KR20030051764A - Improved solid oxide fuel cells - Google Patents

Abstract

The present invention has a thin electrolyte coating, anode and interconnect material that forms a single honeycomb structure that defines a tubular passageway to the atmosphere and gas for passage when bonded and assembled together and has a variety of configurations and geometries of the cathode flow passageway. A solid state electrochemical device incorporating a planar sheet (11). The atmosphere will flow through the cathode flow passage in the cell plate, but the fuel will flow through the passage formed between adjacent cells. Insulated manifolds designed to hold the fuel and the atmosphere separately are bonded at each end of the honeycomb monolith to inject the atmosphere and fuel into a suitable honeycomb passage. The fuel cell stack and manifold are surrounded by a metal housing or cover to provide an exterior wall of the manifold, complete the package, and define individual fuel cell modules for use singly or in groups in a fuel cell power generation system.

Description

IMPROVED SOLID OXIDE FUEL CELLS

A fuel cell is an electrochemical system that generates electricity by chemically reacting fuel gas and oxidant gas on the surface of an electrode. Conventionally, components of one fuel cell include an anode, a cathode, an electrolyte, and an interconnect material. In solid state fuel cells, such as solid oxide fuel cells (SOFCs), the electrolyte is solid and insulates the anode and cathode from each other against electron flow, allowing oxygen ions to flow from cathode to anode, and the interconnect material is electrically The anode of one cell and the cathode of an adjacent cell are connected in series to generate a useful voltage from the assembled fuel cell stack. SOFC process gases and oxidants (ie, oxygen or air), including natural or synthetic fuel gases (ie, gases comprising hydrogen, carbon monoxide, or methane) react at the surface of the active electrode of the cell to produce electrical energy, water vapor, and heat. Generates.

Several configurations have been developed for solid state fuel cells, including tubular, flat, and integral designs. In the tubular design, each one fuel cell includes electrolyte layers applied to the circumference of the electrode and the porous support tube. The inner cathode layers completely surround the interior of the support tube, and the solid electrolyte and outer anode layers are discontinuous to provide space for the electrical interconnection of the interior of one fuel cell to the outer surface of adjacent, parallel cells. The fuel gas is directed outwardly of the tubular cells and the oxidant gas is directed through the interior of the tubular cells.

Flat design incorporates the use of coded electrolyte sheets on opposite sides of the positive and negative material layers. Ribbed distributors may also be provided opposite the coded electrolyte sheet to form a flow channel for the reactant gases. It is constructed when the existing cross flow pattern is on the opposite side of the co-flow patterns, where the flow channels for fuel gas and oxidant gas are parallel, simpler and more stylized manifold ) Can be integrated into the structure of the fuel cell. The manifold system delivers reactant gases to the assembled fuel cell. The coded electrolyte sheets and the distributors of the flat design are firmly stacked between the current-conducting bipolar plates. In an alternative planar design, the uncoded electrolyte sheets are stacked between the porous plates of anode, cathode, and interconnect materials, and gas delivery tubes extend through this structure.

The integrated solid oxide fuel cell (MSOFC) design is characterized by a honeycomb configuration that is fused together in a continuous structure. MOSFCs are characterized by tape casting or calendar rolling of the sheet components of a cell, which is characterized by thin film composites of anode-electrolyte-cathode (A / E / C) materials and anode-interconnect-cathode (A / I / C) materials. Include. These sheet components are corrugated to form co-flow channels, where the fluent gas flows through the channels formed by the anode layers and the oxidant gas flows through the parallel channels formed by the cathode layers. . A monolithic structure comprising a plurality of single cell layers is assembled in a green or unfired and co-sintered state to melt these materials into a rigid, dimensionally stable SOFC core.

These existing designs have been improved over the prior art to achieve higher power densities. Power density is increased by incorporating smaller single cell heights and shorter intercell electrical conduction paths. Thus, SOFC designs incorporate thin film components that are fused together to form a continuous, bonded structure. However, many small components, layers, interconnects and complex configuration steps reduce the reliability of the working fuel cell. In addition, any given fuel cell design should be commercially available as an alternative power generation device, and thus factors affecting the economics of power generation by electrochemical activities, such as overall capital and operating costs, may be incorporated into existing power generation systems. It must be comparable.

Packages for fuel electricity are known, but are generally simple boxes around a stack of solid oxide fuel cells. See, eg, USP 4,824,724; 4827,606; And 4,943,494 disclose box devices for tubular fuel cell designs. USP 5,238,754; 5,268,241; And 5,527,634 disclose spring loaded fasteners for holding the end plate, tie bar and fuel cell plates together.

