MXPA97007329A - Component stacked ion conductor with displacement stamps and polarizac electrodes - Google Patents

Abstract

The present invention relates to an electrochemical device for separating oxygen from an oxygen-containing gas comprising a plurality of planar solid electrolytic plates conductive to the ions and electrically conductive gas-impermeable interconnects assembled in a stacked multi-cell component. The anode and electrically conductive cathode material is applied on opposite sides of each electrolytic plate. A gas-tight denode seal is attached between the anode side of each electrolytic plate and the anode side of the adjacent interconnection. A polarization electrode applied to the anode side of each electrolytic plate between the anode seal and the anode edge eliminates the failure of the anode seal by minimizing the electrical potential through the seal. The seal potential is kept below 40 mV and preferably below approximately 25 mV. The gas-tight seal is applied between the cathode sides of each electrolytic plate and the adjacent interconnection so that the anode and cathode seals move quickly on opposite sides of the plate. The combination of the polarization electrodes and the displacement seals is particularly effective in eliminating deo seal failure

Description

COMPONENT STACKED ION CONDUCTOR WITH DISPLACEMENT STAMPS AND POLARIZATION ELECTRODES TECHNICAL FIELD OF THE INVENTION The invention relates to an electromechanical device for the recovery of oxygen from an oxygen-containing gas, and in particular to an improved stacked design designed for a planar series of electrolytic cells. BACKGROUND OF THE INVENTION The inorganic oxide ceramics that conduct ions of certain compositions transport or permeate ions at elevated temperatures, and this phenomenon is the basis for practical applications in cells of electric batteries, gas analysis and monitoring, and the separation of the gas mixtures. In a number of such practical applications, oxygen ions migrate as current under a potential gradient imposed through an electrolyte that conducts ions from the cathode side, where oxygen ions are generated by the reduction of oxygen or other gases , towards the anode or oxygen side, where the oxygen ions are consumed to form oxygen or other gases. The solid electrolytes that conduct oxygen ions can be constructed in multiple monolithic cell configurations or as honeycomb, flat plates The flat plate configuration, in which a plurality of planar electrolytic cells are stacked to operate in electric series, is favored in Many applications to facilitate assembly and compact dimensions. The practical application of ion conducting systems for the separation of gases, without taking into account the design configuration, requires that the cells operate under differential pressure and / or differential gas composition between the feed side (cathode) and the permeation side (anode). In the separation of oxygen from an oxygen-containing gas, for example, the pressure and / or gaseous composition of the oxygen-containing feed gas and the oxygen-depleted discharge gas (also defined as the non-infiltrated gas) may differ from the pressure and / or gaseous composition of the oxygen produced at the anode (also defined as permeation gas), depending on the stacked design and the product requirements. The gas-tight seals between the selected structural components of the system, therefore, require maintaining the purity of the product gas, in case the product is a discharge gas depleted of oxygen or an oxygen with high purity produced at the anode.

A system that conducts oxygen ions having a disk or a planar stacked configuration is described in US Patent 4,885,142 in which the gas containing the oxygen is introduced through the axial feed ports, flows radially through the the electrolyte devices stacked, and discharged through an axially located axial discharge port preferably centrally. The oxygen product is removed through a series of separate axial discharge ports. The product and feed gases are segregated by interengaged parts of the disk assembly, which is described to form a substantially seal relationship. The stacked component operates with a non-differential pressure through the cells and the use of sealants is not disclosed. A similar system is disclosed in the J.W. Suitor et al, entitled "Air Oxygen Separation Using Solid Electrolytic Membranes of Zirconia" in Proceedings of the 23rd Intersociety Energy Conversion Conference (Proceedings of the 23th Energy Conversion Conference Between Society), volume 2, ASME, New York , 1988, pp 273-277 and DJ Clark et al, entitled "Oxygen Separation Using Solid Zirconia Electrolytic Membranes" in the Separation and Purification of Gas, 1992, Volume 6, No. 4, p 201-205. U.S. Patent 5,186,806 discloses a planar solid electrolytic cell configuration in which alternating plates and gas distribution support members are stacked in series. In a configuration, the plates are made of a non-porous material that conducts ions and the support members are made of a non-porous electrically conductive material. A series of ports and protuberances in the support members coincide with the ports in the electrolyte plates to produce a flow configuration in which the supply air flows radially through the cathode sides of the electrolyte plates in a direction towards the inside, and the oxygen depleted air is withdrawn axially through a centrally located duct formed by the congruent ports in the electrolyte plates and support members. The oxygen formed on the anode sides of the electrolytic plates flows radially outward and is withdrawn through a plurality of axial conduits formed by the congruent ports separated in the electrolytic plates and the distribution members. The sealing between the oxygen side and the feed gas sides of the stacked components according to the disclosure is achieved by direct contact between the electrolytic plates and the flat protuberances in the support members, and also in the periphery stacked by the contact between the continuous flat raised rings on the supporting members and the flat electrolytic plates. A sealant is not disclosed in the seal regions formed by direct contact between the regions of the support members and the electrolyte plates. The seal regions formed by the protuberances in contact with the anode side and the cathode side of each electrolytic plate are displaced radially and circumferentially, but the peripheral seals are congruent or directly opposite. In U.S. Patent 5,298,138 an ion conducting device having a plurality of electrolytic plates in a stacked configuration is disclosed, in which the electrically conducting support interconnections are not used. The electrolytic plates are separated by alternating separate elaborated from an electrolytic material that is fixed near the edges of the plates by means of a glass sealant to allow the feeding of the transverse flow. While this stacked design is simplified by the elimination of the interconnections, the electrolytic plates are not supported in the central region, which only allows operation at very small pressure differentials between the anode and cathode side of the cells. The Publication of the European Patent Application No. 0 682 379 discloses a series of planar electromechanical devices for gas separation in which alternating electrolytic plates and electrically conductive interconnections are assembled in a stacked configuration. The anode and cathode in the electrical contact with the opposite sides of each electrolytic plate are coextensive radially, ie congruent. The interconnections contain channels designed so that the feed gas flows through the cathode side in the cross flow mode and the oxygen formed on the anode side is withdrawn in a cross flow mode in the direction of flow perpendicular to the flow of gas supply. The interconnections and the electrolytic plates are connected by the glass sealing areas parallel to the channels in the interconnections. The portions of the anode and cathode seals are directly opposite in each electrolytic plate.

