and an electroactive species disposed thereon, as discussed in further detail above. In one aspect, the electrolyte can include a liquid electrolyte, a gel electrolyte, a gel polymer electrolyte (GPE), a polymeric ionic liquid (PIL), a room temperature ionic liquid (RTIL), an ionic liquid, a solution including a salt and an organic solvent, or any other suitable electrolyte or combination of electrolytes. Optionally, a crosslinker can be present in the electrolyte.

[0062] In one embodiment, the electrolyte comprises a gel polymer electrolyte (GPE). The GPE comprises a polymer matrix having a high affinity for the electrolyte, and the electrolyte is disposed within the polymer matrix. The electrolytic moiety is not covalently bonded to the polymer matrix. The matrix polymer of the GPE can include, but is not limited to, poly(acrylate), poly(acrylamide), poly(styrene), poly(ethylene oxide), poly(vinylidene fluoride), poly(urethane), poly(siloxane), poly(vinylpyrrolidone), functionalized cellulose, or a combination thereof. Optionally, the polymer can contain functional groups capable of forming crosslinks, e.g., ionic bonds, covalent bonds, or a combination thereof. Crosslinking can be induced by heat, radiation, or a chemical trigger suitable for forming a crosslinked network that colocalizes with the electrolyte.

[0063] In one embodiment, the electrolyte comprises a polymeric ionic liquid (PIL). A PIL comprises an ionic polymer matrix in which cations, anions, or both cations and anions are covalently bound to the polymer backbone. When both cations and anions are covalently bound to the polymer backbone, the polymeric ionic liquid can be referred to as a zwitterion. The polymer backbone of the PIL can include, but is not limited to, poly(acrylate), poly(acrylamide), poly(styrene), poly(siloxane), poly(ethylene), poly(vinylidene fluoride), poly(ethylene oxide), poly(vinylpyrrolidone), poly(N-alkylimidazolium), poly(diallyldialkylammonium), or a combination thereof. Optionally, the polymer matrix can contain functional groups capable of forming crosslinks, e.g., ionic bonds, covalent bonds, or a combination thereof. Crosslinking can be induced by thermal, radiation, or chemical triggers suitable for forming a crosslinked network that colocalizes with the electrolyte. The repeat units bearing crosslinkable functional groups may represent 5 to 95 mole percent of the polymer's composition. Exemplary polymeric ionic liquids are further described in the Examples below.

[0064] In some embodiments, a crosslinker can be added to the electrolyte. The crosslinker can include a small molecule, oligomer, or polymer containing functional groups that can participate in a chemical reaction with the auxiliary functional groups of the GPE, PIL, or both repeat units. Examples of functional groups can include, but are not limited to, vinyl, azido, epoxy, hydroxy, carboxy, amino, isocyanato, aluminum salt, or any combination thereof. The crosslinking reaction of the functional groups can be triggered by heat, radiation, or any suitable chemical trigger, as discussed above.

[0065] In one embodiment, the electrolyte comprises an ionic liquid, such as a room temperature ionic liquid (RTIL). Ionic liquids are also called molten salts because they are liquid at room temperature, e.g., 23° C., and have low volatility, e.g., 10 -5 Less than Pascal (Pa) or 10 -10 ~10-5 The ionic liquid may have a vapor pressure of 0.1 Pa, which may reduce the risk of the separator drying out and allow for reduced loss of electrolyte due to evaporation or wicking. In one aspect, the ionic liquid comprises substantially all of the electrolyte (e.g., at least 80 volume percent (vol %), or at least 90 vol %, or at least 95 vol %, or at least 98 vol %, at least 99 vol %, or at least 99.9-99.99 vol %).

[0066] Ionic liquids contain an anion and a cation. The anion of an ionic liquid can include, but is not limited to, one or more of halides, sulfates, sulfonates, carbonates, bicarbonates, phosphates, nitrates, acetates, PF6, BF4, trifluoromethanesulfonates (triflate), nonaflates, bis(trifluoromethylsulfonyl)amides, trifluoroacetates, heptafluorobutanoates, haloaluminates, triazolides, or amino acid derivatives (e.g., proline with a nitrogen removed and a proton). The cation of an ionic liquid can include, but is not limited to, one or more of imidazolium, pyridinium, pyrrolidinium, phosphonium, ammonium, sulfonium, thiazolium, pyrazolium, piperidinium, triazolium, pyrazolium, oxazolium, guanidinium, alkali cations, or dialkylmorpholinium. In one embodiment, the room temperature ionic liquid comprises imidazolium as the cationic component. In one embodiment, the room temperature ionic liquid comprises 1-butyl-3-methylimidazolium ("BMIM") as the cationic component. In one embodiment, the room temperature ionic liquid comprises bis(trifluoromethyl-sulfonyl)imide ("TFSI") as the anionic component. In one embodiment, the room temperature ionic liquid comprises 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ("[BMIM][TFSI]"). In one embodiment, the room temperature ionic liquid comprises 1-butyl-3-methylimidazolium tetrafluoroborate ("BF4") ("[BMIM][BF4]").

[0067] In one aspect, the electrolyte comprises an ionic liquid that may include unsubstituted or substituted imidazolium, unsubstituted or substituted morpholinium, unsubstituted or substituted pyridinium, unsubstituted or substituted pyrrolidinium, unsubstituted or substituted piperidinium, unsubstituted or substituted piperazinium, unsubstituted or substituted pyrazinium, or combinations thereof. In certain embodiments, the ionic liquid is 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide, 1-ethyl-3-methylimidazolium bis(pentafluorosulfonyl)imide, 1-ethyl-3-methylimidazolium dicyanamide, 1-ethyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, 1-butyl-3-methylpyridinium bis(trifluoromethyl-sulfonyl)imide, N-methyl-N-propylpiperidinium bis(trifluoromethanesulfonyl)imide, or combinations thereof.

[0068] In one aspect, the ionic liquid electrolyte can be maintained in free form within the electrolyte region, for example, by capillary action or wetting of the conductive framework by the ionic liquid. In one aspect, the ionic liquid electrolyte can be maintained within the electrolyte region by a crosslinked ionogel polymer matrix. In one aspect, electrolyte wetting within the gas region of the electrode is avoided, and in one aspect, there is essentially no electrolyte wetting within the gas region of the electrode. Portions without electrolyte wetting remain empty and can function as gas channels.

[0069] In one embodiment, the electrolyte regions can comprise 15 to 85 volume percent electrolyte, based on the total volume of the electrolyte regions. Within this range, the electrolyte can be present in the electrolyte regions in an amount of at least 15 volume percent, at least 20 volume percent, at least 25 volume percent, at least 30 volume percent, at least 35 volume percent, at least 40 volume percent, at least 45 volume percent, at least 50 volume percent, at least 55 volume percent, at least 60 volume percent, at least 65 volume percent, at least 70 volume percent, at least 75 volume percent, or at least 80 volume percent, based on the total volume of each electrolyte region. Also within this range, the electrolyte can be present in the electrolyte regions in an amount of up to 85 volume percent, up to 80 volume percent, up to 75 volume percent, up to 70 volume percent, up to 65 volume percent, up to 60 volume percent, up to 55 volume percent, up to 50 volume percent, up to 45 volume percent, up to 40 volume percent, up to 35 volume percent, up to 30 volume percent, up to 25 volume percent, or up to 20 volume percent, based on the total volume of each electrolyte region. Combinations of the above-referenced values ​​for electrolyte volume percentage within the electrolyte region are also possible.

[0070] In one embodiment, the electrolyte region can include a conductive skeleton having electroactive species disposed thereon in a volume fraction sufficient to provide a permeation path for electron transport within the electrode. In one embodiment, the electrolyte region can include 5 to 85 volume percent of the conductive skeleton, based on the total volume of the electrolyte region. Within this range, the total volume of the conductive skeleton can be at least 5 volume percent, at least 10 volume percent, at least 15 volume percent, at least 20 volume percent, at least 25 volume percent, at least 30 volume percent, at least 35 volume percent, at least 40 volume percent, at least 45 volume percent, at least 50 volume percent, at least 55 volume percent, or at least 60 volume percent, based on the total volume of the electrolyte region. Also within this range, the electrolyte region can include no more than 65 volume percent, no more than 60 volume percent, no more than 55 volume percent, no more than 50 volume percent, no more than 45 volume percent, no more than 40 volume percent, no more than 35 volume percent, no more than 30 volume percent, no more than 25 volume percent, no more than 20 volume percent, no more than 15 volume percent, or no more than 10 volume percent, based on the total volume of the electrolyte region. Combinations of the above-referenced values ​​for the volume percentage of the conductive framework on which the electroactive species is disposed within the electrolyte region are also possible.

[0071] In one embodiment, the electrolyte region can contain a volume fraction of gas. For example, small or ionic pores may not be completely filled with electrolyte during the assembly process and instead contain a gas, such as air or an inert gas, such as nitrogen. The electrolyte region can contain 0 to 15 volume percent of gas, based on the total volume of the electrolyte region. Within this range, the electrolyte region can contain at least 0 volume percent, at least 0.1 volume percent, at least 1 volume percent, at least 5 volume percent, at least 6 volume percent, at least 7 volume percent, at least 8 volume percent, at least 9 volume percent, at least 10 volume percent, or at least 15 volume percent of gas, based on the total volume of the electrolyte region. Also within this range, the electrolyte region can contain no more than 15 volume percent, 10 volume percent, 5 volume percent, 1 volume percent, 0.5 volume percent, 0.2 volume percent, or 0.1 volume percent of gas, based on the total volume of the electrolyte region. Combinations of the above-referenced ranges for the gas volume percentage within the electrolyte region are also possible.

[0072] In one embodiment, the electrolyte region can have a volume that is at least 50% of the total volume of the patterned electrodes. For example, the electrolyte region can have a volume that is at least 55%, at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% of the total volume of the patterned electrodes. The electrolyte region can have a volume that is 99% or less, 95% or less, 90% or less, 85% or less, 80% or less, 75% or less, 70% or less, 65% or less, 60% or less, or 50% or less of the total volume of the patterned electrodes. Combinations of the above-referenced values ​​for the volume percentage of the electrolyte region compared to the total volume of the patterned electrodes are also possible.

[0073] The patterned first electrode further includes a gas region. By including a gas region within the cell, the adsorption time constant of the cell can be reduced. Reducing the adsorption time constant can increase the amount of gas the cell can adsorb per unit area per time. In one embodiment, the gas region can include one or more gases. In one embodiment, the gas can include O 2 , N 2 , CO 2 , SO 2 , NO 2 , NO 2 , H 2 S, CO 2 , H 2 O, or a combination thereof. In one embodiment, the gas region can be filled with an inert gas upon initial application of a first (e.g., cathodic) potential.

[0074] In one embodiment, the gas region can include a conductive framework and an electroactive species. In one embodiment, the gas region can include an electrolyte. For example, the gas region can include the electrolyte in an amount of 0 to 20% by volume, based on the total volume of the gas region. Within this range, the gas region can include electrolyte in an amount of at least 0 vol%, at least 0.1 vol%, at least 0.2 vol%, at least 0.3 vol%, at least 0.4 vol%, at least 0.5 vol%, at least 0.6 vol%, at least 0.7 vol%, at least 0.8 vol%, at least 0.9 vol%, at least 1 vol%, at least 2 vol%, at least 3 vol%, at least 4 vol%, at least 5 vol%, at least 6 vol%, at least 7 vol%, at least 8 vol%, at least 9 vol%, at least 10 vol%, at least 11 vol%, at least 12 vol%, at least 13 vol%, at least 14 vol%, at least 15 vol%, at least 16 vol%, at least 17 vol%, at least 18 vol%, or at least 19 vol%, each based on the total amount of the gas region. Also within this range, the gas region can comprise electrolyte in an amount of 20% by volume or less, 19% by volume or less, 18% by volume or less, 17% by volume or less, 16% by volume or less, 15% by volume or less, 14% by volume or less, 13% by volume or less, 12% by volume or less, 11% by volume or less, 10% by volume or less, 9% by volume or less, 8% by volume or less, 7% by volume or less, 6% by volume or less, 5% by volume or less, 4% by volume or less, 3% by volume or less, 2% by volume or less, 1% by volume or less, 0.9% by volume or less, 0.8% by volume or less, 0.7% by volume or less, 0.6% by volume or less, 0.5% by volume or less, 0.4% by volume or less, 0.3% by volume or less, 0.2% by volume or less, or 0.1% by volume or less, based on the total volume of the gas region. Combinations of the above-referenced ranges for electrolyte content within the gas region are also possible.

[0075] In one aspect, the gas region can have any suitable shape, including spherical, cylindrical, striped, conical, frustoconical, irregular, or any combination thereof. In one aspect, the gas region can span the entire length of the patterned electrode and, if present, can be in physical contact with both the gas flow field and the separator, as discussed further below.

[0076] The gas region may include multiple gas regions. If present, the multiple gas regions may have an average dimension (e.g., thickness) in the y direction of 1 to 100 μm (W G ) within this range, the gas region can have a y-direction (W G ), can have an average dimension in the y-direction (W G ) can have an average size of 100 μm or less, 90 μm or less, 80 μm or less, 70 μm or less, 60 μm or less, 50 μm or less, 40 μm or less, 30 μm or less, 20 μm or less, 10 μm or less, 9 μm or less, 8 μm or less, 7 μm or less, 6 μm or less, 5 μm or less, 4 μm or less, 3 μm or less, or 2 μm or less, respectively. Combinations of the average diameter values ​​referenced above for the gas region are also possible.

[0077] In one embodiment, the gas regions of the plurality of gas regions may be separated by an average distance, e.g., the diffusion length L of the path taken by a Lewis acid gas G to diffuse from a gas region to the active site of an electroactive species P within the electrolyte region, as shown in FIG. Dcan be determined. In other words, the gas regions may be interspersed within a portion of the electrolyte region. The gas regions may be separated from adjacent gas regions by an average distance of 1 μm to 1 mm. Within this range, the gas regions may be separated from adjacent gas regions by an average distance of at least 1 μm, at least 2 μm, at least 3 μm, at least 4 μm, at least 5 μm, at least 6 μm, at least 7 μm, at least 8 μm, at least 9 μm, at least 10 μm, at least 20 μm, at least 30 μm, at least 40 μm, at least 50 μm, at least 60 μm, at least 70 μm, at least 80 μm, at least 90 μm, at least 100 μm, at least 200 μm, at least 300 μm, at least 400 μm, at least 500 μm, at least 600 μm, at least 700 μm, at least 800 μm, or at least 900 μm. Also within this range, the gas regions may be separated from adjacent gas regions by an average distance of 1 mm or less, 900 μm or less, 800 μm or less, 700 μm or less, 600 μm or less, 500 μm or less, 400 μm or less, 300 μm or less, 200 μm or less, 100 μm or less, 90 μm or less, 80 μm or less, 70 μm or less, 60 μm or less, 50 μm or less, 40 μm or less, 30 μm or less, 20 μm or less, 10 μm or less, 9 μm or less, 8 μm or less, 7 μm or less, 6 μm or less, 5 μm or less, 4 μm or less, 3 μm or less, or 2 μm or less. Combinations of the above-referenced ranges for the average distance between gas regions are also possible.

[0078] In one embodiment, the gas region can have a volume that is at least 0.1% of the total volume of the patterned electrode. For example, the gas region can have a volume that is at least 0.5%, at least 1%, at least 2%, at least 3%, at least 4%, at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, or at least 50% of the total volume of the patterned electrode. In one embodiment, the gas region can have a volume that is 50% or less, 45% or less, 40% or less, 35% or less, 30% or less, 25% or less, 20% or less, 15% or less, 10% or less, 5% or less, 4% or less, 3% or less, 2% or less, 1% or less, 0.5% or less, or 0.2% or less of the total volume of the patterned electrode. Combinations of the above-referenced values ​​for the volume percentage of the gas region compared to the total volume of the patterned electrode are also possible.

