Method for generating hydrogen

Abstract

To provide a method for generating hydrogen.SOLUTION: The method for generating hydrogen comprises introducing a first stream comprising fuel into an apparatus, introducing a second stream comprising water into the apparatus, reducing water in the second stream to hydrogen, and extracting hydrogen from the apparatus. The first stream and the second stream do not contact each other within the apparatus.SELECTED DRAWING: Figure 6B

Description

Technical Field

[0001] Cross - reference to Related Applications This application is a continuation-in-part of U.S. Patent Application Nos. 16 / 707,046, 16 / 707,066, and 16 / 707,084, filed on December 9, 2019, which are continuation-in-part of U.S. Patent Application Nos. 16 / 699,453 and 16 / 699,461, filed on November 29, 2019, which are continuation-in-part of U.S. Patent Application Nos. 16 / 693,268, 16 / 693,269, 16 / 693,270, and 16 / 693,271, filed on November 23, 2019, which are continuation-in-part of U.S. Patent Application Nos. 16 / 684,838 and 16 / 684,864, filed on November 15, 2019, which are continuation-in-part of U.S. Patent Application No. 16 / 680,770, filed on November 12, 2019, which is a continuation-in-part of U.S. Patent Application Nos. 16 / 674,580, 16 / 674,629, 16 / 674,657, 16 / 674,695 (all filed on November 5, 2019), each of which claims the benefit under 35 U.S.C. 119(e) of the following: U.S. Provisional Patent Application No. 62 / 756,257, filed on November 6, 2018; U.S. Provisional Patent Application No. 62 / 756,264, filed on November 6, 2018; U.S. Provisional Patent Application No. 62 / 757,751, filed on November 8, 2018; U.S. Provisional Patent Application No. 62 / 758,778, filed on November 12, 2018; U.S. Provisional Patent Application No. 62 / 767,413, filed on November 14, 2018; U.S. Provisional Patent Application No. 62 / 768,864, filed on November 17, 2018; U.S. Provisional Patent Application No. 62 / 771,045, filed on November 24, 2018; U.S. Provisional Patent Application No. 62 / 773,071, filed on November 29, 2018; U.S. Provisional Patent Application No. 62 / 773,912, filed on November 30, 2018; U.S. Provisional Patent Application No. 62 / 777,273, filed on December 10, 2018; U.S. Provisional Patent Application No. 62 / 777,338, filed on December 10, 2018; U.S. Provisional Patent Application No. 62 / 779,005, filed on December 13, 2018; U.S. Provisional Patent Application No. 62 / 780,211, filed on December 15, 2018; U.S. Provisional Patent Application No. 62 / 783, filed on December 20, 2018,U.S. Provisional Patent Application No. 62 / 784,472, filed on December 23, 2018; U.S. Provisional Patent Application No. 62 / 786,341, filed on December 29, 2018; U.S. Provisional Patent Application No. 62 / 791,629, filed on January 11, 2019; U.S. Provisional Patent Application No. 62 / 797,572, filed on January 28, 2019; U.S. Provisional Patent Application No. 62 / 798,344, filed on January 29, 2019; U.S. Provisional Patent Application No. 62 / 804,115, filed on February 11, 2019; U.S. Provisional Patent Application No. 62 / 805,250, filed on February 13, 2019; U.S. Provisional Patent Application No. 62 / 808,644, filed on February 21, 2019; U.S. Provisional Patent Application No. 62 / 809,602, filed on February 23, 2019; U.S. Provisional Patent Application No. 62 / 814,695, filed on March 6, 2019; U.S. Provisional Patent Application No. 62 / 819,374, filed on March 15, 2019; U.S. Provisional Patent Application No. 62 / 819,289, filed on March 15, 2019; U.S. Provisional Patent Application No. 62 / 824,229, filed on March 26, 2019; U.S. Provisional Patent Application No. 62 / 825,576, filed on March 28, 2019; U.S. Provisional Patent Application No. 62 / 827,800, filed on April 1, 2019; U.S. Provisional Patent Application No. 62 / 834,531, filed on April 16, 2019; U.S. Provisional Patent Application No. 62 / 837,089, filed on April 22, 2019; U.S. Provisional Patent Application No. 62 / 840,381, filed on April 29, 2019; U.S. Provisional Patent Application No. 62 / 844,125, filed on May 7, 2019; U.S. Provisional Patent Application No. 62 / 844,127, filed on May 7, 2019; U.S. Provisional Patent Application No. 62 / 847,472, filed on May 14, 2019; U.S. Provisional Patent Application No. 62 / 849,269, filed on May 17, 2019; U.S. Provisional Patent Application No. 62 / 852,045, filed on May 23, 2019; U.S. Provisional Patent Application No. 62 / 856,736, filed on June 3, 2019; U.S. Provisional Patent Application No. 62 / 863,390, filed on June 19, 2019; U.S. Provisional Patent Application No. 62 / 864,492, filed on June 20, 2019; U.S. Provisional Patent Application No. 62 / 866, filed on June 26, 2019,U.S. Provisional Patent Application No. 62 / 869,322, filed on July 1, 2019; U.S. Provisional Patent Application No. 62 / 875,437, filed on July 17, 2019; U.S. Provisional Patent Application No. 62 / 877,699, filed on July 23, 2019; U.S. Provisional Patent Application No. 62 / 888,319, filed on August 16, 2019; U.S. Provisional Patent Application No. 62 / 895,416, filed on September 3, 2019; U.S. Provisional Patent Application No. 62 / 896,466, filed on September 5, 2019; U.S. Provisional Patent Application No. 62 / 899,087, filed on September 11, 2019; U.S. Provisional Patent Application No. 62 / 904,683, filed on September 24, 2019; U.S. Provisional Patent Application No. 62 / 912,626, filed on October 8, 2019; U.S. Provisional Patent Application No. 62 / 925,210, filed on October 23, 2019; U.S. Provisional Patent Application No. 62 / 927,627, filed on October 29, 2019; U.S. Provisional Patent Application No. 62 / 928,326, filed on October 30, 2019; U.S. Provisional Patent Application No. 62 / 934,808, filed on November 13, 2019; U.S. Provisional Patent Application No. 62 / 939,531, filed on November 22, 2019; U.S. Provisional Patent Application No. 62 / 941,358, filed on November 27, 2019; U.S. Provisional Patent Application No. 62 / 944,259, filed on December 5, 2019; U.S. Provisional Patent Application No. 62 / 944,756, filed on December 6, 2019; U.S. Provisional Patent Application No. 62 / 948,759, filed on December 16, 2019; and U.S. Provisional Patent Application No. 62 / 955,443, filed on December 31, 2019. The entire disclosure content of each of these listed applications is hereby incorporated herein by reference.,

[0002] Technical Field This invention generally relates to an electrochemical reactor. More specifically, this invention relates to an electrochemical reactor for producing syngas and hydrogen. BACKGROUND OF THE INVENTION

[0003] Synthesis gas (i.e., syngas) is a mixture mainly composed of hydrogen, carbon monoxide, and often carbon dioxide. It is used as an intermediate for producing various products such as synthetic natural gas, ammonia, methanol, hydrogen, synthetic fuels, synthetic lubricants, etc. Synthesis gas can be produced from almost all hydrocarbon feedstocks such as natural gas, coal, biomass, etc. by steam reforming, dry reforming, partial oxidation, or gasification. Synthesis gas is flammable and is often used in internal combustion engines or for electricity generation, but its energy density is less than half that of natural gas.

[0004] Large amounts of hydrogen are required in the petroleum and chemical industries. For example, large amounts of hydrogen are used in the upgrading of fossil fuels and the production of ammonia or methanol or hydrochloric acid. Petrochemical plants require hydrogen for hydrocracking, hydrodesulfurization, and hydrodealkylation. Hydrogenation processes for increasing the saturation level of unsaturated fats and oils also require hydrogen. Hydrogen is also a reducing agent for metal ores. Hydrogen can be produced from the electrolysis of water, steam reforming, laboratory-scale metal-acid processes, thermochemical methods, or anaerobic corrosion. Many countries are aiming to conserve hydrogen.

[0005] Obviously, there is a continuing need and interest in developing methods and systems for producing these important gases.

Summary of the Invention

[0006] Further aspects and embodiments are provided in the following drawings, the detailed description of the invention, and the claims. Unless otherwise specified, the features described herein are combinable, and all such combinations are within the scope of this disclosure.

[0007] One aspect of the present invention is a method for producing hydrogen, which includes providing an apparatus, introducing a first stream containing fuel into the apparatus, introducing a second stream containing water into the apparatus, reducing water in the second stream to hydrogen, and extracting hydrogen from the apparatus. The first stream and the second stream do not contact each other within the apparatus.

[0008] In another method aspect, the first stream does not contact hydrogen.

[0009] In yet another method aspect, the first stream and the second stream are separated by an electrolyte within the apparatus.

[0010] In still further method aspects, the electrolyte is oxide ion conductive and in a solid state.

[0011] In still further method aspects, the electrolyte contains doped ceria, or the electrolyte contains a material selected from the group consisting of lanthanum chromite or a conductive metal or combinations thereof, and doped ceria, YSZ, LSGM, SSZ, and combinations thereof. Lanthanum chromite includes undoped lanthanum chromite, strontium-doped lanthanum chromite, iron-doped lanthanum chromite, lanthanum calcium chromite, or combinations thereof. The conductive metal includes Ni, Cu, Ag, Au, or combinations thereof.

[0012] In still further method aspects, the electrolyte also conducts electrons and the apparatus does not include an interconnect.

[0013] In another method aspect, the apparatus is tubular.

[0014] In yet another method aspect, the fuel includes hydrocarbons or hydrogen or carbon monoxide or combinations thereof.

[0015] In still further method aspects, the second stream contains hydrogen.

[0016] In yet another method aspect, the first stream further comprises water or carbon dioxide.

[0017] In yet another further method aspect of the invention, the first stream comprises a fuel having little to no water.

[0018] In another method aspect, the device is planar.

[0019] In yet another further method aspect, the device comprises a plurality of repeating units separated by interconnects. Each repeating unit comprises two electrodes and has an electrolyte between the electrodes.

[0020] In yet another further method aspect, the electrodes comprise fluid channels or fluid dispersion components, and the interconnects do not comprise fluid dispersion elements.

[0021] In yet another further method aspect, the method of generating hydrogen comprises introducing the first stream into a reformer before the first stream enters the device.

[0022] In yet another further method aspect of the invention, the reformer is a steam reformer or an autothermal reformer.

[0023] In yet another further method aspect, the method of generating hydrogen comprises operating the device at a temperature of 500 °C or higher.

[0024] In another method aspect, the device comprises a first electrode and a second electrode separated by an electrolyte. The first electrode or the second electrode comprises a material selected from the group consisting of Ni or NiO and YSZ, CGO, SDC, SSZ, LSGM, and combinations thereof.

[0025] In yet another method aspect, the device includes a first electrode and a second electrode separated by an electrolyte. The first electrode includes a material selected from the group consisting of doped or undoped ceria and Cu, CuO, Cu2O, Ag, Ag2O, Au, Au2O, Au2O3, Pt, Pd, Ru, Rh, stainless steel, and combinations thereof.

[0026] In yet a further method aspect, the first electrode includes a catalyst.

[0027] The following drawings are provided to illustrate certain embodiments described herein. The drawings are merely illustrative and are not intended to limit the scope of the claimed invention, nor are they intended to show all possible features or embodiments of the claimed invention. The drawings are not necessarily drawn to scale; in some cases, certain elements of the drawings may be enlarged for illustrative purposes relative to other elements of the drawings.

Brief Description of the Drawings

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BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Summary Embodiments of the methods, materials, and processes described herein are directed to electrochemical reactors. Examples of electrochemical reactors include solid oxide fuel cells, solid oxide fuel cell stacks, electrochemical gas generators, electrochemical compressors, solid-state batteries, or solid oxide flow cells.

[0030] Electrochemical gas generators can be used to produce synthesis gas, hydrogen, or other gases for use as fuels or feedstocks for fuel cells, ammonia production, fertilizer production, hydrogenation reactions, Bosch reactions, or other applications. The disclosure herein describes a method of producing hydrogen using an apparatus. The apparatus can be an electrochemical gas generator and can be planar or tubular in shape.

[0031] Definitions The following description lists various aspects and embodiments of the invention disclosed herein. No particular embodiment is intended to define the scope of the invention. Rather, the embodiments provide non-limiting examples of various compositions and methods that are within the scope of the claimed invention. The description is to be read from the perspective of one of ordinary skill in the art. Thus, information well known to one of ordinary skill in the art is not necessarily included.

[0032] The following terms and phrases have the meanings set forth below unless otherwise defined herein. This disclosure may employ other terms and phrases that are not specifically defined herein. Such other terms and phrases will have the meanings that they have in the context of this disclosure to one of ordinary skill in the art. In some cases, a term or phrase may be defined in either the singular or the plural. In such cases, it is understood that any term in the singular may include its plural counterparts and vice versa, unless the contrary is clearly indicated.

[0033] As used herein, the singular forms "a", "an", and "the" include plural referents unless the context clearly dictates otherwise. For example, reference to "a substituent" includes a single substituent as well as two or more substituents, and the like. As used herein, "for example", "by way of example", "such as", or "including" means introducing an example for further clarification of a more general subject matter. Unless otherwise explicitly indicated, such examples are provided only as an aid for understanding the embodiments disclosed herein and are not meant to limit in any way. These phrases also do not indicate any kind of preference for the disclosed embodiments.

[0034] As used herein, compositions and materials are used interchangeably unless otherwise specified. Each composition / material may have multiple elements, phases, and components. Heating, as used herein, refers to actively adding energy to a composition or material.

[0035] The term "in situ" in this disclosure means that a processing (e.g., heating) process is carried out either at the same location or within the same apparatus as the formation process of the composition or material. For example, a deposition process and a heating process are carried out within the same apparatus and at the same location, that is, without changing the apparatus and without changing the location within the apparatus. For example, a deposition process and a heating process are carried out at different locations within the same apparatus, and this is also considered to be in situ.

[0036] In this disclosure, the major surface of an object is a surface of the object that has a surface area larger than the average surface area of the object, and the average surface area of the object is the total surface area of the object divided by the number of surfaces of the object. In some cases, the major surface refers to a surface of an item or object that has a larger surface area than a smaller surface. In the case of a planar fuel cell or a non-SIS type fuel cell, the major surface is a lateral surface or surface.

[0037] In this specification, "lateral" refers to a direction perpendicular to the stacking direction of layers in a non-SIS type fuel cell. Thus, the lateral direction refers to a direction perpendicular to the stacking direction of layers in a fuel cell, or to the stacking direction of thin flakes forming an object during deposition. "Lateral" also refers to the direction in which the deposition process spreads.

[0038] In this disclosure, a liquid precursor of a substance refers to a dissolved form containing the substance, such as a salt in an aqueous solution. For example, a copper salt dissolved in an aqueous solution is considered a liquid precursor of copper. Copper particles suspended / dispersed (not dissolved) in a liquid are not considered a liquid precursor of copper.

[0039] In this specification, CGO refers to gadolinium-doped ceria (or also known as gadolinia-doped ceria), gadolinium-doped cerium oxide, cerium(IV) oxide, gadolinium-doped, GDC, or GCO, (formula Gd:CeO2). CGO and GDC are used with the same meaning unless otherwise specified.

[0040] Syngas (i.e., synthesis gas) in this disclosure refers mainly to a mixture composed of hydrogen, carbon monoxide, and carbon dioxide.

[0041] In this disclosure, absorbance is a measure of the ability of a substance to absorb electromagnetic radiation (EMR) of a certain wavelength. Absorption of radiation refers to the energy absorbed by the substance when exposed to the radiation.

[0042] In this specification, ceria refers to cerium oxide, also known as ceric oxide, ceric dioxide, or cerium dioxide, which is an oxide of the rare earth metal cerium. Doped ceria refers to ceria doped with other elements, such as samarium-doped ceria (SDC), or gadolinium-doped ceria (GDC or CGO).

[0043] In this specification, chromite refers to chromium oxide, which includes all oxidation states of chromium oxide.

[0044] In this specification, "having little to no water" means having a water content of 1 g / m 3 or less or 200 mg / m 3 or less or 50 mg / m 3 or less as described below.

[0045] In an electrochemical device (e.g., a fuel cell), an interconnect is often either a metal or a ceramic placed between individual cells or repeating units. Its purpose is to connect each cell or repeating unit so that electricity can be distributed or integrated. An interconnect is also called a bipolar plate in an electrochemical device. In this specification, an interconnect that is an impermeable layer indicates that it is a layer that is impermeable to fluid flow. For example, the impermeable layer has a permeability of less than 1 microdarcy or less than 1 nanodarcy.

[0046] In this disclosure, an interconnect having no fluid dispersion elements refers to an interconnect that has no elements (e.g., channels) for dispersing fluid. The fluid can include a gas or a liquid or a mixture of a gas and a liquid. Such a fluid can include one or more of hydrogen, methane, ethane, propane, butane, oxygen, ambient air, or light hydrocarbons (i.e., pentane, hexane, octane). Such an interconnect can have an inlet and an outlet (i.e., an opening) for the material or fluid to pass through.

[0047] In this disclosure, the term "microchannel" is used in the same sense as a microfluidic channel or a microfluid flow channel.

[0048] In this disclosure, sintering refers to a process of forming a solid mass of a material by heat or pressure, or a combination thereof, without melting the material to the extent of liquefaction. For example, the material particles are joined together by heating into a solid or porous mass, where the atoms in the material particles diffuse across the particle boundaries, fusing the particles to form one solid piece. In this disclosure and the appended claims, Tsinter refers to the temperature at which this phenomenon begins to occur.

[0049] In this specification, the term "pore former" is intended to have a relatively broad meaning. A "pore former" may refer to any particulate material that is included in a composition during formation and can create voids, either partially or completely, through processes such as heating, combustion, or vaporization. In this specification, the term "conductive component" is intended to refer to components in a fuel cell that are conductive, such as electrodes and interconnects.

[0050] For purposes of illustration, the production of solid oxide fuel cells (SOFCs) is used as an example of a system in this specification for describing various embodiments. As will be recognized by those skilled in the art, the methods and manufacturing processes described herein are applicable to any electrochemical device, reactor, vessel, catalyst, etc. Examples of electrochemical devices or reactors include electrochemical (EC) gas generators, electrochemical (EC) compressors, solid oxide fuel cells, solid oxide fuel cell stacks, solid-state batteries, or solid oxide flow cells. In one embodiment, the electrochemical reactor includes a solid oxide fuel cell, a solid oxide fuel cell stack, an electrochemical gas generator, an electrochemical compressor, a solid-state battery, or a solid oxide flow cell. The catalyst includes a Fischer-Tropsch (FT) catalyst or a reformer catalyst. The reactor / vessel includes an FT reactor or a heat exchanger.

[0051] Electrochemical (EC) gas generator FIG. 1A shows an electrochemical (EC) gas generator 100 according to one embodiment of this disclosure. The EC gas generation device 100 includes a first electrode 101, an electrolyte 103, and a second electrode 102. The first electrode 101 is configured to receive fuel and not receive oxygen 104. The second electrode 102 is configured to receive water or not receive anything, as indicated by arrow 105. The device 100 is configured to simultaneously generate hydrogen 107 from the second electrode 102 and syngas 106 from the first electrode 101. In one embodiment, 104 represents methane and water or methane and carbon dioxide entering the device 100. In other embodiments, 103 represents an oxide ion conductive membrane. In one embodiment, the first electrode 101 and the second electrode 102 may include Ni-YSZ or NiO-YSZ. Arrow 104 represents the inflow of hydrocarbon and water or hydrocarbon and carbon dioxide. Arrow 105 represents the inflow of water or water and hydrogen. In some embodiments, the electrode 101 includes Cu-CGO that further optionally includes CuO or Cu2O or a combination thereof. The electrode 102 includes Ni-YSZ or NiO-YSZ. Arrow 104 represents the inflow of hydrocarbon having little to no water, no carbon dioxide, and no oxygen, and 105 represents the inflow of water or water and hydrogen. Water is considered an oxidant in this scenario because it provides the oxide ions (transported through the electrolyte) required to oxidize the hydrocarbon / fuel at the counter electrode.

[0052] FIG. 1B shows an EC gas generator 110 according to one embodiment of this disclosure. The EC gas generation device 110 includes a first electrode 111, a second electrode 112, and an electrolyte 113 between the electrodes. The first electrode 111 is configured to receive fuel and not receive oxygen 104, and the second electrode 112 is configured to receive water or not receive anything. In some embodiments, 113 represents a proton conductive membrane, and 111 and 112 represent Ni-barium zirconate electrodes. Hydrogen 107 is generated from the second electrode 112, and syngas 106 is generated from the first electrode 111.

[0053] In this disclosure, "without oxygen" means that there is no oxygen present at the first electrodes 101, 111, or at least there is not enough oxygen to interfere with the reaction. Also, in this disclosure, "water only" means that the intended feedstock is water and does not exclude trace elements or indigenous components in the water. For example, water containing salts or ions is considered within the scope of water only. Water only also does not require 100% pure water, including in this embodiment. In an embodiment, the hydrogen generated from the second electrodes 102, 112 is pure hydrogen, which means that in the gas phase generated from the second electrodes, hydrogen is the main component. In some cases, the hydrogen content is 99.5% or more. In some cases, the hydrogen content is 99.9% or more. In some cases, the hydrogen generated from the second electrodes has the same purity as that generated from the electrolysis of water.

[0054] In one embodiment, the first electrodes 101, 111 are configured to receive methane and water or methane and carbon dioxide. In one embodiment, the fuel includes hydrocarbons having a carbon number in the range of 1-12, 1-10, or 1-8. Most preferably, the fuel is methane or natural gas, which is mainly methane. In one embodiment, the device does not generate electricity. In one embodiment, the device includes a mixer configured to receive at least a portion of the first electrode product and at least a portion of the second electrode product. The mixer can be configured to generate a gas stream having a hydrogen to carbon dioxide ratio of 2 or more, or 3 or more, or between 2 and 3.

[0055] In one embodiment, the first electrodes 101, 111 or the second electrodes 102, 112, or both the first electrodes 101, 111 and the second electrodes 102, 112 include a catalyst and a substrate, and the mass ratio between the catalyst and the substrate is 1 / 100 or more, or 1 / 10 or more, or 1 / 5 or more, or 1 / 3 or more, or 1 / 1 or more. In one embodiment, the catalyst includes nickel oxide, silver, cobalt, cesium, nickel, iron, manganese, nitrogen, tetranitrogen, molybdenum, copper, chromium, rhodium, ruthenium, palladium, osmium, iridium, or platinum, or a combination thereof. In one embodiment, the substrate includes gadolinium, CeO2, ZrO2, SiO2, TiO2, steel, cordierite (2MgO - 2Al2O3 - 5SiO2), aluminum titanate (Al2TiO5), silicon carbide (SiC), all phases of aluminum oxide, yttria or scandia stabilized zirconia (YSZ), gadolinia or samaria doped ceria, or a combination thereof. In some embodiments, the first electrodes 101, 111 or the second electrodes 102, 112, or both the first electrodes 101, 111 and the second electrodes 102, 112 include a promoter, and the promoter is selected from the group consisting of Mo, W, Ba, K, Mg, Fe, and combinations thereof. In one embodiment, the anode (e.g., the first electrode or the second electrode) includes a catalyst, and the catalyst is selected from the group consisting of nickel, iron, palladium, platinum, ruthenium, rhodium, cobalt, and combinations thereof.

[0056] In some embodiments, the electrodes and the electrolyte form repeating units. The device may include two or more repeating units separated by interconnects. In a preferred embodiment, the interconnects do not include fluid dispersion elements. In one embodiment, the first electrodes 101, 111 or the second electrodes 102, 112, or both the first electrodes 101, 111 and the second electrodes 102, 112 include fluid channels. Alternatively, the first electrodes 101, 111 or the second electrodes 102, 112, or both the first electrodes 101, 111 and the second electrodes 102, 112 include fluid dispersion components.

[0057] An assembly method including forming the first electrodes 101, 111, forming the second electrodes 102, 112, and forming the electrolytes 103, 113 between the electrodes is also described herein, and the electrodes and electrolytes are assembled when they are formed. Forming can include material jetting, binder jetting, inkjet printing, aerosol jetting, or aerosol jet printing, vat photopolymerization, powder bed fusion bonding, material extrusion, directed energy deposition, sheet lamination, ultrasonic inkjet printing, or combinations thereof. The electrodes and electrolytes can form repeating units. The method can further include forming two or more repeating units and forming an interconnect between the two or more repeating units. The assembly method can further include forming a fluid channel or fluid dispersion component in the first electrodes 101, 111 or the second electrodes 102, 112, or both the first electrodes 101, 111 and the second electrodes 102, 112. The forming method can include heating in situ. In a preferred embodiment, heating includes EMR. The EMR can include one or more of UV light, near-UV light, near-infrared light, infrared light, visible light, a laser, or an electron beam.

[0058] The first electrodes 101, 111 are configured to receive fuel and not receive oxygen, the second electrodes 102, 112 are configured to receive only water or receive nothing, and the device is configured to simultaneously generate hydrogen from the second electrodes 102, 112 and syngas from the first electrodes 101, 111.

[0059] This specification provides an apparatus including a first electrode 101, 111, a second electrode 102, 112, and an electrolyte 103, 113 between the electrodes, introduces a fuel having no oxygen to the first electrode 101, 111, introduces only water or generates hydrogen without introducing anything to the second electrode 102, 112, extracts hydrogen from the second electrode 102, 112, and extracts syngas from the first electrode 101, 111. In a preferred embodiment, the fuel includes methane and water or methane and carbon dioxide. In a preferred embodiment, the fuel includes hydrocarbons having a carbon number in the range of 1-12 or 1-10 or 1-8.

[0060] In one embodiment, the method includes sending at least a portion of the extracted syngas to a Fischer-Tropsch reactor. In one embodiment, the method includes sending at least a portion of the extracted hydrogen to a Fischer-Tropsch reactor. In one embodiment, at least a portion of the extracted syngas and at least a portion of the extracted hydrogen are adjusted such that the hydrogen-to-carbon monoxide ratio is 2 or more, or 3 or more, or between 2 and 3.

[0061] In one embodiment, fuel is introduced directly to the first electrodes 101, 111, or water is introduced directly to the second electrodes 102, 112, or both the first electrodes 101, 111 and the second electrodes 102, 112. In one embodiment, the first electrodes 101, 111 or the second electrodes 102, 112, or both the first electrodes 101, 111 and the second electrodes 102, 112 include a catalyst and a substrate, and the mass ratio between the catalyst and the substrate is 1 / 100 or more, or 1 / 10 or more, or 1 / 5 or more, or 1 / 3 or more, or 1 / 1 or more. In a preferred embodiment, the catalyst includes nickel oxide, silver, cobalt, cesium, nickel, iron, manganese, nitrogen, tetranitrogen, molybdenum, copper, chromium, rhodium, ruthenium, palladium, osmium, iridium, platinum, or a combination thereof. In a preferred embodiment, the substrate includes gadolinium, CeO2, ZrO2, SiO2, TiO2, steel, cordierite (2MgO-2Al2O3-5SiO2), aluminum titanate (Al2TiO5), silicon carbide (SiC), all phases of aluminum oxide, yttria or scandia stabilized zirconia (YSZ), gadolinia or samaria doped ceria, or a combination thereof.

[0062] In one embodiment, the method includes applying a potential difference between the first electrodes 101, 111 and the second electrodes 102, 112. In one embodiment, the method includes using hydrogen extracted in one or a combination of the following reactions: Fischer-Tropsch (FT) reaction, dry reforming reaction, Sabatier reaction catalyzed by nickel, Bosch reaction, reverse water gas shift reaction, an electrochemical reaction for generating electricity, production of ammonia and / or fertilizer, hydrogen storage, or an electrochemical compressor for fueling a hydrogen vehicle, or a hydrogenation reaction.

[0063] The gas generator, in various embodiments, is not a fuel cell and does not generate electricity. Electricity may be applied to the gas generator at the anode and cathode in some cases. In other cases, electricity is not required.

[0064] This specification discloses an apparatus including a first electrode, a second electrode, and an electrolyte between the electrodes. The first and second electrodes include a metal phase that does not contain a platinum group metal when the apparatus is in use, and the electrolyte is oxide ion conductive. In one embodiment, the first electrode includes a material selected from the group consisting of Ni or NiO and YSZ, CGO, samaria-doped ceria (SDC), scandia-stabilized zirconia (SSZ), LSGM, and combinations thereof. In one embodiment, the first electrode is configured to receive fuel and water or fuel and carbon dioxide. In one embodiment, the fuel includes hydrocarbons or hydrogen or carbon monoxide or combinations thereof.