A technical report entitled "Stacked Oxygen Separation Cells" from C.J. Morrissey in NASA Tech. Brief, Vol. 15, No. 6, concept # 25, June 1991 describes the planar stacked electrolytic cells comprising the alternating electrolytic plates and the interconnections of the gas distribution. The anode and the cathode in each electrolytic plate are directly opposite through the electrolytic plate and the adjacent interconnections, and the seals are directly opposite through the electrolytic plate, ie they are congruent. The glass seals are used between each electrolytic plate and the adjacent interconnections, and the seals are directly opposite through the electrolytic plate, ie they are congruent. This design includes a non-porous electrically insulating layer located on the edge of the stacked component between the interconnections. Plated stacked electrolytic cells comprise alternate electrolytic plates and interconnections having gas passages recorded in a technical report entitled "Thinner and More Efficient Oxygen Separation Cells" from C.J. Morrissey in NASA Tech Brief, Vol. 17, No. 4, Concept # 100, April 1993. Air is introduced into the cells through multiple tubes that pass through the stacked component that provides power in the flow radial through the cathode sides of the cells. The oxygen-depleted air is withdrawn or withdrawn through a centrally located axial manifold. The oxygen product from the anode sides of the cells is removed through the additional multiple axial tubes which pass through the stacked component at the locations arranged circumferentially between the multiple air feed tubes. The anode and the cathode at Each electrolytic plate appears to be directly opposite the electrolytic plate, that is, they are congruent. While the stamps are not specifically discussed in the text, it appears in the drawings that the seals between each electrolytic plate and the adjacent interconnections are directly opposite to the electrolytic plate, that is, they are congruent. So the state-of-the-art technique in the design of stacked ion conductive electrolytic cells teaches methods for sealing the anode and cathode sides of cells to prevent cross-contamination of feed gases and product. However, it has been proven that the difficult sealing, at high temperatures and electrochemically active conditions found in these systems. The practical application of ion conducting systems for gas separation, without taking into account the configuration of the design, requires that the cells operate under differential pressures and / or differential gas compositions between the feed and product sides of the cells , and this in turn requires robust gas-tight seals between the stacked components. This need is indicated in the invention, which is described in the following specification and is defined by the claims that follow. The invention is a method for separating the oxygen-containing gas, which comprises contacting the oxygen-containing gas with a first surface of a planar solid electrolyte layers of transporting the oxygen ions, providing the electrons to the first surface of the electrolyte solid by a cathode in an electrical contact with a part of the first surface, and electrochemically reduced oxygen in the oxygen-containing gas by consuming the electrons to produce the oxygen ions. The resulting oxygen ions are transported as current through the solid electrolyte by the imposition of an electrical potential through the planar solid electrolyte, and the oxygen gas is produced on a second surface of the solid electrolyte by consuming the oxygen ions and the oxygen. electrons produced The electrons are led from the second surface by an anode in electrical contact with a part of the second surface, and the electrons are conducted from the anode by the interconnections which conduct an electrically impermeable gas, which is an electrical contact with the anode. The oxygen gas is collected in a cavity joined at least in part by the second surface of the solid electrolyte, the interconnection leading the electrically impermeable gas and the seal of the gas-tight anode disposed between a part of the second surface of the solid electrolyte and the opposite part of the electrically conductive interconnection. The oxygen gas is removed from the cavity and the oxygen depleted gas is removed from contact with the first surface of the planar solid electrolyte. The potential of the anode seal is kept below about 40 V, preferably by one or more polarization electrodes. At least one of the polarization electrodes may be an extended part of the anode or alternatively may be an electrode that is separated from the anode. Both types of polarization electrodes can be used together. Preferably, at least one of the polarization electrodes is disposed between the anode and the anode seal. Optionally at least one of the polarization electrodes is not disposed between the anode and the anode seal. The pressure of the oxygen gas generated in the second surface of the solid electrolyte may be different than the pressure of the oxygen-containing gas in the first surface of the solid electrolyte. In one embodiment, the oxygen-containing gas comprises air, and the oxygen gas is withdrawn as a pressurized product of high purity at a pressure of at least 5kPa greater than the pressure of the oxygen-containing gas. Alternatively, the oxygen-containing gas contains less than 20.9% of the volume of oxygen. In another embodiment, the oxygen-containing gas comprises argon and an argon-depleted product in the oxygen that is removed after contact of the oxygen-containing gas with the first surface of the solid electrolyte and after the oxygen is removed by reduction (ionization). ) and transport through the solid electrolyte. The product of argon can be obtained at a pressure equal to or greater than the pressure of the oxygen gas in the cavity formed by the anode sides of the electrolytic plate and the interconnection. The invention includes an electrolytic plate for a planar electrolytic cell useful for the separation of oxygen from an oxygen-containing gas mixture, wherein the electrolytic plate has an anode side and a cathode side, and wherein the planar electrolytic cell comprises an electrolytic plate, a surface of a first electrically conductive interconnection of gas impermeable in an electrical contact with the cathode side of the electrolytic plate, and a surface of a second electrically conductive gas-impermeable interconnection in electrical contact with the anode side of the electrolytic plate. The electrolytic plate comprises (a) a planar solid electrolyte capable of transporting oxygen ions, (b) an anode in electrical contact with a planar solid electrolyte surface, (c) a cathode in electrical contact with an opposite surface of the planar solid electrolyte, and (d) one or more polarization electrodes. A polarization electrode is defined as an electrode material, which is in electrical contact with the electrolytic plate, is located in an area of the electrolytic plate, so that the area does not have a cathode material on its opposite side, and this in electrical contact with a second electrically conductive gas-impermeable interconnection. The electrolytic plate can have at least one polarization electrode having an extended portion of the anode, or alternatively at least fewer polarization electrodes that can be separated from the anode. The electrolytic plate also has a gas-tight seal between the cathode side of the electrolytic plate and the surface of the electrically conductive gas-impermeable interconnect, wherein the gas-tight seal comprises an electrically insulating material. The invention is also a planar electrolytic cell useful for the separation of oxygen from an oxygen-containing gas mixture comprising: (a) a solid electrolytic plate capable of transporting the oxygen ions, wherein the plate has an anode side and one side of cathode; (b) a first electrically conductive gas-impermeable interconnect having a cathode side in electrical contact with the cathode side of the electrolyte plate; (c) a second electrically conductive gas-impermeable interconnect having an anode side in electrical contact with the anode side of the electrolyte plate; (d) a first cavity defined at least in part by the cathode side of the electrolytic plate, the cathode side of the first interconnection and one or more gas-tight cathode seals disposed therebetween; and (e) a second cavity defined at least in part by the anode side of the electrolytic plate, the anode side of the second interconnection, and one or more gas-tight anode seals disposed therebetween. The invention is also an electromechanical device for separating oxygen from an oxygen-containing gas comprising a plurality of planar solid electrolytic plates capable of transporting oxygen ions, each plate having an anode side, a cathode side, an outer edge , and an opening through the plate disposed in an inner region of the plate, wherein the anode side has an anode in an electrical contact therewith and surrounded by a region without continuous peripheral electrodes between the outer edge of the plate and the anode. The device includes a plurality of electrically conductive gas-impermeable interconnections, each having an anode side, a cathode side, an outer edge, and at least one opening therethrough in an internal region thereof. The anode side has a continuous peripheral planar region adjacent to the outer edge, and one or more gas passages formed by an interconnected depression on the anode side, said passages being disposed between the peripheral plane region and the aperture and are in fluid communication with the opening. The electrolytic plates and the interconnections are alternately stacked to form a stacked component of electrically planar electrolytic cells connected in series, each cell is defined by an electrolytic plate, the anode side of a first interconnection in electrical contact with the anode side of the electrolytic plate, and the cathode side of a second interconnection in electrical contact with the cathode side of the electrolytic plate. An anode seal is disposed between the region without continuous peripheral electrodes on the anode side of the electrolytic plate of the first interconnection and joined to the same region, which defines at least in part an electrolytic collection cavity for the collection of oxygen gas formed on the anode side of the electrolytic plate. One or more polarization electrodes are in electrical contact with the anode side of each electrolytic plate, and a grounded rib or rib is formed on the anode side of each interconnection as a continuous or discontinuous raised ledge or ridge surrounding the electrode. one or more gas passages formed by an interconnected depression on the anode side of the interconnection. The grounded rib is in contact with at least one of one or more polarization electrodes. The device includes elements to provide an electrical potential through the plurality of planar electrolytic cells that provide a loose of electrons between the adjacent cells through the interconnections, elements for introducing the oxygen-containing gas into the stacked component of the electrolytic cell , elements for extracting or removing the oxygen gas from the stacked component of the electrolytic cells; and elements for extracting the spent oxygen gas from the electrolytic cell component. At least one of one or more polarization electrodes may be an extended part of the anode, or alternatively one of the polarization electrodes may be separated from the anode and disposed between the anode and the anode seal. In this device, the cathode side of each electrolytic plate has a region without continuous peripheral electrodes adjacent to the outer edge of the plate and another region without continuous electrodes surrounding the opening, and the cathode is disposed between the regions without electrodes. The cathode side of each interconnect has a continuous peripheral planar region adjacent the outer edge, a continuous high planar region surrounding the opening, and one or more gas passages formed on the cathode side by a plurality of raised areas that are disposed between the peripheral plane region and the flat region surrounding the opening, wherein the raised areas and the continuous high plane region are coplanar, and wherein the flow passages are in fluid communication with the portions of the continuous flat region adjacent to the edge external. A cathode seal is disposed between the raised continuous flat region surrounding the opening on the cathode side of the interconnection and the continuous electrodeless region on the cathode side of the electrolytic plate surrounding the opening therethrough and attached to them, which forms a partially closed cavity through which the oxygen-containing gas flows. In one embodiment of the device, the electrically insulating support material disposed between the region without continuous peripheral electrodes on the cathode side of each electrolytic plate and the peripheral planar region continues adjacent the outer edge of the cathode side of each adjacent interconnect. The insulating support material is arranged such that a cavity is formed in each electrolytic cell at least in part by the insulating support material, the cathode side of the electrolytic plate, the cathode side of the adjacent interconnect, and the seal of the cathode so that the cavity is in fluid communication with the elements for introducing the oxygen-containing gas into the stacked component of the electrolytic cells and the elements for extracting the spent oxygen gas from the stacked component of the electrolytic cells. The openings in each electrolytic plate and each interconnection in conjunction with the cathode seals form an axial passage through the stacked electrolytic plates and interconnections, said passage being in fluid communication with the oxygen collection cavities, and wherein the axial passage provided for the extraction of oxygen gas. The invention includes a material suitable for use as an electrically insulating support between the electrically conductive interconnect and an electrolyte in an electrochemical device for the separation of oxygen from an oxygen-containing gas. The material is made by igniting a mixture comprising inorganic oxide glass or glass ceramic combined with one or more electrically insulating ceramics above about 700 ° C, where the coefficient of thermal expansion of the mixture after firing differs from the coefficient of thermal expansion of the electrolyte or the coefficient of thermal expansion of the interconnection by less than approximately 2 micrometers / (meter • ° C). In one embodiment, the mixture comprises an inorganic oxide glass or a glass ceramic combined with one or more electrically insulating ceramics before cooking contains about 0.3 to 27% by weight of lithium aluminosilicate glass in a mixture with magnesia of ceramics insulators (MgO) and alumina (AI2O3) and the weight ratio of the magnesia to the alumina in the mixture before cooking is approximately between 0.2 to 8. The invention also includes a method for making a material suitable for use as an electrically insulating support between a electrically conductive interconnection and an electrolyte in an electrochemical device for separating oxygen from an oxygen-containing gas comprising igniting a mixture comprising inorganic oxide glass or a glass ceramic combined with one or more electrically insulating ceramics above about 700 ° C to produce an electrically insulating support material having a coefficient of thermal expansion that differs from the coefficient of thermal expansion of the electrolyte or the coefficient of thermal expansion of the interconnection by less than about 2 micrometers / (meter • ° C). In one embodiment, the mixture comprising the inorganic oxide glass or the glass ceramic combined with one or more electrically insulating ceramics contains approximately 0.3 to 27% by weight of lithium aluminosilicate glass in a mixture with the magnesia of insulating ceramics. (MgO) and alumina (AI2O3) and the ratio by weight of magnesia in relation to the alumina in the mixture before cooking is approximately between 0.2 to 8. Another embodiment of the invention is a material suitable for use as an electrically insulating support between an electrically conductive interconnect and an electrolyte in an electrochemical device for separating oxygen from an oxygen-containing gas, said material is made by sintering a mixture comprising one or more electrically insulating ceramics to produce an electrically insulating support material which has a coefficient of thermal expansion that differs from the coefficient of thermal expansion of the electrolyte or the coefficient of thermal expansion of the electrolyte or the coefficient of thermal expansion of the interconnection by less than about 1 micrometer / (meter • ° C). A representative mixture of the insulating ceramics comprises magnesia of insulating ceramics (MgO) and alumina (AI2O3), which contains a composition such that the ratio by weight of magnesia in relation to the alumina in the mixture before sintering is approximately 0.2 to 8. An alternate embodiment is a method of making a material suitable for use as an electrically insulating support between an electrically conductive interconnect and an electrolyte in an electrochemical device for separating oxygen from an oxygen-containing gas comprising the sintering of a mixture that comprises one or more electrically insulating ceramics to produce an electrically insulating support material having a coefficient of thermal expansion that differs from the coefficient of thermal expansion of the electrolyte or the coefficient of thermal expansion of the interconnection by less than about 1 micrometer / (meter). ° C). The pre-sintering mixture may comprise magnesia from insulating ceramics (MgO) and alumina (A1203) having a composition such that the ratio by weight of magnesia relative to the alumina in the mixture before baking is approximately 0.2 to 8. The method optionally includes joining the insulating support material with the electrolyte by co-igniting the electrically insulating support material with the electrolyte at temperatures sufficient to bond the insulating support directly with the electrolyte. Alternatively, the insulating support material can be attached to the electrolyte and the interconnection by placing the inorganic oxide glass or the glass ceramic between the insulating support and the electrolyte, placing the inorganic oxide glass or the glass ceramic between the insulating support and the interconnection, and turn on at a sufficient temperature to join the insulating support both to the electrolyte and to the interconnection. The inorganic oxide glass or glass ceramic can be a lithium aluminosilicate glass. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a plan view of the cathode side of an electrolytic plate of the present invention. Figure 2 is a plan view of the anode side of the electrolytic plate.