[0079] In one embodiment, the gas region can also be optionally filled with a porous material that is non-wettable by the electrolyte. If present, the porous material in the gas region can include a zeolite. As used herein, the term "zeolite" refers to a crystalline aluminosilicate of Group IA and Group IIA elements, such as sodium, potassium, magnesium, calcium, or combinations thereof. Zeolites can have an extended framework of AlO4 and SiO4 tetrahedrally bonded to each other through the sharing of oxygen ions. The framework generally contains channels or interconnected voids that can provide a host structure permeated by micropores; in some embodiments, these voids can amount to up to 50% of the zeolite by volume. Zeolites can be natural or synthetic. Natural zeolites are hydrated silicates of aluminum, optionally containing sodium or calcium, that have ion exchange properties, high surface area, and uniform and finite porosity. Natural zeolites can include, for example, analcime, chabazite, clinopyroxene, erionite, faujasite, cerium sulphite, heulandite, mordenite, natrolite, philipsite, scolesite, and stilbite. Synthetic zeolites are commercially available from several manufacturers, including Tosoh America Inc. or CB Minerals, and can include, for example, zeolite A, zeolite X, zeolite Y, and zeolite L. Synthetic zeolites are highly porous materials and, in contrast to other adsorbents, have molecular dimensions and uniformly sized pores. Zeolites can have an average particle size of, for example, 1 to 100 micrometers, preferably 2 to 50 micrometers, and more preferably 10 to 20 micrometers. When included in the electrode, the zeolite particles can be present in an amount of 1 to 70 weight percent, or 10 to 60 weight percent, or 10 to 50 weight percent, or 20 to 60 weight percent, or 20 to 50 weight percent, each based on the total weight of the first electrode.

[0080] The patterned first electrode measures the distance L that cations travel from the separator to the active site of the electroactive species P in the ESA cell.I The thickness of the first electrode can be 15 to 500 micrometers. Within this range, the patterned first electrode can have a thickness of at least 15 μm, at least 25 μm, at least 50 μm, at least 100 μm, at least 150 μm, at least 200 μm, at least 250 μm, at least 300 μm, at least 350 μm, at least 400 μm, or at least 450 μm. Also within this range, in one embodiment, the patterned electrode can have a thickness of 450 μm or less, 400 μm or less, 350 μm or less, 300 μm or less, 250 μm or less, 200 μm or less, 150 μm or less, 100 μm or less, 50 μm or less, 40 μm or less, or 30 μm or less. Combinations of the above-referenced thicknesses for the patterned first electrode are also contemplated.

[0081] In one aspect, L D / L I can be 0.001 to 1 (i.e., 0.001 / 1 to 1 / 1). Within this range, L D / L I can be at least 0.001, at least 0.002, at least 0.003, at least 0.004, at least 0.005, at least 0.006, at least 0.007, at least 0.008, at least 0.009, at least 0.01, at least 0.02, at least 0.03, at least 0.04, at least 0.05, at least 0.06, at least 0.07, at least 0.08, at least 0.09, at least 0.1, at least 0.2, at least 0.3, at least 0.4, at least 0.5, at least 0.6, at least 0.7, at least 0.8, or at least 0.9. Also within this range, L D / L Ican be 1 or less, 0.9 or less, 0.8 or less, 0.7 or less, 0.6 or less, 0.5 or less, 0.4 or less, 0.3 or less, 0.2 or less, 0.1 or less, 0.09 or less, 0.08 or less, 0.07 or less, 0.06 or less, 0.05 or less, 0.04 or less, 0.03 or less, 0.02 or less, 0.01 or less, 0.009 or less, 0.008 or less, 0.007 or less, 0.006 or less, 0.005 or less, 0.004 or less, 0.003 or less, or 0.002 or less. D / L I A combination of values ​​is also possible.

[0082] In one aspect, L D / W G can be 1 to 100 (i.e., 1 / 1 to 100 / 1). Within this range, L D / W G can be at least 1, at least 2, at least 3, at least 4, at least 5, at least 6, at least 7, at least 8, at least 9, at least 10, at least 20, at least 30, at least 40, at least 50, at least 60, at least 70, at least 80, or at least 90. Also within this range, L D / W G can be 100 or less, 90 or less, 80 or less, 70 or less, 60 or less, 50 or less, 40 or less, 30 or less, 20 or less, 10 or less, 9 or less, 8 or less, 7 or less, 6 or less, 5 or less, 4 or less, 3 or less, or 2 or less. D / W G A combination of values ​​is also possible.

[0083] In one embodiment, the electroswing adsorption cell can further include a second electrode. The second electrode includes an auxiliary electroactive composite layer. This auxiliary electroactive composite layer can be the same as or different in composition or structure from the patterned first electrode of the present disclosure. The auxiliary electroactive composite layer includes a second electroactive species, which can be the same as or different from the electroactive species of the patterned first electrode.

[0084] In one embodiment, the auxiliary electroactive composite layer comprises the same electroactive species as the patterned first electrode. It is understood that when the composite of the patterned first electrode and the auxiliary electroactive composite layer comprises the same electroactive species, the electroactive species of the patterned first electrode may be in a different oxidation state than the electroactive species of the auxiliary electrode during the charging process. In one embodiment, the auxiliary electroactive composite layer comprises a second electroactive species that is different from the first electroactive species of the patterned first electrode. In one embodiment, the second electroactive species of the auxiliary electroactive composite layer can be an electroactive organic molecule, an electroactive polymer, or an electroactive oligomer, as previously described, or an electroactive inorganic composite, an electroactive metallocene, or a combination comprising any of the foregoing.

[0085] In one aspect, the auxiliary electroactive species is an electroactive inorganic composite, such as a AM 1 X (Wherein A is Li, Na, or K, M 1 is Ni, Co, Mn, Al, Ti, Mo, Fe, V, Si, or a combination thereof, and X is O or PO. In one embodiment, the electroactive species can be LiFePO.

[0086] In one embodiment, the auxiliary electroactive species comprises a metallocene. Examples of suitable metallocenes include, but are not limited to, ferrocene or polymers comprising repeat units derived from ferrocene (e.g., polyvinylferrocene) or derivatives thereof.

[0087] In one embodiment, the second electroactive species of the auxiliary electroactive composite layer comprises MXene, which as used herein refers to a material comprising a metal carbide, nitride, carbonitride, or combination thereof.

[0088] During operation of the electroswing adsorption cell, the second electroactive species of the auxiliary electroactive composite layer can function as an electron source for the reduction of the first electroactive species of the patterned first electrode. Similarly, the second electroactive species of the auxiliary electroactive composite layer can function as an electron sink during the oxidation of the first electroactive species of the patterned first electrode.

[0089] In one embodiment, the second electrode can further include a substrate, which can be disposed proximate to or between the auxiliary electroactive composite layers. The substrate can be in direct or indirect contact with the auxiliary electroactive composite layer or layers. If present, the substrate can include, for example, carbon paper (treated, PTFE-treated, or untreated), carbon cloth, a nonwoven carbon mat, or a nonwoven carbon nanotube mat. In one embodiment, the support can be the same as the conductive scaffold of the patterned first electrode. In one embodiment, the substrate of the second electrode can be a conductive material and can act as a current collector in an electroswing adsorption cell.

[0090] In one embodiment, the patterned first electrode can be a negative electrode and the second electrode can be a positive electrode. The terms anode or negative electrode and cathode or positive electrode are used for convenience and clarity, although they may only be technically accurate when a target gas is captured or released.

[0091] In one embodiment, the second electrode can be disposed between the patterned first electrodes. Each of the patterned first electrodes can be as previously described. In one embodiment, the patterned first electrodes and / or the second electrodes can be identical in construction or composition.

[0092] In one embodiment, the second electrode can have a thickness of 25 to 500 micrometers. In one embodiment, within this range, the second electrode can have a thickness of at least 30 μm, at least 40 μm, at least 50 μm, at least 100 μm, at least 150 μm, at least 200 μm, at least 250 μm, at least 300 μm, at least 350 μm, at least 400 μm, or at least 450 μm. Also within this range, the second electrode can have a thickness of 450 μm or less, 400 μm or less, 350 μm or less, 300 μm or less, 250 μm or less, 200 μm or less, 150 μm or less, 100 μm or less, 50 μm or less, 40 μm or less, or 30 μm or less. Combinations of the thicknesses referenced above for the second electrode are also contemplated.

[0093] The electroswing adsorption cell can further include a separator disposed between the patterned first electrode and the second electrode. The separator can function as a protective layer that can prevent the electrochemical reactions at each electrode from interfering with each other. The separator can also help to electronically isolate the first electrode and the second electrode from each other or from other components in the electroswing adsorption cell to prevent short circuits. Those skilled in the art will be able to select an appropriate separator, given the benefit of this disclosure.

[0094] In one embodiment, the electroswing adsorption cell includes a single separator disposed between patterned first and second electrodes, e.g., between a negative electrode and a positive electrode. Electroswing adsorption cells can be combined to create stacks in any suitable combination of parallel and series configurations. Thus, in one embodiment, the electroswing adsorption cell can include more than one separator. For example, one skilled in the art will understand that, depending on the selected combination of series and parallel configurations, a single separator can be used, or multiple separators may be preferred.

[0095] The separator can be a porous separator. The porous separator can comprise any suitable material. In one embodiment, the porous separator can comprise a polymer film, such as a film comprising polyamide, polyolefin, polyaramid, polyester, polyurethane, acrylic resin, or a combination thereof. The polymer can be coated on one or both sides with ceramic nanoparticles. In one embodiment, the porous separator can comprise cellulose, a synthetic polymer material, or a polymer / ceramic composite material. Further examples of separators include polyvinylidene difluoride (PVDF) separators, polytetrafluoroethylene (PTFE), PVDF-alumina composite separators, or microporous olefins, such as microporous polyethylene or microporous polypropylene.

[0096] In one embodiment, the patterned first electrode can be folded or pleated into a desired configuration. In one embodiment, the patterned first electrode, separator, and second electrode can be folded or pleated together into a desired configuration. Pleated or folded configurations are discussed further below.

[0097] The electroswing adsorption cell can further include a current collector that conducts electrons from the electrode to an adjacent cell (series stack configuration) or from the electrode to an end connection (parallel stack configuration). The current collector can include, for example, carbon, a metal, or a combination thereof. In one embodiment, the current collector can include carbon. Suitable examples of carbon include, but are not limited to, graphite, exfoliated graphite, expanded graphite, carbon fiber, carbon nanotubes, amorphous carbon, graphene, or a combination thereof. The carbon nanotubes can include single-walled carbon nanotubes or multi-walled carbon nanotubes. Carbon nanotubes are primarily carbon, although nanotube fibers may further include other atoms, such as boron, nitrogen, or one or more various metals. In one embodiment, the current collector can include a metal. The metal can include Fe, Zn, Ti, Cu, Al, Ni, Mg, Sn, Cr, Mn, Au, Mo, W, In, V, Nb, Ag, alloys or intermetallics thereof, or combinations thereof. In one embodiment, the alloy is stainless steel, for example, 304 or 316 stainless steel.

[0098] In one embodiment, the carbon or metal may have a spherical, flake, or fibrous morphology. In one embodiment, the metal may be in the form of a metal mesh, foam, felt, or expanded metal. The carbon or metal particles may be oriented. For example, if the metal is in the form of fibers, the fibers may be oriented so that their long axes are oriented perpendicular to the major surfaces of the current collector, e.g., so that the fibers are oriented perpendicular to the surfaces, e.g., in a cross-plane direction.

[0099] In one embodiment, the current collector may include a composite containing carbon, a metal, and a binder. The carbon or metal in the composite may be present in an amount of 10 to 98% by volume, based on the total volume of the composite. In one embodiment, the composite includes carbon or metal in an amount of 50 to 95% by volume, based on the total volume of the composite. In one embodiment, the composite includes carbon nanotubes or graphene, and the carbon nanotubes or graphene may be present in an amount of 10 to 40% by volume, based on the total volume of the composite. The composite may include pores, and the pores may contain a polymer.

[0100] When present, the binder may comprise a polymer. The binder may be thermosetting or thermoplastic. Suitable polymer binders may include, for example, epoxy, phenolic, vinyl ester, polyarylene sulfide, polybenzoxazine, isocyanate, fluoropolymer, rubber, or a combination thereof. Exemplary polymer binders include polyacrylic acid (PAA), polyvinylidene difluoride, polyvinyl alcohol, carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose, regenerated cellulose, polyvinylpyrrolidone, tetrafluoroethylene, polyethylene, polypropylene, ethylene-propylene-diene monomer (EPDM), sulfonated EPDM, styrene-butadiene-rubber, or fluorinated rubber. Combinations comprising one of the foregoing polymer binders may be used.

[0101] The binder can optionally further comprise additives. Specific additives can include flow promoters, mold release agents, or combinations thereof. In one embodiment, the polymer binder can be crosslinked. The polymer can be an electrical insulator or an electrical conductor. Exemplary conductive polymers can be found, for example, in U.S. Patent Application Publication No. 2004 / 977797, the contents of which are incorporated herein by reference in their entirety for all purposes. Optionally, conductive materials, such as carbon black, nanotubes, carbon fibers, graphene, etc., can be embedded in the polymer binder at the surface of the current collector; without wishing to be bound by theory, this is believed to reduce contact resistance to adjacent cell components, such as gas diffusion layers.

[0102] In one aspect, the current collector can optionally include a coating disposed on at least a portion of the surface of the current collector. Without wishing to be bound by theory, the coating can function to reduce corrosion, block ion or gas permeation, or improve electrical contact to the gas diffusion layer or electrode. When present, the coating can include carbon, a metal, an alloy, or an intermetallic material, or a combination thereof, where the metal, alloy, or intermetallic material includes Ni, Zn, Ti, Sn, Au, V, Mo, Cr, or a combination thereof. The coating can include a metal, alloy, or intermetallic oxide, boride, nitride, or carbide. Non-limiting examples of coating compositions include tin oxide, titanium carbide, tungsten carbide, zirconium carbide, indium tin oxide, zinc indium oxide, titanium boride, zirconium boride, titanium niobium oxide, titanium tantalum oxide, lanthanum strontium chromium oxide, lanthanum strontium cobalt oxide, titanium nitride, chromium nitride, vanadium nitride, or combinations thereof. For example, in one embodiment, the current collector can be plated with a metal, such as Fe, Ni, or Au, or a corrosion-resistant material, such as tin. In one embodiment, the coating can include a polymer. Examples of polymer coatings are described, for example, in U.S. Patent Application Publication No. 2007 / 0298267, the contents of which are incorporated herein by reference in their entirety for all purposes. In one embodiment, the coating can include a conductive polymer. In one aspect, the coating can include a binder as described above and particles of a conductive material, such as carbon black, carbon nanotubes, graphene, gold, silver, or a combination thereof. In one aspect, the coating includes vapor-deposited diamond-like carbon or the product of the pyrolysis of a carbonaceous polymer.

[0103] The current collector may have any suitable porosity, and in one aspect is non-porous. In one aspect, the current collector is effectively impermeable to the target gas, for example, carbon dioxide.

[0104] Electroswing adsorption cells can be stacked in series, and the current collector can block the transport of ions, reactants, and released gases from a first cell to a second adjacent cell. Furthermore, the current collector can provide mechanical structure and stability to the electroswing adsorption cell. The current collector can optionally include ribs that form channels that provide flow fields for gas distribution throughout the cell. The ribs can direct electrons throughout the electroswing adsorption cell and optionally provide desirable structural integrity. When present, the ribs can comprise, for example, carbon, metal, composite, or a combination thereof, as disclosed above, and can optionally include a coating, each of which is further described above. The ribs can comprise the same material as the current collector. The ribs can comprise a different material than the current collector. The ribs can comprise a material that can be partially compressed to accommodate manufacturing tolerances in thickness. For example, the ribs can comprise an electronically conductive closed-cell foam or gasket. The ribs can be convex or concave relative to the current collector surface and can have any suitable cross-sectional shape, such as rectangular or round.

[0105] In one embodiment, a first side of the current collector can face an adsorptive electrode (e.g., a patterned first electrode), and the second side, the opposite side of the current collector, faces a non-adsorbent counter electrode (e.g., a second electrode) or an end plate. In one embodiment, both sides of the current collector can face the adsorptive electrode. The side of the current collector facing the adsorptive electrode can include a flow field. The sides of the current collector, e.g., the first side and the second side, can each independently comprise the same or different materials. In one embodiment, an intervening layer comprising a barrier material, e.g., a material that is electrically conductive and can block ion or gas transport, can be inserted between the first and second sides of the current collector. In one embodiment, the barrier material can include a metal foil.