[0065] In one embodiment, the first electrode comprises a material selected from the group consisting of doped or undoped ceria and Cu, CuO, Cu2O, Ag, Ag2O, Au, Au2O, Au2O3, stainless steel, and combinations thereof. In one embodiment, the first electrode is configured to receive a fuel having little to no water. In one embodiment, the fuel comprises hydrocarbons or hydrogen or carbon monoxide or combinations thereof. In one embodiment, the second electrode comprises a material selected from the group consisting of Ni or NiO and yttria-stabilized zirconia (YSZ), ceria gadolinium oxide (CGO), samaria-doped ceria (SDC), scandia-stabilized zirconia (SSZ), lanthanum strontium gallate magnesite (LSGM), and combinations thereof. In one embodiment, the second electrode is configured to receive water and hydrogen and to be configured to reduce water to hydrogen. In one embodiment, the electrolyte comprises doped ceria, or the electrolyte comprises a material selected from the group consisting of lanthanum chromite or a conductive metal or combinations thereof and doped ceria, YSZ, LSGM, SSZ, and combinations thereof. In one embodiment, the lanthanum chromite comprises undoped lanthanum chromite, strontium-doped lanthanum chromite, iron-doped lanthanum chromite, lanthanum calcium chromite, or combinations thereof. In one embodiment, the conductive metal comprises Ni, Cu, Ag, Au, or combinations thereof.

[0066] In one embodiment, either the first electrodes 101, 111, or the second electrodes 102, 112, or both the first electrodes 101, 111 and the second electrodes 102, 112 include fluid channels. Alternatively, either the first electrodes 101, 111, or the second electrodes 102, 112, or both the first electrodes 101, 111 and the second electrodes 102, 112 include fluid dispersion components. In one embodiment, the electrodes and electrolytes 103, 113 form repeating units, and the device includes a plurality of repeating units separated by interconnects. In one embodiment, the interconnects do not include fluid dispersion elements. In one embodiment, the electrodes 101, 102, 111, 112 and the electrolytes 103, 113 may be planar. The fluid dispersion components or fluid channels within the electrodes function to distribute a fluid, such as a reactive gas (e.g., methane, hydrogen, carbon monoxide, air, oxygen, steam, etc.) in an electrochemical reactor. Thus, a conventional interconnect having channels is no longer required. The design and manufacture of such conventional interconnects having channels is complex and costly. According to this disclosure, the interconnect is simply an impermeable layer that conducts or collects electrons and does not have fluid dispersion elements.

[0067] In one embodiment, the device does not include interconnects. In one embodiment, the electrolytes 103, 113 conduct oxide ions and electrons. In one embodiment, the electrodes 101, 102, 111, 112 and the electrolytes 103, 113 are tubular. In some embodiments, the electrochemical reactions at the anode and cathode occur naturally and there is no need to apply potential / electricity to the reactor. In such cases, the interconnects are no longer required, which significantly simplifies the device. In such cases, the electrolyte within the device conducts both oxide ions and electrons.

[0068] In one embodiment, the device includes a reformer upstream of the first electrodes 101, 111, and the first electrodes 101, 111 include Ni or NiO or a combination thereof. In one embodiment, the reformer is a steam reformer or an autothermal reformer. In one embodiment, the device is configured to operate at a temperature of 500 °C or higher, or 600 °C or higher, or 700 °C or higher.

[0069] In one embodiment, the electrode and the electrolyte are tubular, the first electrode is the outermost, the second electrode is the innermost, and the first electrode includes a material selected from the group consisting of doped or undoped ceria and Cu, CuO, Cu2O, Ag, Ag2O, Au, Au2O, Au2O3, stainless steel, and combinations thereof. In one embodiment, the electrode and the electrolyte are tubular, the first electrode is the outermost, the second electrode is the innermost, and the second electrode is configured to receive water and hydrogen.

[0070] Also disclosed herein is a device including a first electrode, a second electrode, and an electrolyte between the electrodes, the first electrode including doped lanthanum chromite and doped or undoped ceria, the second electrode including a material selected from the group consisting of Ni or NiO and YSZ, CGO, samaria-doped ceria (SDC), scandia-stabilized zirconia (SSZ), LSGM, ceria, and combinations thereof, and the electrolyte being oxide ion conductive. In one embodiment, the electrolyte includes YSZ, CGO, LSGM, SSZ, SDC, ceria, or a combination thereof. In one embodiment, the device is planar. In one embodiment, the device is tubular.

[0071] This specification further describes a method of manufacturing a device that includes forming a first electrode, forming a second electrode, and forming an electrolyte between the electrodes. The first electrode includes doped lanthanum chromite and doped or undoped ceria. The second electrode includes a material selected from the group consisting of Ni or NiO and YSZ, CGO, samarium-doped ceria (SDC), scandia-stabilized zirconia (SSZ), LSGM, ceria, and combinations thereof. The electrolyte is oxide ion conductive. In one embodiment, the electrolyte includes YSZ, CGO, LSGM, SSZ, SDC, ceria, or combinations thereof. In one embodiment, the forming includes material injection, binder injection, inkjet printing, aerosol injection, or aerosol jet printing, vat photopolymerization, powder bed fusion bonding, material extrusion, directed energy deposition, sheet lamination, or ultrasonic inkjet printing, or combinations thereof. In one embodiment, the forming includes extrusion, dip coating, spraying, spin coating, brushing, pasting, or combinations thereof. In one embodiment, the forming includes heating using an electromagnetic radiation source or a furnace.

[0072] This specification describes a method of manufacturing a device that includes forming a first electrode, forming a second electrode, and forming an electrolyte between the electrodes. The first and second electrodes include a metal phase that does not include a platinum group metal when the device is in use. The electrolyte is oxide ion conductive. In one embodiment, the electrodes and the electrolyte are assembled when they are formed. In one embodiment, the electrodes and the electrolyte form repeating units, and the method includes forming the plurality of repeating units and forming an interconnect between the repeating units. In one embodiment, the interconnect does not include a fluid dispersion element. In one embodiment, the method includes forming a fluid channel or a fluid dispersion component in the first electrode or the second electrode or both the first and second electrodes.

[0073] In one embodiment, the first electrode comprises a material selected from the group consisting of Ni or NiO and YSZ, CGO, samaria-doped ceria (SDC), scandia-stabilized zirconia (SSZ), LSGM, and combinations thereof. In one embodiment, the first electrode comprises a material selected from the group consisting of doped or undoped ceria and Cu, CuO, Cu2O, Ag, Ag2O, Au, Au2O, Au2O3, stainless steel, and combinations thereof. In one embodiment, the second electrode comprises a material selected from the group consisting of Ni or NiO and YSZ, CGO, samaria-doped ceria (SDC), scandia-stabilized zirconia (SSZ), LSGM, ceria, and combinations thereof. In one embodiment, the electrolyte comprises YSZ, CGO, LSGM, SSZ, SDC, ceria, or combinations thereof.

[0074] In one embodiment, forming comprises material spraying, binder spraying, inkjet printing, aerosol spraying, aerosol jet printing, vat photopolymerization, powder bed fusion bonding, material extrusion, directed energy deposition, sheet lamination, ultrasonic inkjet printing, or combinations thereof. In one embodiment, the method comprises heating in situ. In one embodiment, heating comprises electromagnetic radiation (EMR). In one embodiment, the EMR comprises UV light, near-UV light, near-infrared light, infrared light, visible light, lasers, electron beams, or combinations thereof. In one embodiment, the EMR is provided by a xenon lamp. In one embodiment, the electrodes and the electrolyte are planar. In one embodiment, the device does not include an interconnect. In one embodiment, the electrolyte conducts oxide ions and electrons.

[0075] In one embodiment, forming comprises: a) depositing a composition onto a substrate to form a flake; b) drying the flake using a non-contact dryer; c) heating the flake using electromagnetic radiation (EMR) or conduction or both. In one embodiment, the method includes repeating steps a)-c) to produce the device one flake at a time. In one embodiment, the method includes d) measuring the flake temperature T without contacting the flake within a time t after the final exposure to EMR, where t is 5 seconds or less, or 4 seconds or less, or 3 seconds or less, 2 seconds or less, or 1 second or less. In one embodiment, the method includes e) comparing T to T sinter where T sinter is 45% or more of the melting point of the composition if the composition is non-metallic; or T sinter is 60% or more of the melting point of the composition if the composition is metallic. In one embodiment, the method includes e) comparing T to T sinter where T sinter has been previously determined by correlating the measured temperature with a microstructural image of the flake, a scratch test of the flake, an electrochemical performance test of the flake, a measurement of the expansion rate of the flake, a measurement of the conductivity of the flake, or a combination thereof. In one embodiment, the method includes heating the flake using EMR or conduction or both in a second stage if T is less than 90% of T sinter .

[0076] In one embodiment, drying occurs during a period in the range of 5 minutes or less, or 3 minutes or less, or 1 minute or less, or 1 second to 30 seconds, or 3 seconds to 10 seconds. In one embodiment, the non-contact dryer includes an infrared heater, a hot air blower, an ultraviolet light source, or a combination thereof.

[0077] As an example, all the layers of the EC gas generator are formed and assembled by printing. The materials for manufacturing the anode, cathode, electrolyte, and interconnect are each made into an ink form containing a solvent and particles (e.g., nanoparticles). The ink optionally contains a dispersant, binder, plasticizer, surfactant, co-solvent, or a combination thereof. For the anode and cathode of the gas generator, NiO and YSZ particles are mixed with a solvent, which is water (e.g., deionized water) or alcohol (e.g., butanol) or a mixture of alcohols. Organic solvents other than alcohol can also be used. For the electrolyte, YSZ particles are mixed with a solvent, which is water (e.g., deionized water) or alcohol (e.g., butanol) or a mixture of alcohols. Organic solvents other than alcohol can also be used. For the interconnect, metal particles (e.g., silver nanoparticles) are dispersed or suspended in a solvent, which includes water (e.g., deionized water), organic solvents (e.g., mono-, di-, or triethylene glycol or higher ethylene glycols, propylene glycol, 1,4-butanediol or ethers of such glycols, thiodiglycol, glycerol and their ethers and esters, polyglycerol, mono-, di-, and triethanolamine, propanolamine, N,N-dimethylformamide, dimethyl sulfoxide, dimethylacetamide, N-methylpyrrolidone, 1,3-dimethylimidazolidone, methanol, ethanol, isopropanol, n-propanol, diacetone alcohol, acetone, methyl ethyl ketone, propylene carbonate), and combinations thereof. For the barrier layer, CGO particles may be dissolved, dispersed, or suspended in a solvent, which is water (e.g., deionized water) or alcohol (e.g., butanol) or a mixture of alcohols. Organic solvents other than alcohol can also be used. CGO is used as a barrier layer for LSCF. YSZ can also be used as a barrier layer for LSM.

[0078] Tubular and multitubular EC gas generators Figure 2A shows a tubular EC gas generator 200 (not to scale) according to an embodiment of this disclosure. The tubular EC gas generator 200 includes an inner tubular structure 202, an outer tubular structure 204, and an electrolyte 206 disposed between the inner and outer tubular structures 202, 204, respectively. In some embodiments, the electrolyte 206 may alternatively include a membrane. The tubular gas generator 200 further includes a void 208 for a flow path.

[0079] Figure 2B shows a cross-section of a tubular EC gas generator 200 (not to scale) according to an embodiment of this disclosure. The tubular EC gas generator 200 includes a first inner tubular structure 202, a second outer tubular structure 204, and an electrolyte 206 between the inner tubular structure and the outer tubular structures 202, 204. In some embodiments, the electrolyte 206 may be referred to as a membrane. The tubular gas generator 200 further includes a void 208 for a flow path.

[0080] In one embodiment, the inner tubular structure 202 includes electrodes. The inner tubular structure 202 may be an anode or a cathode. In one embodiment, the inner tubular structure 202 may be porous. The inner tubular structure 202 may include materials selected from the group consisting of Ni or NiO and YSZ, CGO, samaria-doped ceria (SDC), scandia-stabilized zirconia (SSZ), LSGM, and combinations thereof. The inner tubular structure 202 may include materials selected from the group consisting of doped or undoped ceria and Cu, CuO, Cu2O, Ag, Ag2O, Au, Au2O, Au2O3, stainless steel, and combinations thereof. It should be noted that the above list of materials is not limiting.

[0081] In an embodiment, the electrolyte 206 includes doped ceria, or the electrolyte includes materials selected from the group consisting of lanthanum chromite or a conductive metal or combinations thereof and doped ceria, YSZ, LSGM, SSZ, and combinations thereof. In one embodiment, the lanthanum chromite includes undoped lanthanum chromite, strontium-doped lanthanum chromite, iron-doped lanthanum chromite, lanthanum calcium chromite, or combinations thereof. In one embodiment, the conductive metal includes Ni, Cu, Ag, Au, or combinations thereof. The electrolyte 206 is oxide ion conductive. In some cases, the electrolyte 206 is both oxide ion and electron conductive. In some embodiments, the generator 200 further includes one or more interconnects.

[0082] Figure 3A shows a cross-section of a multi-tubular EC gas generator 300 according to an embodiment of the present disclosure. The EC gas generator 300 includes an inner electrode 302, an outer electrode 304, and an electrolyte 306 between the electrodes 302 and 304. In some embodiments, the electrolyte 306 is referred to as a membrane. The inner electrode 302 includes a plurality of tube-like voids 308 that are radially joined together. The voids 308 enable a flow path. The voids 308 are also referred to as flow paths. The multi-tubular structure 300 includes a plurality of flow paths 308 in the axial direction of the tubular structure 300. The cross-section of the voids 308 may be circular-like, elliptical-like, or other similar shapes. The cross-section of the space 308 may be an irregular shape as shown in FIG. 3A. The generator 300 has a cross-section with a certain length and a certain width, the length being at least twice the width, and the cross-section being perpendicular to the axial direction of the tube. The multi-tubular structure 300 is composed of a plurality of individual tubular structures 309 (shown by dotted lines).

[0083] The inner electrode 302 within the generator 300 may be of an integral structure and have no brazed or soldered parts. In one embodiment, the generator 300 may be of an integral structure and have no brazed or soldered parts. In one embodiment, the electrolyte 306 is oxide ion conductive and in a solid state. In one embodiment, the electrolyte includes the materials previously listed herein for the electrolyte 206 in the tubular reactor 200. In embodiments, the electrodes 302, 304 may include one or more of the materials previously listed herein for the tubular structures 202, 204 in the tubular reactor 200. In some embodiments, the generator 300 further includes one or more interconnects.

[0084] FIG. 3B shows a cross-section of a multi-tubular EC gas generator 320 according to an embodiment of the present disclosure. The gas generator has a rectangular-like cross-section. The EC gas generator 320 includes an inner electrode 302, an outer electrode 304, and an electrolyte 306 between the electrodes 302, 304. In some embodiments, a membrane may be used in place of the electrolyte 306. The inner electrode 302 includes a plurality of voids 308 that are radially together in a tubular-like void 308. The voids 308 enable flow paths. The plurality of tubular structures 320 includes a plurality of axial flow paths 308 of the tubular structure 320. The cross-section of the voids 308 can be circular-like, elliptical-like, square-like, hexagonal-like, triangular-like, or other similar shapes randomly or regularly. The generator 320 has a cross-section with a certain length and a certain width, the length is at least twice the width, and the cross-section is perpendicular to the axial direction of the tube.

[0085] The inner electrode 302 within the generator 320 may be of an integral structure and have no brazed or soldered parts. The generator 320 may be of an integral structure and have no brazed or soldered parts. In one embodiment, the electrolyte 306 is oxide ion conductive. In embodiments, the electrolyte may include one or more of the materials previously listed herein for the electrolyte 206 in the tubular reactor 200. In embodiments, the electrodes 302, 304 may include one or more of the materials previously listed herein for the tubular structures 202, 204 in the tubular reactor 200. In some embodiments, the generator 320 further includes one or more interconnects.

[0086] Figure 3C shows a cross-section of a multi-tubular EC gas generator 340 according to an embodiment of the present disclosure. The gas generator 340 has a rectangular-like cross-section. The EC gas generator 340 includes an inner electrode 302, an outer electrode 304, and an electrolyte 306 between the electrodes 302, 304. In some embodiments, the electrolyte 306 is referred to as a membrane. The inner electrode 302 includes a plurality of voids 308 that are axially aligned in the tube. The voids 308 enable flow paths. The plurality of tubular structures 340 includes a plurality of axial flow paths 308 in the tubular structure 340. The cross-section of the voids 308 may be square-like or rectangular-like as shown in Figure 3C, or regularly, other similar shapes, and the cross-sectional area of each void is substantially the same. The generator 340 has a cross-section with a certain length and a certain width, the length is at least twice the width, and the cross-section is perpendicular to the axial direction of the tube.

[0087] The inner electrode 302 within the generator 340 may be of an integral structure and have no brazed or soldered parts. The generator 340 may be of an integral structure and have no brazed or soldered parts. In one embodiment, the electrolyte 306 is oxide ion conductive. In embodiments, the electrolyte may include one or more of the materials previously listed herein for the electrolyte 206 in the tubular reactor 200. In embodiments, the electrodes 302, 304 may include one or more of the materials previously listed herein for the tubular structures 202, 204 in the tubular reactor 200. In some embodiments, the generator 340 further includes one or more interconnects.

[0088] Figure 3D shows a cross-section of an EC gas generator 360 according to an embodiment of the present disclosure. The gas generator 360 has a rectangular-like cross-section. The EC gas generator 360 is similar to the gas generator 340 in Figure 3C, except that there is only one flow path 380 as shown in Figure 3D.

[0089] Manufacture of Tubular and Multi-Tubular EC Gas Generators This specification further describes a method of manufacturing a tubular EC gas generator, shown by apparatuses 200, 300, 320, 340, and 360 (which are merely examples of some tubular designs). At least three methods are described herein regarding how to manufacture the first tube: an extrusion method, a substrate method, and the process shown in FIGS. 5A-5B.

[0090] In one embodiment, a method of manufacturing a tubular EC gas generator includes forming a first tubular structure by extrusion. In some embodiments, the first tubular structure is the inner electrode 202. The method further includes depositing a layer on the outer cylindrical surface of the first tubular structure 202, the layer including the electrolyte 206, and depositing a second tubular structure 204 on the electrolyte 206, the electrolyte 206 being oxide ion conductive. In one embodiment, the first tubular structure 202 and the second tubular structure 204 include a metal phase that does not contain a platinum group metal when the apparatus is in use. In one embodiment, the apparatus does not include an interconnect and the electrolyte is electronically conductive.

[0091] In another manufacturing method embodiment, the method includes extruding an inner tubular structure 202; sintering the inner tubular structure 202 in a furnace or using EMR to form a first electrode; coating the outer surface of the inner tubular structure 202 with an electrolyte material; sintering the electrolyte material in a furnace or using EMR to form an electrolyte 206; coating the electrolyte 206 with an electrode material; sintering the electrode material in a furnace or using electromagnetic radiation (EMR) to form an outer tubular structure 204, wherein the outer tubular structure 204 is a second electrode. In one embodiment, the outer tubular structure 204 comprises a material selected from the group consisting of doped or undoped ceria and Cu, CuO, Cu2O, Ag, Ag2O, Au, Au2O, Au2O3, stainless steel, and combinations thereof; and is sintered using EMR. In one embodiment, the method further includes reducing the outer tubular structure 204 or reducing the inner tubular structure 202 or both tubular structures 202, 204. These methods describe an "inside out" method where the first extruded layer is the inner electrode layer.

[0092] The following method describes an "outside-in" method, where the first layer formed is the outer tubular structure 204 or the outer electrode layer. The method includes extruding the outer tubular structure 204; sintering the outer tubular structure 204 in a furnace or using EMR to form the first electrode; coating the inner surface of the outer tubular structure 204 with an electrolyte material; sintering the electrolyte material in a furnace or with EMR to form the electrolyte 206; coating the inner surface of the electrolyte 206 with an electrode material; sintering the electrode material in a furnace or using electromagnetic radiation (EMR) to form the inner tubular structure 202, where the inner tubular structure 202 is the second electrode. In one embodiment, the inner tubular structure 202 includes a material selected from the group consisting of doped or undoped ceria and combinations of Cu, CuO, Cu2O, Ag, Ag2O, Au, Au2O, Au2O3, stainless steel, and combinations thereof; and is sintered using EMR. In one embodiment, the method further includes reducing the outer tubular structure 204, or reducing the inner tubular structure 202 or both tubular structures 202, 204.

[0093] In one embodiment, the coating processes for use in the "inside-out" and "outside-in" methods include dip coating, spraying, ultrasonic spraying, spin coating, brushing, pasting, or combinations thereof. The electromagnetic radiation includes UV light, near-UV light, near-infrared light, infrared light, visible light, lasers, electron beams, microwaves, or combinations thereof. In one embodiment, the electromagnetic radiation is provided by a xenon lamp. In some embodiments, the device may include one or more interconnects. In one embodiment, the inner tubular structure 202 and the outer tubular structure 204 include one or more fluid channels or one or more fluid dispersion components or both fluid channels and fluid dispersion components.

[0094] In another embodiment, the inner tubular structure 202 or the outer tubular structure 204 may be formed from microparticles, rather than from a liquid precursor, especially when the inner tubular structure 202 or the outer tubular structure 204 comprises a material selected from the group consisting of doped or undoped ceria and Cu, CuO, Cu2O, Ag, Ag2O, Au, Au2O, Au2O3, stainless steel, and combinations thereof. The microparticles may be suspended in a liquid prior to deposition or coating, for example, prior to dip coating, spraying, spin coating, brushing, pasting, or combinations thereof. In such cases, the inner tubular structure 202 or the outer tubular structure 204 is sintered using electromagnetic radiation (EMR).

[0095] In other embodiments, a first tubular substrate is provided. The tubular substrate is substantially in the desired shape of the EC gas generator. In a first embodiment, a first electrode material is deposited on the outside of the tubular substrate. The first electrode material is sintered to form the inner electrode 202. An electrolyte material is then deposited on the surface of the inner electrode layer 202. The electrolyte material is sintered to form the electrolyte 206. A second electrode material is then deposited on the electrolyte 206. The second electrode material is then sintered to form the outer electrode 204. This method may be described as an "inside out substrate method", where the first layer formed on the substrate is the inner electrode layer 202, followed by the electrolyte layer 206 and then the outer electrode layer 204. The first and second electrodes may be anodes or cathodes. Sintering may include thermal or EMR sintering.

[0096] In other similar methods, a tubular substrate is provided. A first electrode material is deposited on the inside of the tubular substrate. The first electrode material is sintered to form the outer electrode 204. An electrolyte material is then deposited on the surface of the outer electrode layer 204. The electrolyte material is sintered to form the electrolyte 206. A second electrode material is then deposited on the electrolyte 206. The second electrode material is then sintered to form the inner electrode 202. This method may be described as an "outside-in substrate method", where the first layer formed on the substrate is the inner electrode layer 202, followed by the electrolyte 206 layer and then the outer electrode layer 204. The first and second electrodes may be the anode or the cathode. Sintering may include thermal or EMR sintering.

[0097] In some embodiments, the substrate may then be removed as soon as the final electrode is formed. The substrate may be removed by physical means. The substrate may be dissolved and removed by a solvent. In some methods, the substrate may be composed of a low melting point material such as a polymer, and the substrate may be melted or gasified and removed during any one of the thermal sintering steps. For example, the substrate may include a combustible material such that the substrate burns out during one of the thermal sintering steps.

[0098] In one embodiment, the first tubular part (inner or outer) and the electrolyte are sintered separately in an oven. In one embodiment, the first tubular part (inner or outer) and the electrolyte are co-sintered in an oven, which means that the first tubular part is coated with the electrolyte material and then sintered. The second tubular part (outer or inner) is deposited on the electrolyte and then sintered using EMR. The second tubular part comprises a material selected from the group consisting of doped or undoped ceria and Cu, CuO, Cu2O, Ag, Ag2O, Au, Au2O, Au2O3, stainless steel, and combinations thereof. FIGS. 4A-4D show various arrangements for sintering the tubular part using an EMR source. The EMR source and the tubular part can move relative to each other, for example, axially or in a helical path, to ensure that the entire surface of the tubular part (inner or outer) is sintered by sufficiently exposing it to the EMR source. In one embodiment, the EMR source is a xenon lamp such as a circular xenon lamp, a long tubular xenon lamp, or a point tubular xenon lamp.

[0099] FIGS. 4A-4D show a sintering method and system for manufacturing a tubular EC gas generator using EMR. FIG. 4A shows a part of a method 400 for manufacturing an EC gas generator using a single-point EMR source according to an embodiment of the present disclosure. An EMR source (e.g., a xenon lamp) 402 and a tubular structure 404 can move relative to each other. As shown in FIG. 4A, the single-point EMR 402 can rotate around the tubular structure 404 in either direction as indicated by arrow 406 (e.g., in a helical-like path). Alternatively, the tubular structure 404 can rotate around the single-point EMR 402. In another embodiment, the tubular structure 404 can rotate around its own axis 408 or move in the vertical direction 410 along its own major axis or in combinations thereof. The single-point EMR source 402 can also move in the vertical direction 412.

[0100] Figure 4B shows a part of a method 420 for manufacturing an EC gas generator using a ring lamp EMR source, according to an embodiment of the present disclosure. As shown in Figure 4B, a circular ring-like lamp (e.g., a xenon lamp) 422 is shown as an EMR source having a hollow circle in the center. A tubular structure 404 is placed in the center of the circular ring lamp 422. In some embodiments, the tubular structure 404 may move up and down 410, or may rotate about its axis 408, while the ring lamp 422 is held in a fixed position. In other embodiments, the tubular structure 404 may be held in a fixed position, while the ring lamp 422 may move along the length of the tubular structure 404. The ring lamp 422 may move up and down 424, or may rotate (426) about its axis, to ensure complete and perfect sintering. In other embodiments, both the tubular structure 402 and the ring lamp 422 can move relative to each other to ensure that the entire tubular structure 404 is sintered surely, thoroughly, and completely. Figures 4A - 4B show embodiments in which the outer surface of the tubular structure 404 is sintered by EMR. These methods can be used to sinter the anode, cathode, electrolyte, and other components of a tubular EC gas generator.

[0101] Figures 4C - 4D show embodiments in which the inner surface of the tubular structure 404 is sintered by EMR. Figure 4C shows a part of a method 440 for manufacturing an EC gas generator using a single-point EMR source, according to an embodiment of the present disclosure. Figure 4C shows a single-point EMR source (e.g., a xenon lamp) 402 placed inside the tubular structure 404. In a first embodiment, the tubular structure 404 may be held in a fixed position, while the single-point EMR source may be moved up and down 412. In a preferred embodiment, the single-point EMR source 402 can irradiate substantially equally in all directions. In another embodiment, the single-point EMR source may be held in a fixed position, while the tubular structure 404 may be moved up and down 410, or may be rotated about its axis 408. In another embodiment, both the tubular structure 404 and the single-point EMR source 402 move relative to each other such that the entire inner surface of the tubular structure 404 is completely and substantially sintered.

[0102] Figure 4D shows a part of a method 460 of manufacturing an EC gas generator using a tubular EMR source according to an embodiment of the present disclosure. Figure 4D shows a cylindrical lamp as an EMR source (e.g., a tubular xenon lamp) 462 placed inside a tubular structure 404 to be sintered. The length of the lamp in this case is such that the entire inner surface of the tubular structure 404 can be sintered without the need for the tubular lamp 462 and the tubular structure 404 to move relative to each other. In one embodiment, the tubular lamp 462 may be held in a fixed position, while the tubular structure 404 may be moved above the lamp 462. The tubular structure 404 may be moved up and down 464. For example, the unsintered tubular structure 404 is moved above the tubular lamp 462 to a specific position, stays at this position until sufficient irradiation is performed and the tubular structure 404 is substantially sintered, and then is moved vertically as indicated by arrow 464 away from the tubular lamp 462 for the next manufacturing step. In another embodiment, the unsintered tubular structure 404 may be held in a fixed position, while the tubular lamp EMR source 462 is moved into the tubular structure 404. The tubular lamp 462 may be moved up and down as indicated by arrow 464. The tubular structure 404 may be formed using any suitable method, such as the methods described herein. For the embodiments of FIGS. 4C-4D, the coating and sintering occur on the inner surface of the tubular structure 404.

[0103] Many variations are possible for the sintering shown in FIGS. 4A-4D. For example, an outer tubular structure 204 is formed and heat-sintered in a furnace to form an anode or a cathode. The electrolyte material may then be coated on the inner surface of the outer tubular structure 204 and then sintered in a furnace or using a point EMR 402 or a tubular lamp EMR 462 inside the tubular structure to form the electrolyte 206. Another electrode material is then coated on the inner surface of the electrolyte 206 and then sintered in a furnace or using the EMR sources 402, 462 to form an inner tubular structure 202, e.g., an anode or a cathode. For example, for a copper, gold, or silver-containing anode, the inner electrode is sintered using an EMR source. For example, for a Ni or NiO-containing anode, the inner electrode is sintered in a furnace or by an EMR source.

[0104] In some embodiments, a combination of an EMR source inside the tubular electrodes 202, 204 or the electrolyte 206 and an EMR source outside the tubular electrodes 202, 204 or the electrolyte 206 can be used simultaneously for sintering. For example, the tubular EMR source 462 and the ring-like EMR source 422 can be used in the same sintering apparatus, either sequentially or simultaneously, for sintering.

[0105] Figures 5A-5B illustrate another method for forming a first tubular or multi-tubular portion in an EC gas generator. Figure 5A shows a first step in a tape casting method 500 for forming a tubular or multi-tubular EC gas generator according to an embodiment of the present disclosure. In the first step, a support 504 is placed on a substrate 502, and the height of the support 504 is preconfigured such that the desired thickness of the tubular electrode 506 is ensured on the bottom side. The substrate 502 and the support 504 can be made of metal, glass, plastic, wood, or any suitable material known in the art. An electrode material 506 in the form of a dispersion or slurry is deposited between the supports 504 on the substrate 502. Although the term slurry is used in the description, a dispersion can also be used in the same sense. One or more spacers 508 are then placed on the upper surface of the slurry 506 and placed on the support 504. FIG. 501 is a top view or upper view, further illustrating and showing an example of how the substrate 502, the support 504, the electrode material 506, and the spacer 508 can be arranged.