Figure 3 is a plan view of the anode side of an alternate electrolytic plate. Figure 4 is a plan view of the cathode side of an interconnection. Figure 5 is a plan view of the anode side of the interconnection. Figure 6A and 6B are schematic sectional views that include a single electrolytic cell. Figure 7A and 7B are assembled sectional views of multiple electrolytic cells in series. Figure 8 is a square section through the insulating support, the electrode and the cathode seal of an assembled stacked component. Figure 9 is a complete section through the insulating support, electrode and cathode seal of an assembled stacked component. Figure 10 is a schematic isometric view of a complete electrolytic stacked component. Figure 11 is a diagram of the flow efficiency compared to the operating time for Examples 2 and 3 in the Specification. Figure 12 is a diagram of the flow efficiency compared to the differential pressure of the stacked component for Examples 3 and 4 in the Specification. Figure 13 is a diagram of the operating time compared to the applied voltage for Example 5 in the Specification. Figure 14 is a diagram of the seal potential compared to the polarization electrode width for Example 6 in the Specification. DETAILED DESCRIPTION OF THE INVENTION Separation devices based on solid electrolytes that conduct oxygen ions have practical applications in the production of high purity oxygen of air and in the removal of residual oxygen from inert gases such as argon or nitrogen. In any application, the solid electrolyte is operated with a difference in gas pressure and / or gaseous composition between the feed side (cathode) and the product or permeation (anode) side of the electrolyte. The resistance of the components in such a separation device and the stability of the gas-tight seals required between these components should be sufficient to sustain the practical pressure and / or compositional differentials over the economic lifetime of the device.

Separation devices based on solid oxygen ion-conducting electrolytes can be constructed in monolithic or honeycomb or flat plate configurations. The flat plate configuration in which a plurality of planar electrolytic cells are stacked to operate in electric series is favored in many applications to facilitate assembly, cost effectiveness and compact dimensions. The flat plate configuration shall be designed with the resistance of the appropriate component and seal integrity to operate at a pressure differential and / or the gas composition differential between the feed and product gas streams, while maintaining the purity requirements of the product gas stream. The present invention employs a design of a thin plate stacked component and an operating method that meets these requirements. Past difficulties have been experienced in maintaining such seals, as reported in the cited references of the prior art summarized above. The anode seal failure occurs rapidly in designs of piles or stacks in which the seals on the anode and cathode sides of the electrolytic plate are directly opposite. This failure is observed as a delamination in the interference between the seal material and the anode side of the electrolytic plate. It is considered that this seal failure could result from residual or wandering anodic current passing through the seal. In the present invention, various improvements in the design of the stacked component are identified, which reduce or eliminate the faults of the anode seal. One of these improvements is the use of one or more polarization electrodes in contact with each electrolytic plate that modifies or polarizes the electrolytic potential in the seal region, so that the current flow through the anode seal is minimized. A polarization electrode may be an extension of the anode beyond the edge of the projected area of the cathode on the opposite side of the electrolytic plate. Alternatively, a separate polarization electrode or ring connected to the ground can be placed on the electrolytic plate between the anode and the anode seal. If desired, the extended anode and the ring connected to separate ground can be used in combination. The term of the polarization electrode as used herein is defined as an electrolytic material that is in electrical contact with the electrolytic plate, is located in an area of the electrolytic plate, so that the area has no cathode material in the opposite side thereof, and maintained at a greater potential approximately -40mV in relation to the lateral interconnection of the anode. This potential is preferably maintained by establishing the electrical contact between the polarization electrode and the lateral interconnection of the anode. The projection of an area on the anode side of the plate covered by a polarization electrode on the cathode side of the electrolytic plate will not be in contact nor will it be superimposed on the cathode material. Typically, the polarization electrode or electrodes are placed on the anode side of the electrolytic plate. If desired, a polarization electrode can be located on the cathode side of the electrolytic plate, in case such a polarization electrode (a) is not in electrical contact with the cathode, (b) it is not in electrical contact with the cathode. interconnection of the cathode side, and (c) this in electrical contact with the interconnection of the anode side. At least a portion of such a polarization electrode on the cathode side is preferably directly opposite the anode seal. Another improvement is the radial displacement of the anode and cathode seals so that the seals do not overlap on the opposite sides of each electrolytic plate. This feature, defined herein as displacement stamps, rres a design geometry of a specific cell, as described below. It has been found that a combination of the displacement seals and the polarization electrodes is particularly effective in reducing or eliminating the anode seal failure by controlling the potential through the minor anode seal of approximately 40 mV. This minimizes the flow of residual current through the seal. The planar or planar plate design of the present invention employs electrolytic plates and alternating electrically conductive interconnections that define the individual electrochemical cells, which operate in an electrical array and isolate the feed gases and the product gas as described above. The key component of each electrochemical cell is the electrolytic plate and associated electrodes, which distribute the electrical potential and electron flow over the surface of the plate. Electrolytic plates will be as thin as possible while maintaining sufficient resistance to operate at the rred pressure differentials.

The electrolytic plates are planar and are stacked in the axial direction; the configuration of the plates in the radial direction can be circular, square, rectangular or any other planar geometric configuration. The preferred electrolytic plate of the present invention is generally square with rounded corners as shown in the plan view of Figure 1, which is the feed side or the cathode side of the plate. The electrode material 1, which is the cathode material forming the cathode, is applied to the central region of the electrolytic plate so that the regions without continuous electrodes 3 and 5 remain. A region without electrodes 5 surrounds the opening 7, which extends through the plate. The region term without electrodes of any region of the electrolytic plate that does not have an electrode material is applied thereon. The electrolytic material is a multi-component ionic conducting metal oxide comprising an oxide of at least two different metals or a mixture of at least two different metal oxides wherein the multi-component metal oxide demonstrates an ionic conductivity at operating temperatures of the device, typically greater than about 500 ° C. Any oxygen ion conduction electrolyte known in the art can be used; representative electrolytes include zirconia stabilized with yttria, ceria added with strontium, ceria added with gadolinium, and vanadium oxide of bismuth. The cathode material is formed of an oxidation resistant metal, an alloy, or a multi-component mixed conducting oxide. Particularly useful electrode material includes lanthanum strontium cobaltite (LSCO), LaxSri-jcCo? 3-z, where x varies from 0.2 to 1 and z is a number that produces the charge-neutral compound. The LSCO can be used with an intermediate coating of lanthanum strontium cobaltite and silver or a palladium-silver alloy that is applied to the surface of the electrodes. The coating can be applied as a paste and sintered, or applied by screen printing or equivalent methods, by electronic deposition or by other techniques well known in the art. The thickness of the cathode is approximately 0.1 to 100 microns. Representative dimensions of the electrolytic plate are 5 to 20 cm in width or diameter and 0.01 to 0.065 cm in thickness. The anode side of the electrolytic plate is shown in the plan view in Figure 2, The electrode material 9 is applied around the opening 7 and is surrounded by a region without continuous electrodes 11 having a width of d2. The width d2 is smaller than the width di of the cathode side of Figure 1, and the additional width or extension of the electrode 9 on the anode side is defined as a polarization electrode that polarizes the potential through the anode seal ( described below) and reduces the flow of current through the seal. Typically the differential between di and d2 is approximately 0.1 to 2.0 cm and defines an extended anode that serves as the polarization electrode. A further definition of the extended anode is a portion of the electrode material which is contiguous with an electrical contact with the anode and is not congruent and is not coextensive with the cathode on the opposite side of the electrolytic plate. An alternate anode side of the electrolytic plate is provided in the plan view in Figure 3. The electrode material 13 is applied to the electrolytic plate and has the same configuration and at least the same peripheral dimensions as the electrode material 1 of Figure 1. The separated polarization electrode 15 is applied between the electrode 13 and the outer portion of a region without electrodes 11. The polarization electrode 15 is also known as a grounded ring, which is defined as an electrode of polarization not in direct contact with the anode.

Optionally, the electrode 13 is slightly larger than the electrode 1 of Figure 1. The opening 7 corresponds to the opening 7 of Figure 1. The width d3 is similar to the width d2 of Figure 2, and the width d3 is smaller than the width di of the cathode side of Figure 1. The anode preferably uses the electrically conductive material similar to the cathode described above, and the polarization electrode described below, although different electrically conductive material can be used for any of these three types of electrodes The distribution of the gas through the cathode side of the electrolytic plate, the extraction of oxygen from the anode side of the plate, and the electron transport of the anode side of an electrolytic plate on the cathode side of an adjacent electrolytic plate they are promoted by planar interconnections that have generally similar external dimensions such as the electrolytic plate. The interconnections are made from a material impervious to oxidation-resistant gas that has a coefficient of thermal expansion comparable to that of the electrolyte, a high electronic conductivity and a low ionic conductivity. The material can be a metal oxide, a metal or a metal alloy or a mixture of the two multicomponent multi-component electrically conductive components. Suitable electrically conductive oxides include strontium lanthanum chromite, lanthanum calcium manganite and lanthanum calcium chromite. Lanthanum strontium manganite (LSM) La0.5Sr0.sMn? 3, is a preferred material for interconnections. The cathode side of an interconnection is shown in the plan view in Figure 4, wherein the interconnection has a generally continuous flat peripheral region 17 and an opening 19 on the opposite side of the interconnection. The interconnection generally has the same configuration and size as the electrolytic plates of Figures 1-3. A generally flat continuous region 21 surrounds the opening 19. The opening 19 typically has the same diameter or similar to that of the opening 7 in the electrolytic plates of Figures 1-3. A plurality of raised areas 23 characterized in this embodiment as conical body protuberances or spherical segments with flattened stops, which may also be described as a dowel, are disposed between the flat regions 17 and 21. The non-elevated or recessed areas continuous between the raised areas in conjunction the adjacent electrolytic plate forms a cavity in fluid communication with the flat peripheral region 17 as described below.