[0106] The current collector may include features to aid in sealing the perimeter of the device. Such features may include grooves, steps, bevels, or combinations thereof. Such features are described, for example, in U.S. Patent Application Publication No. 2002 / 0197519, the contents of which are incorporated herein by reference in their entirety for all purposes.

[0107] The current collector may further include channels extending through the interior of the current collector, preferably through which a coolant may flow. The coolant channels may be arranged so that the coolant flow rate is highest in the region of the cell where the rate of heat generation is expected to be highest, as can be readily determined by one skilled in the art. The use of parallel or serpentine configurations has been described. In one embodiment where a foam or mesh, e.g., a conductive foam or mesh, is used, the coolant may flow through the foam or mesh. The foam or mesh may be provided between two layers of the current collector. In one embodiment, the coolant may flow through a corrugated or wavy structure provided between opposing layers of the current collector.

[0108] In one embodiment, the current collector can include a first sheet containing channels for reactant gas flow on a first surface and channels for coolant on a second, opposite surface. The first sheet can be attached to a second sheet, which provides electrical conduction perpendicular to the plane of the sheet while forming a boundary for the coolant channels. The first sheet can be attached to the second sheet by any suitable method, such as brazing, welding, soldering, lamination, diffusion bonding, compression, or adhesive bonding. The coolant channels can be formed by nesting adjacent plates, which contain flow fields for the first and second electrodes. Coolant channels are described in U.S. Patent No. 6,099,984, and further exemplary coolant flow patterns can be found in U.S. Patent Application Publication Nos. 2004 / 0209150 and 2003 / 0203260, the contents of each of which are incorporated herein by reference in their entireties for all purposes.

[0109] The current collector can further include a sensor, for example, a voltage sensor or voltage sensitive wire connected to the current collector. In one aspect, the current collector can further include a heating element.

[0110] In one embodiment, the current collector may include members to facilitate assembly, such as alignment pins. Alternatively, a frame may be provided around the current collector to aid in alignment or sealing. Examples of various suitable current collector components can be found in U.S. Patent Application Publication No. 2003 / 0022052, the contents of which are incorporated herein by reference in their entirety for all purposes.

[0111] The electroswing adsorption cell can optionally further include a gas flow field. If present, the gas flow field can be disposed between the first electrode and the current collector. If a gas diffusion layer is not present in the electroswing adsorption cell, the gas flow field can be disposed adjacent to the first electrode on the opposite side of the separator. In one embodiment, the gas flow field can be disposed adjacent to the current collector, or the side of the current collector can include a flow field. The flow field can include a structure for directing the reactant fluid to flow from the inlet to the outlet. Without wishing to be bound by theory, the flow field serves to provide uniform reactant flow to the electrode region. Preferably, the flow field provides uniform reactant flow to the electrode region, a low barrier to flow, e.g., low pressure drop, and adequate electrical conduction from the electrode to the current collector through the flow field.

[0112] The gas flow field can optionally further include a gas diffusion layer. The gas diffusion layer can be disposed adjacent to the first electrode on the opposite side of the separator. The gas diffusion layer can include a porous, electrically conductive material. In one embodiment, the gas diffusion layer has a porosity of, for example, greater than or equal to 60%, greater than or equal to 70%, greater than or equal to 75%, greater than or equal to 80%, or greater than this. In one embodiment, the gas diffusion layer has a porosity of less than or equal to 85%, less than or equal to 90%, or greater than this. Combinations of these ranges are possible. For example, in one embodiment, the gas diffusion layer of the first electrode has a porosity of greater than or equal to 60% and less than or equal to 90%. Other porosities are also possible. Examples of suitable materials for the gas diffusion layer include, without limitation, carbon paper (treated, PTFE-treated, or untreated), carbon cloth, or non-woven carbon fiber or carbon nanotube mat.

[0113] In one aspect, the flow field can include a porous foam or mesh that can be bonded to a non-porous plate by conductive adhesive, welding, thermal bonding, or sintering.

[0114] The flow field can include a channel. The channel can be defined by two or more ribs. In one embodiment, the channel, the rib, or both can each independently have an average width of at least 0.1 mm, at least 0.2 mm, at least 0.3 mm, at least 0.4 mm, at least 0.5 mm, at least 0.6 mm, at least 0.8 mm, at least 0.9 mm, at least 1 mm, at least 2 mm, at least 3 mm, at least 4 mm, at least 5 mm, at least 6 mm, at least 7 mm, at least 8 mm, or at least 9 mm. In one embodiment, the channel, the rib, or both can each independently have an average width of 10 mm or less, 9 mm or less, 8 mm or less, 7 mm or less, 6 mm or less, 5 mm or less, 4 mm or less, 3 mm or less, 2 mm or less, 1 mm or less, 0.9 mm or less, 0.8 mm or less, 0.7 mm or less, 0.6 mm or less, 0.5 mm or less, 0.4 mm or less, 0.3 mm or less, or 0.2 mm or less. Combinations of the above-referenced average widths for channels and / or ribs are also possible.

[0115] In one aspect, the channels, ribs, or both can each independently have an average depth of at least 0.1 mm, at least 0.2 mm, at least 0.3 mm, at least 0.4 mm, at least 0.5 mm, at least 0.6 mm, at least 0.8 mm, at least 0.9 mm, at least 1 mm, at least 2 mm, or at least 3 mm. In one aspect, the channels, ribs, or both can each independently have an average depth of 4 mm or less, 3 mm or less, 2 mm or less, 1 mm or less, 0.9 mm or less, 0.8 mm or less, 0.7 mm or less, 0.6 mm or less, 0.5 mm or less, 0.4 mm or less, 0.3 mm or less, or 0.2 mm or less. Combinations of the above-referenced average depths for the channels and / or ribs are also possible.

[0116] Various methods for manufacturing the flow field can be used, such as machining, injection molding, compression molding, extrusion, embossing, or stamping. Exemplary methods are described, for example, in U.S. Patent Application Publication Nos. 2004 / 0151975 and 2003 / 0022052, the contents of each of which are incorporated by reference in their entirety for all purposes. In one aspect, the flow field can include corrugated metal with bonds to route flow from one channel to an adjacent channel, as described, for example, in U.S. Patent Application Publication No. 2002 / 0081477, the contents of which are incorporated by reference in their entirety for all purposes.

[0117] The flow pattern of the flow field can have any suitable configuration, for example, providing parallel, serpentine, or interdigitated flow. Non-limiting examples of serpentine flow patterns are provided in U.S. Pat. No. 6,309,773, the contents of which are incorporated herein by reference in their entirety for all purposes. The flow channels can have uniform cross-sections or can have regions that taper or constrict, for example, to provide proper distribution of reactants across the cell area. The flow channels can also contain disruptions or obstacles to create turbulence, which can improve transport of reactants to the electrodes, for example. Exemplary flow channels are described in U.S. Pat. No. 6,756,149, the contents of which are incorporated herein by reference in their entirety for all purposes. The flow field pattern and dimensions can be the same for each flow field within a cell, or they can vary depending on the location of the cell within the stack and the nature of the electrodes facing the flow field, as can be readily determined by one skilled in the art. In one aspect, when channels are present on both sides of the current collector, the incorporation of channels can also reduce the thickness of the stack.

[0118] In one embodiment, a manifold can be used to deliver process gases, e.g., reactant gases, to the electroswing adsorption cell and to transport product gases, e.g., evolved gases, out of the electroswing adsorption cell. The manifold can distribute the gases. Parameters, e.g., the length and cross-sectional dimensions of the manifold, can be selected to obtain appropriate characteristics, e.g., pressure drop. The manifold also preferably prevents gas leakage. Exemplary manifold designs that can be used include, but are not limited to, those disclosed in U.S. Pat. Nos. 6,159,629; 6,174,616; 5,486,430; 5,776,625; and 6,017,648, the contents of each of which are incorporated herein by reference in their entirety for all purposes.

[0119] In one embodiment, the electroswing adsorption cell can include a seal to prevent leakage of process gas from the electroswing adsorption cell. Surfaces facing the seal area, such as the surfaces of the gas diffusion layer, electrodes, or separator, can be impregnated with a gas-impermeable sealant around their periphery. Preferably, the shape of the seal is selected to avoid introducing stresses that could lead to separator puncture, fatigue, or tearing. The thickness of the seal can be uniform or can vary across different regions of the seal relative to the edges of the electrodes and gas diffusion layer. The seal is electrically insulating and chemically and electrochemically non-reactive. The seal can include a suitable O-ring, gasket, or adhesive. The seal can include ridges or beads of fluid-impermeable material deposited around a member, such as a current collector or manifold. In one embodiment, the seal can include an elastomer, and a thermoset or thermoplastic, such as an epoxy, rubber, polyolefin, silicone, fluoropolymer, fluoroelastomer, or chloropolymer. In one embodiment, the seal can include a foam, such as foamed rubber. In one embodiment, the closure may comprise a heat-shrinkable film. Exemplary sealing materials are described in U.S. Patent No. 6,440,597 and U.S. Patent Application Publication No. 2006 / 0073385, the contents of each of which are incorporated by reference in their entirety for all purposes.

[0120] In one aspect, when the seal is a gasket, the gasket can optionally include a filler, which preferably provides a thermal expansion coefficient of the gasket material that matches that of the adjacent material, e.g., the current collector material. Exemplary fillers can include, but are not limited to, glass, polystyrene, poly(tetrafluoroethylene) (PTFE), or insulating metal oxides, such as silica or alumina.

[0121] Suitable seals can be produced by any suitable method, for example, by injecting a binder polymer into a groove around the cell edge, as described in U.S. Patent Application Publication No. 2003 / 0031914, the contents of which are incorporated herein by reference in their entirety for all purposes. The method can include forming a grooved surface with a correspondingly shaped gasket, as described in U.S. Patent Application Publication No. 2003 / 0072988, the contents of which are incorporated herein by reference in their entirety for all purposes. In one embodiment, the sealant material can be coated, sprayed, laminated, or injection molded onto the current collector or onto an assembly of gas diffusion layers, electrodes, separators, or combinations thereof. The sealant can encapsulate the outward-facing cell edge. Examples of seal geometries are described in U.S. Patent Application Publication Nos. 2007 / 0231619, 2007 / 0042254, and 2002 / 0172852, the contents of each of which are incorporated by reference in their entirety for all purposes, as well as U.S. Patent No. 6,261,711. In one aspect, the gaskets on opposite sides of the separator can be connected to one another via through-holes optionally included in the peripheral region of the separator.

[0122] To improve sealing, in one embodiment, the separator can be non-porous in the peripheral region. Methods for rendering the separator non-porous include heat-pressing the separator to a temperature sufficient to cause the separator material (e.g., polymeric material) to flow, thereby filling the pores. The separator can be heat-pressed or thermally bonded to the gasket, or adhered with a sealant.

[0123] To prevent the internal temperature from rising above a temperature that could damage the electroswing adsorption cell, it may be advantageous to remove heat from the electroswing adsorption cell. Heat removal can be achieved through the use of coolant channels, as previously discussed. In one aspect, the electroswing adsorption cell can be cooled by blowing air over the sides of the electroswing adsorption cell. In one aspect, the electroswing adsorption cell can be cooled by flowing coolant through tubes or ducts parallel to or within the sides of the electroswing adsorption cell. In one aspect, the current collector may not include any coolant channels, and cooling can be provided by effectively using the process gas as a coolant and controlling the flow rate of the process gas through the electroswing adsorption cell. This cooling method can be particularly advantageous when the process gas (reactant gas) is air.

[0124] In one aspect, at least a portion of the electroswing adsorption cell can be heated. For example, the end portions of the electroswing adsorption cell can be heated, or the cell ends (e.g., "end cells") of the electroswing adsorption cell can be heated. Without wishing to be bound by theory, heating the electroswing adsorption cell can enable higher capture rates or prevention of moisture condensation in humid process gases. Electrically resistant heating elements can be incorporated or positioned, for example, adjacent to the end plates or manifolds.

[0125] Applying pressure across the electroswing adsorption cell can be advantageous for reducing contact resistance between components within the electroswing adsorption cell, such as between the flow field and the gas diffusion layer. Applying pressure can also be advantageous for improving the hermeticity of the seals. Pressure can be applied across the electroswing adsorption cell, for example, using tie rods or external clamps. The tie rods can be internal or external to the seals and manifold. It is also preferable to apply pressure evenly without localizing areas of mechanical stress that could lead to mechanical failure. Those skilled in the art are familiar with the design of washers, disc springs, coil springs, Belleville washers, nuts, clamps, frames, fasteners, collets, wedges, or pressure plates to apply pressure evenly and avoid stress concentrations. Examples of compression assemblies are described, for example, in U.S. Pat. No. 6,190,793, the contents of which are incorporated herein by reference in their entirety for all purposes.

[0126] In one aspect, the electroswing adsorption cell advantageously comprises a Lewis acid (e.g., CO) at room temperature and atmospheric pressure and concentration at a rate of at least 1 g of Lewis acid / m 2 / hour, at least 2 g of Lewis acid / m 2 / hour, at least 3g Lewis acid / m 2 / hour, at least 4g Lewis acid / m 2 / hour, at least 5g Lewis acid / m 2 / hour, at least 6g Lewis acid / m 2 / hour, at least 7g Lewis acid / m 2 / hour, at least 8g Lewis acid / m 2 / hour, at least 9g Lewis acid / m 2 / hour, at least 10 g of Lewis acid / m 2 / hour, at least 20 g of Lewis acid / m 2 / hour, at least 30 g of Lewis acid / m 2 / hour, at least 40 g of Lewis acid / m 2 / hour, at least 50 g of Lewis acid / m 2 / hour, at least 60 g of Lewis acid / m 2 / hour, at least 70 g of Lewis acid / m 2 / hour, at least 80 g of Lewis acid / m 2 / hour, at least 90 g of Lewis acid / m 2 / hour, at least 100 g of Lewis acid / m 2 / h, at least 200 g of Lewis acid / m 2 / h, at least 300 g of Lewis acid / m 2 / h, at least 400 g of Lewis acid / m 2 / hour, at least 500 g of Lewis acid / m 2 / h, at least 600 g of Lewis acid / m 2 / hour, at least 700 g of Lewis acid / m 2 / h, at least 800 g of Lewis acid / m 2 / hour, at least 900 g of Lewis acid / m 2 / hour, or at least 1,000 g of Lewis acid / m 2 / Can be captured at the speed of time.

[0127] Electroswing adsorption cells according to various aspects of the present disclosure are further illustrated and described in detail below.

[0128] FIG. 1A is a schematic diagram of an asymmetric electroswing adsorption cell 100 including a first patterned electrode 110. The first patterned electrode 110 includes a conductive backbone 120 on which electroactive species 130 are disposed, an electrolyte region 140, and a gas region 150. The conductive backbone 120 spans and contacts the electrolyte region 140. In one embodiment, the conductive backbone 120 can span the gas region 150. In one embodiment, the gas region 150 does not include the conductive backbone 120. The patterned electrode 110 is coupled to a gas flow field 160, which supplies a gas flow containing a target gas species to the patterned electrode 110. The electroswing adsorption cell 100 further includes a counter electrode 170, which can balance the charge of the electroactive species 130 when the electroactive species 130 is reduced. A separator 180 is disposed between the patterned electrode 110 and the counter electrode 170.

[0129] In one embodiment, it may be desirable to provide a symmetric electrochemical swing adsorption cell as shown in FIG. 1B using a second patterned electrode in place of counter electrode 170. In symmetric electrochemical swing adsorption cell 101, first patterned electrode 111 and second patterned electrode 112 may be compositionally identical to those disclosed for patterned electrode 110, but in use, their charge states will be different. Similarly, first gas flow field 161 and second gas flow field 162 may each independently be as described for gas flow field 160. A symmetric electrochemical swing adsorption cell may be desirable because it may provide additional efficiencies; for example, the first patterned electrode may provide capture, while the second patterned electrode may provide release of the target species. Thus, for clarity and ease of explanation, an asymmetric cell may be described, but a second gas flow field and a second patterned electrode may be used in place of the counter electrode to provide a symmetric cell.