[0106] Figure 5B shows steps 2-4 in a tape casting method 500 for forming a first tubular portion or a first multi-tubular portion in an EC gas generator according to an embodiment of the present disclosure. In step 2, an additional slurry 510 is deposited to cover the spacer(s) 508 and the previously deposited slurry 506. A blade, such as a doctor blade, is used to scrape off the entire upper surface of the additional slurry 510 to ensure a suitable thickness of the upper tubular electrode. In a preferred embodiment, the slurry mainly contains an organic solvent.

[0107] Process 3 shown in FIG. 5B includes immersing substrate 502, support 504, spacer(s) 508, first slurry 506, and second slurry 510 in deionized water, whereby phase inversion of the slurry occurs. Phase inversion is one form of precipitation when a slurry containing a less polar organic solvent is placed in a more polar deionized water. The components of the slurry precipitate as a result, because the components are not compatible with water.

[0108] The substrate 502 and the support 504 are then removed together from the slurries 506, 510 after phase inversion. The slurries 506, 510 are dried (e.g., in ambient air) to remove excess deionized water. The spacer 508 is then removed, for example, pulled out from either end. The electrode materials 506, 510 are sintered to form a first tubular electrode 512 having flow channels 514. The spacer 508 may have any desired regular or irregular shape, for example, circular, oval-like, square-like, rhombus-like, trapezoidal, rectangular, triangular, pentagonal, hexagonal, octagonal, or various other cross-sectional shapes or combinations thereof. When the spacer 508 has a rectangular cross-section, the plurality of combined tubular flow channels 514 have a rectangular cross-section like the flow channels 514 in the inner electrode 512 shown in FIG. 3C. As also seen in FIGS. 3C-3D, the inner electrode 302 has a cross-section having a certain length and a certain width, the length being at least twice the width, and the cross-section being perpendicular to the axial direction of the tube. Similarly, the reactor has a cross-section having a certain length and a certain width, the length being at least twice the width, and the cross-section being perpendicular to the axial direction of the tube.

[0109] In one embodiment, the method shown in step 4 of FIG. 5B further includes coating the outer surface of the first tubular electrode 512 with an electrolyte material. The electrolyte material is then sintered in a furnace or by using electromagnetic radiation to form the electrolyte 516. Step 4 further includes coating the electrolyte 516 with a second electrode material. The second electrode material is sintered in a furnace or by using electromagnetic radiation to form the second outer tubular electrode 518. In one embodiment, the second electrode material includes a material selected from the group consisting of doped or undoped ceria and Cu, CuO, Cu2O, Ag, Ag2O, Au, Au2O, Au2O3, stainless steel, and combinations thereof; it is sintered using EMR to form the second outer tubular electrode 518. In one embodiment, the method includes reducing the second outer tubular electrode 518 or reducing the first inner tubular electrode 512 or both.

[0110] In one embodiment, the coating process includes dip coating, spraying, ultrasonic spraying, spin coating, brushing, pasting, or combinations thereof. In one embodiment, the electromagnetic radiation includes UV light, near-ultraviolet light, near-infrared light, infrared light, visible light, laser, electron beam, microwave, or combinations thereof. In one embodiment, the electromagnetic radiation is provided by a xenon lamp. In one embodiment, the first tubular electrode 512 has a cross-section with a certain length and a certain width, the length is at least twice the width, and the cross-section is perpendicular to the axial direction of the tubular flow path 514. In one embodiment, the EC gas generator does not include an interconnect.

[0111] Operation of the EC gas generator Providing an apparatus including a first electrode, a second electrode, and an electrolyte between the electrodes, introducing a first stream to the first electrode, introducing a second stream to the second electrode, and extracting hydrogen from the second electrode, are disclosed herein, and the first electrode and the second electrode include a metal phase that does not contain a platinum group metal when the apparatus is in use. In one embodiment, the electrolyte is oxide ion conductive. In one embodiment, the apparatus is operated at a temperature of 500 °C or higher, or 600 °C or higher, or 700 °C or higher. In one embodiment, the first stream includes fuel and water or fuel and carbon dioxide. In one embodiment, the fuel includes hydrocarbons or hydrogen or carbon monoxide or combinations thereof. In one embodiment, the first stream is introduced directly to the first electrode, or the second stream is introduced directly to the second electrode, or both.

[0112] In one embodiment, the first stream includes a fuel having little to no water. In one embodiment, the fuel includes hydrocarbons or hydrogen or carbon monoxide or combinations thereof. In one embodiment, the second stream is composed of water and hydrogen.

[0113] In one embodiment, the method includes providing a reformer upstream of the first electrode, the first stream passing through the reformer and then being introduced to the first electrode, and the first electrode includes Ni or NiO. In one embodiment, the reformer is a steam reformer or an autothermal reformer.

[0114] In one embodiment, the method includes using hydrogen extracted in one of a Fischer-Tropsch (FT) reaction, a dry reforming reaction, a Sabatier reaction catalyzed by nickel, a Bosch reaction, a reverse water gas shift reaction, an electrochemical reaction for generating electricity, ammonia production, fertilizer production, hydrogen storage, an electrochemical compressor for fueling a hydrogen vehicle, or a hydrogenation reaction or combinations thereof.

[0115] This specification discloses a method for producing hydrogen, which includes providing an EC gas generator, introducing a first stream containing fuel into the device, introducing a second stream containing water into the device, reducing the water in the second stream to hydrogen, and extracting hydrogen from the device. The first stream and the second stream do not contact each other within the device. In one embodiment, the first stream does not contact hydrogen. In one embodiment, the first stream and the second stream are separated by a membrane within the device. In one embodiment, the fuel includes hydrocarbons or hydrogen or carbon monoxide or combinations thereof. In one embodiment, the second stream contains hydrogen. In one embodiment, the first stream contains fuel and water or fuel and carbon dioxide. In one embodiment, the first stream contains fuel that has little to no water.

[0116] Hydrogen generation system This specification further describes a hydrogen generation system including a fuel source; a water source; and a hydrogen generator. The fuel source and the water source are fluidly connected to the generator, and the fuel and water do not contact each other within the generator. The system may not include an external heat source. In one embodiment, the fuel and water do not contact each other within the system. In one embodiment, the generator includes a first electrode, a second electrode, and an electrolyte between the first electrode and the second electrode. The fuel source is fluidly connected to the first electrode, and the water source is fluidly connected to the second electrode. In one embodiment, the fuel source provides heat for the hydrogen generator, and the hydrogen generator has no additional heat source.

[0117] In one embodiment, the electrolyte includes YSZ, CGO, LSGM, SSZ, SDC, ceria, lanthanum chromite, or combinations thereof, or the electrolyte includes doped or undoped ceria and optionally a material selected from the group consisting of YSZ, LSGM, SSZ, and combinations thereof. In one embodiment, the lanthanum chromite includes undoped lanthanum chromite, strontium-doped lanthanum chromite, iron-doped lanthanum chromite, lanthanum calcium chromite, or combinations thereof. The electrolyte may further include any material listed for electrolyte 206 in the "tubular and multitubular EC gas generators" section herein. In one embodiment, the electrolyte includes doped ceria, or the electrolyte includes lanthanum chromite or a conductive metal or combinations thereof and a material selected from the group consisting of doped ceria, YSZ, LSGM, SSZ, and combinations thereof. In one embodiment, the lanthanum chromite includes undoped lanthanum chromite, strontium-doped lanthanum chromite, iron-doped lanthanum chromite, lanthanum calcium chromite, or combinations thereof. In one embodiment, the conductive metal includes Ni, Cu, Ag, Au, or combinations thereof.

[0118] In one embodiment, the first electrode and the second electrode comprise materials selected from the group consisting of Ni or NiO and YSZ, CGO, samaria-doped ceria (SDC), scandia-stabilized zirconia (SSZ), LSGM, and combinations thereof. In one embodiment, the first electrode comprises materials selected from the group consisting of doped or undoped ceria and Cu, CuO, Cu2O, Ag, Ag2O, Au, Au2O, Au2O3, stainless steel, and combinations thereof; the second electrode comprises materials selected from the group consisting of Ni or NiO and YSZ, CGO, samaria-doped ceria (SDC), scandia-stabilized zirconia (SSZ), LSGM, and combinations thereof. The first electrode and the second electrode can comprise any of the materials recited for the inner tubular structure 202 or the outer tubular structure 204 in the "tubular and multitubular EC gas generators" section herein.

[0119] In one embodiment, the system comprises an oxidant source and a boiler, the boiler being fluidly coupled to the oxidant source, a water source, and the generator. In one embodiment, the boiler is in thermal communication with the generator, a fuel input into the generator, an oxidant, water, or combinations thereof. In one embodiment, the boiler is configured to receive exhaust from the first electrode of the generator and feed steam into the second electrode of the generator. In one embodiment, the fuel is partially oxidized in the generator and further oxidized in the boiler. In one embodiment, the system comprises a steam turbine between the boiler and the generator, the steam turbine being fluidly coupled to the boiler and the generator.

[0120] In one embodiment, water is reduced in the generator to produce hydrogen. In one embodiment, the system includes a condenser configured to receive the exhaust from the second electrode of the generator and recycle water to the boiler and output hydrogen. In one embodiment, the condenser is thermally coupled to the fuel. In one embodiment, the system includes a desulfurization unit between the fuel source and the generator and fluidly coupled to the fuel source and the generator. In one embodiment, the generator is configured to have a fuel inlet temperature of 1000 °C or less or 900 °C or less or 800 °C to 850 °C. In one embodiment, the generator is configured to have a fuel outlet temperature of 600 °C or more.

[0121] FIG. 6A shows an example of a hydrogen generation system 600 without an external heat source according to an embodiment of the present disclosure. The system 600 includes a water source 602, an air / oxidant source 604, a fuel (e.g., methane) source 606, a hydrogen generator 608, and a boiler 610. The system 600 generates hydrogen 612 and exhaust. The hydrogen generator 608 includes an anode and a cathode separated by an electrolyte. The anode and the cathode receive fuel and water, respectively, and the fuel and water do not contact each other within the generator 608. In various cases, the fuel and water do not contact each other throughout the system 600. The heating load is fully satisfied by the system itself and does not require an external heat source. For example, the boiler 610 heats the fuel input stream into the generator 608, the generator 608, the oxidant 604, and the water 602. The operating generator 608 has a fuel inlet temperature of 1000 °C or less or 900 °C or less or 800 °C to 850 °C and a fuel outlet temperature of 600 °C or more.

[0122] Fuel exits from fuel source 606 as stream 600-1, passes through desulfurization unit 614, and becomes stream 600-2. Stream 600-2 enters condenser 616, functions as a coolant for condenser 616, exits as stream 600-3, which is preheated fuel. Stream 600-3 enters heat exchanger (HX2) 618, is further heated to an appropriate temperature by exhaust stream 600-6 from boiler 610, and enters generator 608 as stream 600-4. Stream 600-4 is received by an anode in generator 608, is partially oxidized, and then exits generator 608 as stream 600-5. Stream 600-5 is introduced into boiler 610, is further oxidized by an oxidant in boiler 610, and as a result, heat is generated. The exhaust from boiler 610 exits as stream 600-6, passes through heat exchanger HX2 618 to heat the fuel input into heat generator 608, and becomes stream 600-7. Stream 600-7 heats generator 608 to ensure an appropriate operating temperature for generator 608 and becomes stream 600-19. Stream 600-19 passes through heat exchanger HX1 620 to heat the oxidant and exits as stream 600-20. Stream 600-20 passes through heat exchanger HX3 622 to heat water and exits as stream 600-21.

[0123] Water exits from the water source as stream 600-8, passes through a pump, and becomes stream 600-9. Stream 600-9 is heated by stream 600-20 in heat exchanger HX3 622 and becomes stream 600-10. Stream 600-10 enters boiler 610 and becomes steam (stream 600-11) due to the heat generated from the oxidation reaction in boiler 610. Stream 600-11 passes through turbine 624 and becomes stream 600-12. Turbine 624 is used to power the pump. Stream 600-12 enters hydrogen generator 608 and is received by the cathode of generator 608. The water / steam is reduced to hydrogen at the cathode. The mixture of steam and hydrogen exits from generator 608 as stream 600-13. Stream 600-13 enters condenser 616 and is cooled by the unheated fuel (stream 600-2). Water spills out from the mixture and is recycled from the condenser as stream 600-18. Stream 600-18 combines with stream 600-9, passes through heat exchanger HX3 622, and then re-enters boiler 610. Hydrogen exits from condenser 616 as stream 600-14.

[0124] Air exits from the oxidant source as stream 600-15, passes through air cleaner 626 where particulates and / or oxides are removed, and becomes stream 600-16. Stream 600-16 is heated by stream 600-19 in heat exchanger HX1 620 and becomes stream 600-17. Stream 600-17 enters boiler 610, reacts with stream 600-5 to further oxidize the fuel and generate heat. The reaction products exit from boiler 610 as stream 600-6.

[0125] FIG. 6B shows another hydrogen generation system 650 without an external heat source according to an embodiment of the present disclosure. The steam generator (SG) 652 performs the same function as the boiler 610 in the system 600 in FIG. 6A. Air enters the condenser as stream 650-1 and is used as a coolant in the condenser 616. The air stream 650-2 is then heated in the heat exchanger HX1 620 and then enters the hydrogen generator 608 as stream 650-3 and mixes with the anode output stream. Fuel enters as stream 650-4, is heated by the exhaust in the heat exchanger HX2 618, and then enters the hydrogen generator 608 as stream 650-5. The fuel is oxidized at the anode of the hydrogen generator 608 to become the anode output stream and is further oxidized by air to become the exhaust 650-6. The exhaust provides thermal energy to the heat exchangers (HX1 620 and HX2 618) and the SG652 to generate steam from water. The steam enters the hydrogen generator 608 and is reduced to hydrogen at the cathode. The cathode output stream 650-7 is introduced into the condenser 616. The water from the condenser 616 is recycled as stream 650-8, and hydrogen is extracted from the condenser 616.

[0126] Fuel cell A fuel cell is an electrochemical device that converts chemical energy from a fuel into electricity through an electrochemical reaction. As described above, there are many types of fuel cells, such as proton exchange membrane fuel cells (PEMFCs), solid oxide fuel cells (SOFCs). A fuel cell typically includes an anode, a cathode, an electrolyte, an interconnect, optionally a barrier layer and / or optionally a catalyst. Both the anode and the cathode are electrodes. The list of materials for the electrodes, electrolyte, and interconnects in a fuel cell may, in some cases, be applicable to an EC gas generator and an EC compressor. These lists are merely examples and are not limiting. Further, the designation of the anode material and the cathode material is also not limiting because the function of the material during operation (e.g., whether it oxidizes or reduces) determines whether the material is used as an anode or a cathode.

[0127] Figures 7-8 show various embodiments of components in a fuel cell or fuel cell stack. In these embodiments, the anode, cathode, electrolyte, and interconnect are rectangular parallelepipeds or rectangular prisms.

[0128] Figure 7 shows a fuel cell component according to an embodiment of the present disclosure. Layer 701 schematically shows the anode, layer 702 represents the cathode, layer 703 represents the electrolyte, layer 704 represents the barrier layer, layer 705 represents the catalyst, and layer 706 represents the interconnect.

[0129] Figure 8 schematically shows two fuel cells in a fuel cell stack according to an embodiment of the present disclosure. The two fuel cells are shown as "Fuel Cell 1" and "Fuel Cell 2". Each fuel cell in Figure 8 includes an anode layer 801, a cathode layer 802, an electrolyte layer 803, a barrier layer 804, a catalyst layer 805, and an interconnect layer 806. The two fuel cell repeating units or the two fuel cells form a stack as shown. As can be seen, on one side, the interconnect 806 contacts the maximum surface of the cathode 802 of Fuel Cell 2 (or the fuel cell repeating unit), and on the opposite side, the interconnect 806 contacts the maximum surface of the catalyst 805 (optional) or the anode 801 of the bottom Fuel Cell 2 (or the fuel cell repeating unit). These repeating units or fuel cells are stacked on top of each other and are connected in parallel through direct contact by the interconnect rather than by electrical wiring by sharing the interconnects therebetween. This type of structure shown in Figure 8 is in contrast to the corrugated type (SIS) fuel cell.

[0130] Cathode In some embodiments, the cathode comprises a perovskite, such as LSC, LSCF, or LSM. In some embodiments, the cathode comprises one or more of lanthanum, cobalt, strontium, or manganite. In one embodiment, the cathode is porous. In some embodiments, the cathode comprises one or more of YSZ, nitrogen, nitrogen boron doped graphene, La0.6Sr0.4Co0.2Fe0.8O3, SrCo0.5Sc0.5O3, BaFe0.75Ta0.25O3, BaFe0.875Re0.125O3, Ba0.5La0.125Zn0.375NiO3, Ba0.75Sr0.25Fe0.875Ga0.125O3, BaFe0.125Co0.125, Zr0.75O3. In some embodiments, the cathode comprises LSCo, LCo, LSF, LSCoF, or combinations thereof. In some embodiments, the cathode comprises perovskite LaCoO3, LaFeO3, LaMnO3, (La,Sr)MnO3, LSM-GDC, LSCF-GDC, LSC-GDC. A cathode comprising LSCF is suitable for intermediate temperature fuel cell operation.

[0131] In some embodiments, the cathode comprises a material selected from the group consisting of lanthanum strontium manganite, lanthanum strontium ferrite, and lanthanum strontium cobalt ferrite. In a preferred embodiment, the cathode comprises lanthanum strontium manganite.

[0132] Anode In some embodiments, the anode comprises copper, nickel-oxide, nickel-oxide-YSZ, NiO-GDC, NiO-SDC, aluminum-doped zinc oxide, molybdenum oxide, lanthanum, strontium, chromite, ceria, perovskite (e.g., including LSCF [La{1-x}Sr{x}Co{1-y}Fe{y}O3] or LSM [La{1-x}Sr{x}MnO3], where x is typically in the range of 0.15 - 0.2 and y is in the range of 0.7 - 0.8). In some embodiments, the anode includes an SDC or BZCYYb coating or barrier layer to reduce coking and sulfur poisoning. In one embodiment, the anode is porous. In some embodiments, the anode comprises a combination of an electrolyte material and an electrochemically active material, or a combination of an electrolyte material and a conductive material.

[0133] In preferred embodiments, the anode comprises nickel and yttria-stabilized zirconia. In preferred embodiments, the anode is formed by reduction of a material comprising nickel oxide and yttria-stabilized zirconia. In preferred embodiments, the anode comprises nickel and gadolinium-stabilized ceria. In preferred embodiments, the anode is formed by reduction of a material comprising nickel oxide and gadolinium-stabilized ceria.

[0134] Electrolyte In one embodiment, the electrolyte in the fuel cell comprises stabilized zirconia (e.g., YSZ, YSZ-8, Y 0.16 Zr 0.84 O2). In one embodiment, the electrolyte comprises doped LaGaO3 (e.g., LSGM, La 0.9 Sr 0.1 Ga 0.8 Mg0.2O3). In one embodiment, the electrolyte comprises doped ceria (e.g., GDC, Gd 0.2 Ce 0.8 O2). In one embodiment, the electrolyte comprises stabilized bismuth oxide (e.g., BVCO, Bi2V 0.9 Cu 0.1 O 5.35 ).

[0135] In some embodiments, the electrolyte comprises zirconium oxide, yttria-stabilized zirconium oxide (also known as YSZ, YSZ8 (8 mole% YSZ)), ceria, gadolinia, scandia, magnesia or calcia or combinations thereof. In one embodiment, the electrolyte prevents significant gas transport and prevents significant electrical conduction; and is sufficiently impermeable to allow ionic conductivity. In some embodiments, the electrolyte comprises doped oxides such as cerium oxide, yttrium oxide, bismuth oxide, lead oxide, lanthanum oxide. In some embodiments, the electrolyte is a perovskite, such as, LaCoFeO3 or LaCoO3 or Ce 0.9 Gd 0.1 O2 (GDC) or Ce 0.9 Sm 0.1 O2 (SDC, samarium-doped ceria) or scandia-stabilized zirconia or combinations thereof.

[0136] In some embodiments, the electrolyte comprises a material selected from the group consisting of zirconia, ceria, and gallia. In some embodiments, the material is stabilized with a stabilizing material selected from the group consisting of scandium, samarium, gadolinium, and yttrium. In one embodiment, the material comprises yttria-stabilized zirconia.

[0137] Interconnect In some embodiments, the interconnect comprises silver, gold, platinum, AISI 441, ferritic stainless steel, stainless steel, lanthanum, chromium, chromium oxide, chromite, cobalt, cesium, Cr2O3, or combinations thereof. In some embodiments, the anode comprises a LaCrO3 coating on Cr2O3 or a NiCo2O4 or MnCo2O4 coating. In some embodiments, the interconnect surface is coated with cobalt and / or cesium. In some embodiments, the interconnect comprises a ceramic. In some embodiments, the interconnect comprises lanthanum chromite or doped lanthanum chromite. In one embodiment, the interconnect further comprises a material comprising metal, stainless steel, ferritic steel, crofer, lanthanum chromite, silver, metal alloy, nickel, nickel oxide, ceramic, or lanthanum calcium chromite, or combinations thereof.

[0138] Catalyst In various embodiments, the fuel cell includes a catalyst, such as platinum, palladium, scandium, chromium, cobalt, cesium, CeO2, nickel, nickel oxide, zinc, copper, titania, ruthenium, rhodium, MoS2, molybdenum, rhenium, vanadium, manganese, magnesium, or iron, or combinations thereof. In various embodiments, the catalyst promotes a methane reforming reaction to generate hydrogen and carbon monoxide so that they can be oxidized in the fuel cell. In very many cases, the catalyst is part of the anode, particularly a nickel anode having specific methane reforming characteristics. In one embodiment, the catalyst is between 1% - 5%, or 0.1% - 10% by mass. In one embodiment, the catalyst is used on or within the anode surface. In various embodiments, such an anode catalyst reduces harmful coking reactions and carbon deposits. In various embodiments, a simple oxide version of the catalyst, or a perovskite, can be used as the catalyst. For example, a CeO2 catalyst of about 2% by mass is used for a methane fuel cell. In various embodiments, the catalyst can be impregnated or coated on the anode. In various embodiments, the catalyst is manufactured by an additive manufacturing machine (AMM) and incorporated into the fuel cell using the AMM.

[0139] The unique manufacturing method described herein describes the assembly of ultra-thin fuel cells and fuel cell stacks. Conventionally, to achieve structural integrity, a fuel cell has at least one thick layer per repeating unit. This may be the anode (such as an anode-supported fuel cell) or the interconnect (such as an interconnect-supported fuel cell). As described above, a pressing or compressing step is typically required to assemble the fuel cell components to achieve hermeticity and / or proper electrical contact in the conventional manufacturing process. As such, thick layers are required because not only can conventional methods (such as tape casting) not form ultra-thin layers, but the layers must be thick enough to withstand the pressing or compressing step. The preferred manufacturing method of this disclosure eliminates the need for pressing or compressing. The preferred manufacturing method of this disclosure also enables the manufacture of ultra-thin layers. The multiplicity of layers in a fuel cell or fuel cell stack provides sufficient structural integrity for proper operation when they are manufactured in accordance with this disclosure.

[0140] Disclosed herein is a fuel cell comprising an anode having a thickness of 1 mm or 500 microns or 300 microns or 100 microns or 50 microns or less or 25 microns or less, a cathode having a thickness of 1 mm or 500 microns or 300 microns or 100 microns or 50 microns or less or 25 microns or less, and an electrolyte having a thickness of 1 mm or 500 microns or 300 microns or 100 microns or 50 microns or 30 microns or less. In one embodiment, the fuel cell comprises an interconnect having a thickness of 50 microns or more. Optionally, the fuel cell comprises an anode having a thickness of 25 microns or less, a cathode having a thickness of 25 microns or less, and an electrolyte having a thickness of 10 microns or 5 microns or less. In one embodiment, the fuel cell comprises an interconnect having a thickness of 50 microns or more. In one embodiment, the interconnect has a thickness in the range of 50 microns to 5 cm.

[0141] In a preferred embodiment, the fuel cell includes an anode with a thickness of 100 microns or less, a cathode with a thickness of 100 microns or less, an electrolyte with a thickness of 20 microns or less, and an interconnect with a thickness of 30 microns or less. In a more preferred embodiment, the fuel cell includes an anode with a thickness of 50 microns or less, a cathode with a thickness of 50 microns or less, an electrolyte with a thickness of 10 microns or less, and an interconnect with a thickness of 25 microns or less. In one embodiment, the interconnect has a thickness in the range of 1 micron to 20 microns.

[0142] In a preferred embodiment, the fuel cell includes a barrier layer between the anode and the electrolyte, or between the cathode and the electrolyte, or both barrier layers. In some cases, the barrier layer is the interconnect. In such cases, the reactants are injected directly onto the anode and the cathode.

[0143] In one embodiment, the cathode has a thickness of 15 microns or less, or 10 microns or less, or 5 microns or less. In one embodiment, the anode has a thickness of 15 microns or less, or 10 microns or less, or 5 microns or less. In one embodiment, the electrolyte has a thickness of 5 microns or less, or 2 microns or less, or 1 micron or less, or 0.5 microns or less. In one embodiment, the interconnect is made of a material including metal, stainless steel, silver, metal alloy, nickel, nickel oxide, ceramic, lanthanum chromite, doped lanthanum chromite, or lanthanum calcium chromite. In one embodiment, the fuel cell has an overall thickness of 1 micron or more.

[0144] A fuel cell stack including a multi-fuel cell is also described herein, and each fuel cell includes an anode with a thickness of 25 microns or less, a cathode with a thickness of 25 microns or less, an electrolyte with a thickness of 10 microns or less, and an interconnect with a thickness in the range of 100 nm to 100 microns. In one embodiment, each fuel cell includes a barrier layer between the anode and the electrolyte, or between the cathode and the electrolyte, or both barrier layers. In one embodiment, the barrier layer is the interconnect. For example, the interconnect is made of silver. For example, the interconnect has a thickness in the range of 500 nm to 1000 nm. In one embodiment, the interconnect is made of a material including metal, stainless steel, silver, metal alloy, nickel, nickel oxide, ceramic, or lanthanum calcium chromite.

[0145] In one embodiment, the cathode has a thickness of 15 microns or less, or 10 microns or less, or 5 microns or less. In one embodiment, the anode has a thickness of 15 microns or less, or 10 microns or less, or 5 microns or less. In one embodiment, the electrolyte has a thickness of 5 microns or less, or 2 microns or less, or 1 micron or less, or 0.5 microns or less. In one embodiment, each fuel cell has an overall thickness of 1 micron or more.

[0146] A method of manufacturing a fuel cell including the following is further described herein: (a) forming an anode with a thickness of 25 microns or less, (b) forming a cathode with a thickness of 25 microns or less, and (c) forming an electrolyte with a thickness of 10 microns or less. In one embodiment, steps (a)-(c) are performed using additive manufacturing. In various embodiments, the additive manufacturing uses one or more of extrusion, photopolymerization, powder bed fusion bonding, material jetting, binder jetting, directed energy deposition, or lamination.

[0147] In one embodiment, the method includes assembling an anode, a cathode, and an electrolyte using additive manufacturing. In one embodiment, the method includes forming an interconnect and assembling the interconnect with the anode, cathode, and electrolyte.

[0148] In a preferred embodiment, the method includes manufacturing at least one barrier layer. In a preferred embodiment, the at least one barrier layer is used between the electrolyte and the cathode or between the electrolyte and the anode or both. In one embodiment, the at least one barrier layer also acts as an interconnect.

[0149] In a preferred embodiment, the method includes heating the fuel cell so that the shrinkage rates of the anode, cathode, and electrolyte are balanced. In some embodiments, such heating occurs in less than 30 minutes, preferably less than 30 seconds, and most preferably less than 30 milliseconds. If the fuel cell includes a first composition and a second composition, the first composition has a first shrinkage rate and the second composition has a second shrinkage rate, and the heating described in this disclosure preferably occurs such that the difference between the first shrinkage rate and the second shrinkage rate is 75% or less of the first shrinkage rate.

[0150] In a preferred embodiment, heating is performed using electromagnetic radiation (EMR). In various embodiments, the EMR includes UV light, near-UV light, near-infrared light, infrared light, visible light, lasers, and electron beams. Preferably, the heating is performed in-situ.

[0151] A method of manufacturing a fuel cell stack including multiple fuel cells is also disclosed herein, the method including: (a) forming an anode having a thickness of 25 microns or less in each fuel cell; (b) forming a cathode having a thickness of 25 microns or less in each fuel cell; (c) forming an electrolyte having a thickness of 10 microns or less in each fuel cell; and (d) generating an interconnect having a thickness of 100 nm to 100 microns in each fuel cell.

[0152] In one embodiment, steps (a)-(d) are performed using AM. In various embodiments, AM uses one or more of extrusion, photopolymerization, powder bed fusion, material jetting, binder jetting, directed energy deposition, or lamination processes.