Alternatives to the raised areas 23 may be used, such as ribs or ribs, raised rectangular or triangular areas, and the like that perform essentially the same function as the raised areas 23. The stops of the raised areas 23 and of the flat region 21 are generally coplanar, and this plane is above the plane formed by the planar region 17. The opposite anode side of the interconnection is shown in the plan view in Figure 5. A generally planar continuous region 25 is disposed around the periphery of the plane. the interconnection, and a plurality of raised areas 27 characterized in this embodiment as conical body protrusions or spherical segments with flattened stops, which can also be described as pins, are disposed between the generally flat region 25 and the opening 19. The non-raised areas or continuous recesses between the raised areas in conjunction with an adjacent electrolytic plate form a cavity or interconnected cavities in fluid communication with the opening 19 as further described below. Alternatives to the raised areas 27 can be used, such as ribs, channels and the like which perform essentially the same function at the raised areas 27. The rib connected to continuous ground 28 surrounds the raised areas and is in electrical contact with the polarization electrode. as described below. The stops of the raised areas 27, the top of the rib connected to ground 28 and the flat region 25 are generally planar. A single electrolytic cell is formed by an electrolytic plate having an anode and a cathode, and the adjacent surfaces of two interconnections joined by the appropriate gas-tight anode and cathode seals and electrical connections. A schematic sectional view of a single electrolytic cell is provided in Figure 6A and is not necessarily to scale. A partial electrolyte plate 29, which corresponds to the section A-A of Figures 1 and 2, has a cathode portion 31 and an anode portion 33 applied to the sides of the cathode and the anode respectively. The anode portion 33 further extends in a radially outward direction to the cathode portion 31, and this extended portion forms a portion of the polarization electrode 34. The portion of the polarization electrode 34 is a part of the full polarization electrode. formed by the extension of the anode 9 of Figure 2 beyond the cathode 1 of Figure 1 in a radially outward direction. This extension is defined so that the width d2 of Figure 2 is smaller than the width di of Figure 1. The rib connected to ground 42 makes electrical contact with the polarization electrode 34 when the stacked component is assembled. Preferably the ratio L / t is greater than about 10, where L is the width of the portion of the polarization electrode 34 of Figure 6A, ie the difference between di and the width d2, and t is the thickness of the electrolytic plate 29. The L / t ratio is selected such that the potential through the anode seal 39, which is defined as the potential of the anode seal, is less than about 40 V and preferably less than about 25 mV. The potential of the anode seal is defined as the difference in electrical potential measured between the electrical contact in the interconnection that is adjacent to the anode side of the electrolyte and a reference electrode located in the electrolyte in proximity to the anode seal. Additional specifications that define the potential of the anode seal include the following. The reference electrode is located on the surface of the cathode side of the electrolyte plate directly opposite the anode seal, where the electrical contact area does not extend beyond the region defined by a projection of the anode seal on the side of cathode of the electrolytic plate. The electrical contact in the interconnection that is in direct contact with the anode seal is made on the lateral surface of the cathode directly opposite the anode seal. This electrical contact area does not extend beyond the region defined by a projection of the anode seal on the cathode side of the interconnection. With reference to Figure 6A, for example, the potential of the anode seal will be measured between the location 46 in the electrolytic plate 29 and the location 44 in the interconnection 37. The reference electrode is of the same type (composition, morphology and method). processing) to the anode. In addition, the absolute partial pressure of the oxygen the gas in contact with the reference electrode differs from the absolute partial pressure of the oxygen of the gas in contact with the anode by not more than 5% of the absolute partial pressure of the oxygen of the gas in contact with the anode The potential is measured under non-transient conditions from a stable state to a normal operating temperature of the cell, typically between 600 ° C and 850 ° C and with a normal operating current flowing through the electrolyte from the anode to the cathode , typically between 50-1500 mA / cm2. The placement of the interconnecting contact and the reference electrode is such that the absolute value of the potential of the zero current seal is minimized, and the minimized value of preference is less than about 0.1 mV. The potential of the zero current seal is defined as the potential measured between the interconnection contact and the reference electrode under the same conditions as the measurement of the seal potential, but with a current in the steady state of zero that flows through the cell. Such a zero current potential is generated, for example by the temperature gradients in the electrolyte, and thus the zero current potential is minimized by placing the reference electrode as close as possible to the interconnecting contact. If the absolute value of the potential of the zero current seal is not reduced to less than about 0.1 V by the judicious placement of the reference electrode, the seal potential is corrected by subtracting the zero current potential from the seal potential, and redefining the potential of the seal as the difference. The interconnecting portions 35 and 37 of Figure 6A correspond to section CC of Figures 4 and 5. The anode seal 39 is disposed between the region without continuous electrodes 41 (corresponding to the region without continuous electrodes 11 of the Figure 2) and the flat region generally continuous 43 (corresponding to the generally flat continuous region 25 of Figure 5). The cathode seal 45 is disposed between the continuous electrode region 47 (which corresponds to the continuous electrodeless region 5 of Figure 1) and the generally continuous flat region 49 (corresponding to the generally continuous flat region 21 of Figure 4). ). A preferred material for seals 39 and 45 is a ceramic-glass one derived from a lithium aluminosilicate (LAS) glass, which is a material known in the art for use in seals as described for example in the article of T.J. Headly and R.E. Loehman entitled "Crystallization of a Glass Ceramic by Epitaxial Growth" in the American Ceramic Society Magazine, Vol 67, pp. 620,625, 1984. The anode seal 39 and the cathode seal 45 form gas-tight seal between the respective areas of the electrolytic plate and the interconnection when the stacked component is assembled as described below. Gas-tight seals maintain the purity of the product gas and prevent product loss, and prevent or minimize the mixing of feed streams and product streams. The seals prevent or minimize gas mixing due to the differential pressure and / or the differential gas composition between the feed streams, permeable and non-permeable. The gas tight seals also serve to join the electrolytic plates and the interconnections together in the stacked components as shown below. The seals may be in cooking together and attached directly to the electrolytic plates and interconnections, or alternatively one or more additional materials may be used in joint cooking. Optionally an electrically insulating support is disposed between the cathode side of the electrolytic plate 29 and the cathode side of the interconnection 35, and a portion of this support is denoted as the support 51. This support eliminates the damaging stress in the electrolytic plate 29 when the gas pressure on the anode side of the electrolytic cell is greater than the gas pressure on the cathode side of the cell. The support 51 may be gas-tight or may not be gas-tight, and is not applied continuously as explained in more detail below. A schematic sectional view of an alternative of a single electrolytic cell that is provided in Figure 6B. The components of this alternating electrolytic cell are identical to those of Figure 6A, except that the electrode material applied to the anode side of the electrolytic plate 52 The anode portion 53 has a smaller extension in the radial direction to the outside that the anode portion of Figure 6A, and a separate polarization electrode portion 55 is applied to the anode side of the electrolytic plate 52. The portion of the polarization electrode 55 is a portion of a polarization electrode 15 of the Figure 3. The grounded rib 56 makes electrical contact with the portion of the polarization electrode 55 when the stacked component is assembled. This grounded rib is typically continuous and makes continuous contact with the polarization electrode, but optionally it can be discontinuous, that is, formed as a series of raised areas arranged in a circular pattern that are in electrical contact with the polarization electrode. A plurality of elements described in Figure 6A are assembled by arranging alternating electrolyte plates and interconnections in a stacked component, and the stacked component is subjected to firing to produce a plurality of electrolytic cells in series, three of which are shown in the Figure 7A. In the process of assembling each cell, an electrically conductive material is applied to the surfaces of the raised areas in each interconnection as defined by the elements 23 of Figure 4 and 27 of Figure 5. When the stacked component is subjected to cooking , this conductive material is united in the elevated areas of the interconnections and in the electrodes of each electrolytic plate. The conductive material is shown in Figure 7 as shaped layers 57 disposed between the interconnecting portion 59 and the cathode in the electrolytic plate 61, and the shaped layers 63 disposed between the adjacent interconnecting portion 65 and the anode of the electrolytic plate 61. The formed layers provide the electrical connections between the electrodes and the adjacent interconnections, and also provide the mechanical support for the electrolytic plate. The conductive material is preferably silver initially applied as an ink before firing. In an alternate embodiment described above, a plurality of elements described in Figure 6B are assembled into a stacked component and subjected to firing to produce a plurality of electrolytic cells in series, three of which are shown in Figure 7B. The cells of Figure 7B are identical to those of Figure 7A, except for different polarization electrodes. In Figure 7A, the polarization electrodes 67 are radial extensions of the anodes in the respective electrolytic plates, wherein each anode extends radially beyond the edge of the cathode on the opposite side of the electrolytic plate. This is previously described with reference to Figures 1 and 2, wherein the polarization electrode is the extension of the anode having a width equal to the difference between the width dx and the width d2. In Figure 7B, the individual polarization electrode portions 69 are disposed between each electrolytic plate and the adjacent interconnections. The full polarization electrode for this alternative is shown as the element 15 in Figure 3, where the width d3 is less than the width di in Figure 1. A preferred feature of this embodiment of the present invention is the use of electrodes of polarization that reduce or eliminate the characteristic of the anode seal by reducing the electrical potential through the anode seals to a value significantly lower than 40 mV. A second feature is that each anode seal travels completely in the electrolytic plate in relation to the corresponding cathode seal. Termination displacement stamps are defined as the geometric seal arrangement in which the projection of any area of the anode seal on the cathode side of the electrolytic plate is not in contact with or superimposed on any cathode seal. This is illustrated in Figure 6A where the anode seal portion 39 is disposed adjacent the outer periphery of the electrolytic plate considering that the seal portion of the cathode 45 is disposed adjacent to the central opening in the plate. The combination of the polarization electrodes and the displacement seals as used in the present invention is particularly effective in removing the characteristics of the anode seal. The operation of the planar electrolytic cells as described above may require that the pressure of the oxygen product be greater than the pressure of the oxygen-containing feed gas, so that the cells operate in the way of pumping oxygen. This operation can place a significant mechanical stress on the outer region of the electrolytic plate. As previously described, this problem is alleviated by the use of an electrically insulating support 51 disposed between the cathode side of the electrolytic plate 29 and the interconnection 35 (Figure 6A). This electrically insulating support reduces the potentially damaging stresses in the electrolytic plate 29 when the gas pressure on the anode side of the electrolytic cell is greater than the gas pressure on the cathode side of the cell. The multiple supports are shown in Figure 7A as supports 71 and Figure 7B as supports 73. The electrically insulating support material should have a coefficient of thermal expansion that is substantially equivalent to the coefficient of thermal expansion of the adjacent electrolytic material or that of the material of adjacent interconnection. Substantially equivalent means that the coefficients of thermal expansion of the insulating support and adjacent material during a temperature range of about 20 ° C to 750 ° C differs by less than about 2 microns / (meter • ° C), preferably less than about 1 micrometer / (meter • ° C), and more preferably less than about 0.5 micrometer / (meter • ° C). The insulating support material having lower values in the Young's modulus can tolerate greater differences in the coefficient of thermal expansion compared to the electrolyte and the interconnection materials, while the insulating support materials with higher values in the Young's modulus can tolerate smaller differences in the coefficient of thermal expansion. The insulating support is prepared using one or more electrically insulating ceramics as described below. An electrically insulating ceramic is defined herein as any electrically non-conductive ceramic, does not permit the passage of an electric current when placed in an electric field (see Modern Ceramic Engineering, D. Richerson 2nd Edition, Marcel Deckker, Inc., New York, p 228). The mixtures of such ceramics are selected for having a high electrical resistivity and for having coefficients of thermal expansion similar to those of the electrolyte and the interconnection materials. Representative ceramics for use in the insulating support include but are not limited to the oxides of Mg, Al, Si, Yb, Ca, Be, Sr, Nd, Sm, Er, Eu, Se, The Gd, Dy and Tm. The insulating support can be manufactured by several different methods. In the first of these methods, the insulating support is made by preparing a mixture of inorganic oxide glass or glass ceramic combined with one or more electrically insulating ceramics in a vehicle or organic carrier to form an ink, applying the ink to an interconnection or an electrolytic plate, and cooking it above approximately 500 ° C. The temperature of the cooking preferably reaches or reaches the melting point temperature of the glass, which typically is in the temperature range of about 800 ° C to 1000 ° C. The preferred thermal expansion coefficient of the support material after firing is approximately between 9 to 15 micrometers / (meter • ° C). A typical ink composition is 70% by weight of solids and 30% by weight of the vehicle or liquid organic carrier, although the other compositions can be used as required. A range of the preferred composition of the solids portion of the mixture before firing (excluding the carrier or organic carrier) contains approximately 0.3 to 27% by weight of the lithium aluminosilicate glass and the remainder is magnesia from insulating ceramics (MgO) and alumina (A1203). The ratio by weight of the magnesia to the alumina in the mixture before being subjected to cooking is selected approximately between 0.2 and 8 in order to produce the preferred coefficient of thermal expansion of the insulating support material. In addition, the amount of glass is selected such that the insulating support assembled in a final manner after firing is electrically insulating.