The present invention relates to a solid oxide fuel cell, and more particularly to providing an improvement thereto.

The appended claims present novel features that characterize the invention. However, the additional objects and advantages of the present invention, and the present invention itself may be more readily understood through the following examples and the accompanying drawings.

1 shows an assembled fuel cell stack constructed by stacking planar sheets of integrally connected tubular fuel cells, attaching a manifold, and inserting the assembly into the housing.

2 is an exploded view of the assembled fuel cell of FIG.

3 is a cross sectional view of the planar sheet shown in FIG.

4 shows an example of one flat sheet of integrally connected tubes.

FIG. 5 is a cross sectional view of the tube sheet shown in FIG. 4. FIG.

FIG. 6 shows a stack of tube sheets presented in FIGS. 4 and 5 sintered and coated together to form a monolith.

7 and 8 show disassembled and assembled external manifolds with passages and holes to provide fuel and air to each monolithic passage.

9 is a cross-sectional view of the assembly and attached manifold shown in FIG. 8.

10 shows a different tube configuration combined with an internal manifold configuration.

11 shows an asymmetric tube sheet.

12 shows the series of tube sheets of FIG. 11 assembled to form an integrated stack assembly.

Figure 13 shows a tube shape incorporating sinusoidal-like ripples or peaks to increase the active surface area.

14 shows a tube shape incorporating sinusoidal-like ripples or peaks in an integrated assembly.

Figure 15 is an exploded view of another tube shape as an extruded sheet incorporating inner and outer manifolds in an integrated assembly.

16 and 17 show tube sheets formed by a co-extrusion process with modeled attachment manifolds.

FIG. 19 is an exploded view and FIG. 20 shows an assembled view of a fuel cell incorporating the tube sheets shown in FIGS. 16 and 17.

Figure 21 shows a mold assembly made using a fugitive molding process.

Figure 22 shows a stack of tube sheets made using a temporary molding process.

FIG. 23 is an enlarged view of the stack shown in FIG.

FIG. 24 is an exploded view and FIG. 25 shows an assembled view of a fuel cell incorporating the tube sheet shown in FIGS. 16 and 17 or the tube sheet shown in FIGS. 22 and 23.

The present invention is directed to an improved solid oxide fuel cell structure comprising a housing or cover for a solid oxide fuel cell structure that may be a flat sheet stack similar to an integral honeycomb structure when bonded. The present invention also includes additional improvements that are beneficial for optimizing the overall system. In addition, various improvements in cell design for planar fuel cells and the processes for making them are disclosed.

The present invention relates to a solid state electrochemical device incorporating planar sheets of cathode flow passages in various configurations and geometries through a thin coating of electrolyte, anode and interconnect materials, the sheets being assembled and bonded together to form air and air. This results in an integral honeycomb structure defining the tubular passages for the gas passing therethrough. Air flows through the cathode flow passages into the cell plate, and fuel flows through the passages formed by the spaces between adjacent cells. Electrically insulating manifolds designed to separate fuel and air are bonded to each end of the solid oxide fuel cell structure to allow air and fuel to be delivered to the appropriate paths within the structure. Finally, the fuel cell stack and manifolds are encased in a metal housing or cover to provide the outer walls of the manifolds, complete the package, and use individual fuel cell modules that can be used alone or in groups in a fuel cell power generation system. It is limited.

It is therefore an object of the present invention to provide a solid state fuel cell design that incorporates an array of parallel cathode material tubes that improve fuel distribution and eliminate the formation of hot spots in a fuel cell assembly.

Another object of the present invention is to provide a solid state fuel cell design incorporating a unique parallel cathode material tube array that increases the active surface area per unit fuel cell such that the overall power density of the assembled fuel cell stack is dramatically improved.

Yet another object of the present invention is to eliminate the second operations for forming manifolds and fuel side portions as an integral part of the cell plates.

The main advantage of the present invention is to provide all the advantages of the hollow extruded plate concept while eliminating the second motion and integrating the components.

Further objects and advantages will be detailed in the following examples with reference to the accompanying drawings. The objects and advantages of the invention will be realized and attained by means of the embodiments set forth in the claims and combinations thereof.