[0130] 2A shows an electroswing adsorption cell 200 comprising a patterned electrode 210. As shown in FIG. 2A, the patterned electrode 210 comprises a conductive backbone 220 having electroactive species 230 disposed thereon, an electrolyte region 240, and a gas region 250. The electroswing adsorption cell 200 further comprises a second electrode 270 and a separator 280. In one embodiment, the electroswing adsorption cell 200 further comprises a gas diffusion layer 215 between the patterned electrode 210 and the gas flow field 260.

[0131] The capture rate on a multiphase reaction zone (eg, patterned electrode 210) can be approximated by Fick's law according to Equation 1:

[0132]

number

[0133] where CR is the capture rate of Lewis acid by the electroswing adsorption cell 200 (e.g., grams of Lewis acid / m 2 / hr), ε is the volume fraction of the electrolyte in the electrolyte region 240, and D is the diffusivity of the dissolved Lewis gas in the electrolyte (m 2 / hr), τ is the torsion (often -0.5 (approximated as), c sat is the concentration of dissolved gas in the electrolyte at the interface between the electrolyte region 240 and the gas region 250, and the electrolyte is the concentration of Lewis gas in the gas phase (mol / m 3 ), M is the molecular weight of the target gas species (g / mol), and L D is the diffusion length, e.g., the average thickness of the electrolyte region 240 in the y-direction. Equation 1 shows that the rate at which the electroswing adsorption cell 200 captures gas is inversely proportional to the width of the electrolyte region 240.

[0134] The conductive scaffold 220 can be arranged in a random, uneven pattern, as shown in Figure 2A, or in a regular pattern, such as a woven carbon fiber material. In one embodiment, the particles comprising the conductive scaffold 220 can have a narrow particle size distribution, as shown in Figure 2B. In one embodiment, the particles in the conductive scaffold 220 can include small particles 224, such as nanotubes, vapor-grown carbon fibers, or graphene, arranged on larger fibers 222, such as carbon fibers, as shown in Figure 2C.

[0135] 2D, gas flow field 260 can include channels 262 and ribs 264. In one embodiment, gas diffusion layer 215 can function to spread the gas flow from channels 262 beneath ribs 264. The average width of channels 262, ribs 264, or both (e.g., in the y-direction of FIG. 2D), and the average depth of channels 262 (e.g., in the z-direction of FIG. 2D) can be as described above.

[0136] In one embodiment, for example, as shown in Figure 2E, when gas flow field 260 includes porous metal foam, the ribs and channels may be omitted if desired. In one embodiment, gas flow field 260 can include a portion comprised of porous metal foam and a portion including channels 262 and ribs 264. In one embodiment, the porosity of the gas flow field is greater than the porosity of the gas diffusion layer.

[0137] 3 and 4 show an electroswing adsorption cell 300 with a patterned electrode 310. FIG. 3 shows a cross-sectional view of the electroswing adsorption cell 300, while FIG. 4 shows a front view of the patterned electrode 310. The patterned electrode 310 includes a conductive backbone 320 with electroactive species 330 disposed thereon, an electrolyte region 340, and a gas region 350. The electroswing adsorption cell 300 further includes a gas flow field 360, a second electrode 370, and a separator 380. In one embodiment, the electroswing adsorption cell 300 may include a gas diffusion layer 315 between the patterned electrode 310 and the gas flow field 360. While FIGS. 3 and 4 show the gas region 350 as being cylindrical or conical, the gas region may have any suitable shape.

[0138] 3 and 4 further illustrate the dimension L I , L D , and W G Indicates L I is the cation C + describes the distance that travels from the separator to the active site of the electroactive species P in the ESA cell, e.g., the average distance from the separator 380 to the gas diffusion layer 315. In other words, L I L describes the distance that cations travel in the electrolyte region 340 from the separator 380 to the active sites in the patterned electrode 310. D describes the diffusion length of the Lewis acid gas path, e.g., the average distance between gas regions 350. In other words, L D describes the diffusion length of the target gas species through the electrolyte to the active sites in the patterned electrode 310. Gdescribes the average width of the gas region 350. If the gas region 350 is spherical or cylindrical (e.g., as in Figures 3 and 4), W G is the diameter of the gas region 350. If the gas region 350 contains an irregular shape, W G is the volume average width of the gas region 350.

[0139] L I , L D , and W G can be as explained above. For example, L D can be set to 1 μm to 1 mm. For example, W G For example, L I The thickness can be set to 15 to 500 μm.

[0140] 5 and 6 show an electroswing adsorption cell 400 with a patterned electrode 410. FIG. 5 shows a cross-sectional view of the electroswing adsorption cell 400, while FIG. 6 shows a front view of the patterned electrode 410. The patterned electrode 410 includes a conductive backbone 420 with electroactive species 430 disposed thereon, an electrolyte region 440, and a gas region 450. The electroswing adsorption cell 400 further includes a gas flow field 460, a second electrode 470, and a separator 480. In one embodiment, the electroswing adsorption cell 400 may include a gas diffusion layer 415 between the patterned electrode 410 and the gas flow field 460. FIGS. 5 and 6 show the gas region having a stripe or rectangular shape.

[0141] Dimension L I , L D , and W G are included in Figures 5 and 6 and are defined above.

[0142] 7 and 8 show an electroswing adsorption cell 500 with a patterned electrode 510. FIG. 7 shows a cross-sectional view of the electroswing adsorption cell 500, while FIG. 8 shows a front view of the patterned electrode 510. The patterned electrode 510 includes a conductive backbone 520 coated with an active polymer 530, an electrolyte region 540, and a gas region 550. The electroswing adsorption cell 500 further includes a gas flow field 560, a second electrode 570, and a separator 580. In one embodiment, the electroswing adsorption cell 500 can include a gas diffusion layer 515 between the patterned electrode 510 and the gas flow field 560.

[0143] As shown in FIGS. 7 and 8 , the gas region 550 of the patterned electrode 510 is wider near the gas flow field 560 and narrower near the separator 580. In other words, the gas region 550 has a trapezoidal cross-section. Conversely, the electrolyte region 540 may be wider near the separator 580 and narrower near the gas flow field 560. Without being bound by theory, the overall resistance of the electroswing adsorption cell 500 includes contributions from the ionic resistivity of the electrolyte, the electrical resistivity of the conductive framework 520, charge transfer, and Lewis acid diffusion. Without wishing to be limited by theory, it is understood that in the separator 580, all of the current is carried by ions. As current travels through the patterned electrode 510, it is transferred from ions in the electrolyte phase to electrons in the conductive framework 520 by electrochemical reactions. In the gas flow field 560, all of the current is carried by electrons. The ionic resistivity is proportional to the current density divided by the volume fraction of the electrolyte. Thus, the overall cell resistance of electroswing adsorption cell 500 can be reduced by having a larger volume fraction of electrolyte near separator 580. Including more electrolyte near separator 580 can facilitate the movement of ions transported from counter electrode 570. Furthermore, a geometry with a wider gas region 550 near gas flow field 560 and a narrower gas region 550 near separator 580 can be easier to manufacture and can reduce the risk of defects blocking the gas flow path.

[0144] In one aspect, L I may have the same or substantially similar characteristics / dimensions as above. DS describes the diffusion length of a target gas species to an active site in the patterned electrode 510 near the interface between the patterned electrode 510 and the separator 580. DC describes the diffusion length of a target gas species to an active site in the patterned electrode 510 near the interface between the patterned electrode 510 and the gas diffusion layer 515. S describes the average width of the gas region 550 near the interface between the patterned electrode 510 and the separator 580. W C describes the average width of the gas region 550 near the interface between the patterned electrode 510 and the gas diffusion layer 515. In one embodiment, W S is W G may have the same or substantially similar dimensions as

[0145] In one aspect, W C Within this range, W C can be at least 1 μm, at least 2 μm, at least 3 μm, at least 4 μm, at least 5 μm, at least 6 μm, at least 7 μm, at least 8 μm, at least 9 μm, at least 10 μm, at least 20 μm, at least 30 μm, at least 40 μm, at least 50 μm, at least 60 μm, at least 70 μm, at least 80 μm, at least 90 μm, at least 100 μm, at least 150 μm, at least 200 μm, at least 250 μm, at least 300 μm, at least 350 μm, at least 400 μm, or at least 450 μm. Also within this range, W Ccan be 500 μm or less, 450 μm or less, 400 μm or less, 350 μm or less, 300 μm or less, 250 μm or less, 200 μm or less, 150 μm or less, 100 μm or less, 90 μm or less, 80 μm or less, 70 μm or less, 60 μm or less, 50 μm or less, 40 μm or less, 30 μm or less, 20 μm or less, 10 μm or less, 9 μm or less, 8 μm or less, 7 μm or less, 6 μm or less, 5 μm or less, 4 μm or less, 3 μm or less, or 2 μm or less. C A combination of values ​​is also possible.

[0146] In one aspect, L DC Within this range, L DC can be at least 1 μm, at least 2 μm, at least 3 μm, at least 4 μm, at least 5 μm, at least 6 μm, at least 7 μm, at least 8 μm, at least 9 μm, at least 10 μm, at least 20 μm, at least 30 μm, at least 40 μm, at least 50 μm, at least 60 μm, at least 70 μm, at least 80 μm, at least 90 μm, at least 100 μm, at least 200 μm, at least 300 μm, at least 400 μm, at least 500 μm, at least 600 μm, at least 700 μm, at least 800 μm, or at least 900 μm. Also within this range, L DC can be 1 mm or less, 900 μm or less, 800 μm or less, 700 μm or less, 600 μm or less, 500 μm or less, 400 μm or less, 300 μm or less, 200 μm or less, 100 μm or less, 90 μm or less, 80 μm or less, 70 μm or less, 60 μm or less, 50 μm or less, 40 μm or less, 30 μm or less, 20 μm or less, 10 μm or less, 9 μm or less, 8 μm or less, 7 μm or less, 6 μm or less, 5 μm or less, 4 μm or less, 3 μm or less, or 2 μm or less. DC Combinations of the above ranges are also possible.

[0147] In one aspect, L DS Within this range, L DScan be at least 1 μm, at least 2 μm, at least 3 μm, at least 4 μm, at least 5 μm, at least 6 μm, at least 7 μm, at least 8 μm, at least 9 μm, at least 10 μm, at least 20 μm, at least 30 μm, at least 40 μm, at least 50 μm, at least 60 μm, at least 70 μm, at least 80 μm, at least 90 μm, at least 100 μm, at least 200 μm, at least 300 μm, at least 400 μm, at least 500 μm, at least 600 μm, at least 700 μm, at least 800 μm, or at least 900 μm, at least 1 mm, at least 1.1 mm, at least 1.2 mm, at least 1.3 mm, or at least 1.4 mm. Also within this range, L DS 1.5mm or less, 1.4mm or less, 1.3mm or less, 1.2mm or less, 1.1mm or less, 1mm or less, 900μm or less, 800μm or less, 700μm or less, 600μm or less, 500μm or less, 400μm or less, 300μm or less, 200μm or less, 100μm or less, 9 It can be 0 μm or less, 80 μm or less, 70 μm or less, 60 μm or less, 50 μm or less, 40 μm or less, 30 μm or less, 20 μm or less, 10 μm or less, 9 μm or less, 8 μm or less, 7 μm or less, 6 μm or less, 5 μm or less, 4 μm or less, 3 μm or less, or 2 μm or less. L DS Combinations of the above ranges are also possible.

[0148] In one aspect, W c / W s can be between 1 and 10 (i.e., 1 / 1 and 10 / 1). Within this range, W c / W scan be at least 1, at least 1.1, at least 1.2, at least 1.3, at least 1.4, at least 1.5, at least 1.6, at least 1.7, at least 1.8, at least 1.9, at least 2, at least 2.1, at least 2.2, at least 2.3, at least 2.4, at least 2.5, at least 2.6, at least 2.7, at least 2.8, at least 2.9, at least 3, at least 3.5, at least 4, at least 5, at least 6, at least 7, at least 8, or at least 9. Also within this range, W c / W s can be 10 or less, 9 or less, 8 or less, 7 or less, 6 or less, 5 or less, 4 or less, 3.5 or less, 3 or less, 2.9 or less, 2.8 or less, 2.7 or less, 2.6 or less, 2.5 or less, 2.4 or less, 2.3 or less, 2.2 or less, 2.1 or less, 2 or less, 1.9 or less, 1.8 or less, 1.7 or less, 1.6 or less, 1.5 or less, 1.4 or less, 1.3 or less, 1.2 or less, or 1.1 or less. c / W s A combination of the above values ​​is also possible.

[0149] 9 and 10 show an electroswing adsorption cell 600 with a patterned electrode 610. FIG. 9 shows a cross-sectional view of the electroswing adsorption cell 600, while FIG. 10 shows a front view of the patterned electrode 610. The patterned electrode 610 includes a conductive backbone 620 with electroactive species 630 disposed thereon, an electrolyte region 640, and a gas region 650. The electroswing adsorption cell 600 further includes a gas flow field 660, a second electrode 670, and a separator 680. In one embodiment, the electroswing adsorption cell 600 can include a gas diffusion layer 615 between the patterned electrode 610 and the gas flow field 660.

[0150] As shown in FIGS. 9 and 10, the patterned electrode 610 has dimensions L I , W G , L D , and L M It has. L I , W G , and L Dcan be as described above.

[0151] L M defines the length of the electrolyte-filled region covering the separator 680. L M L D In one embodiment, L M Within this range, L M can be at least 0 μm, at least 1 μm, at least 2 μm, at least 3 μm, at least 4 μm, at least 5 μm, at least 6 μm, at least 7 μm, at least 8 μm, at least 9 μm, at least 10 μm, at least 11 μm, at least 12 μm, at least 13 μm, at least 14 μm, at least 15 μm, at least 16 μm, at least 17 μm, at least 18 μm, at least 19 μm, at least 20 μm, at least 21 μm, at least 22 μm, at least 23 μm, at least 24 μm, at least 25 μm, at least 26 μm, at least 27 μm, at least 28 μm, or at least 29 μm. Also within this range, L M can be 30 μm or less, 29 μm or less, 28 μm or less, 27 μm or less, 26 μm or less, 25 μm or less, 24 μm or less, 23 μm or less, 22 μm or less, 21 μm or less, 20 μm or less, 19 μm or less, 18 μm or less, 17 μm or less, 16 μm or less, 15 μm or less, 14 μm or less, 13 μm or less, 12 μm or less, 11 μm or less, 10 μm or less, 9 μm or less, 8 μm or less, 7 μm or less, 6 μm or less, 5 μm or less, 4 μm or less, 3 μm or less, 2 μm or less, or 1 μm or less. M A combination of values ​​is also possible.

[0152] FIG. 11 shows a three-dimensional representation of an electroswing adsorption cell 700 with a patterned electrode 710. The patterned electrode 710 includes an electrolyte region 740 and a gas region 750. The electroswing adsorption cell 700 further includes a gas flow field 760 with gas channels 762 and ribs 764. The electroswing adsorption cell 700 further includes a second electrode 770 and a separator 780. In one embodiment, the gas region 750 can have a rectilinear cross-sectional shape, such as a rectangular or prismatic shape. In one embodiment, the gas channel 762 can have a rectangular parallelepiped shape. FIG. 11 is not to scale. For example, the widths of the ribs 764 and channels 762 can be on the order of millimeters, as previously described, while the widths of the gas region 750 and electrolyte region 740, respectively, are on the order of W. G and L D is shown by

[0153] The gas region 750 is oriented perpendicular to the gas channels 762 to promote gas flow from the gas channels 762 parallel to the separator 780. This aspect can be particularly advantageous when the flow field 760 has an interdigitated flow arrangement, in which inlet channels alternate with outlet channels. For example, in FIG. 11 , one of the two channels shown is an inlet channel, while the other is an outlet channel. It is understood that FIG. 11 is a subset of a cell, and a cell may have multiple inlet and outlet channels. In the structure shown in FIG. 11 , the gas diffusion layer is omitted to facilitate gas convection through the gas region. The function of the gas diffusion layer can be to provide a compressible material that can accommodate manufacturing thickness variations in the cell components (electrodes, separators, ribs, and current collectors). In embodiments lacking a gas diffusion layer, the ribs may advantageously be constructed of a compressible material such as a conductive closed-cell molding or a gasket.