In another method, a mixture of electrically insulating ceramics is formed in a desired configuration and is sintered to form an electrically insulating support. The electrically insulating sintered support is connected to the electrolyte and the interconnection by placing the inorganic oxide glass or the ceramic-glass between the insulating support and the electrolyte, placing the inorganic oxide glass or the ceramic-glass between the insulating support and the interconnection , and the cooking at a sufficient temperature to join the insulating support both in the electrolyte and in the interconnection. Preferably the inorganic oxide glass or the ceramic-glass is a lithium aluminosilicate glass. Alternatively, the electrically insulating sintered support can be attached to the electrolyte by cooking it at temperatures sufficient to bond the insulating support directly to the electrolyte without the use of an inorganic non-metallic glass. The insulating support is further described in Figure 8, which corresponds to section D-D of Figures 7A and 7B. The insulating support is applied discontinuously so that a portion 75 forms a continuous support and the additional portions 77 form supports separated by the open spaces 79. This is illustrated more clearly in Figure 9, which is an expansion of the DD section in a correspondingly complete section of the entire stacked component in the same axial location. The insulating support portions 81 and 83 are continuous on opposite sides of the stacked component, while the support portions 85 and 87 are discontinuous on opposite sides of the stacked component. The openings 89 and 91 allow the transverse flow of the feed gas through the stacked component, as described more fully below, so that the feed gas containing the oxygen flows through the openings 89, while the gas Oxygen-depleted oxygen leaves the stacked component through the opening 91. The section of Figure 9 also shows the cathode 93 and the cathode seal 95 which surrounds the central opening 97. The entire assembly and operation of the stacked component of the The electrolytic cell is illustrated by the schematic isometric view of Figure 10, which is not to scale. The stacked component of the cell is formed by a series of alternating electrolyte plates 95 with the appropriate anodes and cathodes (not shown), the interconnects 97 and the insulating support material 99 with the negative end plate 101 and the end plate. positive 103. Positive and negative electrical connections provide a direct current to the stacked component, which operates approximately 50 to 700 mV per cell. The oxygen-containing feed gas flows into one side of the stacked component as shown, flows through the cathode sides of the cells in a cross-flow mode, and the oxygen-depleted gas leaves the opposite side of the stacked component . The insulating supports on opposite sides of the stacked component direct the gas in a transverse flow mode as previously described. A section through the stacked component shows the radial flow of the oxygen product gas through the anode side of an interconnection in the direction of the central opening 109. The central openings through the electrolytic plates and the interconnections, in conjunction with the seals of the cathode described previously, form a central conduit in the communication of the gas flow with the anode side of each cell. The central conduit is connected with the oxygen extraction conduit 111, which in turn is connected with a gas-tight seal (not shown) on the positive or base plate 103. Alternatively, an oxygen extraction conduit may be used. connect on a negative end plate 101 (not shown). If desired, the oxygen product can be extracted from both ends of the stacked component (not shown). The stacked component can be operated in at least two alternate modes. In the first mode, the feed gas is an air and a high purity oxygen product comprising at least 99.5% volume of oxygen is extracted through line 111. The feed air is typically introduced at a light pressure higher than atmospheric which is sufficient to sustain adequate air flow through the stacked component. Typically oxygen is produced continuously at a pressure of at least 5kPa above the feed pressure, which is made possible by the application of the displacement seals, polarization electrodes and insulating supports previously described. The stacked component is operated at a temperature higher than 500 ° C. In a second mode of operation, the feed gas is an inert gas such as nitrogen or argon, which contains a low concentration of oxygen as an impurity. The stacked component of the electrolytic cell is operated to remove a larger portion of the oxygen so that the oxygen depleted gas flowing from the cathode sides of the cells typically contains less than about ppbv to less than about 10% volume of oxygen . The oxygen flow from the conduit 11, which will be of a higher purity but of lower volume, can also be a useful product. In this embodiment, it may be desirable to operate the stacked component so that the feed gas and the pressures of the oxygen depleted product are above the pressure of the oxygen product. In such a case, the use of an insulating support material in the stacked component will be optional because the electrolytic plates will receive sufficient mechanical support from the formed layers and anode seals previously described. At higher operating pressures, the assembly of the stacked component may require end constraining elements to maintain the integrity of the stacked component. These end constraining elements operate on the end plates 101 and 103 to provide the axial compressive forces that compensate for the tendency of the stacked component to separate under such pressures. While the present invention is preferably used for the separation of air to recover high purity oxygen and the purification of inert gas to remove residual oxygen, the invention can be applied to any gas mixture containing oxygen for any desired purpose or product. final. The stacked component of the electrolytic cell of the present invention can be manufactured by methods known in the art of ion-conducting ceramics, for example as described in European Patent Application Publication No. 0 682 379 to the aforementioned. The invention can be practiced with any of the materials known in the art and generally used in ion-conductive stacked components for electrolytic plates, electrodes, interconnections and seals. Other geometries of the stacked components can be imagined to be embodiments of the present invention in which the polarization electrodes and the displacement seals are used to control the potential through the anode seal down to approximately 40 mV and preferably below approximately 25 mV. The polarization electrodes and displacement seals can be applied with the alternate stacked component configurations to introduce the feed gas into the stacked component, to extract the spent oxygen gas from the cathode sides of the cells, and / or to extract oxygen from the anode sides of the cells. In an alternate embodiment of the invention, the electrically insulating material is incorporated in the cathode seal and the polarization electrodes are used as described above. The insulating material is preferably prepared by sintering a mixture of magnesium oxide (MgO) and aluminum oxide (AI2O3) and the insulating material is sealed on the sides of the cathode of the electrolytic plate and interconnected with the glass sealant -ceramic, for example such as the derivative of a lithium aluminosilicate glass (LAS). In the preparation of the insulating material, the magnesium oxide is used at a lower thermal expansion coefficient of the magnesium oxide so that the coefficient of thermal expansion of the insulating material coincides with that of the electrolyte and the interconnecting materials. Some spinels of magnesium oxide (MgAl204) can be formed in situ during the sintering of the material. Alternatively, aluminum oxide and magnesium oxide can be fired at sufficiently high temperatures to form the MgO / MgAl20 ceramic. Alternatively, the insulating material can be fired together with the electrolyte at a temperature of about 1550 ° C without the use of a glass sealant. In this alternating mode that employs an insulating material in the cathode seal, a complete displacement of the anode and cathode seals is not required, which allows for additional flexibility in the design of the stacked component. This embodiment can be applied to any stacked component design that has directly opposed anode and cathode or partially opposed seals, while the geometry of the stacked component allows the inclusion of a polarization electrode. For example, the embodiment may be applied to the design of the stacked component described in European Patent Application Publication No. 0 682 379 to the aforementioned. The combination of an insulating cathode seal and the polarization electrode will allow the potential control through the anode seal down to approximately 40 mV and preferably below 25 mV. EXAMPLE 1 The insulating support between the sides of the cathode of the electrolytic plate and the interconnection as described above can be formed by pre-applying the assembly of the stacked component and firing an ink containing the precursor materials in a liquid carrier or carrier. An ink for forming the insulating support material prepared by firing as follows. 59.3 g of alumina (Alcoa, SG16), 255.7 g of magnesia (Martin-Marietta, MC10-325), and 35. Og of lithium aluminosilicate glass (Specialty Glass, Spl484-A) in a bowl were combined and mixed. stainless steel. 72.0 g of a-Terpineol (Kodak) and 78.0 g of V-006 / Heraeus, Cermalloy Division) were mixed in a second stainless steel bowl. A third solid mixture was added slowly to the liquids and mixed together with a rubber spatula until the powder was moistened. This step was repeated with the remaining powder until the powder is incorporated. The mixture was then processed four times through a mill of three mills to produce the final ink, using the separation of the mill registered below: Separation of the La i- Separation of the input nador Laminator of output First pass 0.032 cm 0.019 cm Second pass 0.019 cm 0.006 cm Third pass 0.006 cm <; 0.005 cm Fourth pass (finish) 0.006 cm < 0.005 cm EXAMPLE 2 A stacked two-cell component was constructed and operated to demonstrate the use of a stacked component design incorporating displacement seals and polarization electrodes. A round stacked component with a diameter of 7.6 cm of 2 cells was constructed with two electrolytic plates with 10 mol% of ceria added with strontium (SCO) and three interconnection plates of Lao.sSr0.5Mn03 (LSM) arranged in alternating layers . The electrolytic plates had a thickness of 0.025 cm. I flatten the interconnect plates as the electrolytes had a central hole, and the holes were aligned in the stacked component to form a central axial conduit that collects the oxygen generated electrochemically at each anode. Each interconnect had a circumferential sealing surface with a width of 0.38 cm near the outer periphery of the anode side of the glass-ceramic seal. The interconnecting surface of the cathode side was located around the center hole and also has a width of 0.38 cm. The electrolytic plates had sealing surfaces without electrodes on the sides of the cathode and the anode that were aligned with the corresponding sealing surfaces of the interconnections. The stacked components of the electrolyte and the interconnect were joined together on these sealing surfaces with a lithium aluminosilicate glass-ceramic (LAS) to form the gas tight seals. Electrodes were applied to the electrolytic plates on the anode side and on the cathode side of lanthanum strontium cobaltite (LSCO), LaxSr? -xCo03-a, where x varies from 0.2 to 1.0 and z is a number that produces a composed of neutral charge. An overcoat of LSCO and a silver-palladium alloy was applied to the electrodes. The electrodes were thus treated, so that the anode was oversized in relation to the cathode by 0.14 cm at the outer edge, so that the anode portion extended beyond the outer circumference of the cathode which forms a polarizing electrode as It was previously described. In addition, a separate external polarization electrode or a grounded ring of the same electrode composition was applied outside the extended anode. The polarization electrode of the ring connected to earth was 0.18 cm wide, and was separated from the anode by an SCO electrolyte with a bare space of 0.13 cm in width. The cathode area was 21 cm2 per plate. Thus, the anode and polarization electrode configuration was similar to that described in Figures 3, 6B and 7B. The insulating support of Figure 6B was not used. The electrodes were connected to ribs with a height of 0.05 cm (0.13 wide) in the interconnection separated by the 0.13 cm wide channels. The silver was applied as the conductive layer between the upper surface of the ribs formed in a common plane with the sealing surface for the glass-ceramic seal on both sides of the interconnection. The channels allow oxygen to flow radially to the central collection gate at the anode and the air flows through the cathode in the transverse flow mode. One of the terminal interconnection plates or end plates is fixed to a 0.4 cm O.D. of a 446 stainless steel tube for the extraction or removal of oxygen. The central hole in the other end interconnection plate or end plate was closed with a LSM plate of 2 square inches fixed with LAS. The air is supplied to the cathode side of the stacked component at approximately a standard of 2 liters per minute. A voltage of about IV was applied between the two terminal LSM interconnection plates at a temperature of 750 ° C, and the electric current of the stacked component and the resulting flow expense of the electrochemically generated oxygen were measured. A meter was used digital mass flow set in tube SS446 to measure the flow. The anode side pressure was controlled by a manual valve fixed on tube SS446 and monitored by a Bourdon-tube pressure gauge. The integrity of the seal was determined by calculating the flow efficiency as follows: 100 x measured by the flow rate of 02 (standard cc / min) Efficiency of. = theoretical flow rate of 02 (100% efficient flow (%)) = 100 x measured by the flow rate of 02 (standard cc / min) measured current (amperes) x 3.75 XN where N is the number of cells in the stacked component and 3.75 is a conversion factor that has units of (standard cc / min) (amps). The flow in standard cc / min is defined at 21 ° C. The theoretical flow rate is realized when all the currents are completely used to produce the collected oxygen product, that is, when an oxygen molecule is produced by four electrons that flow through each cell, and all the oxygen is collected by the absence of leaks in the seals.