[0153] In one embodiment, a method of manufacturing a fuel cell stack includes assembling an anode, a cathode, an electrolyte, and an interconnect using AM. In one embodiment, the method includes manufacturing at least one barrier layer in each fuel cell. In one embodiment, the at least one barrier layer is used between the electrolyte and the cathode or between the electrolyte and the anode or both. In one embodiment, the at least one barrier layer also acts as an interconnect.

[0154] In one embodiment, a method of manufacturing a fuel cell stack includes heating each fuel cell such that the shrinkage rates of the anode, cathode, and electrolyte are balanced. In one embodiment, such heating occurs in less than 30 minutes, or less than 30 seconds, or less than 30 milliseconds. In a preferred embodiment, the heating includes one or more electromagnetic radiations (EMR). In various embodiments, the EMR includes UV light, near-UV light, near-infrared light, infrared light, visible light, lasers, electron beams. In one embodiment, the heating is performed in-situ.

[0155] In one embodiment, the method includes heating the entire fuel cell stack such that the shrinkage rates of the anode, cathode, and electrolyte are balanced. In some embodiments, such heating occurs in less than 30 minutes, or less than 30 seconds, or less than 30 milliseconds.

[0156] Disclosed herein is a method for producing an electrolyte, comprising: (a) formulating a colloidal suspension, the colloidal suspension comprising an additive, particles having a diameter range and a size distribution, and a solvent; (b) forming an electrolyte containing the colloidal suspension; and (c) heating at least a portion of the electrolyte, wherein formulating the colloidal suspension is preferably optimized by controlling the pH of the colloidal suspension, or the concentration of a binder in the colloidal suspension, or the composition of the binder in the colloidal suspension, or the diameter range of the particles, or the maximum diameter of the particles, or the median diameter of the particles, or the size distribution of the particles, or the boiling point of the solvent, or the surface tension of the solvent, or the composition of the solvent, or the thickness of the minimum dimension of the electrolyte, or the composition of the particles, or a combination thereof.

[0157] Disclosed herein is a method for manufacturing a fuel cell, including: (a) obtaining a cathode and an anode; (b) modifying the cathode surface and the anode surface; (c) formulating a colloidal suspension, the colloidal suspension containing an additive, particles having a certain diameter range and a certain size distribution, and a solvent; (d) forming an electrolyte containing the colloidal suspension between the modified anode surface and the modified cathode surface; and (e) heating at least a portion of the electrolyte; wherein formulating the colloidal suspension includes controlling the pH of the colloidal suspension, or the concentration of the binder in the colloidal suspension, or the composition of the binder in the colloidal suspension, or the diameter range of the particles, or the maximum diameter of the particles, or the median diameter of the particles, or the size distribution of the particles, or the boiling point of the solvent, or the surface tension of the solvent, or the composition of the solvent, or the minimum dimension thickness of the electrolyte, or the composition of the particles, or a combination thereof. In various embodiments, the anode and the cathode are obtained by any suitable means. In one embodiment, the modified anode surface and the modified cathode surface have a maximum height profile roughness that is less than the average diameter of the particles in the colloidal suspension. The maximum height profile roughness 900 refers to the maximum distance between any trough 902 and the adjacent peak 904 of the anode surface or the cathode surface, as shown in FIG. 9. In various embodiments, the anode surface and the cathode surface are modified by any suitable means.

[0158] Disclosed herein is a method for manufacturing a fuel cell, comprising: (a) obtaining a cathode and an anode; (b) formulating a colloidal suspension, wherein the colloidal suspension comprises an additive, particles having a certain diameter range and a certain size distribution, and a solvent; (c) forming an electrolyte containing the colloidal suspension between the anode and the cathode; and (d) heating at least a portion of the electrolyte; wherein formulating the colloidal suspension includes controlling the pH of the colloidal suspension, or the concentration of a binder in the colloidal suspension, or the composition of the binder in the colloidal suspension, or the diameter range of the particles, or the maximum diameter of the particles, or the median diameter of the particles, or the size distribution of the particles, or the boiling point of the solvent, or the surface tension of the solvent, or the composition of the solvent, or the minimum dimension thickness of the electrolyte, or the composition of the particles, or a combination thereof. In various embodiments, the anode and the cathode are obtained via any suitable means. In one embodiment, the anode surface in contact with the electrolyte and the cathode surface in contact with the electrolyte have a maximum height profile roughness that is less than the average diameter of the particles in the colloidal suspension.

[0159] In a preferred embodiment, the solvent includes water. In a preferred embodiment, the solvent includes an organic component. The solvent may include ethanol, butanol, alcohol, terpineol, diethyl ether, 1,2-dimethoxyethane (DME (ethylene glycol dimethyl ether)), 1-propanol (n-propanol, n-propyl alcohol), or butyl alcohol, or a combination thereof. In some embodiments, the surface tension of the solvent is less than half of the surface tension of water in air. In one embodiment, the surface tension of the solvent is less than 30 mN / m under atmospheric conditions.

[0160] In some embodiments, the electrolyte is formed adjacent to the first substrate, or the electrolyte is formed between the first substrate and the second substrate. In some embodiments, the first substrate has a maximum height profile roughness that is less than the average diameter of the particles. In some embodiments, the particles have a packing density of greater than 40%, or greater than 50%, or greater than 60%. In one embodiment, the particles have a packing density close to the random close packing (RCP) density.

[0161] Random close packing (RCP) is an empirical parameter used to characterize the maximum volume fraction of a solid object obtained when they are randomly packed. A container is randomly filled with objects, and then the container is shaken or gently tapped until the objects no longer pack any further. At this point, the packing state is RCP. The packing fraction is the volume taken up by the number of particles in a certain volume space. The packing fraction determines the packing density. For example, when a solid container is filled with particles, shaking the container reduces the volume occupied by the objects, thus allowing more particles to be added to the container. Shaking increases the density of the objects being packed. When shaking no longer increases the packing density, the limit is reached, and when this limit is reached without an obvious packing into a regular crystal lattice, this is the empirical random close packing density.

[0162] In some embodiments, the median particle size is from 50 nm to 1000 nm, or from 100 nm to 500 nm, or approximately 200 nm. In some embodiments, the first substrate comprises particles having a certain median particle size, and the median particle size of the electrolyte can be 10 times or less, and 1 / 10 or more, of the median particle size of the first substrate. In some embodiments, the first substrate is bimodal having a first mode and a second mode, each comprising a particle size distribution having a certain median particle size. In some embodiments, the median particle size in the first mode of the first substrate is more than 2 times, or more than 5 times, or more than 10 times that in the second mode. The particle size distribution of the first substrate can be adjusted to change the behavior of the first substrate during heating. In some embodiments, the first substrate has a shrinkage that is a function of the heating temperature. In some embodiments, the particles in the colloidal suspension can have a maximum particle size and a minimum particle size, and the maximum particle size is less than 2 times, or less than 3 times, or less than 5 times, or less than 10 times the minimum particle size. In some embodiments, the minimum dimension of the electrolyte is less than 10 microns, or less than 2 microns, or less than 1 micron, or less than 500 nm.

[0163] In some embodiments, the electrolyte has a gas permeability of 1 millidarcy or less, preferably 100 microdarcies or less, and most preferably 1 microdarcy or less. Preferably, the electrolyte does not have cracks that penetrate the minimum dimension of the electrolyte. In some embodiments, the boiling point of the solvent is 200 °C or higher, or 100 °C or higher, or 75 °C or higher. In some embodiments, the boiling point of the solvent is 125 °C or lower, or 100 °C or lower, or 85 °C or lower, 70 °C or lower. In some embodiments, the pH of the colloidal suspension is 7 or higher, or 9 or higher, or 10 or higher.

[0164] In some embodiments, the additive includes polyethylene glycol (PEG), ethyl cellulose, polyvinylpyrrolidone (PVP), polyvinyl butyral (PVB), butyl benzyl phthalate (BBP), polyalkylene glycol (PAG), or a combination thereof. In one embodiment, the additive concentration is 100 mg / cm3 or less, or 50 mg / cm3 or less, or 30 mg / cm3 or less, or 25 mg / cm3 or less.

[0165] In one embodiment, the colloidal suspension is milled. In one embodiment, the colloidal suspension is milled using a rotary mill, and the rotary mill is operated at 20 rpm or more, or 50 rpm or more, or 100 rpm or more, or 150 rpm or more. In one embodiment, the colloidal suspension is milled using zirconia milling balls or tungsten carbide balls, and the colloidal suspension is milled for 2 hours or more, or 4 hours or more, or 1 day or more, or 10 days or more.

[0166] In some embodiments, the particle concentration in the colloidal suspension is 30 wt% or less, or 20 wt% or less, or 10 wt% or less. In some embodiments, the particle concentration in the colloidal suspension is 2 wt% or more. In some embodiments, the particle concentration in the colloidal suspension is 10 vol% or less, or 5 vol% or less, or 3 vol% or less, or 1 vol% or less. In one embodiment, the particle concentration in the colloidal suspension is 0.1 vol% or more.

[0167] In a preferred embodiment, the electrolyte is formed using an additive manufacturing machine (AMM). In a preferred embodiment, the first substrate is formed using an AMM. In a preferred embodiment, heating includes the use of electromagnetic radiation (EMR), and the EMR includes one or more of UV light, near-UV light, near-infrared light, infrared light, visible light, or a laser. In a preferred embodiment, the first substrate and the electrolyte are heated to cause co-sintering. In a preferred embodiment, the first substrate, the second substrate, and the electrolyte are heated to cause co-sintering. In one embodiment, the EMR is controlled to preferentially sinter the first substrate over the electrolyte.

[0168] In one embodiment, the electrolyte is compressed after heating. In one embodiment, the first substrate and the second substrate apply a compressive stress to the electrolyte after heating. In one embodiment, the first substrate and the second substrate applying the compressive stress are the anode and cathode of the fuel cell. In some embodiments, the minimum dimension of the electrolyte is 500 nm to 5 microns, or 1 micron to 2 microns.

[0169] The detailed description described herein uses the production of a solid oxide fuel cell (SOFC) as an example. As will be recognized by those skilled in the art, the methods and manufacturing processes described herein are applicable to all fuel cell types. As such, the production of all fuel cell types is within the scope of this disclosure.

[0170] Reactor cartridge In various embodiments, an electrochemical (EC) reactor is formed in a cartridge form. The discussion herein uses a fuel cell or a fuel cell stack as an example. The cartridge design is applicable to other electrochemical reactors such as an EC gas generator, an EC compressor, a flow cell, etc. In various embodiments, a fuel cell stack is configured to be manufactured in a cartridge form such as an easily removable flanged fuel cell cartridge (FCC) design. FIG. 9A shows a perspective view of a fuel cell cartridge (FCC) 900 according to an embodiment of the present disclosure. FCC 900 includes a rectangular shape shown in FIG. 9A. Other form factors are possible, for example, square-like, cylindrical-like, hexagonal-like or combinations thereof. The form factor may depend on the application in which the FCC can be used, for example, within a company, at home, in an automobile or other applications. FCC 900 also includes holes 902 for bolts to fix the FCC in the system or in series with other FCCs or both. The FCC cartridge 900 housing may be composed of aluminum, steel, plastic, ceramic, or combinations thereof. FCC 900 includes an upper interconnect 904.

[0171] FIG. 9B shows a perspective cross-sectional view of a fuel cell cartridge (FCC) 900 according to an embodiment of the present disclosure. FCC 900 includes holes 902 for bolts, a cathode layer 906, a barrier layer 908, an anode layer 910, gas channels 912 in the electrodes (anode and cathode), an electrolyte layer 914, an air heat exchanger 916, a fuel heat exchanger 918, and an upper interconnect 904. The combined air heat exchanger 916 and fuel heat exchanger 918 form an integrated multi-fluid heat exchanger. In some embodiments, there is no barrier layer between the cathode 906 and the electrolyte 914. FCC 900 includes, for example, a second interconnect 920 between the anode layer 910 and the fuel heat exchanger 918. FCC 900 further includes openings 922, 924 for the fuel passage.

[0172] Figure 9C shows a cross-sectional view of a fuel cell cartridge (FCC) according to an embodiment of the present disclosure. The FCC 900 in Figure 9C includes bolt electrical insulation 926, an anode 910, a seal 928 that blocks the anode 910 from the air flow, a cathode 906, and a seal 930 that blocks the cathode 906 from the fuel flow. The bolt can also be electrically insulated by the seal. In various embodiments, the seal may be a dual-functional seal (DFS) including YSZ (yttria-stabilized zirconia) or a mixture of 3YSZ (ZrO2 containing 3 mol% Y2O3) and 8YSZ (ZrO2 containing 8 mol% Y2O3). In some embodiments, the DFS is impermeable to non-ionic substances and electrically insulating. In some embodiments, the mass ratio of 3YSZ / 8YSZ is in the range of 10 / 90 to 90 / 10. In some embodiments, the mass ratio of 3YSZ / 8YSZ is about 50 / 50. In some embodiments, the mass ratio of 3YSZ / 8YSZ is 100 / 0 or 0 / 100.

[0173] Figure 9D shows a top view and a bottom view of a fuel cell cartridge (FCC) according to an embodiment of the present disclosure. The FCC 900 includes bolt holes 902, an air inlet 932, an air outlet 934, a fuel inlet 922, a fuel outlet 924, the bottom 936 of the FCC 900, and an upper interconnect 904. Figure 9D further shows a top view and a bottom view of an embodiment of the FCC 900. The length of the oxidant side of the FCC 900 is indicated by L o and the length of the fuel side of the FCC 900 is indicated by L f The width of the oxidant (air inlet 932) inlet is indicated by W o and the width of the fuel inlet 922 is indicated by W f as shown. In Figure 9D, two fluid outlets are shown (air outlet 934 and fuel outlet 924). In some embodiments, the anode exhaust and the cathode exhaust can be mixed and extracted through one fluid outlet. In some cases, the bottom 936 is an interconnect, and 932, 934, 922, 924 are openings for flow paths in a direction perpendicular to the lateral direction, for example.

[0174] Disclosed herein is a fuel cell cartridge (FCC) 900 including an anode 910, a cathode 906, an electrolyte 914, at least one interconnect, a fuel inlet on the fuel side of the fuel FCC 900, an oxidant inlet on the oxidant side of the FCC, and at least one fluid outlet, where the fuel inlet has a width of W f and the fuel side of the FCC has a length of L f and the oxidant inlet has a width of W o and the oxidant side of the FCC has a length of L o and W f / L f is in the range of 0.1 to 1.0, or 0.1 to 0.9, or 0.2 to 0.9, or 0.5 to 0.9, or 0.5 to 1.0, and W o / L o is in the range of 0.1 to 1.0, or 0.1 to 0.9, or 0.2 to 0.9, or 0.5 to 0.9, or 0.5 to 1.0.

[0175] In some embodiments, the air and fuel inlets and outlets are on one surface of the FCC 900, and the FCC 900 does not include flow channels protruding on the said surface. In some embodiments, the surface is smooth and has a maximum height variation of 1 mm or less, or 100 microns or less, or 10 microns or less.

[0176] In some embodiments, the FCC 900 includes a barrier layer between the electrolyte and the cathode, or between the electrolyte and the anode, or both. In one embodiment, the FCC includes a dual-functional seal (DFS) that is impermeable to non-ionic substances and electrically insulating. In some embodiments, the DFS includes a mixture of YSZ (yttria-stabilized zirconia) or 3YSZ (ZrO2 containing 3 mol% Y2O3) and 8YSZ (ZrO2 containing 8 mol% Y2O3).

[0177] In some embodiments, the interconnect does not include a fluid dispersion element, and the anode and cathode include fluid dispersion components. In some embodiments, the interconnect does not include a fluid dispersion element, while the anode and cathode include fluid channels.

[0178] In some embodiments, the fuel cell cartridge (FCC) 900 includes an anode, a cathode, an electrolyte, an interconnect, a fuel inlet, an oxidant inlet, and at least one fluid outlet, the inlets and outlets are on one surface of the FCC, and the FCC does not include flow channels protruding on the surface. In some embodiments, the surface may be smooth and have a maximum height variation of 1 mm or less, or 100 microns or less, or 10 microns or less.

[0179] In some embodiments, the FCC 900 includes a DFS that is impermeable to non-ionic substances and electrically insulating. In one embodiment, the interconnect does not include a fluid dispersion element, and the anode and cathode include fluid dispersion components. In one embodiment, the interconnect does not include a fluid dispersion element, and the anode and cathode include fluid channels.

[0180] In one embodiment, the FCC 900 is removably fixed to the mating surface, and the mating surface is neither soldered nor welded. In one embodiment, the FCC is bolted or pressed onto the mating surface. The mating surface includes a mating fuel inlet, a mating oxidant inlet, and at least one mating fluid outlet.

[0181] An assembly including a fuel cell cartridge (FCC) and a mating surface is further disclosed herein, the FCC including an anode, a cathode, an electrolyte, an interconnect, a fuel inlet on the fuel side of the FCC, an oxidant inlet on the oxidant side of the FCC, and at least one fluid outlet, the fuel inlet having a width of W f and the fuel side of the FCC having a length of L f the oxidant inlet having a width of W o and the oxidant side of the FCC having a length of L o where W f / L f is in the range of 0.1 to 1.0, or 0.1 to 0.9, or 0.2 to 0.9, or 0.5 to 0.9, or 0.5 to 1.0, and W o / L ois in the range of 0.1 to 1.0, or 0.1 to 0.9, or 0.2 to 0.9, or 0.5 to 0.9, or 0.5 to 1.0, and the FCC is removably fixed to the mating surface.

[0182] In some embodiments, the inlet and outlet are on one surface of the FCC, and the FCC does not include a flow channel protruding on the surface. The surface may be smooth and have a maximum height variation of 1 mm or less, or 100 microns or less, or 10 microns or less.

[0183] In one embodiment, the interconnect does not include a fluid dispersion element, and the anode and cathode include a fluid dispersion component. In one embodiment, the interconnect does not include a fluid dispersion element, and the anode and cathode include a fluid channel.

[0184] A method is described herein that includes pressurizing or bolting together a fuel cell cartridge (FCC) and a mating surface. The method excludes welding or soldering the FCC and the mating surface together, and the FCC includes an anode, a cathode, an electrolyte, an interconnect, a fuel inlet on the fuel side of the FCC, an oxidant inlet on the oxidant side of the FCC, and at least one fluid outlet. The fuel inlet has a width of W f and the fuel side of the FCC has a length of L f the oxidant inlet has a width of W o and the oxidant side of the FCC has a length of L o where W f / L f is in the range of 0.1 to 1.0, or 0.1 to 0.9, or 0.2 to 0.9, or 0.5 to 0.9, or 0.5 to 1.0, and W o / L o is in the range of 0.1 to 1.0, or 0.1 to 0.9, or 0.2 to 0.9, or 0.5 to 0.9, or 0.5 to 1.0, and the FCC and the mating surface are removable.

[0185] In one embodiment, the inlet and the outlet are on one surface of the FCC, and the FCC does not include flow channels protruding on the surface. The surface is smooth and has a maximum height variation of 1 mm or less, or 100 microns or less, or 10 microns or less. In one embodiment, the interconnect does not include a fluid dispersion element, and the anode and the cathode include fluid dispersion components. In one embodiment, the interconnect does not include a fluid dispersion element, and the anode and the cathode include fluid channels.

[0186] As used herein, a fuel cell cartridge (FCC) including a fuel cell and a fuel cell casing is disclosed. The fuel cell includes an anode, a cathode, and an electrolyte, and at least a part of the fuel cell casing is manufactured from the same material as the electrolyte. In one embodiment, the electrolyte contacts a part of the fuel cell casing manufactured from the same material. In one embodiment, the electrolyte and the part of the fuel cell casing are manufactured by DFS. DFS includes 3YSZ (ZrO2 containing 3 mol% Y2O3) and 8YSZ (ZrO2 containing 8 mol% Y2O3), and the mass ratio of 3YSZ / 8YSZ ranges from 100 / 0 to 0 / 100 or from 10 / 90 to 90 / 10. DFS is impermeable to non-ionic substances and is electrically insulating. In one embodiment, the mass ratio of 3YSZ / 8YSZ is about 50 / 50 or 40 / 60 or 60 / 40 or 30 / 70 or 70 / 30 or 20 / 80 or 80 / 20.

[0187] In one embodiment, the fuel cell casing includes a fuel inlet and a fuel passage for the anode, an oxidant inlet and an oxidant passage for the cathode, and at least one fluid outlet. In one embodiment, the inlet and the at least one outlet are on one surface of the FCC, and the FCC does not include flow channels protruding on the surface. In one embodiment, the fuel cell casing contacts at least a part of the anode.

[0188] In one embodiment, the FCC includes a barrier layer between the electrolyte and the cathode and between the fuel cell casing and the cathode. In one embodiment, the FCC includes an interconnect that does not include a fluid dispersion element, and the anode and cathode include fluid dispersion components. In one embodiment, the FCC includes an interconnect that does not include a fluid dispersion element, and the anode and cathode include fluid channels.

[0189] In one embodiment, the FCC is removably fixed to the mating surface, and the mating surface is neither soldered nor welded. In one embodiment, the mating surface includes a mating fuel inlet, a mating oxidant inlet, and at least one mating fluid outlet.

[0190] DFS including 3YSZ (ZrO2 containing 3 mol% Y2O3) and 8YSZ (ZrO2 containing 8 mol% Y2O3) is also described herein, the mass ratio of 3YSZ / 8YSZ is in the range of 10 / 90 to 90 / 10, and the DFS is impermeable to non-ionic substances and is electrically insulating. In one embodiment, the mass ratio of 3YSZ / 8YSZ is about 50 / 50 or 40 / 60 or 60 / 40 or 30 / 70 or 70 / 30 or 20 / 80 or 80 / 20. In one embodiment, the DFS is used as an electrolyte in a fuel cell, or as part of the fuel cell casing, or both.

[0191] A method is further disclosed herein that includes providing DFS in a fuel cell system, the DFS includes 3YSZ (ZrO2 containing 3 mol% Y2O3) and 8YSZ (ZrO2 containing 8 mol% Y2O3), the mass ratio of 3YSZ / 8YSZ is in the range of 100 / 0 to 0 / 100 or 10 / 90 to 90 / 10, and the DFS is impermeable to non-ionic substances and is electrically insulating. In one embodiment, the mass ratio of 3YSZ / 8YSZ is about 50 / 50 or 40 / 60 or 60 / 40 or 30 / 70 or 70 / 30 or 20 / 80 or 80 / 20.

[0192] In one embodiment, the DFS is used as part of or both the electrolyte and the fuel cell casing in a fuel cell system. Part of the fuel cell casing can be the entire fuel cell casing. Part of the fuel cell casing is a coating on the fuel cell casing. The above-mentioned part of the electrolyte and the fuel cell casing are in contact.

[0193] A fuel cell system is disclosed herein that includes an anode having six surfaces, a cathode having six surfaces, an electrolyte, and an anode enclosure that contacts at least three surfaces of the anode. The electrolyte is part of the anode enclosure, and the anode enclosure is made of the same material as the electrolyte. In one embodiment, the same material is a DFS including 3YSZ (ZrO2 containing 3 mol% Y2O3) and 8YSZ (ZrO2 containing 8 mol% Y2O3). The mass ratio of 3YSZ / 8YSZ is in the range of 100 / 0 to 0 / 100 or 10 / 90 to 90 / 10. The DFS is impermeable to non-ionic substances and is electrically insulating. In one embodiment, the mass ratio of 3YSZ / 8YSZ is about 50 / 50 or 40 / 60 or 60 / 40 or 30 / 70 or 70 / 30 or 20 / 80 or 80 / 20. In one embodiment, the anode enclosure contacts five surfaces of the anode.

[0194] In one embodiment, the fuel cell system includes a barrier layer between the cathode and the cathode enclosure. The barrier layer contacts at least three surfaces of the cathode. The electrolyte is part of the cathode enclosure, and the cathode enclosure is made of the same material as the electrolyte.

[0195] In one embodiment, the fuel cell system includes fuel passages and oxidant passages in the anode enclosure and the cathode enclosure. In one embodiment, the fuel cell system includes an interconnect that does not include a fluid dispersion element, and the anode and the cathode include fluid dispersion components. In one embodiment, the fuel cell system includes an interconnect that does not include a fluid dispersion element, and the anode and the cathode include fluid channels.

[0196] Tubular design In various cases, the electrochemical reactors described in this disclosure are tubular. The discussion in this section takes a tubular fuel cell (TFC) as an example of a tubular electrochemical reactor. The tubular design is applicable to other types of electrochemical reactors, such as EC gas generators, EC compressors, or flow batteries. Disclosed herein is a tubular fuel cell (TFC) including an internal cathode, an external anode, an electrolyte disposed between the anode and the cathode, and an interconnect. In some embodiments of the TFC, the electrolyte is considered a membrane. The cross-section of the cathode is a non-circular shape with rounded corners, the cross-section is perpendicular to the longitudinal axis of the TFC, the interconnect contacts the cathode but not the anode, the interconnect has a contact surface configured to contact the anode of an adjacent TFC, and the anode has a contact surface and a non-contact surface configured to contact the interconnect of another adjacent TFC.

[0197] In one embodiment, the TFC includes a barrier layer between the cathode and the electrolyte or between the anode and the electrolyte or both. In one embodiment, the rounded non-circular shape includes a rounded rectangle, a rounded square, a rounded hexagon, a rounded trapezoid, a rounded parallelogram, a rounded pentagon, a rounded triangle, a rounded octagon, an oval, an ellipse, or a rounded irregular shape or a combination thereof.

[0198] In one embodiment, the ratio of the area of the contact surface of the interconnect to the area of the non-contact surface of the anode is 1 or less, or 0.75 or less, or 0.5 or less. In one embodiment, the ratio of the area of the contact surface of the interconnect to the area of the non-contact surface of the anode is 0.3 or less, or 0.1 or less, or 0.05 or less.

[0199] In one embodiment, the thickness of the cathode is in the range of about 10 microns to about 1,000 microns; or about 50 to about 150 microns; or about 90 to about 110 microns; or about 100 microns. In one embodiment, the thickness of the anode is in the range of about 1 micron to about 50 microns; or about 5 microns to about 25 microns; or about 8 microns to about 12 microns; or about 10 microns. In one embodiment, the thickness of the electrolyte is in the range of about 100 nm to about 10 microns; or about 500 nm to about 5 microns; or about 800 nm to about 2 microns; or about 1 micron. In one embodiment, the thickness of the barrier layer is in the range of about 100 nm to about 10 microns; or about 500 nm to about 5 microns; or about 800 nm to about 2 microns; or about 1 micron. In one embodiment, the thickness of the interconnect is in the range of about 10 microns to about 1,000 microns; or about 50 microns to about 500 microns; or about 80 microns to about 200 microns; or about 100 microns.

[0200] In one embodiment, the TFC has a length L, a cross-section has a characteristic length of W, and the ratio of L / W is 1 or more. In one embodiment, the ratio of L / W is 2 or more or 10 or more or 100 or more.

[0201] In one embodiment, the TFC includes a support within the cathode. In one embodiment, the support contacts the cathode. In one embodiment, the support is an integral part of the cathode. In one embodiment, the support and the cathode are made of the same material. In one embodiment, the support and the cathode are made of different materials. In one embodiment, the electrolyte is impermeable to the fluid. In one embodiment, the cathode and the anode are porous.

[0202] A fuel cell stack including a multi-tubular fuel cell (TFC) is also described herein, each of the TFCs including an internal cathode, an external anode, an electrolyte disposed between the anode and the cathode, and an interconnect, the cross-section of the cathode being a non-circular shape with rounded corners, the cross-section being perpendicular to the longitudinal axis of the TFC, the interconnect contacting the cathode but not the anode, the interconnect having a contact surface configured to contact the anode of an adjacent TFC, and the anode having a contact surface and a non-contact surface configured to contact the interconnect of another adjacent TFC.

[0203] In one embodiment, each of the TFCs includes a barrier layer between the cathode and the electrolyte or between the anode and the electrolyte or both. In one embodiment, the rounded non-circular shape includes a rounded rectangle, a rounded square, a rounded hexagon, a rounded trapezoid, a rounded parallelogram, a rounded pentagon, a rounded triangle, a rounded octagon, an oval, an ellipse, a rounded irregular shape.

[0204] In one embodiment, the ratio of the area of the contact surface of the interconnect to the area of the non-contact surface of the anode is 1 or less, or 0.75 or less, or 0.5 or less. In one embodiment, the ratio of the area of the contact surface of the interconnect to the area of the non-contact surface of the anode is 0.3 or less, or 0.1 or less, or 0.05 or less.

[0205] In one embodiment, each of the TFCs has a length L, the cross-section has a characteristic length of W, and the ratio of L / W is 1 or more, or 2 or more, or 10 or more, or 100 or more.

[0206] In one embodiment, each of the TFCs includes a support within the cathode. In one embodiment, the support contacts the cathode. In one embodiment, the support is an integral part of the cathode. In one embodiment, the support and the cathode are manufactured from the same material.

[0207] Disclosed herein is a tubular fuel cell (TFC) including an internal anode, an external cathode, an electrolyte disposed between the anode and the cathode, and an interconnect, wherein the cross-section of the anode is a non-circular shape with rounded corners, the cross-section is perpendicular to the longitudinal axis of the TFC, the interconnect contacts the anode but not the cathode, the interconnect has a contact surface configured to contact the cathode of an adjacent TFC, and the cathode has a contact surface and a non-contact surface configured to contact the interconnect of another adjacent TFC.