The present invention relates to a solid state electrochemical device that provides increased active surface area and improves the distribution of process gas. The present invention is described through a detailed description of its application in the operation of a solid state fuel cell (solid oxide fuel cell (SOFC)) having a solid oxide electrolyte. However, those skilled in the art will appreciate that the present invention may be applied to any electrochemical system, including electrolytic cells, heat exchangers, chemical exchange devices, oxygen generators, and the like.

The present invention is directed to improving the active area and process gas distribution available in solid state fuel cells having a unique solid oxide fuel cell structure design. In this fuel cell structure concept, fuel and air enter the stack at one surface and flow through the near space parallel passages to the second surface where they are exhausted together. This stack is composed of a cathode material cell plate, anode and interconnect materials with an electrolyte thin film coating. These cell plates are bonded together to form a structure similar to an integral honeycomb structure, but not limited thereto. Air flows through the passages into the cell plate. Fuel flows through the passageways formed by adjacent cell plates. Nail current collector members can be located in each cell plate to significantly increase the active surface area of the fuel cell stack.

Such devices isolate air in hollow cell plates and surround the cell plates with fuel. By providing electrically insulated manifolds bonded to the ends of the honeycomb integral structure, proper flow of air and fuel is readily accomplished without the need for cross-flow of reactants. These manifolds are designed to keep fuel and air separate and deliver them to appropriate holes in a honeycomb-like structure. These designs also allow internal manifolds in the form of fuel or air sides. They are opened through the plates for circulation of air and fuel. These design improvements reduce the hot spots in the fuel cell and can provide electrical continuity because the surfaces can be continuous.

The asymmetric tube integral embodiment enables the flow of air through the array of parallel cathode material tubes, with fuel flowing in parallel in the passages between the tubes. Such tubes are coated with electrolyte and negative electrode layers except for the interconnect area. This interconnect area is coated with a conductive ceramic film. Cathode tubes are the main structural elements, and the anode layer bonds them together to form unifield cell plates that can be easily processed and stacked. These cell plates are bonded together during a burn-in period to form an integral honeycomb-like structure.

Current flows from the anode to the cathode through the electrolyte layer and then through the interconnect to the anode of the next cell layer. The fact that the anode layer surrounds the cathode except the interconnect area provides electrical continuity, making both the top and bottom surfaces of the plate.

Manifolds are added to the extrusions to form complete cell plates. The inlet manifold forms a vertical air injection passage through a seal around its boundary when the cell plates are stacked. Air supply holes are led from the air intake passage to each air tube in the extrusion. This stack is enclosed by fuel that is in the plenum and flows between the plates from each side through the fuel intake passage. Fuel flows into each fuel passage through fuel metering notches. The mixed exhaust manifold forms a vertical exhaust passage through the seal around the boundary when the cell plates are stacked. Air exhaust gas flows through the air exhaust holes into the mixed exhaust manifold and fuel exhaust gas flows through the fuel exhaust notches into the mixed exhaust manifold.

This device isolates the air in the intake manifold, the cathode air tube, and the mixed exhaust manifold. These components are ceramic and are not affected by oxidation. The stack is surrounded by fuel, creating a reducing environment in which metal components such as power take-offs, pressure plates and tie bars can be used.

Cell plates comprise a cathode, an anode and an electrolyte layer and are made using an extrusion process. The manifolds are molded with cathode materials and bonded at each end of the extrudate in the green state. The green cell plate assembly is then fired to remove binder and transient materials and to solidify the cathode and electrolyte layers. The manifolds become the unifield part of the plate. The ceramic interconnect material is then applied to a particular region using a plasma spray treatment to form a fully concentrated layer without subsequent firing. The plates are then stacked. Initial burn-in sinters the plates together to reduce the anode nickel metal oxide and form an integral structure. The complete assembly may be evaluated in consideration of the illustration of the non-repeating feature.

1 shows an assembled fuel cell 1, which comprises a housing cover 2 for sealing and supporting the elements of the fuel cell. The fuel cell package has a fuel inlet 3, a fuel outlet 4, an air outlet 6 and terminals 8 located above and below the fuel cell.