The stacked component was maintained at a permanent differential pressure of 2 kPa (a higher anode side pressure) for the first 025 hours of operation, and subsequently at a differential pressure of 10kPa (upper anode side pressure). The operation of the stacked component was continuously monitored for 5,000 hours and the oxygen flow measured was essentially 100% of the theoretical flow rate over the entire period. This indicates the integrity of the seal and the absence of detectable leaks. EXAMPLE 3 A round stacked component with a diameter of 7.6 cm and 2 cells was constructed according to the procedure described in Example 2, except that the electrodes are coextensive at their outer edges in the electrolytic plates, ie the external diameter of both electrodes was equivalent there were no polarization electrodes on the anode side. The cathode area was 31 cm2 per plate. The stacked component was operated at 750 ° C in a manner similar to Example 2, except that a voltage of IV was applied to the stacked component at a permanent differential pressure of 6.9 kPa (a pressure from the upper anode side). The flow efficiency was monitored in-line for 480 hours in the same manner as described in Example 2. After the operation of the stacked component for 480 hours, the flow efficiency was measured over the differential pressure range of 0 to 6.9. kPa (the pressure of the upper anode side). The operation of the stacked component was completed after 505 hours due to a significant loss in flow efficiency. The loss in flow efficiency was found to be the result of disuniting the interface between the LAS seal and the electrolyte on the anode side of the electrolytic plate. In Figure 11 the performance of the stacked component is shown as a function of online operating time for comparison with the performance of the stacked component of Example 2. this comparison showed that polarization electrodes are required in the stacked components employing stamping seals. displacement to provide a robust gas tight seal. EXAMPLE 4 A round stacked component with a diameter of 7.6 cm of 5 cells was constructed according to the procedure described in Example # 2, except that electrolytic plates and six interconnections were used. The anode was oversized in relation to the cathode by an external edge of 0.11 cm. The ring electrode connected to the external ground on the anode side was 0.19 cm wide and separated from the anode by a 0.10 cm ANCO naked space SCO electrolyte. The cathode area was 24 cm2 per plate. An insulating support similar to that described in the reference to Figures 6b, 7B, 8 and 9 was used, using the material prepared according to Example 1. The insulating support material was attached to the periphery without electrodes on the cathode side of the electrolyte and the flat area adjacent to the periphery of the interconnection. The spaces were periodically left in the insulating support layer to allow air to flow through the cathodes and the oxygen depleted air is extracted from the cathodes in a manner similar to the flow configuration shown in Figure 10. The stacked component was operated at 750 ° C in a manner similar to Example 2, except for a voltage of 2V and a permanent differential pressure of about 35 kPa (the pressure of the upper anode side). After operating the stacked component for 1680 hours, the flow efficiency was measured during a differential pressure range between 0 to 83 kPa (upper anode side pressure) and was essentially 100% as shown in Figure 12. This indicates excellent seal integrity that was maintained by the use of polarization electrodes, and the integrity of the electrolytic plate that was maintained by the use of the insulating support layer ends. Figure 12 also shows the operation data over the differential pressure range of 0.6.9 kPa for the stacked component of Example 3, which had no polarization electrodes. It is observed that the efficiency of the flow for the design of a stacked component decreases rapidly as the differential pressure increases. EXAMPLE 5 In order to determine the maximum voltage above which disengagement occurs at the interface between the anode seal of glass-ceramic LAS and the electrolyte on the anode side of the electrolytic plate, various samples granules or pellets were prepared and operated at various voltages. Each test sample comprised a 2.5 cm granule of the LSM interconnecting material, which was directly linked to LAS with an electrolytic disk with a thickness of 0.038 and a diameter of 2.6 cm made of SCO. The electrolyte had an LSCO electrode of 4 cm2 with an overcoat of LSCO and a silver-palladium alloy applied on the air side. Then a layer of porous plate was applied over the electrode to act as a current collector at a temperature of 750 ° C, so that the electrode was negatively charged, simulating thus the configuration of LAS and SCO in the anode seal of a stacked component. The voltage was measured as a function of time. After continuous periods of operation from 300 to 3300 hours, the granule samples were removed from the test and the binding of the LAS electrolyte with SCO was proved by delamination with a shaving blade. The relationship between the operating time, the applied voltage and the integrity of the joint is shown in the diagram of Figure 13. The interval of the voltages applied to each pellet is shown, and the points of the data are indicated with the Maximum voltage applied in each test. The results clearly show that the potential or voltage through the anode seal and in particular through the joints of the stacked component of LAS: SCO should be kept below 40 mV, and preferably below 25 mV in order to avoid delamination at the LAS interface: SCO and maintain the integrity of the anode seal. EXAMPLE 6 The effects of the polarization electrode width and the electrolyte thickness at the voltage measured between the anode and the reference electrode (approaching the potential of the anode seal in a stacked component) were examined using a series of samples of The test comprising a rectangular electrolytic plate of SCO 2.5 cm by 5.0 cm with a thickness of 0.015 or 0.038. A LSCO overcoat and a silver-palladium alloy on both sides of the electrolytic plate were applied to the LSCO electrodes. In each case the dimensions of the anode were 1.9 by 1.9 cm and the cathode was dimensioned inferiorly in relation to the anode when varying the quantities. This caused variable widths in the polarization electrodes formed because the anode is larger than the cathode. The LSCO reference electrode was fixed to the anode side, at the anode glass-ceramic seal location in a fully assembled stacked component, approximately 0.065 cm from the edge of the anode. Alternatively, an LSM block was fixed with the LAS sealant at the anode glass-ceramic seal location on the stacked component fully assembled, while the reference electrode was fixed on the cathode side opposite the LSM block. In several cases, the additional polarization electrode or the grounded ring on the anode side (similar to Figure 3) was applied between the anode and the reference electrode. The width of the grounded ring and the space between the grounded ring and the anode were included in the reported measurements of the width of the entire polarization electrode; this width is equal to the radial distance between the outer edge of the grounded ring and the outer edge of the cathode. A porous silver layer was then applied over the electrodes and the reference electrode to act as a current collector. A fixed voltage of 0.7 V was applied to the main electrodes at a temperature of 750 ° C in the air, and the grounded ring (if present) and the LSM block (if present) are electrically connected to the anode The potential of the seal was measured between the anode and the reference electrode for each test sample, and the seal potential as a function of the width of the polarization electrode that is in the diagram of Figure 14. The data in the diagram demonstrate clearly that the use of a polarization electrode reduces the potential of the seal. In addition, the data indicate that a ring connected to earth is effective in reducing the potential of the seal as a continuous extension with an equivalent size of the anode, and similar reductions were obtained in the seal potential with SCO electrolytes with a thickness of 0.015 cm and 0.038 cm. The study showed that for this particular geometry, temperature and electrolytic material, a polarization electrode at least approximately 0.05 cm wide is necessary to maintain the potential of the anode seal of the stacked component below 40 mV, when a voltage of 0.7V is applied across the cell. A polarization electrode approximately 0.1 cm wide will keep the potential of the anode seal down to approximately 25 mV with an applied voltage of 0.7V applied across the cell. The ratio of the seal potential to the width of the polarization electrode can easily be determined for other cell geometries, materials, and operating conditions when carrying out similar experiments. EXAMPLE 7 The insulating material was prepared to use the cathode seals or electrically insulating support material as previously described. 81.2 grams of magnesium oxide powder (Baker chromatographic grade 2477-5) and 18.8 grams of aluminum oxide powder (Alcoa A-16) were added to a one-liter polyethylene vessel (approximately half filled with 12.5 mm diameter of the grounding medium [Zr02 of high purity (3% of moles of Y203) containing the reagent grade liquids (92.3 grams of toluene and 22. grams of ethanol) and 0.5 grams of the dispersant (Witco Chemical grade PS- 21A) The slurry was mixed for 16 hours with stirring at 115 rpm 55.0 grams of a previously dissolved binder / plasticizer (18.0 grams of polyvinyl butyral binder [Monsanto grade Butvar B-79), 7.2 grams of a Butylbenzyl phthalate plasticizer [Monsanto grade Santicizer S-160, 23.8 grams of toluene, and 7.0 grams of ethanol) and this portion was mixed for an additional 3 hours. The slurry was sprayed in a vacuum desiccator and the tape was emptied on a thin 0.075 mm polyester film with a doctor blade with a height of 0.41 mm. The dried tape had a thickness of 0.14 mm. This 18.8% by weight of MgO and the tape of A1203 were cooked in an alpha-alumina fixative using the following program: 20-500 ° C for 18 hours, 500-1450 ° C for 6 hours (2 hours maintained at 1450 ° C), 7 hours at 20 ° C. The sintered tape had a density of 3.50 g / cc or 97.8% of a theoretical density (based on the diffraction of X-rays, which showed that the only phases present were MgO and MgAl204). The calculated amount of MgAl20 formed was 26.3% by volume. The multiple tapes were laminated on a strip configured as a bar at a pressure of 25 MPa at 65 ° C for one minute. These bars were sintered using the same program at the same density. The thermal expansion showed an identical shrinkage / expansion between 20 and 1100 ° C both with the SCO electrolyte and with the materials interconnecting lanthanum strontium manganite (LSM). EXAMPLE 8 A seo electrolytic material was prepared and co-fired with the insulating material of the Example 7 to demonstrate the union between the two materials.