[0154] FIG. 12 shows an electroswing adsorption cell 600 with a patterned electrode 610. The patterned electrode 610 includes an electrolyte region 640 with a conductive backbone 620 on which electroactive species 630 are disposed, an electrolyte 645 disposed within the electrolyte region, and a gas region 650. The electroswing adsorption cell 600 further includes a gas flow field 660, a second electrode 670, a separator 680, and a gas diffusion layer 615. The patterned electrode 610 can be assembled by pleating or folding the electrolyte region 640 with the gas region 650. As shown in FIG. 12, folding the electrolyte region 640 with the gas region 650 forms a layer of the gas region 650 between the electrolyte region and the flow field (e.g., the electrolyte region does not contact the flow field). Similarly, folding the electrolyte region 640 with the gas region 650 forms a layer of the electrolyte region 640 between the gas region and the separator (e.g., the gas region does not contact the separator). In addition, the cation migration distance L I and gas region W G The width of W is shown in FIG. 12. For the folded or pleated electrode configuration described in FIG. G is the unfolded state W F The diffusion length L for the patterned electrode 610 can be twice the thickness of the gas region 650. D is shown in Figure 12, which shows the unfolded state L M In one embodiment, the thickness of the electrolyte region 640 at L I , W G , and L D are L as described above with respect to Figures 3 and 4, respectively. I , W G , and L D In one embodiment, W G and L D may be constant in the z direction. G and L D may be different in the z direction.

[0155] FIG. 13 shows an electroswing adsorption cell 1600 comprising a patterned electrode-separator assembly 1610. The patterned electrode-separator assembly 1610 comprises an electrolyte region 1640 comprising a conductive framework and electrolyte in which electroactive species are disposed, a gas region 1650, a second electrode 1670, and a separator 1680. The electroswing adsorption cell 1600 further comprises a gas flow field 1660 and an optional gas diffusion layer 1615. The patterned electrode-separator assembly 1610 can be assembled by placing the electrolyte region 1640 on the separator 1680, placing the gas region 1650 on the electrolyte region 1640, and placing the second electrode 1670 on the opposite side of the separator 1680 to provide the electrode-separator assembly 1610. The electrode-separator assembly 1610 can be pleated or folded. The patterned electrode-separator assembly 1610 can then be combined with a gas diffusion layer 1615 and a flow field 1660 to provide the cell 1600 .

[0156] Electroswing adsorption cells according to the present disclosure can have any combination of the features described above with reference to Figures 1-13. For example, those skilled in the art of flow field design will recognize that combinations of embodiments are possible. For example, the cell of Figure 11, including flow channels oriented perpendicular to the gas region, can be combined with the patterned electrodes of Figures 12 or 13, with the electrolyte regions 640 or 1640 of Figures 12 or 13, respectively, oriented perpendicular to the flow channels of Figure 11.

[0157] Methods for fabricating the above-described patterned electrodes represent other aspects of the present disclosure. In one aspect, an electrode comprising multiple electrolyte regions, multiple gas regions, and a conductive scaffold can be fabricated by depositing a composite material on a separator or gas diffusion layer, the composite material including an electrolyte, and the conductive scaffold coated with an electroactive species to form an electrode comprising multiple electrolyte regions and multiple gas regions.

[0158] In one aspect, the composite material deposited on the sacrificial carrier film or separator can include an electroactive species, electronically conductive particles, an electrolyte, and a sacrificial porogen. In one aspect, the composite mixture can be a bicontinuous emulsion. In one aspect, the deposited composite material can include a mixture of an electroactive species, electronically conductive particles, and an electrolyte. In one aspect, the composite material can include an electroactive species, a crosslinker, conductive particles, and a carrier solvent. In one aspect, the composite material can include an electroactive polymer for forming a gel with the electrolyte. In one aspect, the electrolyte can be incorporated into the composite material by capillary action.

[0159] The deposited composite material can comprise an electronically conductive skeleton. In one aspect, the electronically conductive skeleton can have a very high surface energy with the electrolyte (e.g., the electronically conductive skeleton can be ionophobic, e.g., not wettable by the electrolyte). In one aspect, the electronically conductive skeleton can comprise one or more inks printed onto the electronically conductive skeleton. In one aspect, a first ink can comprise an electrolyte and a thermally initiated precursor to form a gel. In one aspect, the first ink can comprise an electroactive species in a carrier solvent. In one aspect, the first ink can comprise an ionophilic active material with a crosslinker. In one aspect, the second ink can comprise a sacrificial pore former. In one aspect, the pore former can comprise a low melting point wax. In one aspect, the deposited composite material can comprise an electronically conductive skeleton coated with an electroactive species and filled with an electrolyte comprising a polymer precursor.

[0160] Depositing the composite material onto a sacrificial carrier film or separator can be accomplished by a variety of commonly known methods, including, but not limited to, coating, spray coating, uniform coating, slot-die coating, gravure coating, inkjet printing, 3D printing, extrusion, coextrusion of multiple phases, or any combination thereof. Electrodes can be fabricated using one or more coating layers. In one embodiment, patterns can be formed by coating, extrusion, or printing two inks, where one ink contains the electronically conductive framework, active material, electrolyte, and gel former, and the second ink contains the sacrificial porogen. In one embodiment, the composite material can uniformly fill the pores of the ionophobic, electronically conductive framework.

[0161] In one aspect, as detailed above, the composite material can optionally undergo a chemical reaction, preferably prior to removing portions of the composite material. In one aspect, the chemical reaction can form ionophobic regions (i.e., regions that repel electrolyte) and ionophilic regions (i.e., regions that attract electrolyte). In one aspect, the chemical reaction can include forming a gel from the reaction of an electrolyte with an electroactive species. In one aspect, the electroactive material precursor can undergo patterned crosslinking to form the electroactive material. In one aspect, crosslinking can be selectively performed to produce crosslinked material only in desired regions of the composite material, allowing the uncrosslinked material to be removed. In one aspect, crosslinking can be induced, for example, by ultraviolet (UV) radiation, infrared (IR) radiation, thermal radiation, patterned thermal radiation, chemical reagents, or any combination thereof. In one aspect, the application of heat can polymerize the active material precursor to form a gel. In one aspect, selective crosslinking can be induced by using a mask, lithography, interference patterns, patterned thermal radiation, or any combination thereof. In one aspect, the method can include treating the electrolyte and electroactive species with a reagent to form an ionogel that fills the pores of the conductive scaffold.

[0162] In one aspect, the electroactive species can be made ionophobic upon contact with a reagent. In one aspect, the reagent can include radiation (e.g., by UV light, e-beam, infrared, etc.) or a chemical reagent. The reagent can be applied through a patterned mask to form a pattern of ionophilic and ionophobic regions in the composite (i.e., forming a patterned electrode). The coating can include an electroactive material precursor, a crosslinking agent, conductive particles, and a carrier solvent. In one aspect, the electroactive active material precursor can undergo patterned crosslinking, as described above.

[0163] The method includes adding a reagent to the composite material to form a first phase and a second phase, with the portion of the composite material removed to form the patterned electrode being the second phase. The first phase can include crosslinked electrode material, and the second phase includes uncrosslinked electrode precursor. The reagent can be a crosslinker added in a patterned structure by a mask, lithography, an interference pattern, patterned thermal radiation, or a combination thereof.

[0164] The method can include removing portions of the composite material to form a patterned electrode. This can include removing a sacrificial porogen. In one aspect, the sacrificial porogen can be removed by, for example, evaporation, rinsing, decomposition, melting, or any suitable chemical or physical removal method, or a combination thereof. In one aspect, removing the portions of the composite material can include laser ablation, lithography, mechanical imprinting, or any combination thereof. In one aspect, removing the portions of the composite material can include rinsing the composite material with a solvent that washes away uncrosslinked electrode precursor but does not remove the crosslinked active material. In one aspect, removing the portions of the composite material can include applying heat to evaporate the sacrificial pore former. In one aspect, removing the portions of the composite material can include dissolving the sacrificial pore former and rinsing with a solvent. Porogen removal by dissolution is further described in the Examples below.

[0165] In one aspect, the chemical reaction step can be carried out partially or completely simultaneously with the removal step. For example, the application of heat can simultaneously polymerize the gel former in the electrolyte while evaporating the sacrificial pore former.

[0166] In one aspect, the electrolyte can be included or deposited with the composite material, hi one aspect, the electrolyte can be added after removing a portion of the composite material to form a patterned electrode.

[0167] In one embodiment, a printer can print a pattern with two inks into a scaffold. The first ink can include an active material and an ionic compound. The ionic compound can be physically mixed with the electroactive species. The ionic compound can be incorporated into the electroactive polymer by copolymerization. The second ink can include an ionic compound that renders regions of the scaffold ionophobic. The scaffold can be ionophilic. In one embodiment, the first ink can include the electroactive species, while the second ink can include an ionic compound that renders regions of the scaffold ionophobic. The inked scaffold can be placed on a sacrificial carrier film or separator prior to composite deposition. The scaffold can then be coupled to a gas flow field and a counter electrode to form an electroswing adsorption cell.

[0168] In one aspect, removal of a portion of the composite material can leave behind pores. In one aspect, the pores can be gas-filled pores. In one aspect, the pores can be permeable gas-filled pores. In one aspect, the pores can be air-filled pores. In one aspect, the pores can have a conical shape, a frustoconical shape, a spherical shape, a striped shape, a rectangular shape, an irregular shape, an amorphous shape, or any combination thereof.

[0169] A method for fabricating an electroswing adsorption cell represents another aspect of the present disclosure.

[0170] In one aspect, an electroswing adsorption cell can be fabricated by depositing a composite material on a separator, the composite material including a conductive scaffold coated with an electrolyte and an electroactive species, forming a first electrode including multiple electrolyte regions and multiple gas regions (e.g., a first patterned electrode), and coupling a gas flow field and a second electrode to the first patterned electrode to provide the electroswing adsorption cell.

[0171] In one aspect, the composite material deposited on the sacrificial carrier film or separator can include an electroactive species, electronically conductive particles, an electrolyte, and a sacrificial porogen. In one aspect, the composite mixture can be a bicontinuous emulsion. In one aspect, the deposited composite material can include a mixture of an electroactive species, electronically conductive particles, and an electrolyte. In one aspect, the composite material can include an electroactive species, a crosslinker, conductive particles, and a carrier solvent. In one aspect, the composite material can include an electroactive polymer for forming a gel with the electrolyte. In one aspect, the electrolyte can be incorporated into the composite material by capillary action.

[0172] The deposited composite material can include an electronically conductive skeleton. In one aspect, the electronically conductive skeleton can have a very high surface energy with the electrolyte (e.g., the electronically conductive skeleton can be ionophobic, e.g., not wettable by the electrolyte). In one aspect, the electronically conductive skeleton can include one or more inks printed onto the electronically conductive skeleton. In one aspect, a first ink can include an electrolyte and a thermally initiated precursor to form a gel. In one aspect, the first ink can include an electroactive species in a carrier solvent. In one aspect, the first ink can include an ionophilic active material with a crosslinker. In one aspect, the second ink can include a sacrificial pore former. In one aspect, the pore former can include a low melting point wax. In one aspect, the deposited composite material can include an electronically conductive skeleton coated with an electroactive species and filled with an electrolyte comprising a polymer precursor.

[0173] Depositing the composite material onto the sacrificial carrier film or separator, as described above, can be accomplished by a variety of commonly known methods, including, but not limited to, coating, uniform coating, slot die coating, gravure coating, inkjet printing, 3D printing, extrusion molding, co-extrusion of multiple phases, or any combination thereof.

[0174] In one aspect, the composite material can undergo a chemical reaction, as detailed above, optionally but preferably prior to removing the portion of the composite material. In one aspect, the electroactive species can become ionophobic upon exposure to a reagent, as detailed above. The method can further include adding a reagent to the composite material to form a first phase and a second phase, as detailed above, and the portion of the composite material removed to form the patterned electrode is the second phase. The method can include removing a portion of the composite material to form the patterned electrode, as detailed above.

[0175] Removal of a portion of the composite material can leave behind pores. In one aspect, the pores can be gas-filled pores. In one aspect, the pores can be permeable gas-filled pores. In one aspect, the pores can be air-filled pores. In one aspect, the pores can have a conical shape, a frustoconical shape, a spherical shape, a striped shape, a rectangular shape, an irregular shape, an amorphous shape, or any combination thereof.

[0176] The method of fabricating an electroswing adsorption cell further includes bonding a patterned electrode to the separator, the gas flow field, and the counter electrode to form the electroswing adsorption cell.

[0177] In one aspect, an electroswing adsorption cell comprising a first patterned electrode having a pleated or folded structure can be provided by providing a composite layer comprising an electrolyte coated with an electroactive species and a first conductive scaffold, providing a second conductive scaffold comprising gas-filled pores, pleating the composite layer with a second composite layer to provide the first patterned electrode, and coupling a gas flow field, a separator, and a second electrode to the first patterned electrode to provide an electrochemical swing adsorption cell having a pleated or folded structure.

[0178] Methods for fabricating patterned electrodes and electroswing adsorption cells according to the present disclosure are further described in Figures 14-19 and in the Examples below.

[0179] 14 illustrates a method 1200 for forming an electroswing adsorption cell. Method 1200 optionally includes depositing a composite material on a sacrificial carrier film in step 1201. Method 1200 includes depositing the composite material on a separator in step 1202, followed by removing the carrier film. Method 1200 optionally includes chemically reacting the composite material in step 1203. Method 1200 also includes removing a portion of the composite material to form a patterned electrode in step 1204, and coupling a gas flow field and a second electrode to the patterned electrode to form a cell in step 1205.

[0180] 15 illustrates a method 1300 for forming an electroswing adsorption cell. Method 1300 optionally includes depositing a composite material on a sacrificial carrier film in step 1301. Method 1300 includes depositing the composite material on a separator in step 1302, with or without a sacrificial carrier film between the composite material and the separator. Method 1300 optionally includes adding a reagent to induce ionophobic and ion-attractive regions in the composite material in step 1303. Method 1300 also includes coupling a gas flow field and a counter electrode to the patterned electrode to form a cell in step 1304.

[0181] FIG. 16 illustrates a method 1500 for forming an electroswing adsorption cell. In step 1501, electroactive material is combined with a conductive scaffold to create a porous composite active layer, which can serve as the electrolyte region. The pores of the active layer can be filled with an electrolyte in step 1502. Optionally, this step can include a gel former, followed by treatment with heat and / or UV light to form a gel electrolyte. The layer of active material and the layer of gas-containing material are pleated to form a patterned electrode. The patterned electrode can be laminated to a cell in step 1520 along with the second electrode, separator, optional gas diffusion layer, and flow fields created in step 1510 to provide the cell.

[0182] FIG. 17 illustrates a method 1900 for forming an electroswing adsorption cell. In step 1901, an electroactive material is combined with a conductive framework material to create a porous composite active layer that can function as an electrolyte region. The active layer can be placed on a separator, and a second electrode can be placed on the opposite side of the active layer in step 1902. The pores of the active layer, separator, and counter electrode can be filled with an electrolyte in step 1903. The electrode-separator-electrode assembly can be pleated with a layer of gas-containing material in step 1904 to create a pleated electrode-separator assembly. The electrode-separator assembly can be laminated into a cell along with gas diffusion layers and flow fields in step 1920.

[0183] Electroswing adsorption cells can be particularly useful for separating a target gas from a gas mixture when the gas mixture contacts the electroswing adsorption cell, and are thus particularly well suited for use in a gas separation system that includes a plurality of electroswing adsorption cells in fluid communication with a gas inlet and a gas outlet.

[0184] A gas mixture, also referred to as an input gas, can be at least partially separated upon exposure to the electroswing adsorption cell. The gas mixture can be, for example, ambient air (e.g., air from the surrounding environment, e.g., outside air). In one aspect, the gas separation system can be used for direct air capture. The systems and methods described herein can be useful for directly removing a target gas, e.g., carbon dioxide, from outside air (e.g., to reduce greenhouse gas levels) without the need for any preconcentration step. Certain aspects of the present disclosure can make the systems and methods described herein particularly useful for direct air capture (e.g., the ability to combine with the target gas while being thermodynamically disfavored from reacting with the major components of outside air, e.g., oxygen).