[0208] In one embodiment, the non-circular shape with rounded corners includes a rounded rectangle, a rounded square, a rounded hexagon, a rounded trapezoid, a rounded parallelogram, a rounded pentagon, a rounded triangle, a rounded octagon, an oval, an ellipse, a rounded irregular shape, or a combination thereof. In one embodiment, the ratio of the area of the contact surface of the interconnect to the area of the non-contact surface of the cathode is 1 or less, or 0.75 or less, or 0.5 or less, 0.3 or less, or 0.1 or less, or 0.05 or less. In one embodiment, the TFC includes a barrier layer between the cathode and the electrolyte or between the anode and the electrolyte or both.

[0209] Figures 10A - 10C show fuel cells with different aspect ratios and how they can be connected in a multi - tubular fuel cell (TFC) unit that includes two or more TFCs. The TFCs include rounded edges. FIG. 10A shows a cross - sectional view of a TFC 1000 according to an embodiment of the present disclosure. The TFC 1000 includes an internal cathode layer 1002, a barrier layer 1004, an electrolyte layer 1006, an external anode layer 1008, an interconnect 1010, and a flow path 1012. Optionally, the barrier layer 1004 is disposed between the anode 1008 and the electrolyte 1006. Optionally, two barrier layers are disposed (1) between the cathode 1002 and the electrolyte 1006 and (2) between the anode 1008 and the electrolyte 1006. The interconnect 1010 contacts the cathode 1002 but does not contact the anode 1008. The upper surface of the interconnect 1010 is configured to contact the anode 1008 of an adjacent TFC. The anode 1008 has a contact surface on the bottom surface configured to contact the interconnect 1010 of another adjacent TFC. The anode 1008 has non - contact surfaces on both sides with the structure shown in FIGS. 10A - 10C. In this example of FIG. 10A, the TFC 1000 has a rounded rectangular shape connected by the interconnect 1010 at the short end of the rectangular shape.

[0210] FIG. 10B shows a cross - sectional view of a TFC 1020 according to an embodiment of the present disclosure. The TFC 1020 is similar to the TFC 1000 in configuration but is connected by the interconnect 1010 at the long side of the rectangular shape.

[0211] FIG. 10C shows a cross - sectional view of a TFC 1040 according to an embodiment of the present disclosure. The TFC 1040 in FIG. 10C is similar to the TFCs in FIGS. 10A - 10B in configuration but includes a rounded square - like shape with substantially the same side lengths. The TFC 1040 is further connected by the interconnect 1010.

[0212] In other embodiments, the anode 1008 can be configured to be internal and the cathode 1002 can be external. Optionally, the barrier layer can be disposed between the cathode and the electrolyte. Optionally, two barrier layers are disposed (1) between the cathode and the electrolyte and (2) between the anode and the electrolyte. All other structures and features discussed above are also applicable in this embodiment.

[0213] In some embodiments, the TFC can further include one or more supports as shown in FIGS. 11A - 11C within the cathode layer. FIG. 11A shows a cross - sectional view of a TFC 1100 including a support, according to one embodiment of the present disclosure. The TFC 1100 includes a cathode 1002, a barrier layer 1004, an electrolyte 1006, an anode layer 1008, an interconnect 1010, and at least one flow channel 1012. The shape and design of how the TFC 1100 is arranged is similar to the TFC of FIG. 10A. The TFC 1100 further includes one or more supports. The supports can be of any suitable shape, number, size, and material. Optionally, the support 1102 is manufactured from the same material as an internal electrode layer such as the cathode layer 1002. Optionally, the support 1104 is manufactured from a material different from the internal electrode layer material such as the cathode 1002. For example, an inert material in the context of a fuel cell. Optionally, the support can be manufactured from more than one material. In one embodiment, one or more supports 1102, 1104 are in contact with the cathode 1002. In one embodiment, one or more supports 1102, 1104 are an integral part of the cathode. In one embodiment, one or more supports 1102, 1104 are manufactured as an integral part of the cathode.

[0214] Figure 11B shows a cross-sectional view of TFC 1120 including supports according to an embodiment of the present disclosure. The shape and design of how TFC 1120 is arranged are the same as those of the TFC in Figure 10B. TFC 1120 further includes one or more supports. Support 1102 may be a linear support of the same material as the inner electrode such as cathode 1002. Support 1104 may be a linear support 1104 constructed of a different material. Support 1106 may be an oval or circular-like support constructed of the same material as the inner electrode such as cathode 1002. Support 1108 may be an oval or circular-like support constructed of a different material from the inner electrode such as cathode 1002. As shown in Figure 11B, the TFC may include linear supports 1102, 1104 and circular supports 1106, 1108.

[0215] Figure 11C shows a cross-sectional view of TFC 1140 including supports according to an embodiment of the present disclosure. The shape and design of how TFC 1140 is arranged are the same as those of the TFC in Figure 10C. TFC 1140 further includes one or more supports. In this example, all supports 1106, 1108 may be circular-like or elliptical-like in shape, but linear supports 1102, 1104 may also be used.

[0216] In some embodiments, the inner electrode may be the anode layer 1008 in TFCs 1100, 1120, 1140. Supports 1102, 1104, 1106, 1108 may be constructed of the same material as the inner anode layer, or may not be constructed of the anode layer 1008, or may be a combination thereof.

[0217] This specification describes a method that includes disposing a fluid mixture between two tubular fuel cells (TFCs), where the two TFCs have a gap with a minimum distance of 1 mm or less; and heating the fluid mixture such that the two TFCs are connected; the fluid mixture has a viscosity of 1000 centipoises or less. In one embodiment, the fluid mixture has a viscosity of 500 centipoises or less or 300 centipoises or less or 200 centipoises or less or 100 centipoises or less or 50 centipoises or less. In one embodiment, the minimum distance of the gap is 500 microns or less, or 300 microns or less, or 200 microns or less, or 100 microns or less, or 50 microns or less.

[0218] In one embodiment, disposing the fluid mixture includes aerosol injection, material injection, inkjet printing, or a combination thereof. In one embodiment, the fluid mixture includes a fluid and a solid, and heating the fluid mixture dissipates the fluid and leaves the solid. In one embodiment, heating the fluid mixture solidifies it. In one embodiment, heating includes the use of electromagnetic radiation (EMR). In one embodiment, the EMR includes UV light, near-UV light, near-infrared light, infrared light, visible light, lasers, electron beams, microwaves, or a combination thereof. In one embodiment, heating includes oven heating, furnace heating, kiln heating, plasma heating, high-temperature surface heating, or a combination thereof. In one embodiment, heating is achieved by conduction, convection, irradiation, or a combination thereof. In one embodiment, the above heating causes sintering, co-sintering, annealing, densification, solidification, evaporation, drying, or a combination thereof.

[0219] In one embodiment, the fluid mixture includes gold, silver, platinum, nickel, iron, steel, stainless steel, chromium, cobalt, carbon, or inconel. In one embodiment, the fluid mixture includes a material used for an electrode in a fuel cell, or a material used for an interconnect in a fuel cell, or both.

[0220] In one embodiment, each of the TFCs includes an internal cathode, an external anode, an electrolyte disposed between the anode and the cathode, and an interconnect. The cross-section of the cathode is a non-circular shape with rounded corners and no sharp corners. The cross-section is perpendicular to the longitudinal axis of the TFC. The interconnect contacts the cathode but does not contact the anode. The interconnect has a contact surface configured to contact the anode of an adjacent TFC. The anode has a contact surface and a non-contact surface configured to contact the interconnect of another adjacent TFC.

[0221] In one embodiment, each of the TFCs includes an internal anode, an external cathode, an electrolyte disposed between the anode and the cathode, and an interconnect. The cross-section of the anode is a non-circular shape with rounded corners and no sharp corners. The cross-section is perpendicular to the longitudinal axis of the TFC. The interconnect contacts the anode but does not contact the cathode. The interconnect has a contact surface configured to contact the cathode of an adjacent TFC. The cathode has a contact surface and a non-contact surface configured to contact the interconnect of another adjacent TFC.

[0222] A method is also described herein that includes applying a contact paste onto a first tubular fuel cell (TFC) and disposing a second TFC in contact with the contact paste on the opposite side of the first TFC. Each of the first TFC and the second TFC includes an internal cathode, an external anode, an electrolyte disposed between the anode and the cathode, and an interconnect. The cross-section of the cathode is a non-circular shape with rounded corners and no sharp corners. The cross-section is perpendicular to the longitudinal axis of the TFC. The interconnect contacts the cathode but does not contact the anode. The interconnect has a contact surface configured to contact the anode of an adjacent TFC. The anode has a contact surface and a non-contact surface configured to contact the interconnect of another adjacent TFC.

[0223] In one embodiment, the contact paste is applied by dipping, coating, spreading, spraying, airbrushing, spray pyrolysis, or painting or combinations thereof. In one embodiment, the contact paste includes gold, silver, platinum, nickel, iron, steel, stainless steel, chromium, cobalt, carbon, or inconel or combinations thereof. In one embodiment, the contact paste includes a material used for an electrode in a fuel cell, or a material used for an interconnect in a fuel cell, or both. In one embodiment, the TFC includes a barrier layer between the cathode and the electrolyte or between the anode and the electrolyte or both.

[0224] In one embodiment, the rounded non-circular shape includes a rounded rectangle, a rounded square, a rounded hexagon, a rounded trapezoid, a rounded parallelogram, a rounded pentagon, a rounded triangle, a rounded octagon, an oval, an ellipse, or a rounded irregular shape. In one embodiment, the ratio of the area of the contact surface of the interconnect to the area of the non-contact surface of the anode is 1 or less, or 0.75 or less, or 0.5 or less. In one embodiment, the ratio of the area of the contact surface of the interconnect to the area of the non-contact surface of the anode is 0.3 or less, or 0.1 or less, or 0.05 or less. In one embodiment, the TFC has a length L, a cross-section has a characteristic length of W, and the ratio of L / W is 1 or more, or 2 or more or 10 or more or 100 or more.

[0225] In one embodiment, the TFC includes a support within the cathode. In one embodiment, the support contacts the cathode. In one embodiment, the support is an integral part of the cathode. In one embodiment, the support and the cathode are manufactured from the same material.

[0226] In one embodiment, the method includes heating a contact paste. In one embodiment, heating includes the use of electromagnetic radiation (EMR). In one embodiment, the EMR includes UV light, near-UV light, near-infrared light, infrared light, visible light, a laser, an electron beam, or a combination thereof. In one embodiment, heating includes oven heating, furnace heating, kiln heating, plasma heating, hot surface heating, or a combination thereof. In one embodiment, the heating is achieved by conduction, convection, irradiation, or a combination thereof. In one embodiment, the heating causes sintering, co-sintering, annealing, densification, solidification, evaporation, drying, or a combination thereof.

[0227] Also described herein is a method that includes applying a contact paste onto a first tubular fuel cell (TFC) and disposing a second TFC in contact with the contact paste on an opposite side of the first TFC, wherein each of the first TFC and the second TFC includes an internal anode, an external cathode, an electrolyte disposed between the anode and the cathode, and an interconnect, the cross-section of the anode is a non-circular shape that is rounded and not angular, the cross-section is perpendicular to the longitudinal axis of the TFC, the interconnect contacts the anode but not the cathode, the interconnect has a contact surface configured to contact the cathode of an adjacent TFC, and the cathode has a contact surface and a non-contact surface configured to contact the interconnect of another adjacent TFC.

[0228] In one embodiment, the contact paste is applied by dipping, coating, spreading, spraying, painting, or a combination thereof. In one embodiment, the contact paste includes gold, silver, platinum, nickel, iron, steel, stainless steel, chromium, cobalt, carbon, or Inconel or a combination thereof. In one embodiment, the contact paste includes a material used for an electrode in a fuel cell, or a material used for an interconnect in a fuel cell, or both. In one embodiment, the TFC includes a barrier layer between the cathode and the electrolyte or between the anode and the electrolyte or both. In one embodiment, the ratio of the area of the contact surface of the interconnect to the area of the non-contact surface of the anode is 1 or less, or 0.75 or less, or 0.5 or less, or 0.3 or less, or 0.1 or less, or 0.05 or less. In one embodiment, the TFC has a length L, a cross-section has a characteristic length of W, and the ratio of L / W is 1 or more, or 2 or more or 10 or more or 100 or more.

[0229] In one embodiment, the TFC includes a support within the anode. In one embodiment, the support contacts the anode. In one embodiment, the support is an integral part of the anode. In one embodiment, the support and the anode are manufactured from the same material.

[0230] In one embodiment, the method includes heating the contact paste. In one embodiment, heating includes the use of electromagnetic radiation (EMR). In one embodiment, the EMR includes UV light, near-ultraviolet light, near-infrared light, infrared light, visible light, lasers, electron beams, microwaves. In one embodiment, the above heating includes oven heating, furnace heating, kiln heating, plasma heating, high-temperature surface heating, or a combination thereof. In one embodiment, heating is achieved by conduction, convection, irradiation, or a combination thereof. In one embodiment, the above heating causes sintering, co-sintering, annealing, densification, solidification, evaporation, drying, or a combination thereof.

[0231] Integrated heat exchanger An electrochemical (EC) reactor, such as an EC gas generator or a solid oxide reactor (SOR), is disclosed herein that includes a first electrode, a second electrode, an electrolyte between the first and second electrodes, and a first heat exchanger, where the first heat exchanger is in fluid connection with the first electrode. The minimum distance between the first electrode and the first heat exchanger is 10 cm or less. In some embodiments, the minimum distance is 5 cm or less. In other embodiments, the minimum distance is 1 cm or less. In still other embodiments, the minimum distance is 5 mm or less. In yet still other embodiments, the minimum distance is 1 mm or less. In one embodiment, the EC reactor includes a second heat exchanger, where the second heat exchanger is in fluid connection with the second electrode. The minimum distance between the second electrode and the second heat exchanger is 10 cm or less. In some embodiments, the minimum distance is 5 cm or less. In other embodiments, the minimum distance is 1 cm or less. In still other embodiments, the minimum distance is 5 mm or less. In yet still other embodiments, the minimum distance is 1 mm or less.

[0232] In one embodiment, the first heat exchanger is adjacent to the first electrode, or alternatively, the second heat exchanger is aligned with or adjacent to the second electrode. One or more heat exchangers can be arranged alongside components in the EC reactor, or above or below components (i.e., electrodes) of the EC reactor. FIG. 9B is an example where an integrated multi-fluid heat exchanger including 916 and 918 is present at the bottom of a repeat unit / stack in a fuel cell that is separated from the anode 910 only by the interconnect layer 920. In this case, the minimum distance between the heat exchanger and the repeat unit / stack is only the thickness of the interconnect, which is 1 mm or less, 0.5 mm or less, 200 microns or less, or in the range of about 100 nm to about 100 microns. In some embodiments, the first heat exchanger and the second heat exchanger are the same heat exchanger, and the heat exchanger forms a multi-fluid heat exchanger. The EC reactor can include a solid oxide fuel cell, a solid oxide flow battery, an electrochemical gas generator, or an electrochemical compressor. The EC reactor can include a reformer upstream of the first electrode, a reformer in contact with the first electrode, or a reformer within the first heat exchanger. The EC reactor can include two or more repeat units separated by interconnects, and each repeat unit includes a first electrode, a second electrode, and an electrolyte. Each repeat unit can include at least one heat exchanger adjacent to the repeat unit.

[0233] Also disclosed herein are EC reactors, including stacks and heat exchangers, such as solid oxide reactors (SORs). The stack has a certain stack height and includes a plurality of repeating units separated by interconnects, and each repeating unit includes a first electrode, a second electrode, and an electrolyte between the first electrode and the second electrode. The heat exchanger is fluidly connected to the stack, and the minimum distance between the stack and the heat exchanger is less than or equal to twice the stack height, or less than or equal to the stack height, or less than or equal to half the stack height. The heat exchanger may be adjacent to the stack. The heat exchanger includes at least three fluid inlets and at least three fluid channels, and each of the at least three fluid channels has a minimum dimension of 30 mm or less. The stack or the heat exchanger may further include a reformer. The reformer may be incorporated into the stack or the heat exchanger. In one embodiment, the interconnect does not include a fluid dispersion element, and the electrodes include a fluid dispersion component or a fluid channel.

[0234] In one embodiment, the EC reactor is in the form of a cartridge (such as that shown in FIGS. 9A-9D). The cartridge may include a fuel inlet on the fuel side of the cartridge, an oxidant inlet on the oxidant side of the cartridge, and at least one fluid outlet, and the fuel inlet has a width of W f and the fuel side of the cartridge has a length of L f the oxidant inlet has a width of W o and the oxidant side of the cartridge has a length of L o where W f / L f is in the range of 0.1 to 1.0, 0.1 to 0.9, 0.2 to 0.9, 0.5 to 0.9, or 0.5 to 1.0, and W o / L ois in the range of 0.1 to 1.0, 0.1 to 0.9, 0.2 to 0.9, 0.5 to 0.9, or 0.5 to 1.0. In some embodiments, the inlet and outlet are on one surface of the cartridge, and the cartridge does not include a flow path protruding on the surface. The cartridge may be removably fixed to the mating surface, and the mating surface is neither soldered nor welded. The cartridge is fixed to the mating surface with bolts or can be pressurized. The mating surface may include a mating fuel inlet, a mating oxidant inlet, and at least one mating fluid outlet.

[0235] An EC reactor cartridge, such as a solid oxide reactor cartridge (SORC) including a first electrode, a second electrode, an electrolyte between the first and second electrodes, and a heat exchanger, is further disclosed herein, and the heat exchanger is fluidly connected to the first electrode or the second electrode or both. The minimum distance between the heat exchanger and the first electrode or the second electrode is 10 cm or less, or 5 cm or less, or 1 cm or less, or 5 mm or less, or 1 mm or less.

[0236] In one embodiment, the EC reactor cartridge includes a reformer upstream of the first electrode or a reformer in contact with the first electrode or a reformer in the heat exchanger. The EC reactor cartridge may include a fuel inlet on the fuel side of the cartridge, an oxidant inlet on the oxidant side of the cartridge, and at least one fluid outlet, and the fuel inlet has a width of W f and the fuel side of the cartridge has a length of L f and the oxidant inlet has a width of W o and the oxidant side of the cartridge has a length of L o . The ratio of W f / L f is in the range of 0.1 to 1.0, 0.1 to 0.9, 0.2 to 0.9, 0.5 to 0.9, or 0.5 to 1.0, and the ratio of W o / L oThe ratio is in the range of 0.1 to 1.0, 0.1 to 0.9, 0.2 to 0.9, 0.5 to 0.9, or 0.5 to 1.0. The inlet and outlet may be present on one surface of the cartridge, and the cartridge does not include a flow path protruding on the surface. The EC reactor cartridge may be detachably fixed to the mating surface, and the mating surface is neither soldered nor welded.

[0237] As described herein, a method of forming an EC reactor, such as a solid oxide reactor (SOR), includes forming a first electrode within the device, forming an electrolyte within the same device, forming a second electrode within the same device, and forming a heat exchanger within the same device. The electrolyte is present between the first electrode and the second electrode and contacts the electrodes. The heat exchanger may be in fluid connection with the first electrode or the second electrode or both. The forming method may include one or more of material injection, binder injection, inkjet printing, aerosol injection, aerosol jet printing, vat photopolymerization, powder bed fusion bonding, material extrusion, directed energy deposition, sheet lamination, ultrasonic inkjet printing, direct (dry) powder deposition, or combinations thereof. Preferably, the forming is achieved by inkjet printing.

[0238] In one embodiment, the method of forming an EC reactor further includes heating the EC reactor. The heating can be performed in situ. The heating can be performed using electromagnetic radiation (EMR). The method of forming an EC reactor may further include forming a plurality of repeating units and interconnects between the repeating units. The repeating units include a first electrode, an electrolyte, and a second electrode. In one embodiment, forming the repeating units and the interconnects occurs within the same device. In a preferred embodiment, the method includes heating the repeating units and the interconnects in situ using EMR. In a preferred embodiment, the method further includes forming a reformer. The reformer can be formed within the same device.

[0239] In one embodiment, the interconnect within the EC reactor does not include a fluid dispersion element. In one embodiment, a method of forming an EC reactor includes forming a first mold plate during formation of a first electrode, the first mold plate contacting the first electrode; removing at least a portion of the first mold plate to form a channel within the first electrode. The method further includes forming a second mold plate during formation of a second electrode, the second mold plate contacting the second electrode; removing at least a portion of the second mold plate to form a channel within the second electrode. In one embodiment, the first electrode includes a fluid dispersion component (FDC) or a fluid channel; the second electrode includes a fluid dispersion component (FDC) or a fluid channel.

[0240] In one embodiment, an EC reactor, such as a SOR, is formed in a cartridge. The cartridge includes a fuel inlet on the fuel side of the cartridge, an oxidant inlet on the oxidant side of the cartridge, and at least one fluid outlet, the fuel inlet having a width of W f and the fuel side of the cartridge having a length of L f the oxidant inlet having a width of W o and the oxidant side of the cartridge having a length of L o . The ratio of W f / L f may be in the range of 0.1 to 1.0, 0.1 to 0.9, 0.2 to 0.9, 0.5 to 0.9, or 0.5 to 1.0, and the ratio of W o / L o is in the range of 0.1 to 1.0, 0.1 to 0.9, 0.2 to 0.9, 0.5 to 0.9, or 0.5 to 1.0. In one embodiment, the inlet and outlet are on one surface of the cartridge, and the cartridge does not include a flow channel protruding on the surface. In one embodiment, the cartridge is removably fixed to the mating surface and is neither soldered nor welded to the mating surface. The cartridge may be bolted or pressed onto the mating surface. In one embodiment, the method includes forming a reformer upstream of the first electrode or a reformer within a reformer or heat exchanger in contact with the first electrode. The reformer may be formed within the same device.

[0241] Methods are also disclosed herein that include forming an EC reactor stack and a heat exchanger. A stack having a certain stack height includes a plurality of repeating units separated by interconnects, and each repeating unit includes a first electrode, a second electrode, and an electrolyte between the first electrode and the second electrode. The heat exchanger can be in fluid connection with the stack, and the minimum distance between the stack and the heat exchanger is no more than twice the stack height, or no more than the stack height, or no more than half the stack height.

[0242] In one embodiment, an EC reactor stack, such as an SOR, and a heat exchanger are formed within the same device. The method can include forming the stack and the heat exchanger in a cartridge. The cartridge can be removably fixed to a mating surface, and the mating surface is neither soldered nor welded.

[0243] Methods are further described herein that include forming an EC reactor, such as an SOR, that includes a first electrode, a second electrode, an electrolyte between the first electrode and the second electrode, and a heat exchanger. The heat exchanger can be in fluid connection with the first electrode or the second electrode or both. The minimum distance between the heat exchanger and the first electrode or the second electrode is no more than 10 cm, no more than 5 cm, no more than 1 cm, no more than 5 mm, or no more than 1 mm. In some cases, the electrodes, the electrolyte, and the heat exchanger are formed within the same device. In some cases, the method also includes forming the EC reactor in a cartridge. The cartridge can be removably fixed to a mating surface, and the mating surface is neither soldered nor welded.

[0244] A method of forming an EC reactor cartridge is disclosed herein, including forming a first electrode, forming a second electrode, forming an electrolyte between the first and second electrodes, and forming a heat exchanger. In one embodiment, the heat exchanger is in fluid communication with the first electrode or the second electrode or both. In one embodiment, the electrode, electrolyte, and heat exchanger are formed within the same device. In one embodiment, the method includes forming a reformer upstream of the first electrode or in contact with the first electrode or in the heat exchanger. In one embodiment, the reformer is formed within the same device.

[0245] Fisher-Tropsch The methods and systems of this disclosure are suitable for manufacturing a catalyst or catalyst composite, such as a Fisher-Tropsch (FT) catalyst or catalyst composite. A Fisher-Tropsch (FT) catalyst composite including a catalyst and a substrate is disclosed herein, and the mass ratio between the catalyst and the substrate is 1 / 100 or more, or 1 / 10 or more, or 1 / 5 or more, or 1 / 3 or more, or 1 / 1 or more. In one embodiment, the catalyst includes Fe, Co, Ni, or Ru. The substrate includes Al2O3, ZrO2, SiO2, TiO2, CeO2, modified Al2O3, modified ZrO2, modified SiO2, modified TiO2, modified CeO2, gadolinium, steel, cordierite (2MgO-2Al2O3-5SiO2), aluminum titanate (Al2TiO5), silicon carbide (SiC), all phases of aluminum oxide, yttria or scandia stabilized zirconia (YSZ), gadolinia or samaria doped ceria, or combinations thereof. In one embodiment, the catalyst composite includes a promoter, and the promoter includes a noble metal, a metal cation, or a combination thereof. The promoter may include B, La, Zr, K, Cu, or combinations thereof. In one embodiment, the catalyst composite includes a fluid channel or a fluid dispersion component instead thereof.

[0246] The FT reactor / system of this disclosure is much smaller than conventional FT reactors / systems (e.g., 3 - 100 times smaller or 100+ times smaller for the same FT product production rate). The high catalyst-to-substrate ratio cannot be achieved by conventional methods of manufacturing FT catalysts. As such, in some embodiments, the FT reactor / system is miniaturized compared to conventional FT reactors / systems.

[0247] Methods are also described herein that include depositing an FT catalyst on a substrate to form an FT catalyst composite, and the depositing includes material injection, binder injection, inkjet printing, aerosol injection, or aerosol jet printing, vat photopolymerization, powder bed fusion bonding, material extrusion, directed energy deposition, sheet lamination, ultrasonic inkjet printing, or combinations thereof. In one embodiment, the mass ratio between the catalyst and the substrate is 1 / 100 or more, or 1 / 10 or more, or 1 / 5 or more, or 1 / 3 or more, or 1 / 1 or more. In a preferred embodiment, the deposition method includes forming a fluid channel or alternatively a fluid dispersion component within the catalyst composite.

[0248] Systems are further described herein that include a Fischer - Tropsch (FT) reactor including an FT catalyst composite including a catalyst and a substrate, and the mass ratio between the catalyst and the substrate is 1 / 100 or more, or 1 / 10 or more, or 1 / 5 or more, or 1 / 3 or more, or 1 / 1 or more. In one embodiment, the catalyst includes Fe, Co, Ni, or Ru. In one embodiment, the substrate includes Al2O3, ZrO2, SiO2, TiO2, CeO2, modified Al2O3, modified ZrO2, modified SiO2, modified TiO2, modified CeO2, gadolinium, steel, cordierite (2MgO - 2Al2O3 - 5SiO2), aluminum titanate (Al2TiO5), silicon carbide (SiC), all phases of aluminum oxide, yttria or scandia stabilized zirconia (YSZ), gadolinia or samaria doped ceria, or combinations thereof. In one embodiment, the catalyst composite includes a promoter.

[0249] As an example, the FT catalyst composite is formed by printing. The catalyst and the substrate / support are manufactured in the form of an ink containing a solvent and particles (e.g., nanoparticles). The ink optionally contains a dispersant, a binder, a plasticizer, a surfactant, a co-solvent, or a combination thereof. The ink may be any kind of suspension. The ink can be processed using a mixing process such as sonication or high-shear mixing. In some cases, the iron ink is in an aqueous environment. In some cases, the iron ink is in an organic environment. The iron ink may also contain a promoter. The substrate / support may be a suspension or an ink of alumina in an aqueous or organic environment. The substrate ink can be processed using a mixing process such as sonication or high-shear mixing. In some cases, the substrate ink contains a promoter. In some cases, the promoter is added as its own ink in an aqueous or organic environment. In some cases, the various inks are printed separately and sequentially. In some cases, the various inks are printed separately and simultaneously, for example, via different print heads. In some cases, the various inks are printed as a combination in a mixture.

[0250] As an example, the exhaust from a fuel cell contains hydrogen, carbon dioxide, water, and optionally carbon monoxide. The exhaust passes over an FT catalyst (e.g., an iron catalyst) to produce a synthetic fuel or a lubricant. The FT iron catalyst has the property of promoting the water gas shift reaction or the reverse water gas shift reaction. The FT reaction occurs at a temperature in the range of 150 - 350 °C and a pressure in the range of 1 to several atmospheres (e.g., 15 atm or 10 atm or 5 atm or 1 atm). Additional hydrogen can be added to the exhaust stream to reach a hydrogen-to-carbon dioxide ratio (carbon dioxide and carbon monoxide) of 2 or more or 3 or more or between 2 and 3.

[0251] Fluid dispersion component Figure 12A shows an impermeable interconnect 1202 having a fluid dispersion component 1204 according to one embodiment of the present disclosure. Figure 12B shows an impermeable interconnect 1202 having two fluid dispersion components 1204 according to one embodiment of the present disclosure. The fluid dispersion component 1204 contacts both sides (major surfaces) of the interconnect 1202. As such, the interconnect is shared between two repeating units within an electrochemical reactor, e.g., an EC gas generator. The fluid dispersion component 1204 functions to distribute a fluid, e.g., a reactive gas (e.g., methane, hydrogen, carbon monoxide, air, oxygen, etc.) within the electrochemical reactor. As such, a conventional interconnect having channels is no longer needed. The design and manufacture of such conventional interconnects having channels is complex and costly. According to this disclosure, the interconnect is a mere impermeable layer that conducts or collects electrons and has no fluid dispersion elements.