They were added in a 1 liter polyethylene container 279. 4 grams of cerium oxide powder (Rhone-Poulenc) and 26. 6 grams of strontium carbonate powder (Solvay) (filled in half with a diameter of 12.5 mm with the grounding medium [Zr? 3 of high purity (3% moles of Y2O3)] containing the reagent grade liquids (64.2 grams of toluene and 6.1 grams of ethanol) and 2.6 grams of the dispersant (Witco Chemical grade PS-21A). The water paste was mixed for 16 hours by rotation at 115 rpm. 80.6 grams of a previously dissolved binder / plasticizer (18.0 grams of polyvinyl butyral binder [Monsanto grade Butvar B-79], 7.2 grams of a butylbenzyl phthalate plasticizer [Monsanto grade Santicizer S-160], 23.8 grams of toluene, and 6.0 grams of ethanol) and this portion was mixed for an additional 3 hours. The slurry was sprayed in a vacuum desiccator and the tape was emptied on a thin 0.075 mm polyester film with a doctor blade with a height of 0.41 mm. The dried tape had a thickness of 0.14 mm. This 13.8% by weight of Ce02 and the tape of A1203 of Example 7 at a pressure of 25 MPa at 65 ° C for one minute. The laminated tape was baked in an alumina fixative using the following program: 20-500 ° C for 18 hours, 500-1540 ° C for 9.5 hours (2 hours was maintained at 1540 ° C), 8 hours at 20 ° C. The sintered parts combined well with excellent interface junction. The energy dispersive spectroscopy showed the strontium migration of the SCO electrolyte in the insulating magnesia / spinel layer, presumably forming a strontium aluminate phase in the insulating layer. Thus, the present invention comprises several improvements in the design of the stacked components of planar electrolytic cells that eliminate the faults of the anode seal. One of these improvements is the radial displacement of the anode and cathode seals so that the seals do not overlap on opposite sides of the electrolytic plate. This requires a design geometry of specific cells as described above. Another improvement is the use of a polarization electrode on the anode side of the electrolytic plate that modifies or polarizes the potential of the electrolyte in the seal region, so that the current flow through the anode seal is minimized. The polarization electrode may be an extension of the anode beyond the outer edge of the cathode on the opposite side of the electrolytic plate. Alternatively or additionally, a separate polarization electrode may be placed in the electrolytic plate preferably between the anode and cathode seal. It has been found that a combination of displacement seals and polarization electrodes is particularly effective in reducing or eliminating the anode seal failure by controlling the potential through the anode seal by at least about 40 V. Another feature of the invention is the insulating support placed between the sides of the cathode of the electrolyte and the interconnection which eliminates the potentially harmful stresses in the electrolytic plate 29, when the pressure of the gas on the anode side of the electrolytic cell is greater than the pressure of the gas in the cathode side of the cell. The improvements of the present invention are not limited to the geometries of the stacked components disclosed herein. The polarized electrodes and the displacement seals can be applied to alternative stacked component configurations having different methods for introducing the feed gas into the stacked component, for extracting the spent oxygen gas from the cathode sides of the cells, and / or the extraction of oxygen from the anode sides of the cells. In any application, the polarization electrodes and the Displacement seals can be used to control the potential through the anode seal approximately below 40 mV and preferably below approximately 25 mV. The essential features of the present invention are fully described in the above disclosure. A person skilled in the art can understand the invention and make various modifications without departing from the basic spirit of the invention and without deviating from the scope and equivalents of the following claims:

Claims (26)