[0185] In one embodiment, the amount of target gas in the treated gas mixture (e.g., a gas mixture from which a quantity of target gas has been removed by exposure to an electroswing adsorption cell) is less than or equal to 50%, less than or equal to 25%, less than or equal to 10%, less than or equal to 5%, less than or equal to 2%, less than or equal to 1%, less than or equal to 0.5%, or less than or equal to 0.1% of the amount of target gas (in volume percent) in the original gas mixture before treatment (e.g., the amount of target gas in the gas mixture before exposure to an electroswing adsorption cell). In one embodiment, the amount of target gas in the treated gas mixture is greater than or equal to 0.001%, greater than or equal to 0.005%, greater than or equal to 0.01%, greater than or equal to 0.05%, greater than or equal to 0.1%, greater than or equal to 0.5%, greater than or equal to 1%, greater than or equal to 2%, or greater than or equal to 5% of the amount of target gas (in volume percent) in the original gas mixture before treatment. In one embodiment, the concentration of the target gas in the gas mixture is relatively low, for example, when the gas mixture is ambient air. For example, the concentration of the target gas in the gas mixture before exposure to the electroswing adsorption cell may be less than or equal to 500 ppm, or less than or equal to 450 ppm, or less than or equal to 400 ppm, or less than or equal to 350 ppm, or less than or equal to 300 ppm, or less than or equal to 200 ppm. In one embodiment, the concentration of the target gas in the gas mixture may be as low as 100 ppm, or as low as 50 ppm, or as low as 10 ppm.

[0186] In one aspect, the gas mixture (e.g., input gas mixture) is ventilated air. The ventilated air can be air from an enclosed or at least partially enclosed space (e.g., air is circulated within an enclosed space). Examples of spaces where the gas mixture (e.g., ventilated air) may be located include, but are not limited to, enclosed buildings, partially ventilated spaces, automobile cabins, occupied submersibles, aircraft, medical and personal ventilation devices, etc.

[0187] The concentration of the target gas in the ventilated air may be higher than that of ambient air, but lower than that typical for industrial processes. In one embodiment, the concentration of the target gas in the gas mixture prior to exposure to the electroswing adsorption cell is less than or equal to 5,000 ppm, or less than or equal to 4,000 ppm, or less than or equal to 2,000 ppm, or less than or equal to 1,000 ppm. In one embodiment, the concentration of the target gas in the gas mixture (e.g., when ventilated air or air in an enclosed space) is as low as 1,000 ppm, or as low as 800 ppm, or as low as 500 ppm, or as low as 200 ppm, or as low as 100 ppm, or as low as 10 ppm.

[0188] In one embodiment, the gas mixture includes oxygen gas (O). In one embodiment, the gas mixture has a relatively high concentration of oxygen gas (e.g., prior to exposure to the electroswing adsorption cell). Certain aspects of the systems and methods described herein (e.g., selection of a particular electroactive species, gas handling methods in the system, etc.) can contribute to the ability to capture a target gas in a gas mixture where oxygen gas is present without harmful interference. In one embodiment, oxygen gas is present in the gas mixture (e.g., prior to exposure to the electroswing adsorption cell) at a concentration greater than or equal to 0% by volume, or greater than or equal to 0.1% by volume, or greater than or equal to 1% by volume, or greater than or equal to 2% by volume, or greater than or equal to 5% by volume, or greater than or equal to 10% by volume, or greater than or equal to 20% by volume, or greater than or equal to 50% by volume, or greater than or equal to 75% by volume, or greater than or equal to 90% by volume, or greater than or equal to 95% by volume. In one embodiment, oxygen gas is present in the gas mixture at a concentration of less than or equal to 99% by volume, or less than or equal to 95% by volume, or less than or equal to 90% by volume, or less than or equal to 75% by volume, or less than or equal to 50% by volume, or less than or equal to 25% by volume, or less than or equal to 21% by volume, or less than or equal to 10% by volume, or less than or equal to 5% by volume, or less than or equal to 2% by volume.

[0189] In one embodiment, the gas mixture includes water vapor. The gas mixture can include water vapor, for example, because it is ambient air or ventilated air or includes ambient air or ventilated air. In one embodiment, the gas mixture (e.g., prior to exposure to the electroswing adsorption cell) has a relatively high relative humidity. For example, in one embodiment, the gas mixture can have a relative humidity of greater than or equal to 0%, greater than or equal to 5%, greater than or equal to 10%, greater than or equal to 25%, greater than or equal to 50%, greater than or equal to 75%, or greater than or equal to 90% at at least one temperature in the range of −50 to 140° C. In one embodiment, the gas mixture can have a relative humidity of less than or equal to 100%, or less than or equal to 95%, or less than or equal to 90%, or less than or equal to 75%, or less than or equal to 50%, or less than or equal to 25%, or less than or equal to 10% at at least one temperature in the range of -50 to 140°C.

[0190] A target gas can be separated from a gas mixture in a gas separation system by applying a potential difference across an electroswing adsorption cell of the gas separation system. One of ordinary skill in the art, with the benefit of this disclosure, will understand how to apply a potential across an electroswing adsorption cell. For example, the potential can be applied by connecting the negative and positive electrodes to a suitable power source capable of polarizing the negative and positive electrodes. In one aspect, the power source can be a DC voltage. Non-limiting examples of suitable power sources include batteries, a power grid, regenerative power (e.g., wind power generation, solar power generation, tidal power generation), generators, etc., and combinations thereof.

[0191] The potential difference can be applied to the electroswing adsorption cell during at least a portion of the time that the gas mixture is exposed to the electroswing adsorption cell. In one aspect, the potential difference can be applied before exposing the gas mixture to the electroswing adsorption cell.

[0192] Application of a positive voltage to the electroswing adsorption cell during the input mode results in a redox reaction at the negative electrode, in which the electroactive species is reduced. As discussed herein, the electroactive species is selected to have a higher affinity for the target gas in its reduced state than when it is in its oxidized state. By reducing the electroactive species and passing the gas mixture across the first electrode, the target gas can bind to the electroactive species. In this manner, the target gas can be removed from the gas mixture to obtain a treated gas mixture (e.g., containing a smaller amount of target gas than the initial gas mixture).

[0193] During the loading mode, the potential difference applied across the electroswing adsorption cell can have a specific voltage. The potential difference applied across the electroswing adsorption cell can depend, for example, on the reduction potential for generating at least one reduced state of the first electroactive species and the standard potential for interconversion between the reduced and oxidized states of the electroactive species at the second electrode. The voltage further includes the current multiplied by the electrochemical resistance of the stack. In one embodiment, the potential difference is at least 0 V, or at least 0.1 V, or at least 0.2 V, or at least 0.5 V, or at least 0.8 V, or at least 1.0 V, or at least 1.5 V. In one embodiment, the potential difference is less than or equal to 2.0 V, or less than or equal to 1.5 V, or less than or equal to 0.5 V, or less than or equal to 0.2 V.

[0194] In one embodiment, when the electroactive species of the first electrode comprises a quinone, the electroactive species can be reduced to at least one of its reduced states:

[0195] [ka]

[0196] In one embodiment, when the electroactive species of the first electrode comprises a quinone and the electroactive species is reduced in the presence of a target gas, e.g., carbon dioxide, the reduced form of the electroactive species can bind carbon dioxide:

[0197] [ka]

[0198] In one embodiment, an electroactive species is reduced at a first electrode while a second electroactive species (e.g., a redox-active polymer, e.g., polyvinylferrocene) is oxidized at a second electrode. During the injection mode, the oxidation of the second electroactive species provides a source of electrons to drive the reduction of the first electroactive species.

[0199] While the exemplary reactions shown above are shown to occur in one direction, it should be understood that some reversibility may be exhibited. Similar reactions may occur with different electroactive species as understood by those skilled in the art.

[0200] In one aspect, a relatively large amount of target gas is removed from the gas mixture during the processes described herein. Removing a relatively large amount of target gas can, in some cases, be beneficial for any of a variety of applications, such as capturing gases that could be harmful for environmental reasons if released into the atmosphere. For example, the target gas can include carbon dioxide, and removing a relatively large amount of carbon dioxide from the gas mixture can be beneficial to either limit the greenhouse gas impact of the process (e.g., industrial or transportation processes) or to further reduce the amount of carbon dioxide in a room or atmosphere (either for thermodynamic reasons for heating and air conditioning processes or for environmental reasons).

[0201] In one embodiment, a second potential difference can be applied across the electroswing adsorption cell after at least a portion of the target gas binds to the electroactive species. The second potential difference can be different from the first potential difference. In one embodiment, applying the second potential difference results in releasing some or all of the target gas bound to the electroactive species to produce a second treated gas mixture. The second treated gas mixture can have a greater amount of target gas than the input gas mixture. For example, the target gas can be present in the second treated gas mixture in an amount such that its volume percentage is 10% higher, 20% higher, 50% higher, 100% higher, 200% higher, 1000% higher, and / or up to 2,000% higher, 5,000% higher, 10,000% higher, or more than the amount in the first gas mixture.

[0202] The gas separation system can include an external circuit connecting the negative and positive electrodes of each electroswing adsorption cell to a power source configured to apply a potential difference across the negative and positive electrodes of each electroswing adsorption cell. Each of the electroswing adsorption cells of the gas separation system can be as described above. The electroswing adsorption cells of the gas separation system can be stacked according to various configurations commonly known in the art, including parallel or series.

[0203] In one embodiment, a gas separation system includes a first set of electroswing adsorption cells and a second set of electroswing adsorption cells. Each of the first and second sets can include one or more of the electroswing adsorption cells described throughout this disclosure. The first and second sets can be operated in parallel in an alternating manner, such that one set of cells operates in an input mode to capture a target gas (e.g., CO) from a gas mixture, while the other set of cells operates in an output mode to release the target gas (e.g., CO). The system can include separate enclosures for each set of electroswing adsorption cells. The system can further include conduits and valves arranged to direct the flow in a desired manner. The gas separation system can enable nearly continuous separation of a gas mixture (e.g., a gas stream), where at a given moment, the gas mixture is directed to a set of cells operating in an input / capture mode, while a separate, target-gas-enriched, processed mixture is produced by the other set of cells operating in an output / release mode. Furthermore, additional sets of electroswing adsorption cells can be added in parallel or in series depending on the application needs.

[0204] A gas mixture (e.g., a gas stream, e.g., an input gas stream) can be introduced into a gas separation system at a particular flow rate. In one aspect, the flow rate can be greater than or equal to 0.001 L / sec, greater than or equal to 0.005 L / sec, greater than or equal to 0.01 L / sec, greater than or equal to 0.05 L / sec, greater than or equal to 0.1 L / sec, greater than or equal to 0.5 L / sec, greater than or equal to 1 L / sec, greater than or equal to 5 L / sec, greater than or equal to 10 L / sec, greater than or equal to 1050 L / sec, or greater than or equal to 100 L / sec. In one aspect, the flow rate of the gas mixture (e.g., gas flow, e.g., input gas flow) may be less than or equal to 500 L / sec, less than or equal to 400 L / sec, less than or equal to 300 L / sec, less than or equal to 200 L / sec, less than or equal to 100 L / sec, less than or equal to 50 L / sec, less than or equal to 10 L / sec, less than or equal to 1 L / sec, less than or equal to 0.5 L / sec, or less than or equal to 0.1 L / sec.

[0205] In one aspect, during or after the step of releasing the target gas, the method further includes applying a vacuum to the electroswing adsorption cell to remove at least a portion or all of the target gas released from the electroswing adsorption cell. Those skilled in the art, with the benefit of this disclosure, will understand suitable techniques and devices for applying a vacuum to the electroswing adsorption cell. For example, a vacuum pump can be fluidly connected to the gas outlet of the electroswing adsorption cell. The vacuum pump can be activated to create a negative pressure difference between the electroswing adsorption cell bed and a downstream location. This vacuum can provide sufficient force to force the target gas released during the above-described release step out of the electroswing adsorption cell. Vacuum conditions can be applied such that the pressure inside the electroswing adsorption cell during or after release of the target gas is less than or equal to 760 Torr, less than or equal to 700 Torr, less than or equal to 500 Torr, less than or equal to 100 Torr, less than or equal to 50 Torr, less than or equal to 10 Torr, and / or as low as 5 Torr, as low as 1 Torr, as low as 0.5 Torr, or as low as 0.1 Torr.

[0206] In one embodiment, the composite of the first electrode has a specific capacity to absorb a target gas (e.g., CO). For example, the composite may have a specific capacity to absorb a target gas (e.g., CO) per square meter (moles / m 2 ) at least 0.01 moles, at least 0.02 moles / m 2 , at least 0.05 mol / m 2 In one embodiment, the complex can have an absorbency of 0.2 moles / m or greater. 2 Less than or equal to 0.08 mol / m 2 Less than or equal to 0.05 mol / m 2 Less than or equal to 0.03 mol / m 2 For example, the complex may have an absorbency of at least 0.01 mole / m 2 and 0.2 mol / m 2Less than or equal to, or at least 0.02 mol / m 2 and 0.08 mol / m 2 It may have an absorbency less than or equal to this.

[0207] In one embodiment, the first electrode composite is exposed to a gas mixture, e.g., 5 cm 2 Greater than or equal to 8 cm 2 Greater than or equal to 10 cm 2 Greater than or equal to, or 100 cm 2 Up to 400cm 2 The surface area may be up to or even greater than this.

[0208] The various components of the system, such as electrodes (e.g., anode, cathode), power source, electrolyte, separator, container, circuitry, insulating material, etc., can be fabricated by one skilled in the art from any of a variety of components. The components can be molded, machined, extruded, pressed, isopressed, printed, infiltrated, coated, or formed by any other suitable technique in a green or fired state.

[0209] The electrodes (e.g., negative electrodes, positive electrodes) described herein can be of any suitable size or shape. Non-limiting examples of shapes include sheets, cubes, cylinders, hollow tubes, spheres, etc. The electrodes can be of any suitable size depending on the application for which they are used (e.g., separation of gases from ventilated air, direct air capture, etc.). Additionally, the electrodes can include means for connecting the electrode to another electrode, a power source, and / or another electrical device. Those skilled in the art will readily recognize techniques for forming the components of the systems herein.

[0210] Various electrical components of the system may be in electrical communication with at least one other electrical component by a means for connection. The means for connection can be any material that allows electrical flow to occur between a first component and a second component. A non-limiting example of a means for connecting two electrical components is a wire comprising a conductive material (e.g., copper, silver, etc.). In one embodiment, the system may include an electrical connector between two or more components (e.g., a wire and an electrode). In one embodiment, the wire, electrical connector, or other means for connection may be selected to have a low resistivity of the material. In one embodiment, the resistivity may be substantially lower than the resistivity of the electrodes, electrolyte, or other components of the system.

[0211] The electroswing adsorption cells, systems, and methods described herein can be implemented in a variety of applications. The following aspects provide some non-limiting examples of applications. In one aspect, the systems and methods described herein can be for removing target gases (e.g., CO2) from ambient air and enclosed spaces, such as airtight buildings, automobile cabins (reducing the cost of heating incoming air for ventilation), and submarines and space capsules where increased CO2 levels could be catastrophic. In an aspect directed to the power industry, the systems and methods can be used to capture carbon dioxide after combustion at different concentrations. In one aspect, the systems and methods are suitable for separating target gases from industrial flue gases or industrial process gases. The systems and methods can also be used to capture sulfur dioxide and other gases from flue gases. In an aspect directed to the oil and gas industry, the disclosed systems and methods can be used to capture carbon dioxide and other gases from various processes and divert them for downstream compression or processing. The disclosed systems and methods can be applied to capture carbon dioxide from burning natural gas used to heat greenhouses in mild and cold climates, and then divert the captured dioxide to the greenhouse for use by plants in photosynthesis, i.e., to nourish the plants.