[0252] Figures 12C - F schematically show segmented fluid dispersion components 1204 on the upper surface of an impermeable interconnect 1202 according to embodiments of the present disclosure. Such segments can have different compositions, shapes, densities, porosities, pore sizes, pore shapes, permeabilities, or combinations thereof. The segments can be discontinuous. Figure 13C shows segmented fluid dispersion components 1204 of similar shape but different sizes on an impermeable interconnect 1202. Figure 13D shows segmented fluid dispersion components 1204 of similar shape and similar size on an impermeable interconnect 1202 according to one embodiment of the present disclosure. Figure 12E shows segmented fluid dispersion components 1204 of similar shape and similar size but tightly packed on an impermeable interconnect 1202 according to one embodiment of the present disclosure. Figure 12F shows segmented fluid dispersion components 1204 of different shapes and different sizes on an impermeable interconnect 1202 according to one embodiment of the present disclosure. It is also contemplated that these segments have different compositions, densities, porosities, pore sizes, pore shapes, permeabilities, or combinations thereof.

[0253] Figures 12G-I schematically show an impermeable interconnect 1202 having a fluid dispersion component 1204, according to an embodiment of the present disclosure. Different fluid inlet and outlet designs are further shown. The fluid dispersion component may have various densities, porosities, pore sizes, pore shapes, compositions, or permeabilities, or combinations thereof, in different portions (e.g., horizontally or perpendicular to the horizontal). Such variability provides control and tunability of fluid flow in the fluid dispersion component. FIG. 12G shows an impermeable interconnect 1202 and a fluid dispersion component 1204, according to one embodiment of the present disclosure. FIG. 12H shows an impermeable interconnect 1202 and a fluid dispersion component 1204, according to one embodiment of the present disclosure. FIG. 12I shows an impermeable interconnect 1202 and a fluid dispersion component 1204, according to one embodiment of the present disclosure. 1206 and 1208 in FIGS. 12G-I represent different inlet and outlet designs, according to embodiments of the present disclosure. The interconnect 1202 has a matching inlet and outlet for each configuration. In FIG. 12I, 1206 represents a fluid inlet and 1208 represents a fluid outlet. The fluid flow is indicated by arrow 1210. FIG. 12J shows an impermeable interconnect 1202 and a fluid dispersion component 1204, according to one embodiment of the present disclosure. Another fluid flow design, indicated by arrows, is further shown in FIG. 12J. For example, the fluid may flow across the fluid dispersion component from left to right; or the fluid may flow across the fluid dispersion component from front to back.

[0254] FIG. 12K shows a fluid dispersion component 1204, according to one embodiment of the present disclosure. The fluid dispersion component 1204 design includes four corners labeled A, B, C, and D. Location A includes a fluid flow inlet 1212. Location B includes a fluid flow outlet 1214.

[0255] This specification describes an electrochemical reactor (e.g., a fuel cell) that includes an impermeable interconnect without a fluid dispersion element, an electrolyte, and a fluid dispersion component (FDC) between the interconnect and the electrolyte. In one embodiment, the fuel cell includes two FDCs. The two FDCs can be symmetrically arranged in contact with the interconnect, on opposite sides thereof, or facing the major surfaces. As such, the interconnect is shared between two repeating units in the electrochemical reactor, and each repeating unit includes one of the two FDCs. The FDC can be in the form of, or include, an open-cell foam, or a lattice structure.

[0256] In a preferred embodiment, the FDC is segmented, and the segments have different compositions, materials, shapes, sizes, densities, porosities, pore sizes, pore shapes, permeabilities, or combinations thereof. The shape of the segments can include columns, hollow cylinders, cubes, rectangular parallelepipeds, trigonal trapezohedrons, frustums of square pyramids, parallelepipeds, triangular dipyramids, rhombic dodecahedrons, pyramids, pentagonal pyramids, prisms, or combinations thereof.

[0257] In some embodiments, the FDC has various densities, porosities, pore sizes, pore shapes, permeabilities, or combinations thereof, and the density, porosity, pore size, pore shape, or permeability or combinations thereof are controlled. In some embodiments, the density, porosity, pore size, pore shape, or permeability or combinations thereof are controlled to regulate the flow of fluid through the FDC. In other embodiments, the density, porosity, pore size, pore shape, or permeability or combinations thereof are controlled to cause a uniform fluid flow from a first point within the FDC to a second point within the FDC. The fluid flow pattern can be adjusted as desired. For example, it need not be uniform. The fluid flow can be increased or decreased by the reactivity of the FDC or the reaction rate of the fluid at various portions of the FDC. Alternatively, and / or in combination, the fluid flow can be increased or decreased by the fluid flow rate to an anode or cathode at various portions of the FDC. Alternatively, and / or in combination, the fluid flow can be increased or decreased by the reaction rate at an anode or cathode associated with or in contact with various portions of the FDC.

[0258] In one embodiment, the density is higher at the center of the FDC. In one embodiment, the density is lower at the center of the FDC. In one embodiment, the porosity or permeability or pore throat size is lower towards the center of the FDC. In one embodiment, the porosity or permeability or pore throat size is higher towards the center of the FDC.

[0259] In one embodiment, at least a portion of the FDC is a portion of an anode or a portion of a cathode. In a preferred embodiment, the FDC is an anode or a cathode. In one embodiment, the impermeable interconnect has a thickness of 10 microns or less, or 1 micron or less, or 500 nm or less. In a preferred embodiment, the impermeable interconnect includes an inlet and an outlet for the fluid. In a preferred embodiment, the fluid includes reactants for a fuel cell.

[0260] Also disclosed herein is a method of manufacturing a fuel cell, including: (a) forming an impermeable interconnect having no fluid dispersion elements; (b) forming an electrolyte; (c) forming a fluid dispersion component (FDC); and (d) disposing the FDC between the interconnect and the electrolyte.

[0261] In one embodiment, the FDC is formed by fabricating multiple segments and assembling the segments. The segments have different compositions, materials, shapes, sizes, densities, porosities, pore sizes, pore shapes, permeabilities, or combinations thereof, and the shapes include columns, hollow cylinders, cubes, rectangular parallelepipeds, trigonal trapezohedrons, frustums of square pyramids, parallelepipeds, triangular dipyramids, anorthic crystals, pyramids, pentagonal pyramids, prisms, or combinations thereof. The FDC may be a foam, an open-cell foam; or include a lattice structure.

[0262] In a preferred embodiment, the method of forming the FDC includes various densities, porosities, pore sizes, pore shapes, permeabilities, or combinations thereof. In one embodiment, the method includes controlling the density, porosity, pore size, pore shape, permeability, or combinations thereof of the FDC. The method may include controlling the density, porosity, pore size, pore shape, permeability, or combinations thereof of the FDC to regulate the flow of fluid through the FDC. The method may include controlling the density, porosity, pore size, pore shape, permeability, or combinations thereof of the FDC to cause a uniform fluid flow from a first point within the FDC to a second point within the FDC. The method may include controlling the density, porosity, pore size, pore shape, permeability, or combinations thereof of the FDC to cause a patterned fluid flow from a first point within the FDC to a second point within the FDC.

[0263] The fluid flow pattern can be adjusted as desired. For example, it does not need to be uniform. The fluid flow can be increased or decreased by the reactivity of the FDC or the reaction rate of the fluid in various parts of the FDC. Alternatively, and / or in combination, the fluid flow can be increased or decreased by the fluid flow rate to the anode or cathode in various parts of the FDC. Alternatively, and / or in combination, the fluid flow can be increased or decreased by the reaction rate at the anode or cathode associated with or in contact with various parts of the FDC.

[0264] In one embodiment, step (c) includes forming the FDC by varying the various compositions of the materials used. In one embodiment, step (c) includes forming the FDC by varying the various particle sizes used. In one embodiment, step (c) includes heating different parts of the FDC to different temperatures. In one embodiment, the heating includes electromagnetic radiation (EMR). In one embodiment, the EMR includes one or more of UV light, near-UV light, near-infrared light, infrared light, visible light, laser, or electron beam.

[0265] In one embodiment, steps (a)-(d) or steps (b)-(d) are performed using additive manufacturing (AM). In various embodiments, AM includes extrusion, photopolymerization, powder bed fusion bonding, material jetting, binder jetting, directed energy deposition, or lamination, or combinations thereof.

[0266] In one embodiment, the method of forming the FDC includes heating the fuel cell such that the shrinkage rates of the FDC and the electrolyte are matched, or such that the shrinkage rates of the interconnect, FDC, and electrolyte are matched. In a preferred embodiment, the heating includes EMR. In one embodiment, the EMR includes UV light, near-UV light, near-infrared light, infrared light, visible light, laser, or electron beam, or combinations thereof. In a preferred embodiment, the heating is performed in-situ. In a preferred embodiment, the heating occurs for 30 minutes or less, or 30 seconds or less, or 30 milliseconds or less.

[0267] In a preferred embodiment, at least a portion of the FDC is a portion of the anode or a portion of the cathode. In a preferred embodiment, the FDC is the anode or the cathode. In a preferred embodiment, the impermeable interconnect has a thickness of 10 microns or less, or 1 micron or less, or 500 nm or less. Preferably, the impermeable interconnect includes an inlet and an outlet for the fluid. More preferably, the fluid includes reactants for the fuel cell.

[0268] Grooved electrode Disclosed herein is a method including providing a mold plate that contacts an electrode material; and removing at least a portion of the mold plate to form channels in the electrode material, such as in an EC gas generator. FIG. 13A shows a mold plate 1300 for manufacturing a grooved electrode according to an embodiment of the present disclosure. Such a mold plate can be removed either after the electrochemical reactor is manufactured or at the start of utilization of the reactor by oxidation, melting, vaporization, reduction, or any suitable means.

[0269] In one embodiment, the grooved electrode material includes NiO, YSZ, GDC, LSM, LSCF, or a combination thereof. The grooved electrode material can include any of the materials previously described herein for the cathode or anode. In one embodiment, providing a template includes printing a template or a precursor that is assembled to form the template. Providing a template includes polymerizing one or more monomers or photoinitiators, or both. In one embodiment, the method includes curing the monomer and / or oligomer by internal or external techniques. In various embodiments, the internal technique includes polymerization by free radical molecule initiation and / or initiation by in-situ reduction / oxidation. In various embodiments, the external technique includes photolysis, exposure to ionizing radiation, (ultra)sonication, and pyrolysis to form initiating species. In a preferred embodiment, the curing includes UV curing. In one embodiment, the method includes adding a polymerization agent, which includes a photoinitiator. In one embodiment, the polymerization agent is printed on the upper surface of the monomer or within each piece of the monomer.

[0270] In one embodiment, providing a template includes dispersing metal oxide particles in a monomer ink prior to printing the template. In one embodiment, the metal oxide includes NiO, CuO, LSM (lanthanum strontium manganite), LSCF (lanthanum strontium cobalt ferrite), GDC (gadolinium-doped ceria), SDC (samarium-doped ceria), or a combination thereof. In one embodiment, the monomer includes alcohol, aldehyde, carboxylic acid, ester, and / or ether functional groups. In one embodiment, the template includes NiO, Cu(I)O, Cu(II)O, an organic compound, a photopolymer, or a combination thereof.

[0271] In one embodiment, removing at least a portion of the template includes heating, combustion, solvent treatment, oxidation, reduction, or combinations thereof. In one embodiment, the combustion leaves no deposits and is not explosive. In one embodiment, reduction occurs in the metal oxide to produce a porous template. In one embodiment, the method of providing the template includes in-situ heating.

[0272] In one embodiment, the template and the electrode material are printed one by one, a second sheet is printed on top of the first sheet, and then the first sheet is heated, and the heating removes at least a portion of the template. In one embodiment, the heating includes EMR. In one embodiment, the EMR includes one or more of UV light, near-UV light, near-infrared light, infrared light, visible light, laser, and electron beam.

[0273] In one embodiment, the channels and the electrode material form an electrode layer. In one embodiment, the channels have regular trajectories within the electrode layer. For example, the channels are parallel to each other. The channels may extend from one end, edge, or corner of the electrode layer to the opposite end, edge, or corner. The channels may bend 90° from one end, edge, or corner of the electrode and extend to another end, edge, or corner. The channels have random trajectories within the electrode layer. For example, the channels may have a meandering trajectory without regularity. The channels may have more than one inlet point and more than one outlet point. More than one inlet point and more than one outlet point are distributed across the electrode layer. The inlet and outlet points of the channels within the electrode layer may be on any side of the electrode layer, including the top surface or side and the bottom surface or side.

[0274] In some embodiments, the volume fraction of the template in the electrode layer is in the range of 5% - 95%, or 10% - 90%, or 20% - 80%, or 30% - 70%, or 40% - 60%. The volume fraction of the channels in the electrode layer is in the range of 10% - 90%, or 20% - 80%, or 30% - 70%, or 40% - 60%. The total effective porosity of the electrode layer having channels is preferably in the range of 20% - 80%, or 30% - 70%, or 40% - 60%. Such total effective porosity of the electrode layer having channels is greater than or equal to the porosity of the electrode material. The serpentine of the electrode layer having channels is less than or equal to the natural serpentine of the electrode material.

[0275] In a preferred embodiment, the gas channel extends across the height of the electrode layer. The gas channel may occupy a height less than the height of the electrode layer. As an example, the electrode layer has a thickness of about 50 microns. In one embodiment, the gas channel width is 10 microns or more. In one embodiment, the gas channel width is 100 microns or more.

[0276] Also described herein is a method comprising: (a) printing a first template and a first electrode material to form a first electrode layer, wherein the first template contacts the first electrode material; (b) printing an electrolyte layer; (c) printing a second template and a second electrode material to form a second electrode layer, wherein the second template contacts the second electrode material; and (d) printing an interconnect. In a preferred embodiment, the steps are performed in any order. In a preferred embodiment, the method includes repeating steps (a) - (d) in any order to form a stack or a repeating unit of the stack.

[0277] In one embodiment, the method includes (e) removing at least a portion of the first and second templates to form channels in the first and second electrode layers. In one embodiment, the removal includes heating, combustion, solvent treatment, oxidation, reduction, or combinations thereof. In one embodiment, the removal occurs in situ. The removal can occur after the stack or repeating unit of the stack has been printed. The removal can occur when the stack is initiated to operate. In one embodiment, the printing occurs sheet by sheet, with the second sheet printed on top of the first sheet, and then the first sheet is heated, the heating removing at least a portion of the template. The printing step includes material jetting, binder jetting, inkjet printing, aerosol jetting, or aerosol jet printing, or combinations thereof.

[0278] Also described herein is a method including: (a) printing a first electrode layer; (b) printing an electrolyte layer; (c) printing a second electrode layer; and (d) printing an interconnect. In one embodiment, printing includes material jetting, binder jetting, inkjet printing, aerosol jetting, or aerosol jet printing. In a preferred embodiment, the steps are performed in any order. In a preferred embodiment, the method includes repeating steps (a)-(d) in any order to form a stack or repeating unit of the stack. Also disclosed herein is a method including aerosol jetting or aerosol jet printing an electrode layer, or an electrolyte layer, or an interconnect, or combinations thereof.

[0279] FIG. 13B is a cross-sectional view of a half-cell between a first interconnect and an electrolyte according to one embodiment of the present disclosure. The stack in FIG. 13B includes a bottom / first interconnect 1301, an optional layer 1302 including a bottom interconnect material and a first electrode material, a first electrode segment 1303, a first filler material forming a first template 1304, and an electrolyte 1305.

[0280] FIG. 13C is a cross-sectional view of a half-cell between a second interconnect and an electrolyte according to an embodiment of the present disclosure. The half-cell includes an electrolyte 1305, a second electrode segment 1306, a filler material forming a second template 1307, and an upper / second interconnect 1308. The figures shown in FIGS. 13B and 13C are perpendicular to each other.

[0281] FIG. 13D is a cross-sectional view of a half-cell between a first interconnect and an electrolyte according to an embodiment of the present disclosure. The half-cell includes a bottom interconnect 1301, an optional layer 1302 including a bottom interconnect material and a first electrode material, a first electrode segment 1303, a first filler material 1304 forming a first template, an electrolyte 1305, and an optional shield 1409 for the first filler material when the first electrode is heated and / or sintered.

[0282] FIG. 13E is a cross-sectional view of a half-cell between a second interconnect and an electrolyte according to an embodiment of the present disclosure. The half-cell includes an electrolyte 1305, a second electrode segment 1306, a filler material 1307 forming a second template, an upper interconnect 1308, and an optional shield for the second filler material when the upper interconnect is heated and / or sintered. The figures shown in FIGS. 13D and 13E are perpendicular to each other.

[0283] In some embodiments, there is a layer (not shown) between 1307 and 1308, which includes an upper interconnect material and a second electrode material. In some embodiments, 1305 represents an electrolyte having a barrier for the first electrode or the second electrode. 1309 represents an optional shield for the first filler when the first electrode is heated / sintered. 1310 represents an optional shield for the second filler when the upper interconnect is heated / sintered. In some cases, the electrolyte 1305 or the electrolyte-barrier layer contacts the first electrode and continuously contacts the second electrode along its opposing major surface. The shapes of the electrode segments and fillers in these cross-sectional views are only representative and not exact. They can take on any regular or irregular shape. When the electrochemical reactor (e.g., a fuel cell stack or a gas generator) is manufactured, for example, by in-furnace heating, the fillers and / or templates are removed. Or alternatively, they are removed using the effects of oxidation, melting, vaporization, gasification, reduction, or combinations thereof when the electrochemical reactor starts operating by passing hot gas / fluid through. These removed fillers and / or templates become channels within the electrodes. In various embodiments, multiple rows of channels are present within the electrodes. In an example, the electrode has a thickness of 25 microns and has multiple channels with a height of 20 microns. In another example, the electrode has a thickness of 50 microns and has two rows of multiple channels, and each row of channels has a height of 20 microns. In various embodiments, the fillers include carbon, graphite, graphene, cellulose, metal oxides, polymethyl methacrylate, nanodiamonds, or combinations thereof.

[0284] In one embodiment, the unit in an electrochemical reactor that includes an interconnect, a first electrode, an electrolyte, and a second electrode is manufactured by this method: providing the interconnect, depositing a first electrode material on the interconnect in segments, sintering the first electrode material, depositing a first filler material between the first electrode material segments, depositing additional first electrode material and covering the filler material, sintering the additional first electrode material and forming the first electrode, depositing an electrolyte material on the first electrode, sintering the electrolyte material to form the electrolyte, depositing a second electrode material on the electrolyte such that multiple valleys are formed within the second electrode material, sintering the second electrode material to form the second electrode, depositing a second filler material within the valleys of the second electrode, depositing a second interconnect material to cover the second electrode and the second filler material, and sintering the second interconnect material. In various embodiments, the deposition is performed using inkjet printing or ultrasonic inkjet printing. In various embodiments, the sintering is performed using electromagnetic radiation (EMR). In some cases, the first and second filler materials absorb little to no EMR; the absorption is so small that the filler materials have no measurable change. In some cases, a shield is deposited to cover the first filler material or the second filler material or both, such that the heating and / or sintering process for the upper layer does not cause a measurable change in the first filler material or the second filler material or both. In some cases, the shield includes YSZ, SDC, SSZ, CGO, NiO-YSZ, Cu, CuO, Cu2O, LSM, LSCF, lanthanum chromite, stainless steel, LSGM, or combinations thereof.

[0285] Double porosity electrode Figures 14A-D show various embodiments of a double-porosity electrode having 1, 2, or 3 layers shown in detail, which can be used in an electrochemical reactor such as an EC gas generator. Figure 14A schematically shows a segment of a fluid dispersion component in a first layer according to an embodiment of the present disclosure. The first layer 1400 includes a fluid dispersion component segment 1402. The segment 1402 can have different compositions, shapes, densities, porosities, pore sizes, pore shapes, permeabilities, or combinations thereof. The volume fraction (VFc) of the channels with respect to the layer 1400 containing the channels is also shown. Herein, electrodes in an EC reactor containing materials and channels are described, where the materials and channels form a first layer within an electrode having a first layer porosity. The materials have a material porosity. The channels have a volume fraction VFc, which is the ratio between the volume of the channels and the volume of the first layer. The first layer porosity indicates the average porosity of the first layer as a whole. The first layer porosity is at least 5% greater than the material porosity. VFc ranges from 0 - 99%, or 1 - 30%, or 10 - 90%, or 5 - 50%, or 3 - 30%, or 1 - 50%. VFc is 5%, or 10%, or 20%, or 30%, or 40%, or 50% or more.

[0286] Figure 14B schematically shows a fluid dispersion component in a first layer together with a second layer in an electrode, according to one embodiment of the present disclosure. The electrode embodiment in Figure 14B shows a first layer 1404 and a second layer 1406 of fluid dispersion component segment 1405. The segments shown in Figure 14B can have different compositions, shapes, densities, porosities, pore sizes, pore shapes, permeabilities, or combinations thereof. The electrode includes a second layer, and the second layer has a second layer porosity. The second layer porosity indicates the average porosity of the second layer as a whole. In one embodiment, the second layer porosity is less than or equal to the first layer porosity, or the second layer porosity is greater than or equal to the first layer porosity. The second layer 1406 can include the same material as the first layer. The second layer 1406 can also include variability in composition, shape, density, porosity, pore size, pore shape, permeability, or combinations thereof, laterally or perpendicular to the lateral direction.

[0287] Figure 14D schematically shows a fluid dispersion component 1408 in a first layer together with a second layer 1412, according to one embodiment of the present disclosure. The electrode embodiment in Figure 14D is similar to the embodiment in Figure 14B. The electrode in Figure 14D includes a first layer 1408 that further includes a fluid dispersion component segment 1410, and the segment 1410 can have different compositions, shapes, densities, porosities, pore sizes, pore shapes, permeabilities, or combinations thereof. The second layer 1412 can include the same material as the first layer. The second layer 1412 can also include variability in composition, shape, density, porosity, pore size, pore shape, permeability, or combinations thereof, laterally or perpendicular to the lateral direction.

[0288] Figure 14C schematically shows fluid dispersion components in a first layer together with second and third layers, according to one embodiment of the present disclosure. The electrode embodiment in Figure 14C includes a first layer 1414, a second layer 1416, and a third layer 1418. In one embodiment, the second and third layers are present on both sides of the first layer. In one embodiment, the second and third layers are in continuous contact with both sides of the first layer. The first layer 1414 may include segments 1420 having different compositions, shapes, densities, porosities, pore sizes, pore shapes, permeabilities, or combinations thereof. The second layer or the third layer may include the same material as the first layer. The second layer or the third layer may also include variability in composition, shape, density, porosity, pore size, pore shape, permeability, or combinations thereof, in the lateral direction, or perpendicular to the lateral direction.

[0289] In one embodiment, the material porosity of the first, second, or third layer is in the range of 20 - 60%, in the range of 30 - 50%, in the range of 30 - 40%, or in the range of 25 - 35%. In one embodiment, the material porosity is 25%, or 35%, or 45% or more.

[0290] In one embodiment, the electrode has a thickness of 10 cm, or 5 cm, or 1 cm or less. In one embodiment, the electrode has a thickness of 8 mm, or 5 mm, or 1 mm or less. In one embodiment, the electrode has a thickness of 100 microns, or 80 microns, or 60 microns or less.

[0291] In one embodiment, the contribution of the first layer's permeability from the channels is greater than the contribution of the first layer's permeability from the material. In one embodiment, 50%, or 70%, or 90% or more of the permeability of the first layer is due to the permeability of the channels. In one embodiment, the permeability of the material in the first layer is 50% or less, or 10% or less, or 1% or less, or 0.001% or less of the permeability of the channels in the first layer.

[0292] Disclosed herein is a method for manufacturing a conductive component (ECC) of an electrochemical reactor (e.g., a fuel cell) including the following: (a) depositing a first composition including a first pore former having a first pore former volume fraction VFp1 on a substrate; (b) depositing a second composition including a second pore former having a second pore former volume fraction VFp2 on the substrate, wherein the first composition and the second composition form a first layer in the ECC; and (c) heating the first layer so that the first pore former and the second pore former form void spaces. In one embodiment, the VFp1 is in the range of 0-100%, or 10-90%, or 30-70%, or 50-100%, or 90-100%. In one embodiment, the VFp2 is in the range of 0-100%, or 0-70%, or 25-75%, or 30-60%. In one embodiment, heating includes a reduction reaction or an oxidation reaction, or both a reduction and an oxidation reaction.

[0293] FIG. 15 is an example of an electrode having double porosity according to an embodiment of the present disclosure. FIG. 15 shows an EC component 1500 including a grooved electrode having double porosity. The device 1500 includes an anode gas inlet 1501, an anode gas outlet 1502, a cathode gas inlet 1503, and a cathode gas outlet 1504. The exploded perspective view 1505 is a view of a part of the cathode layer. FIG. 1506 is a closer view of the cathode, and FIG. 1506 represents a thin slice passing through the cathode layer composed of the cathode 1507. The cathode 1507 is a porous cathode formed using a micropore former. The channel 1508 represents a channel formed from a macropore former.

[0294] In one embodiment, (a) and (b) are achieved by printing, or extrusion, or additive manufacturing (AM), or tape casting, or spraying, or deposition, or sputtering, or screen printing. In one embodiment, the additive manufacturing includes extrusion, photopolymerization, powder bed fusion bonding, material jetting, binder jetting, directed energy deposition, lamination.

[0295] In one embodiment, the first pore former and the second pore former are the same. In one embodiment, the first pore former and the second pore former are different. In one embodiment, the first pore former or the second pore former has an average diameter in the range of 10 nm to 1 mm or 100 nm to 100 microns or 500 nanometers to 50 microns. In one embodiment, the first pore former or the second pore former has a size distribution. In one embodiment, the first pore former or the second pore former comprises carbon, graphite, polymethyl methacrylate (PMMA), cellulose, metal oxide, or a combination thereof.

[0296] In one embodiment, the method includes repeating (a) and (b) to form a second layer in the ECC; and heating the second layer. In one embodiment, heating the second layer occurs simultaneously with heating the first layer. In one embodiment, heating the second layer occurs at a different time than heating the first layer. In one embodiment, heating the second layer and heating the first layer have at least a partial overlap period. In one embodiment, the method includes repeating (a) and (b) to form a third layer in the ECC; and heating the third layer. In one embodiment, the second layer and the third layer are present on both sides of the first layer. In one embodiment, heating the first, second, and third layers is simultaneous. Alternatively, the first, second, and third layers are heated at different times. In one embodiment, heating of the first, second, and third layers has an overlap period. In one embodiment, the first, second, or third layer is heated two or more times.

[0297] In one embodiment, at least a portion of the void space caused by the second pore former or the first pore former or both becomes channels within the first layer. In one embodiment, the channels have a volume fraction VFc, which is the ratio between the volume of the channels and the volume of the first layer. In one embodiment, the VFc ranges from 0 - 99% or 1 - 30% or 10 - 90% or 5 - 50% or 3 - 30% or 1 - 50%. In one embodiment, the VFc is 5% or 10% or 20% or 30% or 40% or 50% or more.

[0298] In one embodiment, VFp1 is different from VFp2. In one embodiment, the first layer has double porosity, material porosity, and layer porosity. In one embodiment, the material porosity ranges from 20 - 60%, or 30 - 50%, or 30 - 40%, or 25 - 35%. In one embodiment, the material porosity is 25% or 35% or 45% or more.

[0299] In one embodiment, the ECC has a thickness of 10 cm or 5 cm or 1 cm or less. In one embodiment, the ECC has a thickness of 8 mm or 5 mm or 1 mm or less. In one embodiment, the ECC has a thickness of 100 microns or 80 microns or 60 microns or less.

[0300] In one embodiment, the first layer later contains (c) channels and materials, and the contribution of the channels to the permeability of the first layer is greater than the contribution of the materials to the permeability of the first layer. In one embodiment, 50% or 70% or 90% or more of the permeability of the first layer is due to the permeability of the channels. In one embodiment, the permeability of the materials in the first layer is 50% or less or 10% or less or 1% or less or 0.001% or less of the permeability of the channels in the first layer.

[0301] This specification describes a method that includes: (a) providing a first material to an additive manufacturing machine (AMM); (b) providing a second material to the AMM; (c) mixing the first material and the second material into a mixture; and (d) forming the mixture into a part. In one embodiment, the first material or the second material is a gas, or a liquid, or a solid, or a gel.

[0302] In one embodiment, the additive manufacturing includes extrusion, photopolymerization, powder bed fusion, material jetting, binder jetting, directed energy deposition, lamination. In one embodiment, the AM includes direct metal laser sintering (DMLS), selective laser sintering (SLS), selective laser melting (SLM), directed energy deposition (DED), laser metal deposition (LMD), electron beam (EBAM), or metal binder jetting. In one embodiment, steps (c) and (d) occur continuously.

[0303] In one embodiment, step (c) includes varying the ratio of the first material and the second material in the mixture. In one embodiment, the ratio of the first material and the second material in the mixture varies in situ. In one embodiment, the ratio of the first material and the second material in the mixture varies in real time. In one embodiment, the ratio of the first material and the second material in the mixture varies continuously. In one embodiment, the ratio of the first material and the second material in the mixture varies according to a composition profile. In one embodiment, the ratio of the first material and the second material in the mixture varies according to a manual algorithm, a computational algorithm, or a combination thereof. In one embodiment, the ratio of the first material and the second material in the mixture is varied by controlling the material flow rate or the pumping speed.