1. NOVELTY OF THE INVENTION Having described the invention as above, the content of the following is considered to be our property: CLAIMS 1. A method for separating oxygen from an oxygen-containing gas comprising: (a) contacting the oxygen-containing gas with a first surface of a planar solid electrolyte capable of transporting the oxygen ions; (b) supplying electrons to the first surface of the planar solid electrolyte by a cathode in electrical contact with a portion of the first surface; (c) reducing oxygen electrochemically in the oxygen-containing gas by consuming the electrons to produce oxygen ions; (d) transporting the resulting oxygen ions as current through the solid electrolyte by imposing an electric potential through the solid electrolyte; (e) producing the oxygen gas on a second surface of the solid electrolyte by consuming the oxygen ions and producing electrons; 5 (f) conducting the electrons of step (e) from the second surface by an anode in electrical contact with a part of the second surface; (g) conducting the electrons of step (f) from the anode by an electrically conductive interconnection impervious to the gas that is in electrical contact with the anode; (h) collecting the oxygen gas in a cavity joined at least in part by the second surface of the solid electrolyte, the electrically conductive gas-impermeable interconnection and the gas-tight anode seal disposed between a portion of the second surface of the solid electrolyte and an opposite portion of the electrically conductive interconnection; (i) extracting the oxygen gas from the cavity; (j) extracting the spent oxygen gas from contact with the first surface of the planar solid electrolyte; and (k) maintaining the potential of the anode seal down to approximately 40 mV.
2. 2. The method of claim 1, wherein the potential is maintained at least at about 40 mV by one or more polarization electrodes.
3. 3. The method of claim 1, wherein the pressure of the oxygen gas generated in the second surface of the solid electrolyte is greater than the pressure of the oxygen-containing gas in the first surface of the solid electrolyte.
4. 4. The method of claim 1, wherein the oxygen-containing gas is air.
5. The method of claim 1, wherein the oxygen-containing gas comprises argon and the argon product depleted in oxygen is extracted after contacting the oxygen-containing gas with the first surface of the solid electrolyte and after the oxygen is removed by reduction and transported through the solid electrolyte in steps (c) and (d).
6. 6. An electrolytic plate for a planar electrolytic cell useful for the separation of oxygen from an oxygen-containing gas mixture, wherein the electrolytic plate has an anode side and a cathode side, wherein the planar electrolytic cell comprises the plate electrolytic, a surface of a first electrically conductive gas-impermeable interconnection in electrical contact with the cathode side of the electrolytic plate and a surface of a second electrically conductive gas-impermeable interconnection in electrical contact with the anode side of the electrolytic plate, the electrolytic plate comprises: (a) a planar solid electrolyte capable of transporting the oxygen ions; (b) an anode in electrical contact with a surface of a planar solid electrolyte; (c) a cathode in electrical contact with the opposite surface of the planar solid electrolyte; and (d) one or more polarization electrodes are defined as any electrode that is: (di) in electrical contact with the electrolytic plate; (d2) located in an area of the electrolytic plate so that the area does not have the cathode material on its opposite side, and (d3) in electrical contact with the second electrically conductive gas-impermeable interconnection.
7. The electrolytic plate of claim 6 further comprising a gas-tight seal between the cathode side of the electrolytic plate and the surface of the first electrically conductive gas-impermeable interconnect where the gas-tight seal comprises the electrically insulating material .
8. 8. A planar electrolytic cell useful for the separation of oxygen from an oxygen-containing gas comprising: (a) a solid electrolytic plate capable of transporting the oxygen ions, wherein the plate has an anode side and a cathode side; (b) a first electrically conductive gas-impermeable interconnect having a cathode side in electrical contact with the cathode side of the electrolyte plate; (c) a second electrically conductive gas-impermeable interconnect having an anode side in electrical contact with the anode side of the electrolyte plate; (d) a first cavity defined at least in part by the cathode side of the electrolytic plate, the cathode side of the first interconnection and one or more gas-tight seals disposed therebetween; and (e) a second cavity defined at least in part by the anode side of the electrolytic plate, the anode side of the second interconnection, and one or more gas-tight anode seals disposed therebetween; wherein each or more of the anode seals are displaced completely with respect to each of one or more of the cathode seals on opposite sides of the electrolytic plate, so that the projection of each anode seal on the side of the anode The cathode of the electrolytic plate does not overlap any of one or more of the cathode seals.
9. 9. An electrochemical device for separating oxygen from an oxygen-containing gas comprising: (a) a plurality of planar solid electrolytic plates capable of transporting the oxygen ions, each plate having an anode side, a cathode side, a outer edge and an opening through the plate disposed in an internal region of the plate, wherein the anode side has an anode in electrical contact therewith and surrounded by a region without continuous peripheral electrodes between the outer edge of the plate and the anode, and wherein the cathode side has a cathode in electrical contact therewith; (b) a plurality of gas-impermeable planar electrically conductive interconnections, each having an anode side, a cathode side, an outer edge and at least one opening through an internal region thereof, wherein: the anode has a continuous peripheral flat region adjacent to the outer edge, and one or more passages formed by an interconnected depression on the anode side, said passages are disposed between the peripheral plane region and the aperture and are in fluid communication with the aperture, Electrolytic plates and interconnects are alternatively stacked components to form a stacked component of electrically planar electrolytic cells connected in series, each cell is defined by an electrolytic plate, the anode side of a first interconnection in electrical contact with the anode side of the electrolytic plate, and the cathode side of a second interconnection in electrical contact rich with the cathode side of an electrolytic plate; and an anode seal is disposed between the region without continuous peripheral electrodes on the anode side of the electrolytic plate and attached to the same region and a continuous peripheral planar region adjacent to the external edge of the anode side of the first interconnection, which defines when less in part a cavity for collecting oxygen formed on the anode side of the electrolytic plate. (c) one or more polarization electrodes in electrical contact with the anode side of each electrolytic plate, (d) a grounded rib formed on the anode side of each interconnect as a raised rim surrounding one or more formed passages by an interconnected depression in the anode side of the interconnection, wherein the rib connected to ground is in contact with at least one or more polarization electrodes; (e) elements for providing an electrical potential through the plurality of electrolytic cells that provide a flow of electrons between the adjacent cells through the interconnections; (f) elements for introducing the oxygen-containing gas into the stacked component of the electrolytic cells; (h) elements for extracting the spent oxygen gas from a stacked component of electrolytic cells.
10. The device of claim 9, wherein the cathode side of each electrolytic plate has a region without continuous peripheral electrodes adjacent to the outer edge of the plate and another region without continuous electrodes surrounding the opening, wherein the cathode is disposed between regions without electrons.
11. The device of claim 10, wherein the cathode side of each interconnect has a continuous peripheral planar region adjacent to the outer edge, a continuous high region surrounding the opening, and one or more gas passages formed on the side of cathode by a plurality of raised areas that are disposed between the peripheral planar region and the planar region surrounding the opening, wherein the raised areas and the continuous high planar region are coplanar, and wherein the gas passages are in fluid communication with the portions of the planar region continue adjacent to the outer edge.
12. The device of claim 11 wherein the cathode seal is disposed between the raised continuous plane region surrounding the aperture and attached thereto on the cathode side of the interconnect and the continuous electrodeless region on the cathode side of the electrolytic plate that surrounds the opening therethrough, which forms a partially closed cavity through which the oxygen-containing gas flows.
13. The device of claim 12, comprising an electrically insulating support material disposed between the region without continuous peripheral electrodes on the cathode side of each electrolytic plate and the continuous peripheral region adjacent to the outer edge of the cathode side of each interconnection adjacent.
14. The device of claim 13, wherein the insulating support material is arranged such that the cavity is formed in each electrolytic cell at least in part by an insulating support material, the cathode side of an electrolytic plate, the cathode side of an adjacent interconnect, and the cathode seal so that the cavity is in fluid communication with the elements for introducing the oxygen-containing gas into the stacked component of electrolytic cells and the elements for extracting the oxygen depleted gas from the Stacked component of electrolytic cells.
15. The device of claim 14, wherein the openings in each electrolytic plate and each interconnection in conjunction with the cathode seals form an axial passage through the electrolytic plates and interconnected stacks, said passage being in fluid communication with the cavities of oxygen collection, and where the axial passage is provided for the extraction of oxygen gas.
16. 16. A material suitable for use as an electrically insulating support between an electrically conductive interconnect and an electrolyte in an electrochemical device for separating oxygen from an oxygen-containing gas, said material is made by firing a mixture comprising the inorganic oxide glass or glass-ceramic combined with one or more electrically insulating ceramics approximately above 700 ° C, where the coefficient of thermal expansion of the mixture after annealing differs from the coefficient of thermal expansion of the electrolyte or the coefficient of thermal expansion of the interconnection by less approximately 2 micrometres / (meter • ° C).
17. The material of claim 16, wherein the mixture comprising the inorganic oxide glass or the glass-ceramic combined with one or more electrically insulating ceramics prior to annealing contains about 0.3 to 27% by weight of an aluminosilicate glass of lithium in a mixture with the magnesia of electrically insulating ceramic (MgO) and alumina (Al203), and the ratio by weight of magnesia with respect to the alumina in the mixture before being subjected to cooking is approximately between 0.2 to 8.
18. 18. A method for making a material suitable for use as an electrically insulating support between the electrically conductive interconnect and an electrolyte in an electrochemical device for separating oxygen from an oxygen-containing gas comprising cooking a mixture comprising inorganic oxide glass or glass-ceramic combined with one or more electrically insulating ceramics above approximately 700 ° C to produce an electrically insulating support material having a coefficient of thermal expansion that differs from the coefficient of thermal expansion of the electrolyte or the coefficient of thermal expansion of the interconnection for less than about 2 micrometers / (meter • ° C).
19. The method of claim 18, wherein the mixture comprises inorganic oxide glass or a ceramic glass combined with one or more insulating ceramics prior to firing containing about 0.3 to 27% by weight of an aluminosilicate glass of lithium in a mixture with the magnesia of electrically insulating ceramics (MgO) and alumina (A1203) and the ratio by weight of magnesia with respect to the alumina in the mixture before subjecting it to cooking is approximately between 0.2 to 8.
20. 20. A material suitable for use as an electrically insulating support between an electrically conductive interconnect and an electrolyte in an electrochemical device for separating oxygen from an oxygen-containing gas said material is processed by sintering a mixture comprising one or more electrically insulating ceramics for producing an electrically insulating support material having a coefficient of thermal expansion that differs from the coefficient of thermal expansion of the electrolyte or the coefficient of thermal expansion of the interconnection by less than about 1 micrometer (meter • ° C).
21. The material of claim 20 wherein the mixture comprises magnesia (MgO) and alumina (1203) having a composition such that the ratio by weight of the magnesia to the alumina in the mixture before subjecting it to sintering is approximately between 0.2 to 8.
22. 22. A method for making a material suitable for use as an electrically insulating support between an electrically conductive interconnect and an electrolyte in an electrochemical device for separating oxygen from an oxygen-containing gas comprising the sintering of a mixture. comprising one or more electrically insulating ceramics to produce an electrically insulating support material having a coefficient of thermal expansion that differs from the coefficient of thermal expansion of the electrolyte or the coefficient of thermal expansion of the interconnection for less than about 1 micrometer / (meter • ° C).
23. 23. The method of claim 22 wherein the mixture comprises magnesia (MgO) and alumina (AI2O3) having a composition such that the ratio by weight of magnesia to alumina in the mixture prior to cooking is between 0.2 to 8.
24. 24. The method of claim 22 further comprising attaching the electrically insulating support material to the electrolyte by subjecting it to cooking together with the electrically insulating support material at sufficient temperatures to bond the insulating support directly to the electrolyte. electrolyte.
25. 25. The method of claim 22 further comprising bonding the electrically insulating support material with the electrolyte and the interconnecting by placing the inorganic oxide glass or the glass-ceramic between the insulating support and the electrolyte., placing the inorganic oxide glass or the glass-ceramic between the insulating support and the interconnection and subjecting it to cooking at a sufficient temperature to join the insulating support both in the electrolyte and in the interconnection.
26. 26. The method of claim 25 wherein the inorganic oxide glass or the glass-ceramic is a lithium aluminosilicate glass.