[0212] Thus, electroswing adsorption cells containing patterned electrodes represent a significant improvement, particularly with respect to the improvement of gas separation systems. [Example]

[0213] Example 1 Simulation of CO2 adsorption by an electroswing adsorption cell with pleated electrodes The active layer contains 25 volume percent (vol%) carbon nanotubes, 10 vol% poly(phenylnaphthoquinone) (PPNQ) disposed on the surface of the carbon nanotubes, and 65 vol% gel electrolyte. The electrolyte contains 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (BMIM-TFSI) ionic liquid. The electrolyte further contains poly(ethylene glycol) diacrylate (PEGDA) as a gel-forming agent to immobilize the ionic liquid. The mass ratio of BMIM-TFSI to PEGDA is 90:10. The carbon nanotubes are in the form of a mat, such as MIRALON™, available from Nanocomp Technologies, Inc. The active layer thickness is 2 micrometers.

[0214] A second layer of nanotube mat with air-filled pores is placed on the active layer. This spacer layer is 2 micrometers thick and has a gas volume fraction of 70 vol%. The active and gas layers are pleated together. The pleat height (e.g., L in Figure 12) is I The pleated electrode is placed on a microporous polypropylene separator that is 16 microns thick and has a porosity of approximately 40 vol%. A counter electrode containing carbon nanotubes and poly(vinylferrocene) is placed on the opposite side of the separator. The pores of the separator and counter electrode are filled with an electrolyte containing BMIM-TFSI and PEGDA.

[0215] The performance of the cell of Example 1 adsorbing CO2 from flowing air at room temperature was simulated. In the simulation, the concentrations of CO2 in both the gas phase and dissolved in the electrolyte phase are understood to be governed by Fick's law of diffusion. The CO2 concentration in the electrolyte at the interface between the electrolyte and the gas phase is assumed to be in equilibrium with the gas phase. Application of a cathodic potential to the adsorbent electrode drives an electrochemical current that leads to the reduction of the adsorbent material. The current distribution is modeled using porous electrode theory. Because the ratio of kinetic resistivity to ionic and electronic resistivity is greater than 1, the reaction rate distribution is fairly uniform across the active layer. The reduced material can adsorb CO2 from the electrolyte, thereby reducing the concentration of CO2 in the electrolyte, which drives the dissolution of CO2 from the gas into the electrolyte. Because the adsorption kinetics are sufficiently fast relative to the CO2 diffusivity, the reduced adsorbent rapidly adsorbs CO2 if the CO2 concentration in the adjacent electrolyte exceeds zero. Gas enters the system through gas inlet channels, transports via diffusion and convection through the gas diffusion layer and gas region, reacts via dissolution in the electrolyte phase, and exits through gas outlet channels. 2-D simulations were performed using COMSOL Multiphysics software. The diffusivity of CO2 in the BMIM-TFSI electrolyte is 6.4e-10 m, as measured according to Ying Hou and Ruth E. Baltus, "Experimental Measurement of the solubility and diffusivity of CO2 in room-temperature ionic liquids using a transient thin-liquid-film method," Ind. Eng. Chem. Res. 2007, Vol. 46, No. 24, pp. 8166-8175, the contents of which are incorporated herein by reference in their entirety. 2 / s. The diffusivity in the pure electrolyte was calculated as (electrolyte volume fraction) to approximate the effective diffusivity in the active complex, as predicted by the Bruggeman relation. 1.5The Henry's law constant for the equilibrium concentration of CO2 in BMIM-TFSI was 29 bar, as measured according to Javid Safarov, Rena Hamidova, Martin Stephan, Norbert Schmotz, Ismail Kul, Astan Shahverdiyev, and Egon Hassel, "Carbon dioxide solubility in 1-butyl-3-methylimidazolium-bis(trifluormethylsulfonyl)imide over a wide range of temperatures and pressures," J Chem Therm 2013, Vol. 67, pp. 181-189, the contents of which are incorporated herein by reference in their entirety. The diffusivity of CO2 in air is 1.6 x 10 -5 m 2 / s. The inlet mole fraction of CO2 was 400 ppm and the inlet pressure was 1 bar. The inlet flow rate of CO2 was twice the amount of CO2 consumed by the reaction, resulting in an outlet concentration of CO2 that was half that of the inlet concentration.

[0216] Figure 18 shows the CO2 concentration in both the electrolyte and gas phase in the active area; the counter electrode, flow field channels, and most of the gas diffusion layer are not shown for clarity. The gas phase CO2 concentration was 0.0075 mol / m3 in the gas diffusion layer adjacent to the pleated electrode. 3 and 0.0046 mol / m in the gas region closest to the separator. 3 As a result of the lower CO2 concentration in the gas region, CO2 dissolution into the electrolyte is reduced, which limits the utilization of the active material at the bottom of the pleats.

[0217] FIG. 19 shows simulated maximum CO flux (grams of CO per apparent area per hour of charge, gCO / m) for different pleat heights, spacer layer thicknesses, and outlet concentrations (which are determined by the gas flow rate relative to the applied current) for an inlet gas with a composition of typical ambient air (400 ppm CO, 20° C.). 2 / h charge ) for pleat heights less than 150 micrometers, flux is primarily limited by the diffusion of CO2 within the electrolyte across the 2-micrometer-thick active layer. Increasing the pleat height allows for higher flux by expanding CO2 transport across a larger area of ​​the electrolyte. Above 150 micrometers, there is no further increase in flux with increasing pleat height. While not wishing to be bound by theory, it is understood that flux does not increase further because gas-phase diffusion is limiting performance, which is consistent with the results shown in FIG. 18. Furthermore, because the gas-phase concentration at the bottom of the pleats is low and driven by diffusion, the adsorbent material beyond 150 micrometers away from the gas diffusion layer is not effectively utilized.

[0218] (Comparative Example 1) Evaluation of CO2 flux using PPNQ-CNT mat composite electrode Poly(phenylnaphthoquinone) (PPNQ) was dissolved in tetrahydrofuran at a concentration of 10 milligrams per milliliter. A 15-micrometer-thick carbon nanotube (CNT) mat, Miralon™, commercially available from Nanocomp Technologies, Inc., was immersed in the PPNQ solution in a sealed vial and left at room temperature for 1 to 72 hours. The mat sample was then removed from the vial, rinsed using the same solvent used for the immersion process, and then dried under reduced pressure at temperatures between 60 and 80°C for at least 12 hours. The mass of the CNT mat pieces after immersion in the polymer solution was compared to the initial mass of the intact CNT mat. For each solution, the amount of PPNQ was approximately 0.1 mg / cm. 2For example, 0.1 to 0.5 mg of polymer per square inch of CNT mat. The PPNQ-CNT mat composite electrode was then 1.98 cm 2 The nanotube counter electrode was cut into a disk of 0.01g CO2 / m3, and the poly(vinylferrocene)-nanotube counter electrode, Celgard 3401 separator, and the amount of CO2 / m3 filling the pores of the electrode and separator were measured. 2 / h charge The cells were assembled with a TFSI electrolyte. In this planar configuration, with no gas domains at the electrodes, the CO flux was 0.2 g CO / m in flowing air at room temperature. 2 / h charge It was.

[0219] (Synthesis Example 1) Preparation of polymeric ionic liquids A polymeric ionic liquid was synthesized as shown in Figure 20 and according to the following procedure. Polyvinylbenzyl chloride (PVBzCl) (10 g, Mw 100 kDa) was dissolved in DMF (50 mL) and the solution was heated to 80 °C. To this, N-vinylimidazole (0.93 g) was added, and the contents were stirred for 18 hours. N-butylimidazole (8.14 g) was then added, and the contents were stirred for another 18 hours. After cooling to room temperature, the polymer was precipitated with excess ethyl acetate to obtain PIL-Cl. PIL-Cl was dissolved in deionized water and precipitated from an aqueous solution of LiNTf2 (2 × molar equivalents). This process was repeated once more. The isolated polymer was washed extensively with deionized water and dried in a vacuum oven at 50 °C for 24 hours to obtain PIL-NTf2 with a vinyl content of 15 mole percent.

[0220] (Synthesis Example 2) Preparation of polymeric ionic liquids A polymeric ionic liquid was synthesized according to the procedure of Synthesis Example 1, except that the amount of N-vinylimidazole was 1.54 g and the amount of N-butylimidazole was 8.14 g, providing a PIL-NTf2 polymer with a vinyl content of 25 mole percent.

[0221] (Comparative Example 2) Preparation of non-patterned electrodes Multiwalled carbon nanotubes (MWCNTs) (2.4 g), 0.24 g of PPNQ, and 2 mL of THF were combined in a glass vial and mixed twice for 20 minutes at 15,000 rpm using a rotor / stator (IKA). Separately, 0.86 g of the polymeric ionic liquid from Synthesis Example 2 was dissolved in 4 mL of THF, and 0.46 g of polyethylene glycol (PEG) molecular weight 400 and 0.71 g of BMIM TFSI ionic liquid were added to this solution. This solution was combined with the MWCNT / PPNQ dispersion, and 0.27 g of water was added. The material was coated onto 28BC with a 10-mil drawdown bar (BYK Gardiner) and allowed to dry. Half of the coating was dried in a vacuum oven.

[0222] Example 2 Preparation of patterned electrodes The coating of Comparative Example 2 was immersed in water for 3 hours, dried in ambient conditions and then in a vacuum oven overnight.

[0223] To evaluate the flux of the unpatterned and patterned electrodes of Comparative Example 2 and Example 2, respectively, the electrodes were subjected to constant current and constant potentiostatic analysis in a sealed test fixture. A counter electrode made of 3.8 mg of polyvinylferrocene, two layers of Celgard 3401 separator, and a 2 cm 2 cm 3 electrode with a total of 60 μL of BMIM TFSI electrolyte was used. 2 The working electrodes were assembled into electrochemical cells. Each electrochemical cell was 6.5 cm 3 The sample was enclosed in a sealed apparatus with an internal volume of 1000 kJ / cm2 and equipped with a pressure transducer. The apparatus was stored and the entire experiment was carried out in an environmental chamber with a fixed temperature of 25°C. CO2 capture was evaluated by pressure drop at three CO2 concentrations (1%, 10%, and 100% CO2 in N2).

[0224] As shown in Table 1, immersion in water to provide the patterned electrodes of Example 2 facilitated the removal of polyethylene glycol, leading to higher CO flux values ​​relative to the coating of Comparative Example 2. Without wishing to be bound by theory, it is believed that the removal of polyethylene glycol allows for the formation of gas domains, thereby improving flux.

[0225] [Table 1]

[0226] (Comparative Example 3) Preparation of non-patterned electrodes Multiwalled carbon nanotubes (MWCNTs) (0.275 g), 0.0688 g of PPNQ, and 2 g of MEK were combined in a glass vial and mixed twice for 20 minutes at 15,000 rpm using a rotor / stator (IKA). Separately, 0.275 g of the polymeric ionic liquid from Synthesis Example 1 was dissolved in 4 mL of MEK, and 0.6 g of polyethylene glycol (PEG) molecular weight 400 and 0.22 g of BMIM TFSI ionic liquid were added to this solution. This solution was combined with the MWCNT / PPNQ dispersion, and 0.27 g of water was added. The material was coated onto 28BC with a 10-mil drawdown bar (BYK Gardiner) and allowed to dry. Half of the coating was dried in a vacuum oven.

[0227] Example 3 Preparation of patterned electrodes The coating of Comparative Example 3 was immersed in water for 4 hours, dried in ambient conditions and then in a vacuum oven overnight.

[0228] To evaluate the flux of the unpatterned and patterned electrodes of Comparative Example 3 and Example 3, respectively, the electrodes were each subjected to constant current and constant potentiostatic analysis in a sealed test fixture. A counter electrode made of 3.8 mg of polyvinylferrocene, two layers of Celgard 3401 separator, and a 2 cm 2 sieve containing a total of 60 μL of BMIM TFSI electrolyte was used. 2The working electrode was assembled in an electrochemical cell of 6.5 cm. 3 The samples were enclosed in a sealed apparatus with an internal volume of 1000 kJ / cm and fitted with a pressure transducer. The apparatus was stored and the entire experiment was carried out in an environmental chamber with a fixed temperature of 25°C. CO capture was assessed at three CO concentrations (1%, 10% and 100% CO in N) by pressure drop, and the flux was measured in gCO / m. 2 / h charge The values ​​are reported in units of

[0229] As shown in Table 2, immersion in water to provide the patterned electrode of Example 3 facilitated the removal of polyethylene glycol, leading to higher CO flux values ​​relative to the coating of Comparative Example 3. Without wishing to be bound by theory, it is believed that the removal of polyethylene glycol allows for the formation of gas regions, thereby improving flux at 10% and 100% CO. Figure 21 shows graphs of pressure drop and cell voltage versus time for an electroswing adsorption cell containing the patterned electrode of Example 3 at 10% CO in N. The decrease in pressure over time indicates CO capture in the electroswing adsorption cell.

[0230] [Table 2]

[0231] Comparative Example 4 Preparation of non-patterned electrodes LITX™ 300 (Cabot Corp.) (0.6 g), 0.15 g of PPNQ, and 4 mL of THF were combined in a glass vial and mixed twice for 20 minutes at 15,000 rpm using a rotor / stator (IKA). Separately, 0.6 g of the polymeric ionic liquid from Synthesis Example 2 was dissolved in 4 mL of THF, and to this solution was added 1.2 g of polyethylene glycol (PEG) molecular weight 400 and 0.48 g of BMIM TFSI ionic liquid. This solution was combined with the LITX™ 300 / PPNQ dispersion, and 0.27 g of water was added. The material was coated onto a Miralon™ carbon fiber mat (Huntsman Corp.) using a 10-mil drawdown bar (BYK Gardiner) and allowed to dry. Half of the coating was dried in a vacuum oven.

[0232] Example 4 Preparation of patterned electrodes The coating of Comparative Example 4 was immersed in water for 6 hours, dried in ambient conditions and then in a vacuum oven overnight.

[0233] Flux was evaluated as described in the previous examples. As shown in Table 3, water immersion facilitated the removal of polyethylene glycol to provide the patterned electrode of Example 4, leading to higher CO flux values ​​relative to the coating of Comparative Example 4. Without wishing to be bound by theory, it is believed that the removal of polyethylene glycol allows for the formation of gas domains, thereby improving flux at 1%, 10%, and 100% CO.

[0234] [Table 3]

[0235] (Comparative Example 5) Preparation of non-patterned electrodes The polymeric ionic liquid from Synthesis Example 1 (1.2 grams) was dissolved in MEK (18 grams). To this solution, MWCNT (1.2 grams) and PPNQ (0.3 grams) were added. The resulting mixture was subjected to shearing at 20,000 rpm twice for 20 minutes each using a rotor / stator (IKA), followed by 40 minutes of sonication. BMIM TFSI (0.96 grams) was added to the mixture and stirred for 20 minutes. The mixture was coated onto a MIRALON substrate using a 20-mil drawdown bar (BYK Gardiner) and allowed to dry.

[0236] Example 5 Preparation of patterned electrodes A patterned electrode was prepared following the same procedure as in Comparative Example 5, except that sodium Y zeolite (2.4 grams) was added to the material before forming the coating.

[0237] CO2 flux was evaluated as described in the previous examples. Flux for the patterned electrode of Example 5 containing zeolite particles was found to be higher at low CO2 concentrations (e.g., 1% CO2) relative to the flux for Comparative Example 5. Flux was observed to be the same as that of Comparative Example 5 for higher CO2 concentrations (e.g., 10% and 100%). Flux for Example 5 and Comparative Example 5 at 1%, 10%, and 100% CO2 is provided in Table 4.

[0238] [Table 4]

[0239] The present disclosure further includes the following non-limiting aspects.

[0240] Aspect 1: A patterned electrode for an electroswing adsorption cell, comprising a plurality of electrolyte regions, a plurality of gas regions, and a conductive backbone, wherein the conductive backbone spans the plurality of electrolyte regions and comprises electroactive species capable of binding to a target gas when the electroactive species is in a reduced state and capable of releasing the target gas when the electroactive species is in an oxidized state.

[0241] Embodiment 2: The patterned electrode of embodiment 1, wherein the first electrode has a thickness of 15 to 500 micrometers.

[0242] Aspect 3: The patterned electrode of Aspect 1 or 2, wherein the diffusion length of the target gas species through the electrolyte region to the active sites in the patterned electrode is between 1 μm and 1 mm.

[0243] Embodiment 4: The patterned electrode of any one of embodiments 1 to 3, wherein the plurality of electrolyte regions and the plurality of gas regions form a regular pattern.