[0304] In one embodiment, step (d) includes disposing the mixture on a substrate in a pattern. In one embodiment, step (d) includes disposing the mixture according to a predetermined specification.

[0305] In one embodiment, the formed part has various properties. In one embodiment, the properties include strength, weight, density, electrical performance, electrochemical performance, or a combination thereof. In various embodiments, the formed part has superior properties, such as strength, density, weight, electrical performance, or electrochemical performance, or a combination thereof, compared to similar parts formed by different processes.

[0306] In one embodiment, step (d) includes depositing the above mixture onto a substrate. In one embodiment, mixing occurs before, during, or after deposition. In one embodiment, mixing occurs within the AMM, or in air, or on the substrate. In one embodiment, mixing occurs by advection, dispersion, diffusion, melting, fusion, pumping, stirring, heating, or a combination thereof.

[0307] Disclosed herein is an additive manufacturing machine (AMM) that includes (a) a first material source; (b) a second material source; and (c) a mixer configured to mix the first material and the second material to form a mixture; the AMM is configured to form the mixture into a part. In one embodiment, the first material or the second material is a gas, or a liquid, or a solid, or a gel.

[0308] In one embodiment, the AMM is configured to perform extrusion, photopolymerization, powder bed fusion bonding, material jetting, binder jetting, directed energy deposition, or lamination. In one embodiment, the AMM is configured to perform direct metal laser sintering (DMLS), selective laser sintering (SLS), selective laser melting (SLM), directed energy deposition (DED), laser metal deposition (LMD), electron beam (EBAM), or metal binder jetting.

[0309] In one embodiment, the mixer is configured to continuously mix a first material and a second material, during which the AMM forms the mixture into a part. In one embodiment, the mixer is configured to vary the ratio of the first material and the second material in the mixture. In one embodiment, the mixer is configured to vary in situ the ratio of the first material and the second material in the mixture. The mixer may be configured to vary in real time the ratio of the first material and the second material in the mixture. In one embodiment, the mixer may be configured to continuously vary the ratio of the first material and the second material in the mixture. In one embodiment, the mixer is configured to vary the ratio of the first material and the second material in the mixture according to a composition profile. In one embodiment, the mixer is configured to vary the ratio of the first material and the second material in the mixture according to a manual algorithm, a computational algorithm, or a combination thereof. In one embodiment, the mixer is configured to vary the ratio of the first material and the second material in the mixture by controlling the material flow rate or the pumping speed.

[0310] In one embodiment, the AMM is configured to dispose the mixture on a substrate in a pattern. In one embodiment, the AMM is configured to dispose the mixture according to a predetermined specification.

[0311] In one embodiment, the formed part has various characteristics. In one embodiment, the characteristics include strength, weight, density, electrical performance, electrochemical performance, or a combination thereof. In various embodiments, the formed part has superior characteristics, such as strength, density, weight, electrical performance, or electrochemical performance, or a combination thereof, compared to similar parts formed using different apparatuses.

[0312] In one embodiment, the AMM is configured to deposit the above mixture onto a substrate. In one embodiment, mixing occurs before, during, or after deposition. In one embodiment, mixing occurs within the AMM, in air, or on the substrate. In one embodiment, mixing occurs by advection, dispersion, diffusion, melting, fusion, pumping, stirring, heating, or combinations thereof.

[0313] Integrated Deposition and Heating A method is disclosed herein that includes depositing a composition one piece at a time onto a substrate (which may also be described as line-by-line deposition) to form an object; and heating the object in situ using electromagnetic radiation (EMR); the composition includes a first material and a second material, and the second material has a higher EMR absorbance than the first material. In various embodiments, heating can cause effects including drying, curing, sintering, annealing, sealing, alloying, evaporation, reconfiguration, foaming, or combinations thereof. In some embodiments, the EMR has a peak wavelength in the range of 10 - 1500 nm and a minimum energy density of 0.1 joules / cm 2 and the peak wavelength is based on the irradiance with respect to wavelength. In some embodiments, the EMR includes one or more of UV light, near-UV light, near-infrared light, infrared light, visible light, a laser, or an electron beam.

[0314] FIG. 16 shows a system for integrated deposition and heating using electromagnetic radiation (EMR) according to one embodiment of the present disclosure. The system 1600 can be used to assemble an electrochemical reactor such as a fuel cell or an EC gas generator. FIG. 16 further shows an object 1603 on a receiver 1604 formed by the system 1600, a deposition nozzle 1601, and the EMR 1602 for heating in situ according to one embodiment of this disclosure. The receiver 1604 can be a moving platform and can further receive deposition, heat, irradiation, or combinations thereof. The receiver 1604 can also be referred to as a chamber, and the chamber can be fully enclosed, partially enclosed, or completely open to the atmosphere.

[0315] In some embodiments, the first material includes yttria-stabilized zirconia (YSZ), 8YSZ (8 mol% YSZ powder), yttrium, zirconium, gadolinia-doped ceria (GDC or CGO), samaria-doped ceria (SDC), scandia-stabilized zirconia (SSZ), lanthanum strontium manganite (LSM), lanthanum strontium cobalt ferrite (LSCF), lanthanum strontium cobaltite (LSC), lanthanum strontium gallium magnesium oxide (LSGM), nickel, NiO, NiO-YSZ, Cu-CGO, Cu2O, CuO, cerium, copper, silver, crofer, steel, lanthanum chromite, doped lanthanum chromite, ferritic steel, stainless steel, or combinations thereof. In other embodiments, the first material includes YSZ, SSZ, CGO, SDC, NiO-YSZ, LSM-YSZ, CGO-LSCF, doped lanthanum chromite, stainless steel, or combinations thereof. In some embodiments, the second material includes carbon, nickel oxide, nickel, silver, copper, CGO, SDC, NiO-YSZ, NiO-SSZ, LSCF, LSM, doped lanthanum chromite ferritic steel, or combinations thereof. The first material may include any electrode material previously disclosed herein.

[0316] In some embodiments, the object 1603 includes a catalyst, a catalyst support, a catalyst composite, an anode, a cathode, an electrolyte, an electrode, an interconnect, a seal, a fuel cell, an electrochemical gas generator, an electrolysis device, an electrochemical compressor, a reactor, a heat exchanger, a container, or combinations thereof.

[0317] In some embodiments, the second material can be deposited on the same wafer as the first material. In other embodiments, the second material can be deposited on a wafer adjacent to the wafer containing the first material. In some embodiments, the heating can remove at least a portion of the second material. In preferred embodiments, the heating leaves a minimal residue of the second material, such that there is no significant residue that would interfere with subsequent steps or operations in the process of the device being constructed. More preferably, this leaves no measurable residue of the portion of the second material.

[0318] In some embodiments, the second material can add thermal energy to the first material during heating. In other embodiments, the second material has a radiation absorbance that is at least 5 times that of the first material; the second material has a radiation absorbance that is at least 10 times that of the first material; the second material has a radiation absorbance that is at least 50 times that of the first material, or the second material has a radiation absorbance that is at least 100 times that of the first material.

[0319] In some embodiments, the second material can have a peak absorbance wavelength of 200 nm, or 250 nm, or 300 nm, or 400 nm, or 500 nm or more. In other embodiments, the first material has a peak absorbance wavelength of 700 nm, or 600 nm, or 500 nm, or 400 nm, or 300 nm or less. In other embodiments, the EMR has a peak wavelength of 200 nm, or 250 nm, or 300 nm, or 400 nm, or 500 nm or more.

[0320] In some embodiments, the second material may include carbon, nickel oxide, nickel, silver, copper, CGO, NiO-YSZ, LSCF, LSM, ferritic steel, other metal oxides, or combinations thereof. Optionally, the ferritic steel is Crofer 22APU. In some embodiments, the first material includes YSZ, CGO, NiO-YSZ, LSM-YSZ, other metal oxides, or combinations thereof. In one embodiment, the second material includes LSCF, LSM, carbon, nickel oxide, nickel, silver, copper, or steel. In some embodiments, the carbon includes graphite, graphene, carbon nanoparticles, nanodiamonds, or combinations thereof. The second material may include any electrode material previously disclosed herein.

[0321] In some embodiments, the deposition method includes material injection, binder injection, inkjet printing, aerosol injection, aerosol jet printing, vat photopolymerization, powder bed fusion bonding, material extrusion, directed energy deposition, sheet lamination, ultrasonic inkjet printing, or combinations thereof.

[0322] In some embodiments, the deposition method further includes one or more of the steps of controlling the distance from the EMR to the receiver, the EMR energy density, the EMR spectrum, the EMR voltage, the EMR exposure period, the EMR exposure area, the EMR exposure volume, the EMR burst frequency, and the number of EMR exposure repetitions. In one embodiment, the object does not change position between the deposition step and the heating step. In one embodiment, the EMR has a power output of 1 W, or 10 W, or 100 W, or 1000 W or more.

[0323] A system including at least one deposition nozzle, an electromagnetic radiation (EMR) source, and a deposition receiver is also disclosed herein, and the deposition receiver is configured to receive EMR exposure and deposition at the same location. Optionally, the receiver is configured such that it receives deposition for a first period and moves to a different location within the system to receive EMR exposure for a second period.

[0324] The following detailed description describes the production of solid oxide fuel cells (SOFCs) for illustrative purposes. As will be recognized by those skilled in the art, the methods and manufacturing processes are applicable to all fuel cell types. As such, the production of all fuel cell types is within the scope of this disclosure.

[0325] Additive manufacturing Additive manufacturing (AM) refers to a group of technologies that create objects by joining materials, usually one at a time or layer by layer on top of each other. AM is contrasted with subtractive manufacturing methods that involve the removal of some of the material by machining, cutting, grinding, or etching. AM may also be referred to as rapid prototyping, additive process, additive technology, additive layer manufacturing, layer manufacturing, or freeform fabrication. Some examples of AM are extrusion, photopolymerization, powder bed fusion bonding, material jetting, binder jetting, directed energy deposition, lamination, direct metal laser sintering (DMLS), selective laser sintering (SLS), selective laser melting (SLM), directed energy deposition (DED), laser metal deposition (LMD), electron beam (EBAM), and metal binder jetting. 3D printers are one type of AM machine (AMM). Inkjet printers or ultrasonic inkjet printers are additional examples of AMMs.

[0326] In a first aspect, the invention is a method of manufacturing an electrochemical reactor such as an EC gas generator or a fuel cell, comprising: (a) generating an anode using AMM; (b) fabricating an electrolyte using AMM; and (c) manufacturing a cathode using AMM. In a preferred embodiment, the anode, electrolyte, and cathode are assembled into a fuel cell using AMM in addition to other steps that are not completed using AMM. In a preferred embodiment, the fuel cell is formed using only AMM. In other embodiments, steps (a), (b), and (c) exclude tape casting and screen printing. In one embodiment, the method of assembling a fuel cell using AMM excludes compression in the assembly. In other embodiments, the layers are stacked and deposited in a stepwise manner, such that the assembly is achieved simultaneously with the deposition. The method described herein is useful in the manufacture of planar fuel cells. The method described herein is also useful in the manufacture of fuel cells in which the current is perpendicular to the lateral electrolyte when the fuel cell is in use.

[0327] In one embodiment, the interconnect, anode, electrolyte, and cathode are formed by stacking layer upon layer, for example, printed by stacking layer upon layer. It is important to note that within the scope of the invention, the order in which these layers are formed can be varied. In other words, either the anode or the cathode may be formed before the other. Of course, the electrolyte is formed such that it is between the anode and the cathode. The barrier layer(s), catalyst layer(s), and interconnect(s) are formed to be present in appropriate positions within the fuel cell to perform their functions.

[0328] In some embodiments, each of the interconnect, anode, electrolyte, and cathode has six faces. In a preferred embodiment, the anode is printed on the interconnect and in contact with the interconnect; the electrolyte is printed on the anode and in contact with the anode; the cathode is printed on the electrolyte and in contact with the electrolyte. Each print can be sintered, for example, using EMR. As such, the assembly process and the forming process occur simultaneously, which is not possible with conventional methods. Moreover, with the preferred embodiment, the required electrical contact and airtightness are also achieved simultaneously. In contrast, conventional fuel cell assembly processes achieve this by pressurizing or compressing the fuel cell components or layers. The pressurization or compression process can cause undesirable cracks in the fuel cell layers.

[0329] In some embodiments, the AM method includes manufacturing at least one barrier layer using AMM. In a preferred embodiment, at least one barrier layer can be disposed between the electrolyte and the cathode or between the electrolyte and the anode or both. In other embodiments, at least one barrier layer can be assembled with the anode, electrolyte, and cathode using AMM. In some embodiments, the barrier layer is not required or used in the fuel cell.

[0330] In some embodiments, the AM method includes manufacturing the interconnect using AMM. In other embodiments, the interconnect can be assembled with the anode, electrolyte, and cathode using AMM. In some embodiments, AMM forms a catalyst and incorporates the catalyst into the fuel cell.

[0331] In some embodiments, the anode, electrolyte, cathode, and interconnect are manufactured at a temperature exceeding 100°C. In some embodiments, the AM method includes heating a fuel cell, the fuel cell including an anode, electrolyte, cathode, interconnect, and optionally at least one barrier layer. In some embodiments, the fuel cell includes a catalyst. In some embodiments, the method includes heating the fuel cell to a temperature exceeding 500°C. In some embodiments, the fuel cell is heated using one or both of EMR or oven curing.

[0332] In a preferred embodiment, the AMM utilizes a multi-nozzle additive manufacturing method. In a preferred embodiment, the multi-nozzle additive manufacturing method includes nanoparticle injection. In some embodiments, a first nozzle delivers a first material, a second nozzle delivers a second material, and a third nozzle delivers a third material. In some embodiments, particles of a fourth material are disposed in contact with a partially constructed fuel cell and adhered to the partially constructed fuel cell using laser, photoelectric effect, light, heat, polymerization, or bonding. In one embodiment, the anode, or cathode, or electrolyte includes the first, second, third, or fourth material. In a preferred embodiment, the AMM implements multiple AM techniques. In various embodiments, the AM techniques include one or more of extrusion, photopolymerization, powder bed fusion bonding, material jetting, binder jetting, directed energy deposition, or lamination. In various embodiments, the AM is a deposition technique including material jetting, binder jetting, inkjet printing, aerosol jetting, or aerosol jet printing, vat photopolymerization, powder bed fusion bonding, material extrusion, directed energy deposition, sheet lamination, ultrasonic inkjet printing, or combinations thereof.

[0333] An AM method for manufacturing a fuel cell stack is further described herein, comprising: (a) generating an anode using an additive manufacturing machine (AMM); (b) fabricating an electrolyte using the AMM; (c) manufacturing a cathode using the AMM; (d) manufacturing an interconnect using the AMM, wherein the anode, electrolyte, cathode, and interconnect form a first fuel cell; (e) repeating steps (a)-(d) to manufacture a second fuel cell; and (f) assembling the first fuel cell and the second fuel cell into a fuel cell stack.

[0334] In some embodiments, the first fuel cell and the second fuel cell are formed from an anode, an electrolyte, a cathode, and an interconnect using the AMM. In one embodiment, the fuel cell stack is formed using only the AMM. In other embodiments, steps (a)-(f) exclude one or both of tape casting and screen printing.

[0335] In some embodiments, the AM method includes manufacturing at least one barrier layer using the AMM. In some embodiments, the at least one barrier layer is disposed between the electrolyte and the cathode or between the electrolyte and the anode or both, for the first fuel cell and the second fuel cell.

[0336] In some embodiments, steps (a)-(d) are performed at a temperature above 100 °C. In other embodiments, steps (a)-(d) are performed at a temperature of 100 °C to 500 °C. In some embodiments, the AMM manufactures a catalyst and incorporates the catalyst into the fuel cell stack.

[0337] In some embodiments, the AM method includes heating the fuel cell stack. In one embodiment, the AM method includes heating the fuel cell stack to a temperature above 500°C. In some embodiments, the fuel cell stack is heated using EMR or oven curing. In some embodiments, the laser has a laser beam, and the laser beam is expanded to produce a heating zone having a uniform power density. In some embodiments, the laser beam is expanded by using one or more mirrors. In some embodiments, each layer of the fuel cell is cured separately by EMR. In some embodiments, a combination of one or more fuel cell layers can be cured together by EMR. In some embodiments, the first fuel cell is EMR cured, assembled with the second fuel cell, and then the second fuel cell is EMR cured. In other embodiments, the first fuel cell is assembled with the second fuel cell, and then the first fuel cell and the second fuel cell are cured separately by EMR. In some embodiments, the first fuel cell and the second fuel cell can be cured separately by EMR and then the first fuel cell is assembled with the second fuel cell to form a fuel cell stack. In some embodiments, the first fuel cell is assembled with the second fuel cell to form a fuel cell stack, and then the fuel cell stack can be cured by EMR.

[0338] Also described herein is an AM method for manufacturing a multi-fuel cell comprising: (a) simultaneously generating multiple anodes using an additive manufacturing machine (AMM); (b) fabricating multiple electrolytes simultaneously using the AMM; and (c) manufacturing multiple cathodes simultaneously using the AMM. In preferred embodiments, the anode, electrolyte, and cathode are simultaneously assembled into a fuel cell using the AMM. In other preferred embodiments, the fuel cell is formed using only the AMM.

[0339] In some embodiments, the method includes manufacturing at least one barrier layer for each of the multiple fuel cells using an additive manufacturing machine (AMM) simultaneously. The at least one barrier layer can be disposed between the electrolyte and the cathode, or between the electrolyte and the anode, or both. In a preferred embodiment, the at least one barrier layer can be assembled for each fuel cell using an AMM together with the anode, electrolyte, and cathode.

[0340] In some embodiments, the method includes manufacturing interconnects for each of the multiple fuel cells using an AMM simultaneously. The interconnects can be assembled for each fuel cell using an AMM together with the anode, electrolyte, and cathode. In other embodiments, the AMM forms a catalyst and incorporates the catalyst into each of the fuel cells for each of the multiple fuel cells simultaneously. In other embodiments, the heating of each layer or the combination of layers of the multiple fuel cells occurs simultaneously. The multiple fuel cells can include two or more fuel cells.

[0341] In a preferred embodiment, the AMM uses two or more different nozzles for simultaneously injecting or printing different materials. In a first example, in the AMM, simultaneously, the first nozzle deposits an anode layer for fuel cell 1, the second nozzle deposits a cathode layer for fuel cell 2, and the third nozzle deposits an electrolyte for fuel cell 3. In a second example, in the AMM, simultaneously, the first nozzle deposits an anode for fuel cell 1, the second nozzle deposits a cathode for fuel cell 2, the third nozzle deposits an electrolyte for fuel cell 3, and the fourth nozzle deposits an interconnect for fuel cell 4.

[0342] An additive manufacturing machine (AMM) including a chamber in which the manufacturing of the fuel cells occurs is disclosed herein. The chamber can withstand a temperature of at least 100 °C. In one embodiment, the chamber enables the production of fuel cells. The chamber enables in-situ heating of the fuel cells when the components of the fuel cells are deposited.

[0343] In some embodiments, the chamber can be heated by a laser, electromagnetic wave / electromagnetic radiation (EMR), a thermal fluid, or a heating element associated with the chamber, or a combination thereof. The heating element can include a heating surface, a heating coil, or a heating rod. In other embodiments, the chamber is configured to apply pressure to an inner fuel cell. The pressure can be applied via a movable part associated with the chamber. The movable part can be a movable stamp or a plunger. In some embodiments, the chamber is configured to withstand pressure. The chamber can be configured to be pressurized or depressurized by a fluid. The fluid within the chamber can be changed or replaced when necessary.

[0344] In some cases, the chamber can be enclosed. In some cases, the chamber can be sealed. In some cases, the chamber can be open to the ambient atmosphere or a controlled atmosphere. In some cases, the chamber can be a platform without an upper wall and side walls.

[0345] Referring to FIG. 16, system 1600 includes a deposition nozzle or material injection nozzle 1601, an EMR source 1602 (e.g., a xenon lamp), an object 1603 to be formed, and a chamber or receiver 1604 as part of the AMM. As shown in FIG. 16, the chamber or receiver 1604 is configured to receive both the deposit from the nozzle and the radiation from the EMR source 1602. In various embodiments, the deposition nozzle 1601 can be movable. In various embodiments, the chamber or receiver 1604 can be movable. In various embodiments, the EMR source 1602 is movable. In various embodiments, the object includes a catalyst, a catalyst support, a catalyst composite, an anode, a cathode, an electrolyte, an electrode, an interconnect, a seal, a fuel cell, an electrochemical gas generator, an electrolyzer, an electrochemical compressor, a reactor, a heat exchanger, a container, or a combination thereof.

[0346] AM technologies suitable for this disclosure include extrusion, photopolymerization, powder bed fusion, material jetting, binder jetting, directed energy deposition, and lamination. In some embodiments, extrusion can be used for AM. Extrusion AM involves spatially controlled deposition of a material (e.g., a thermoplastic). Extrusion AM can also be referred to in this disclosure as fused filament fabrication (FFF) or fused deposition modeling (FDM).

[0347] In some embodiments, AM includes photopolymerization (i.e., stereolithography (SLA)) for the processes of this disclosure. SLA involves spatially defined curing of a photoactive liquid (“photoresin”) using a scanning laser or high-resolution projected image and converting the photoactive liquid to a crosslinked solid. Photopolymerization can produce parts with features and dimensions in the range of micrometers to meters.

[0348] In some embodiments, AM includes powder bed fusion (PBF). The PBF AM process builds an object by melting a powdered feedstock, e.g., a polymer or a metal. The PBF process starts by spreading a thin layer of powder across the build area. The cross-section is then melted, one layer at a time, most often using a laser, an electron beam, or a high-intensity infrared lamp. In some embodiments, metal PBF can use selective laser melting (SLM) or electron beam melting (EBM). In other embodiments, polymer PBF can use selective laser sintering (SLS). In various embodiments, an SLS system can print thermoplastic polymer materials, polymer composites, or ceramics. In various embodiments, an SLM system can be suitable for various pure metals and alloys, and the alloys are compatible with the rapid solidification that occurs in SLM.

[0349] In some embodiments, AM may include material jetting. AM by material jetting can be achieved by depositing small droplets (or liquid droplets) of material through spatial control. In various embodiments, material jetting is performed three-dimensionally (3D), two-dimensionally (2D), or both. In preferred embodiments, 3D jetting is achieved layer by layer. In preferred embodiments, print creation converts computer-aided design (CAD), along with specifications of material composition, color, and other variables, into printing instructions for each layer. Binder jetting AM includes inkjet deposition of a liquid binder onto a powder bed. In some cases, binder jetting is combined with other AM processes, such as spreading powder to create a powder bed (similar to SLS / SLM), and inkjet printing.

[0350] In some embodiments, AM may include directed energy deposition (DED). Instead of using the powder bed described above, the DED process uses a directed stream of powder or wire feed along with an energy-intensive source such as a laser, electric arc, or electron beam. In preferred embodiments, DED is a direct writing process where the location of material deposition is determined by the movement of the deposition head, which enables large metal structures to be built without the constraints of a powder bed.

[0351] In some embodiments, AM may include laminated AM, or laminated object manufacturing (LOM). In preferred embodiments, successive layers of sheet material are successively adhered and cut to form a 3D structure.

[0352] Conventional methods of manufacturing a fuel cell stack may include over 100 steps. These steps include, but are not limited to, milling, grinding, filtering, analyzing, mixing, binding, evaporating, aging, drying, extruding, rolling, tape casting, screen printing, stacking, heating, pressing, sintering, and compressing. The methods disclosed herein describe the manufacture of a fuel cell or fuel cell stack using one AMM.

[0353] The AMM of this disclosure preferably performs both extrusion and inkjet printing to manufacture a fuel cell or a fuel cell stack. Extrusion can be used to manufacture thicker layers of the fuel cell, such as the anode and / or cathode. Inkjet printing can be used to manufacture thin layers of the fuel cell. Inkjet printing can be used to manufacture the electrolyte. The AMM can operate in a temperature range sufficient to enable curing within the AMM itself. Such a temperature range is 100 °C or higher, 100 °C - 300 °C or 100 °C - 500 °C.

[0354] As a preferred example, all layers of the fuel cell are formed and assembled by printing. The materials for manufacturing the anode, cathode, electrolyte, and interconnect can each be made in the form of an ink containing a solvent and particles (e.g., nanoparticles). There are two categories of ink formulations - aqueous inks and non-aqueous inks. In some cases, aqueous inks contain an aqueous solvent (e.g., water, deionized water), particles, a dispersant, and a surfactant. In some cases, aqueous inks contain an aqueous solvent, particles, a dispersant, and a surfactant but do not contain a polymer binder. Aqueous inks optionally can contain a co-solvent, such as an organic miscible solvent (methanol, ethanol, isopropyl alcohol). Such a co-solvent preferably has a boiling point lower than water. The dispersant can be an electrostatic dispersant, a steric dispersant, an ionic dispersant, or a non-ionic dispersant, or a combination thereof. The surfactant is preferably non-ionic, e.g., an alcohol alkoxylate or an alcohol ethoxylate. Non-aqueous inks can contain an organic solvent (e.g., methanol, ethanol, isopropyl alcohol, butanol) and particles.

[0355] For example, CGO powder is mixed with water to form an aqueous ink that further contains a dispersant and a surfactant but does not contain a polymer binder. The CGO ratio based on mass (expressed herein as weight % (wt%)) is in the range of 10 wt% to 25 wt%. For example, CGO powder is mixed with ethanol to form a non-aqueous ink that further contains added polyvinyl butaryl, and the CGO ratio is in the range of 3 wt% to 30 wt%. For example, LSCF is mixed with n-butanol or ethanol to form a non-aqueous ink that further contains polyvinyl butaryl, and the LSCF ratio is in the range of 10 wt% to 40 wt%. For example, YSZ particles are mixed with water to form an aqueous ink that further contains a dispersant and a surfactant but does not contain a polymer binder. The YSZ ratio is in the range of 3 wt% to 40 wt%. For example, NiO particles are mixed with water to form an aqueous ink that further contains a dispersant and a surfactant but does not contain a polymer binder, and the NiO ratio is in the range of 5 wt% to 25 wt%.

[0356] As an example, for the cathode of a fuel cell, LSCF or LSM particles are dissolved in a solvent, and the solvent is water or alcohol (e.g., butanol) or a mixture of alcohols. In other examples, organic solvents other than alcohol can also be used. As an example, LSCF is deposited (e.g., printed) onto a layer. A xenon lamp can be used to irradiate the LSCF layer with EMR to sinter the LSCF. The xenon flash lamp can be a 10 kW unit applied at a voltage of 400 V and a frequency of 10 Hz during a total exposure period of 1000 ms.

[0357] For example, regarding electrolytes, the YSZ particles are mixed with a solvent, and the solvent is water (e.g., deionized water) or alcohol (e.g., butanol) or a mixture of alcohols. In other examples, organic solvents other than alcohols can also be used. Regarding the interconnect, metal particles (e.g., silver nanoparticles) are dissolved in a solvent, and the solvent can include water (e.g., deionized water) and an organic solvent. The organic solvent can include mono, di, or triethylene glycol or higher ethylene glycols, propylene glycol, 1,4-butanediol or ethers of such glycols, thiodiglycol, glycerol and its ethers and esters, polyglycerol, mono, di, and triethanolamine, propanolamine, N,N-dimethylformamide, dimethyl sulfoxide, dimethylacetamide, N-methylpyrrolidone, 1,3-dimethylimidazolidone, methanol, ethanol, isopropanol, n-propanol, diacetone alcohol, acetone, methyl ethyl ketone or propylene carbonate, or combinations thereof. Regarding the barrier layer in a fuel cell, the CGO particles are dissolved in a solvent, and the solvent can be water (e.g., deionized water) or alcohol. The alcohol can include methanol, ethanol, butanol or a mixture of alcohols. Organic solvents other than alcohols can also be used. CGO can be used as a barrier layer for LSCF. YSZ can also be used as a barrier layer for LSM. In some cases, for aqueous inks where water is the solvent, a polymer binder may not need to be added to the aqueous ink.

[0358] Conventional fuel cell manufacturing processes sometimes involve over 100 steps and use dozens of machines. According to one embodiment of this disclosure, a method of manufacturing a fuel cell includes manufacturing the fuel cell using only one AMM, and the fuel cell includes an anode, an electrolyte, and a cathode. In a preferred embodiment, the fuel cell includes at least one barrier layer, for example, between the electrolyte and the cathode, or between the electrolyte and the cathode, or both. The at least one barrier layer is also preferably manufactured by the same AMM. In a preferred embodiment, the AMM can also generate an interconnect and assemble the interconnect together with the anode, cathode, at least one barrier layer, and electrolyte. Such manufacturing methods and systems are applicable not only to the manufacture of fuel cells but also to the manufacture of other types of electrochemical devices. The following discussion uses fuel cells as an example, but any reactor or catalyst is within the scope of this disclosure.