[0244] Embodiment 5: The patterned electrode of any of embodiments 1-3, wherein the plurality of gas regions are randomly dispersed throughout the electrode.

[0245] Embodiment 6: The patterned electrode of any of embodiments 1-5, wherein the plurality of gas regions have dimensions between 1 and 100 micrometers.

[0246] Embodiment 7: The patterned electrode of any of embodiments 1-6, wherein the gas region comprises zeolite particles.

[0247] Embodiment 8: The patterned electrode of embodiment 7, wherein the zeolite particles have an average diameter of 1 to 100 micrometers.

[0248] Aspect 9: The patterned electrode of aspect 7 or 8, wherein the zeolite particles are synthetic zeolite, preferably zeolite A, zeolite X, zeolite Y, zeolite L, or a combination thereof, more preferably zeolite Y.

[0249] Embodiment 10: The patterned electrode of any of embodiments 1-9, wherein the first electrode has a pleated or folded configuration.

[0250] Embodiment 11: The patterned electrode of any of embodiments 1-10, wherein the electrode comprises two or more layers.

[0251] Embodiment 12: The patterned electrode of any one of embodiments 1 to 11, wherein the conductive skeleton spans multiple gas regions.

[0252] Embodiment 13: The patterned electrode of any one of embodiments 1 to 12, wherein each of the plurality of gas regions has an average diameter and is separated by an average distance, and the ratio of the average diameter to the average distance is between 0.01 and 0.5.

[0253] Embodiment 14: The patterned electrode of any of embodiments 1-13, wherein the electrolyte region comprises an electrolyte comprising an ionic liquid.

[0254] Embodiment 15: The patterned electrode of any of embodiments 1-14, wherein the electrolyte region comprises an electrolyte comprising a gel or a polymer.

[0255] Embodiment 16: The patterned electrode of any of embodiments 1-15, wherein the conductive scaffold in the electrolyte region or the conductive scaffold in the gas region comprises a carbon nanotube mat.

[0256] Embodiment 17: The patterned electrode of any of embodiments 1-16, wherein the conductive framework in the gas region comprises carbon black and a binder.

[0257] Embodiment 18: The patterned electrode of any of embodiments 1-17, wherein each of the plurality of electrolyte regions has an average path length of 0.5 to 50 micrometers.

[0258] Embodiment 19: The patterned electrode of any of embodiments 1-18, wherein the electroactive species comprises an electroactive polymer, an electroactive oligomer, an electroactive organic compound, or a combination thereof.

[0259] Embodiment 20: A patterned electrode of any of embodiments 1-19, wherein the electroactive species comprises a substituted or unsubstituted quinone or tetrone, preferably benzoquinone, 1,4-naphthoquinone, 1,2-naphthoquinone, anthraquinone, phenanthrenequinone, benzanthraquinone, dibenzanthraquinone, 4,5,9,10-pyrenetetrone, or a combination thereof, or a polymer or oligomer comprising repeat units derived from a substituted or unsubstituted quinone or tetrone, preferably a polymer comprising repeat units derived from benzoquinone, 1,4-naphthoquinone, 1,2-naphthoquinone, anthraquinone, phenanthrenequinone, benzanthraquinone, dibenzanthraquinone, 4,5,9,10-pyrenetetrone, or a combination thereof.

[0260] Embodiment 21: An electroswing adsorption cell comprising the patterned electrode of any of embodiments 1-20, a second electrode comprising a supplemental electroactive composite layer, and a separator between the patterned electrode and the second electrode.

[0261] Example 22: An electroswing adsorption cell according to example 21, wherein the patterned electrode, the second electrode, and the separator are folded or pleated together.

[0262] Embodiment 23: The electroswing adsorption cell of embodiment 20 or 21, further comprising a gas flow field adjacent to the patterned electrode, the gas flow field comprising flow field channels.

[0263] Embodiment 24: An electroswing adsorption cell according to embodiment 23, wherein the flow field channel is disposed perpendicular to the gas region of the first electrode.

[0264] Embodiment 25: The electroswing adsorption cell of embodiment 23 or 24, wherein the gas flow fields have an interdigitated flow pattern.

[0265] Embodiment 26: The electroswing adsorption cell of embodiment 23, wherein the gas flow field comprises a plurality of ribs, and the ribs comprise a compressible, conductive, and impermeable material.

[0266] Embodiment 27: A method of manufacturing an electrode for an electroswing adsorption cell according to any one of embodiments 1 to 20, comprising depositing a composite material on a separator, the composite material comprising a conductive scaffold coated with an electrolyte and an electroactive species, and forming a patterned electrode comprising a plurality of electrolyte regions and a plurality of gas regions, wherein forming the patterned electrode is by machining, lithography, etching, self-assembly, porogen removal, or a combination thereof.

[0267]

[0071] Embodiment 28: The method of embodiment 27, wherein the composite material comprises a porogen that can be removed by heating or extraction with a solvent.

[0268] Embodiment 29: A method of manufacturing an electroswing adsorption cell, comprising depositing a composite material on a separator, the composite material comprising a conductive scaffold coated with an electrolyte and an electroactive species, forming a patterned first electrode comprising a plurality of electrolyte regions and a plurality of gas regions, and bonding a gas flow field and a second electrode to the patterned first electrode to obtain an electroswing adsorption cell.

[0269] Embodiment 30: The method of embodiment 29, wherein the step of forming the first patterned electrode includes removing portions of the composite material to form a plurality of electrolyte regions and a plurality of gas regions, and the step of removing portions of the composite material is by laser ablation, lithography, mechanical marking, machining, etching, porogen removal, or a combination thereof.

[0270] Embodiment 31: A method of manufacturing an electroswing adsorption cell, comprising providing a composite layer comprising a conductive scaffold coated with an electrolyte and a first electroactive species, providing a second conductive scaffold comprising gas-filled pores, pleating the composite layer with the second composite layer to obtain a patterned first electrode, and bonding a gas flow field and a second electrode to the patterned first electrode to obtain an electroswing adsorption cell.

[0271] Aspect 32: A gas separation system comprising a plurality of electroswing adsorption cells in fluid communication with a gas inlet and a gas outlet, each of the plurality of electroswing adsorption cells being according to any of aspects 21-26.

[0272] Additionally, the present disclosure may include other innovations not currently described. The applicants reserve all rights in such innovations, including the right to embody such innovations and to file additional applications, continuations, continuations-in-part, divisional applications, etc. Accordingly, it should be understood that advantages, embodiments, examples, functions, features, logic, operation, organization, structure, form, and / or other aspects of the present disclosure should not be considered limitations on the present disclosure as defined by the embodiments or limitations on equivalents of the embodiments.

[0273] All definitions as defined and used herein should be understood to supersede dictionary definitions, definitions in documents incorporated by reference, and / or ordinary meanings of the defined terms.

[0274] As used herein, in particular embodiments, the terms "about" or "approximately," when preceding a numerical value, indicate a range of plus or minus 10% of the value. Where a range of values ​​is provided, unless the context clearly dictates otherwise, each intervening value between the upper and lower limits of that range, to the tenth of the unit of the lower limit, and any other stated or intervening value in that stated range, is understood to be encompassed within the disclosure. The upper and lower limits of these smaller ranges may independently be included in the smaller ranges, and are also encompassed within the disclosure, subject to any specifically excluded limit in the stated range. Where a stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included within the disclosure.

[0275] The phrase "and / or," as used herein and in the embodiments, should be understood to mean "either or both" of the elements so conjoined, i.e., elements that are present conjunctively in some cases and disjunctively in other cases. Multiple elements listed with "and / or" should be construed in the same manner, i.e., "one or more" of the elements so conjoined. Other elements, whether related or unrelated to those elements specifically identified, are optionally present in addition to the elements specifically identified by the "and / or" clause. Thus, as a non-limiting example, a reference to "A and / or B," when used in conjunction with open-ended language such as "comprising," can refer, in one embodiment, to A only (optionally including elements other than B); in another embodiment, to B only (optionally including elements other than A); in yet another embodiment, to both A and B (optionally including other elements); and so forth.

[0276] As used herein and in the embodiments, "or" should be understood to have the same meaning as "and / or" as defined above. For example, when separating items in a list, "or" or "and / or" shall be construed as inclusive, i.e., at least one but including more than one of a number of elements or a list, and optionally including additional unlisted items. Only terms clearly indicated to the contrary, such as "only one of" or "exactly one of," or, when used in the embodiments, "consisting of," shall refer to the inclusion of exactly one number of elements or a list. In general, the term "or," as used herein, shall only be construed to indicate exclusive alternatives (i.e., "one or the other, but not both") when preceded by exclusive terms, such as "either," "one of," "only one of," or "exactly one of." "Consisting essentially of," when used in the embodiments, shall have its ordinary meaning as used in the field of patent law.

[0277] As used herein and in the embodiments, the phrase "at least one," in reference to a list of one or more elements, should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but not necessarily including at least one of each and every element specifically listed within the list of elements, nor excluding any combination of elements in the list of elements. This definition, moreover, allows for the optional presence of elements other than those specifically identified within the list of elements to which the phrase "at least one" refers, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, "at least one of A and B" (or, equivalently, "at least one of A or B," or, equivalently, "at least one of A and / or B") can refer to, in one embodiment, at least one, optionally more than one A, and no B (and optionally including elements other than B); in another embodiment, at least one, optionally more than one B, and no A (and optionally including elements other than A); in yet another embodiment, at least one, optionally more than one A, and at least one, optionally more than one B (and optionally including other elements); etc.

[0278] In the embodiments, as well as throughout the specification above, all transitional phrases, such as "comprising," "including," "holding," "having," "containing," "involving," "holding," "consisting of," etc., are to be understood to be open-ended, i.e., to mean including but not limited to. Only the transitional phrases "consisting of" and "essentially of" shall be closed or semi-closed transitional phrases, respectively, as set forth in U.S. Patent Office Manual of Patent Examining Procedures 2111.03.

[0279] While specific embodiments of the present disclosure have been outlined above, many alternatives, modifications, and variations will be apparent to those skilled in the art. Accordingly, the embodiments described herein are intended to be illustrative and not limiting. Various changes may be made without departing from the spirit and scope of the present disclosure. Where the methods and steps described above indicate certain events occurring in a certain order, those skilled in the art having the benefit of this disclosure will recognize that the order of certain steps may be changed and that such changes are in accordance with variations of the invention. Additionally, certain steps may be performed simultaneously in a parallel process where possible, as well as sequentially as described above. While embodiments have been particularly shown and described, it will be understood that various changes in form and detail may be made. [Explanation of symbols]

[0280] 100 Asymmetric Electroswing Adsorption Cell 101 Symmetrical Electrochemical Swing Adsorption Cell 110 First patterned electrode 112 Second patterned electrode 120 Conductive skeleton 130 Electroactive Species 140 Electrolyte area 150 Gas Region 160 Gas flow field 161 First gas flow field 162 Second gas flow field 170 Counter Electrode 180 Separator

Claims

1. 1. A patterned electrode for an electroswing adsorption cell, comprising: a plurality of electrolyte regions comprising a conductive framework and an electrolyte; and a plurality of gas regions separated by said plurality of electrolyte regions; the conductive framework comprises electroactive species capable of binding with a Lewis acid gas when the electroactive species is in a reduced state and capable of releasing a Lewis acid gas when the electroactive species is in an oxidized state; A patterned electrode, wherein the ratio of the diffusion length of a path of a Lewis acid gas from a gas region in the patterned electrode to an active site to the thickness of the patterned electrode (L D / L I ) is from 0.001:1 to 1:

1.

2. The patterned electrode described in claim 1, wherein the patterned electrode has a thickness of 15 to 500 micrometers.

3. 3. The patterned electrode of claim 1, wherein the diffusion length of a Lewis acid gas through the electrolyte region to the active sites in the patterned electrode is from 1 μm to 1 mm.

4. 4. The patterned electrode of claim 1, wherein the plurality of electrolyte regions and the plurality of gas regions form a regular pattern.

5. 4. The patterned electrode of claim 1, wherein the plurality of gas regions are randomly distributed throughout the electrode.

6. 6. The patterned electrode of claim 1, wherein the plurality of gas regions have dimensions of 1 to 100 micrometers.

7. 7. The patterned electrode of claim 1, wherein the gas region comprises zeolite particles.

8. The patterned electrode of claim 7, wherein the zeolite particles have an average diameter of 1 to 100 micrometers.

9. 9. The patterned electrode of claim 1, wherein the first electrode has a pleated or folded configuration.

10. 10. The patterned electrode of claim 1, wherein the electrode comprises two or more layers.

11. 11. The patterned electrode of claim 1, wherein the conductive skeleton spans multiple gas regions.

12. 12. The patterned electrode of claim 1, wherein each of the plurality of gas regions has an average diameter and is separated by an average distance, the ratio of the average diameter to the average distance being between 0.01 and 0.

5.

13. 13. The patterned electrode of claim 1, wherein the electrolyte comprises an ionic liquid, a gel electrolyte, a gel polymer electrolyte, or a polymeric ionic liquid.

14. 14. The patterned electrode of claim 1, wherein each of the plurality of electrolyte regions has an average path length of 0.5 to 50 micrometers.

15. The electroactive species is an electroactive polymer, an electroactive oligomer, an electroactive organic compound, or a combination thereof.

15. The patterned electrode of claim 1, comprising:

16. The electroactive species is a substituted or unsubstituted quinone or tetrone, or Polymers or oligomers containing repeating units derived from substituted or unsubstituted quinones or tetrones 16. The patterned electrode of claim 1, comprising:

17. The electroactive species is benzoquinone, 1,4-naphthoquinone, 1,2-naphthoquinone, anthraquinone, phenanthrenequinone, benzanthraquinone, dibenzanthraquinone, 4,5,9,10-pyrenetetrone, or a combination thereof; or Polymers containing repeating units derived from benzoquinone, 1,4-naphthoquinone, 1,2-naphthoquinone, anthraquinone, phenanthrenequinone, benzanthraquinone, dibenzanthraquinone, 4,5,9,10-pyrenetetrone, or combinations thereof 17. The patterned electrode of claim 1, comprising:

18. 18. A patterned electrode according to any one of claims 1 to 17. a second electrode comprising a supplemental electroactive composite layer; and Separator between the patterned electrode and the second electrode Electroswing adsorption cell comprising:

19. 20. The electroswing adsorption cell of claim 18, wherein the patterned electrode, the second electrode, and the separator are folded or pleated together.

20. 18. A method for manufacturing a patterned electrode for an electroswing adsorption cell according to any one of claims 1 to 17, comprising the steps of: depositing a composite material on a separator, the composite material comprising an electrolyte and a conductive scaffold coated with an electroactive species; and forming a patterned electrode comprising a plurality of electrolyte regions and a plurality of gas regions; The method, wherein forming the patterned electrode is by laser ablation, lithography, mechanical imprinting, machining, etching, porogen removal, or a combination thereof.

21. 1. A method for manufacturing an electroswing adsorption cell, comprising: depositing a composite material on a separator, the composite material comprising an electrolyte and a conductive scaffold coated with an electroactive species; forming a patterned first electrode including a plurality of electrolyte regions and a plurality of gas regions; and coupling a gas flow field and a second electrode to the patterned first electrode to obtain an electroswing adsorption cell; forming the first patterned electrode includes removing portions of the composite material to form a plurality of electrolyte regions and a plurality of gas regions, and removing the portions of the composite material is by laser ablation, lithography, mechanical imprinting, machining, etching, porogen removal, or a combination thereof; 18. A method wherein the patterned first electrode is a patterned electrode according to any one of claims 1 to 17.

22. 1. A method for manufacturing an electroswing adsorption cell, comprising: providing a composite layer comprising an electrolyte and a conductive scaffold coated with a first electroactive species; providing a second conductive scaffold comprising gas-filled pores; pleating the composite layer with a second composite layer to obtain a patterned first electrode; and coupling a gas flow field and a second electrode to the patterned first electrode to obtain an electroswing adsorption cell; 18. A method wherein the patterned first electrode is a patterned electrode according to any one of claims 1 to 17.

23. 20. A gas separation system comprising a plurality of electroswing adsorption cells in fluid communication with a gas inlet and a gas outlet, each of the plurality of electroswing adsorption cells being according to claim 18 or 19.

Images