[0359] In various embodiments, a single AMM manufactures a first fuel cell, and the fuel cell includes an anode, an electrolyte, a cathode, at least one barrier layer, and an interconnect. In various embodiments, a single AMM manufactures a second fuel cell. In various embodiments, a single AMM is used to assemble the first fuel cell together with the second fuel cell to form a fuel cell stack. In various embodiments, the generation of fuel cells using AMM can be repeated as many times as desired. A fuel cell stack including two or more fuel cells is thus assembled using AMM. In some embodiments, the various layers of the fuel cell are generated by AMM above ambient temperature. For example, the temperature may be above 100°C, in the range of 100°C to 500°C, or in the range of 100°C to 300°C. In various embodiments, the fuel cell or fuel cell stack is heated after it is assembled. In some embodiments, the fuel cell or fuel cell stack is heated at a temperature above 500°C. In a preferred embodiment, the fuel cell or fuel cell stack is heated at a temperature in the range of 500°C to 1500°C.

[0360] In various embodiments, the AMM includes a chamber in which the manufacturing of the fuel cell takes place. This chamber can withstand the high temperatures that enable the generation of the fuel cell, where the high temperature is at least 300 °C, at least 500 °C, at least 1000 °C or at least 1500 °C. In some cases, this chamber also enables the heating of the fuel cell to occur within the chamber. Various heating methods can be applied, such as laser heating / curing, electromagnetic wave heating, thermal fluid heating or one or more heating elements associated with the chamber. The heating element can be a heating surface, a heating coil or a heating rod and is associated with the chamber such that the contents within the chamber are heated to the desired temperature range. In various embodiments, the chamber of the AMM can also apply pressure to the inner fuel cell(s). For example, the pressure can be applied via a movable part such as a movable stamp or plunger. In various embodiments, the chamber of the AMM can withstand pressure. The chamber can be pressurized or depressurized as desired by a fluid. The fluid within the chamber can also be changed or replaced as needed.

[0361] In a preferred embodiment, the fuel cell or fuel cell stack is heated using EMR. In other embodiments, the fuel cell or fuel cell stack may be heated using oven curing. In other embodiments, the laser beam is expanded (e.g., by use of one or more mirrors) to produce a heating zone having a uniform power density. In a preferred embodiment, each layer of the fuel cell can be separately cured by EMR. In a preferred embodiment, a combination of fuel cell layers, e.g., a combination of an anode layer, an electrolyte layer, and a cathode layer, can be separately EMR cured. In some embodiments, the first fuel cell is EMR cured, assembled with the second fuel cell, and then the second fuel cell is EMR cured. In one embodiment, the first fuel cell is assembled with the second fuel cell, and then the first fuel cell and the second fuel cell are separately EMR cured. In one embodiment, the first fuel cell is assembled with the second fuel cell to form a fuel cell stack, and then the fuel cell stack is EMR cured. A fuel cell stack including two or more fuel cells can be EMR cured. A series of laser heating / curing and assembly is applicable to all other heating methods.

[0362] In a preferred embodiment, the AMM produces each layer of the multiple fuel cells simultaneously. In a preferred embodiment, the AMM assembles each layer of the multiple fuel cells simultaneously. In a preferred embodiment, the heating of each layer of the multiple fuel cells or the heating of a combination of layers occurs simultaneously. All discussions and all features described herein for a fuel cell or fuel cell stack are applicable to the production, assembly, and heating of multiple fuel cells. In a preferred embodiment, the multiplicity of fuel cells can be 2 or more, 20 or more, 50 or more, 80 or more, 100 or more, 500 or more, 800 or more, 1000 or more, 5000 or more, or 10,000 or more.

[0363] Processing process This specification discloses a processing process including one or more of the following effects: heating, drying, curing, sintering, annealing, sealing, alloying, evaporation, reconfiguration, foaming or sintering. The preferred processing process is sintering. The processing process includes exposing a substrate to an electromagnetic radiation (EMR) source. In some embodiments, the EMR is exposed to a substrate having a first material. In various embodiments, the EMR has a peak wavelength in the range of 10 - 1500 nm. In various embodiments, the EMR has a minimum energy density of 0.1 joules / cm 2 One embodiment, the EMR has a burst frequency of 10 -4 -1000 Hz or 1 - 1000 Hz or 10 - 1000 Hz. In one embodiment, the EMR has an exposure distance of 50 mm or less. In one embodiment, the EMR has an exposure period of 0.1 ms or 1 ms or more. In one embodiment, the EMR is applied using a capacitor voltage of 100 V or more. For example, a single pulse of EMR is applied using an exposure distance of about 10 mm and an exposure period of 5 - 20 ms. For example, multiple pulses of EMR are applied at a burst frequency of 100 Hz using an exposure distance of about 10 mm and an exposure period of 5 - 20 ms. In some embodiments, the EMR consists of 1 exposure. In other embodiments, the EMR includes 10 exposures or less, or 100 exposures or less, or 1000 exposures or less, or 10,000 exposures or less.

[0364] In various embodiments, metals and ceramics are sintered almost instantaneously (milliseconds at <<10 microns) using pulsed light. The sintering temperature can be controlled to be in the range of 100 °C to 2000 °C. The sintering temperature can be adjusted as a function of depth. In one example, the surface temperature is 1000 °C, maintained at 100 °C below the surface, and 100 microns below the surface. In some embodiments, suitable materials for this process include yttria-stabilized zirconia (YSZ), 8YSZ (8 mol% YSZ powder), yttrium, zirconium, gadolinia-doped ceria (GDC or CGO), samaria-doped ceria (SDC), scandia-stabilized zirconia (SSZ), lanthanum strontium manganite (LSM), lanthanum strontium cobalt ferrite (LSCF), lanthanum strontium cobaltite (LSC), lanthanum strontium gallium magnesium oxide (LSGM), nickel, NiO, NiO-YSZ, Cu-CGO, Cu2O, CuO, cerium, copper, silver, crofer, steel, lanthanum chromite, doped lanthanum chromite, ferritic steel, stainless steel, or combinations thereof. This process may be suitable for any of the electrode or electrolyte materials previously listed herein.

[0365] This process is applicable in the manufacturing process of fuel cells. In preferred embodiments, the layers in a fuel cell (i.e., anode, cathode, electrolyte, seal, catalyst, etc.) are processed using the processes described herein and heated, cured, sintered, sealed, alloyed, foamed, evaporated, reconfigured, dried, or annealed, or combinations thereof. In preferred embodiments, some of the layers in a fuel cell are processed using the processes described herein and heated, cured, sintered, sealed, alloyed, foamed, evaporated, reconfigured, dried, annealed, or combinations thereof. In preferred embodiments, combinations of layers of a fuel cell are processed using the processes described herein and heated, cured, sintered, sealed, alloyed, foamed, evaporated, reconfigured, dried, annealed, or combinations thereof, and the layers may be full or partial layers.

[0366] The processing process of this disclosure is preferably rapid, with the processing period varying from microseconds to milliseconds. The processing period can be accurately controlled. The processing process of this disclosure can generate a fuel cell layer without cracks or with minimal cracks. The processing process of this disclosure controls the power density or energy density in the processing volume (the volume of the object being processed) of the material being processed. The processing volume can be accurately controlled. In one embodiment, the processing process of this disclosure provides the same energy density or different energy densities in the processing volume. In one embodiment, the processing process of this disclosure provides the same processing period or different processing periods in the processing volume. In one embodiment, the processing process of this disclosure provides simultaneous processing for one or more processing volumes. In one embodiment, the processing process of this disclosure provides simultaneous processing for one or more fuel cell layers or partial layers or combinations of layers. In one embodiment, the processing volume changes by changing the processing depth.

[0367] In one embodiment, the first portion of the processing volume is processed by electromagnetic radiation of a first wavelength; the second portion of the processing volume is processed by electromagnetic radiation of a second wavelength. In some cases, the first wavelength is the same as the second wavelength. In some cases, the first wavelength is different from the second wavelength. In one embodiment, the first portion of the processing volume has a different energy density from the second portion of the processing volume. In one embodiment, the first portion of the processing volume has a different processing period from the second portion of the processing volume.

[0368] In one embodiment, the EMR has a broad emission spectrum such that the desired effect is achieved for a wide range of materials having different absorption characteristics. In this disclosure, the absorption of electromagnetic radiation (EMR) refers to the process by which the energy of photons is captured by a substance such as the electrons of an atom. Thus, the electromagnetic energy is converted into the internal energy of the absorber, for example, thermal energy. For example, the EMR spectrum extends from the deep ultraviolet (UV) range to the near-infrared (IR) range, and the peak pulse power is at a wavelength of 220 nm. The power of such EMR is on the order of megawatts. Such an EMR source performs tasks such as chemical bond breaking, sintering, ablating, or sterilization.

[0369] In one embodiment, the EMR has an energy density of 0.1, 1, or 10 joules / cm 2 or more. In one embodiment, the EMR has a power output of 1 watt (W), 10 W, 100 W, 1000 W or more. The EMR delivers 1 W, 10 W, 100 W, 1000 W or more of power to the substrate. In one embodiment, such EMR exposure heats the material in the substrate. In one embodiment, the EMR has a range or spectrum of different wavelengths. In various embodiments, the substrate to be processed is at least a part of the anode, cathode, electrolyte, catalyst, barrier layer, or interconnect of a fuel cell.

[0370] In one embodiment, the peak wavelength of the EMR is between 50 and 550 nm or between 100 and 300 nm. In one embodiment, the absorption of at least a part of the substrate for at least one frequency of the EMR between 10 and 1500 nm is 30% or more, or 50% or more. In one embodiment, the absorption of at least a part of the substrate for at least one frequency between 50 and 550 nm is 30% or more, or 50% or more. In one embodiment, the absorption of at least a part of the substrate for at least one frequency between 100 and 300 nm is 30% or more, or 50% or more.

[0371] Sintering is a process of compressing and forming a solid mass of material by heat or pressure without melting it to its melting point. In this disclosure, the substrate under EMR exposure is sintered but not melted. In a preferred embodiment, the EMR includes one or more of UV light, near-ultraviolet light, near-infrared light, infrared light, visible light, laser, electron beam, and microwave. In one embodiment, the substrate is exposed to EMR for 1 microsecond or more, 1 millisecond or more. In one embodiment, the substrate is exposed to EMR for less than 1 second at a time or less than 10 seconds at a time. In one embodiment, the substrate is exposed to EMR for less than 1 second or less than 10 seconds. In one embodiment, the substrate is repeatedly exposed to EMR, for example, more than 1 time, more than 3 times, more than 10 times. In one embodiment, the substrate is separated from the EMR source by less than 50 cm, less than 10 cm, less than 1 cm, or less than 1 mm.

[0372] In some embodiments, after EMR exposure, a second material is added to or disposed on the first material. In various cases, the second material is the same as the first material. The second material can be exposed to EMR. In some cases, a third material can be added. The third material is exposed to EMR.

[0373] In some embodiments, the first material includes YSZ, 8YSZ, yttrium, zirconium, GDC, SDC, LSM, LSCF, LSC, nickel, NiO, or cerium, or a combination thereof. The second material can include graphite. In some embodiments, the electrolyte, anode, or cathode includes the second material. In some cases, the volume fraction of the second material in the electrolyte, anode, or cathode is less than 20%, 10%, 3%, or 1%. The absorption rate of the second material for at least one frequency (for example, between 10 - 1500 nm, between 100 - 300 nm, or between 50 - 550 nm) is more than 30% or more than 50%.

[0374] In various embodiments, one or a combination of parameters can be controlled, such parameters including the distance between the EMR source and the substrate, the energy density of the EMR, the spectrum of the EMR, the voltage of the EMR, the exposure period, the burst frequency, and the number of EMR exposures. Preferably, these parameters are controlled to minimize the formation of cracks in the substrate.

[0375] In one embodiment, the EMR energy is delivered over a surface area of 1 mm 2 or more, or 1 cm 2 or more, or 10 cm 2 or more, or 100 cm 2 or more. In some cases, during the EMR exposure of the first material, at least a portion of an adjacent material is heated at least in part by conduction of heat from the first material. In various embodiments, the layers of the fuel cell (e.g., anode, cathode, electrolyte) are thin. Preferably, they are 30 microns or less, 10 microns or less, or 1 micron or less.

[0376] In some embodiments, the first material of the substrate is in the form of a powder, sol-gel, colloidal suspension, hybrid solution, or sintered material. In various embodiments, the second material can be added by vapor deposition. In preferred embodiments, the second material coats the first material. In preferred embodiments, the second material reacts with light (e.g., focused light), such as by a laser, and is sintered or annealed with the first material.

[0377] Advantages The preferred processing process of this disclosure enables the rapid manufacture of fuel cells by eliminating conventional, costly, time-consuming, and expensive sintering processes and replacing them with a rapid in-situ method that enables the continuous manufacture of the layers of the fuel cell in a single machine if desired. This process also shortens the sintering time from hours and days to seconds or milliseconds and even microseconds.

[0378] In various embodiments, this processing method is used in combination with manufacturing techniques such as screen printing, tape casting, spraying, sputtering, physical vapor deposition, and additive manufacturing.

[0379] This preferred processing method enables adjusted and controlled heating by adjusting EMR characteristics (e.g., wavelength, energy density, burst frequency, and exposure period) in combination with controlling the layer thickness of the substrate and heat conduction to adjacent layers, allowing each layer to be sintered, annealed, or cured at each desired target temperature. This process enables more uniform energy application, reducing or eliminating cracks, which improves electrolyte performance. Substrates processed with this preferred process also have less thermal stress due to more uniform heating.

[0380] Particle Size Control Although not wishing to be bound by any theory, we have unexpectedly discovered that the sintering process may require much less energy consumption and much less time than traditionally required when the particle size distribution of the particles in the material is controlled to meet certain criteria. In some cases, such a particle size distribution includes D10 and D90, 10% of the particles have a diameter of D10 or less, 90% of the particles have a diameter of D90 or less, and D90 / D10 is in the range of 1.5 to 100. In some cases, such a particle size distribution is bimodal, so the average particle size in the first mode is at least 5 times the average particle size in the second mode. In some cases, such a particle size distribution includes D50, 50% of the particles have a diameter of D50 or less, and D50 is 100 nm or less. The sintering process utilizes electromagnetic radiation (EMR), or plasma, or a furnace, or a heat fluid, or a heating element, or a combination thereof. Preferably, the sintering process utilizes electromagnetic radiation (EMR). For example, an EMR source just sufficient to sinter a material without using the process disclosed herein has a power capacity P. Using the process disclosed herein, the material is sintered using an EMR source having a much lower power capacity, for example, 50%P or less, 40%P or less, 30%P or less, 20%P or less, 10%P or less, 5%P or less.

[0381] Disclosed herein is a method of sintering a material, including mixing particles with a liquid to form a dispersion, wherein the particles have a particle size distribution including D10 and D90, 10% of the particles have a diameter of D10 or less, 90% of the particles have a diameter of D90 or less, and D90 / D10 is in the range of 1.5 to 100; depositing the dispersion on a substrate to form a layer; and treating the layer to sinter at least a portion of the particles.

[0382] In some embodiments, the particle size distribution is a number distribution determined by dynamic light scattering. Dynamic light scattering (DLS) is a technique that can be used to determine the size distribution profile of small particles in a dispersion or suspension. In the DLS range, temporal fluctuations are typically analyzed by intensity or photon autocorrelation function (also known as photon correlation spectroscopy or quasi-elastic light scattering). In time-domain analysis, the autocorrelation function (ACF) usually starts at zero delay time and decays, and faster dynamics due to smaller particles result in faster decorrelation of the scattering intensity trace. The intensity ACF has been shown to be the Fourier transform of the power spectrum, and thus DLS measurements can be equally well performed in the spectral domain.

[0383] In one embodiment, the particle size distribution is determined by transmission electron microscopy (TEM). TEM is a microscopy technique in which an electron beam is transmitted through a specimen to form an image. In this case, the specimen is most often a suspension on a grid. The image is formed from the interaction of the electrons with the specimen as the beam is transmitted through the specimen. The image is then magnified and focused onto a sensor such as an imaging device like a fluorescent screen or a scintillator coupled to a charge-coupled device.

[0384] Disclosed herein is a method of sintering a material, including: mixing particles with a liquid to form a dispersion, wherein the particles have a particle size distribution including D50, 50% of the particles have a diameter less than or equal to D50, and D50 is less than or equal to 100 nm; depositing the dispersion onto a substrate to form a layer; and treating the layer to sinter at least a portion of the particles. In various embodiments, D50 is less than or equal to 50 nm, or less than or equal to 30 nm, or less than or equal to 20 nm, or less than or equal to 10 nm, or less than or equal to 5 nm. In one embodiment, the layer has a thickness of less than or equal to 1 mm or less than or equal to 500 microns or less than or equal to 300 microns or less than or equal to 100 microns or less than or equal to 50 microns.

[0385] In some embodiments, depositing the material includes spraying, binder jetting, inkjet printing, aerosol jetting, or aerosol jet printing, vat photopolymerization, powder bed fusion, material extrusion, directed energy deposition, sheet lamination, ultrasonic inkjet printing, or combinations thereof. In some embodiments, the liquid includes water and at least one organic solvent having a boiling point lower than water and being miscible with water. In some embodiments, the liquid includes water, a surfactant, a dispersant, and does not include a polymer binder. In some embodiments, the liquid includes one or more organic solvents and does not include water. In some embodiments, the particles include Cu, CuO, Cu2O, Ag, Ag2O, Au, Au2O, Au2O3, titanium, yttria-stabilized zirconia (YSZ), 8YSZ (8 mol% YSZ powder), yttrium, zirconium, gadolinia-doped ceria (GDC or CGO), samaria-doped ceria (SDC), scandia-stabilized zirconia (SSZ), lanthanum strontium manganite (LSM), lanthanum strontium cobalt ferrite (LSCF), lanthanum strontium cobaltite (LSC), lanthanum strontium gallium magnesium oxide (LSGM), nickel (Ni), NiO, NiO-YSZ, Cu-CGO, cerium, crofer, steel, lanthanum chromite, doped lanthanum chromite, ferritic steel, stainless steel, or combinations thereof. The particles can include any of the materials previously listed herein for electrodes or electrolytes.

[0386] In some embodiments, the particles have a bimodal particle size distribution, and the average particle size in the first mode is at least 5 times the average particle size in the second mode. In some embodiments, D10 is in the range of 5 nm to 50 nm or 5 nm to 100 nm or 5 nm to 200 nm. In some embodiments, D90 is in the range of 50 nm to 500 nm or 50 nm to 1000 nm. In some embodiments, D90 / D10 is in the range of 2 to 100 or 4 to 100 or 2 to 20 or 2 to 10 or 4 to 20 or 4 to 10.

[0387] In some embodiments, the method includes drying the dispersion after deposition. In some embodiments, drying includes heating the dispersion before deposition, heating the substrate in contact with the dispersion, or a combination thereof. Drying can occur for a period ranging from 1 ms to 1 minute or 1 second to 30 seconds or 3 seconds to 10 seconds. In some embodiments, the dispersion can be deposited at a temperature ranging from 40°C to 100°C or 50°C to 90°C or 60°C to 80°C or about 70°C.

[0388] In some embodiments, the treatment includes the use of electromagnetic radiation (EMR), or a furnace, or a plasma, or a thermal fluid, or a heating element, or a combination thereof. In some embodiments, the EMR includes UV light, near-ultraviolet light, near-infrared light, infrared light, visible light, a laser, an electron beam or a microwave or a combination thereof. In one embodiment, the EMR is composed of 1 exposure. In other embodiments, the EMR has an exposure frequency of 10 -4 -1000 Hz or 1 - 1000 Hz or 10 - 1000 Hz. In one embodiment, the EMR has an exposure distance of 50 mm or less. In one embodiment, the EMR has an exposure period of 0.1 ms or 1 ms or more. In one embodiment, the EMR is applied using a capacitor voltage of 100 V or more.

[0389] Examples The following examples are provided as part of the disclosure of various embodiments of the present invention. As such, none of the information provided below should be construed as limiting the scope of the invention.

[0390] Example 1. Manufacture of an EC Reactor Stack Example 1 describes a preferred method for manufacturing an EC reactor stack, for example, a fuel cell stack. The method uses an AMM model no. 0012323 manufactured by Ceradrop and an EMR model no. 092309423 manufactured by Xenon. The interconnect substrate is placed and printing is started.

[0391] As a first step, the anode layer is manufactured by AMM. This layer is deposited by AMM as slurry A having the composition shown in the table below. This layer is dried by applying heat with an infrared lamp. This anode layer is sintered by irradiating it with electromagnetic pulses from a xenon flash lamp for 1 second.

[0392] The electrolyte layer is formed on the upper surface of the anode layer by AMM that deposits slurry B having the composition shown in the table below. This layer is dried by applying heat with an infrared lamp. This electrolyte layer is sintered by irradiating it with electromagnetic pulses from a xenon flash lamp for 60 seconds.

[0393] Next, the cathode layer is formed on the upper surface of the electrolyte layer by AMM that deposits slurry C having the composition shown in the table below. This layer is dried by applying heat with an infrared lamp. This cathode layer is sintered by irradiating it with electromagnetic pulses from a xenon flash lamp for 1 / 2 second.

[0394] The interconnect layer is formed on the upper surface of the cathode layer by AMM that deposits slurry D having the composition shown in the table below. This layer is dried by applying heat with an infrared lamp. This interconnect layer is sintered by irradiating it with electromagnetic pulses from a xenon flash lamp for 30 seconds.

[0395] These steps are then repeated 60 times, and the anode layer is formed on the upper surface of the interconnect. The result is a fuel cell stack having 61 fuel cells.

Table 1

[0396] Example 2. LSCF in ethanol Mix 200 ml of ethanol with 30 grams of LSCF powder in a beaker. Centrifuge the mixture to obtain an upper dispersion and a lower dispersion. Take out the upper dispersion and deposit it on a substrate using a 3D printer to form an LSCF layer. Use a xenon lamp (10 kW) to irradiate the LSCF layer at a voltage of 400 V and a burst frequency of 10 Hz during a total exposure period of 1,000 ms.

[0397] Example 3. CGO in Ethanol Mix 200 ml of ethanol with 30 grams of CGO powder in a beaker. Centrifuge the mixture to obtain an upper dispersion and a lower dispersion. Take out the upper dispersion and deposit it on a substrate using a 3D printer to form a CGO layer. Use a xenon lamp (10 kW) to irradiate the CGO layer at a voltage of 400 V and a burst frequency of 10 Hz during a total exposure period of 8,000 ms.

[0398] Example 4. CGO in Water Mix 200 ml of deionized water with 30 grams of CGO powder in a beaker. Centrifuge the mixture to obtain an upper dispersion and a lower dispersion. Take out the upper dispersion and deposit it on a substrate using a 3D printer to form a CGO layer. Use a xenon lamp (10 kW) to irradiate the CGO layer at a voltage of 400 V and a burst frequency of 10 Hz during a total exposure period of 8,000 ms.

[0399] Example 5. NiO in Water Mix 200 ml of deionized water with 30 grams of NiO powder in a beaker. Centrifuge the mixture to obtain an upper dispersion and a lower dispersion. Take out the upper dispersion and deposit it on a substrate using a 3D printer to form a NiO layer. Use a xenon lamp (10 kW) to irradiate the NiO layer at a voltage of 400 V and a burst frequency of 10 Hz during a total exposure period of 15,000 ms.

[0400] Example 6. Sintering Results Figure 17 is a scanning electron microscope image (side view). Figure 17 shows the sintered electrolyte (YSZ) 1701 printed on the electrode (NiO-YSZ) 1702. The scanning electron microscope image shows a side view of the sintered structure, which demonstrates the airtight contact between the electrolyte and the electrode, the complete densification of the electrolyte, and the sintered porous electrode microstructure.

[0401] Example 7. Fuel Cell Stack Structure The 48-volt fuel cell stack has 69 cells with a power output of approximately 1000 watts. The fuel cells in this stack have dimensions of approximately 4 cm × 4 cm in length × width and approximately 7 cm in height. The 48-volt fuel cell stack has 69 cells with a power output of approximately 5000 watts. The fuel cells in this stack have dimensions of approximately 8.5 cm × 8.5 cm in length × width and approximately 0.7 cm in height.

[0402] Example 8. Grooved Electrode / Fluid Dispersion Component FIG. 18 schematically shows an example of a half-cell in an EC reactor. As shown in FIG. 18, the half-cell 1700 includes an interconnect 1801. The interconnect 1801 includes doped lanthanum chromite. The half-cell 1800 includes an anode segment 1802 printed on the interconnect 1801. The anode segment is composed of NiO-YSZ. The anode segment 1802 is sintered using EMR (see Example 1). The half-cell 1800 includes a filler material deposited between the anode segments 1802. The filler material is polymethyl methacrylate (PMMA). The half-cell 1800 includes a shield 1804 printed on a filler material 1803 composed of YSZ. An additional anode material 1806 is printed to cover the anode segment 1802 and the shield 1804, and then sintered using EMR. The additional anode material is NiO-YSZ. The electrolyte 1805 is printed on the additional anode material 1806 and sintered using EMR. The electrolyte 1805 is YSZ. A barrier layer (not shown) composed of CGO is further printed on the electrolyte and sintered using EMR. A layer of cathode composed of LSCF (not shown) is printed on the CGO barrier and sintered. A cathode segment composed of LSCF (not shown) is printed on this layer and sintered. These segments form valleys, and the filler PMMA is deposited to fill these valleys (not shown). A shield composed of YSZ is printed on the filler (not shown). Doped lanthanum chromite is printed to cover the shield and the cathode segment, and then sintered to form another interconnect (not shown). The filler is removed by furnace heating to generate a grooved electrode, or a fluid dispersion component is formed between the electrolyte and the interconnect (not shown).

[0403] It should be understood that this disclosure describes exemplary embodiments for performing different features, structures, or functions of the invention. Exemplary embodiments of components, arrangements, and structures are described to simplify the present disclosure; however, these exemplary embodiments are provided merely as examples and are not intended to limit the scope of the invention. The embodiments presented herein can be combined if not otherwise specified. Such combinations do not depart from the scope of the present disclosure.

[0404] In addition, certain terms are used throughout the description and claims to denote specific components or steps. As will be recognized by those skilled in the art, different entities can refer to the same component or process step by different names, and as such, the naming convention for the elements described herein is not intended to limit the scope of the invention. Further, the terms and naming conventions used herein are not intended to distinguish between components, features, and / or steps that have different names but perform the same function.

[0405] This disclosure is susceptible to various modifications and alternative forms, and specific embodiments thereof are shown by way of example in the drawings and description. However, the drawings and detailed description are not intended to limit the disclosure to the particular forms disclosed, but on the contrary, are intended to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the disclosure.

Claims

Claim 1 A method of producing hydrogen, comprising providing a device, introducing a first stream containing fuel into the device, introducing a second stream containing water into the device, reducing the water in the second stream to hydrogen, and extracting hydrogen from the device, wherein the first stream and the second stream do not contact each other within the device. Claim 2 The method according to claim 1, wherein the first stream does not contact the hydrogen. Claim 3 The method according to claim 1, wherein the first stream and the second stream are separated by an electrolyte within the device. Claim 4 The method according to claim 3, wherein the electrolyte is oxide ion conductive and in a solid state. Claim 5 The method according to claim 3, wherein the electrolyte comprises doped ceria or the electrolyte comprises a material selected from the group consisting of lanthanum chromite or a conductive metal or combinations thereof and doped ceria, YSZ, LSMG, SSZ, and combinations thereof. Claim 6 The method according to claim 5, wherein the lanthanum chromite comprises undoped lanthanum chromite, strontium-doped lanthanum chromite, iron-doped lanthanum chromite, lanthanum calcium chromite, or combinations thereof; and wherein the conductive metal comprises Ni, Cu, Ag, Au, or combinations thereof. Claim 7 The method according to claim 4, wherein the electrolyte also conducts electrons and the device does not include an interconnect. Claim 8 The method according to claim 1, wherein the device is tubular. Claim 9 The method according to claim 1, wherein the fuel comprises a hydrocarbon or hydrogen or carbon monoxide or combinations thereof. Claim 10 The method according to claim 1, wherein the second stream contains hydrogen. Claim 11 The method according to claim 1, wherein the first stream further comprises water or carbon dioxide. Claim 12 The method according to claim 1, wherein the first stream comprises a fuel having little to no water. Claim 13 The method according to claim 1, wherein the device is planar. Claim 14 The method according to claim 13, wherein the device comprises a plurality of repeating units separated by interconnects, each repeating unit comprising two electrodes together with an electrolyte between the electrodes. Claim 15 The method of claim 14, wherein the electrode comprises a fluid channel or a fluid dispersion component and the interconnect does not comprise a fluid dispersion element. **Claim 16** The method of claim 1, comprising introducing the first stream into a reformer before the first stream enters the apparatus. **Claim 17** The method of claim 16, wherein the reformer is a steam reformer or an autothermal reformer. **Claim 18** The method of claim 1, wherein the apparatus is operated at a temperature of 500 °C or higher. **Claim 19** The method of claim 1, wherein the apparatus comprises a first electrode and a second electrode separated by an electrolyte, and the first electrode or the second electrode comprises a material selected from the group consisting of Ni or NiO and YSZ, CGO, SDC, SSZ, LSMG, and combinations thereof. **Claim 20** The device includes a second electrode separated by a first electrode and an electrolyte, and the first electrode includes a material selected from the group consisting of doped or undoped ceria and Cu, CuO, Cu ２ O, Ag, Ag ２ O, Au, Au ２ O, Au ２ O ３ , Pt, Pd, Ru, Rh, stainless steel, and combinations thereof, according to the method of claim 1. **Claim 21** The method of claim 20, wherein the first electrode comprises a catalyst.

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