2 is an assembly view of a fuel cell package, which further illustrates the assembly. The cover 2 comprises an upper section 9 and a lower section 10, both of which enclose a fuel cell stack 11. When assembled, the fuel cell stack 11 is located between the nickel felt layer and the current collector plate, which is best shown in the cross section of the fuel cell assembly shown in FIG. 3. The felt is marked 13. Finally, a ceramic insulator layer 14 is placed on the current collector plate. When the two half parts 9, 10 are assembled, they are held in place, for example by welding two pieces of metal cells so that the assembly can be held firmly together. This is easily accomplished by using the spacer 14 at the bottom of the cell cover. Air and fuel passages in the fuel cell stack are supplied and exhausted by branch pipe assemblies attached to each end of the fuel stack. As shown in FIG. 2, an injection branch 15 is attached to the fuel cell stack and defines an injection gallery 16. Branch pipe 17 defines a fuel discharge gallery 22 and has an air outlet 6. The two branch tubes 15, 17 are provided with a packing groove 18 around the branch tube to seal the branch tube in place when the inlet cover 19 and outlet cover 20 are assembled with the cover half. Will have As shown in FIG. 3, air enters the fuel cell through the inlet 21 but fuel enters through the inlet 3. The fuel is dispersed through the fuel inlet gallery 16 and flows through the fuel cell stack 11, exits the stack through the fuel discharge gallery 22 and flows to the fuel discharge plenum 23 and finally the outlet 14 Is discharged through). Air flows through the air tubes in the fuel cell stack and exits through the fuel flow passages in the stack.

The fuel cell stack includes an assembly of extruded tube sheets, such as the tube sheet 30 shown in FIGS. 4 and 5. 4 shows an individual flat tube sheet 30 of tubes 31 integrally connected. The seat 30 is composed of a suitable fuel cell component material and will include a cathode, anode, electrolyte and interconnect material or a combination thereof. As shown in FIG. 5, the cathode material 32 defines an air passage 33 and has an extrusion cathode or electrolyte and anode coating 34 extruded therewith. In addition, the air layers defining the air passages are interconnected and anode coated 35.

As shown in FIG. 6, a number of flat sheets 50 are stacked to define a fuel passage. Preferably, the sheet 30 may be composed of cathode material in a single extrusion step or may be produced by coextrusion of the cathode material and the electrolyte and anode mixture. Although they can be prepared by extruding the cathode material and then coating the tubes consisting of parallel rows of longitudinally aligned tubes extending flat and extending along the length of the sheet. Although the tube is shown as being triangular, the tube can have any cross section and can be symmetrical or asymmetrical. For example, the cross section may be triangular, rectangular, trapezoidal, circular and polygonal.

As shown in FIGS. 7 and 8, the assembled stack, described as a honeycomb stack, is assembled with an outer branch or plate structure bonded to the face of the honeycomb monolith. For example, as shown in FIG. 7, the air passage 33 and the fuel passage 36 are bonded to the branch pipe structures 37, 38. The branch pipe structure 37 is a distributor of the air via passage 39 and the fuel via passage 40, which are connected to the air passage 33 and the fuel passage 36, respectively, in the fuel cell monolith. The header 38 is connected with the distributor 37 to treat the air holes 41 aligned with the air passages 39 and 33 to allow air to pass through the openings 41 and 39 into the air passages in the fuel cell stack. . The header 38 and distributor 37 define a fuel gallery 47 in which an air passage 39 is sealed by the header 38. When the cover or housing 2, 3 is in place, the seal is formed with the header 38 by placing the appropriate sealing material in the sealing groove 18. The seal is a fire resistant fiber optic rope. The seal provides sufficient compliance to prevent stress due to other thermal expansions formed between the ceramic stack and the metallic stack contaminant structure.

The outer branch arrangement shown in FIG. 9 connects the air passages 41, 39, 36 by connecting the distributor 37 to the stack 44 at 44 and the header 38 to the distributor at 45. The fuel gallery 43 is distributed to the passage 36 through the opening 40. The air passage passes straight through the stack from the outer planar surface of the header plate. Fuel surrounds the sides of the stack and is fed to the stack fuel passageway through the fuel gallery. As mentioned above, the shape of the air passage and the seat is not critical.

As shown in FIG. 10, the tube sheet 50 consists of an octagonal passageway, where the octagonal tube forms a fuel passageway 52 in which the cathode material is coated or coextruded with electrolyte, anode and / or interconnect material. The stack of sheets is the defining and cathode material defining the air passage 51 and space between the combined tubes. A further property is the use of an internal branch pipe in which the connecting material between the tubes defining the air passages is removed to form the fuel side 53. The fuel side facilitates the equivalent of fuel between the levels of the fuel cells of the fuel cell and prevents the occurrence of hot spots in operation.

11 shows a tube sheet using an asymmetric tube structure. As shown, the tube sheet 54 may be a single extrusion of the cathode material into an asymmetrical shape formed by extruding individual tubes and connecting the tubes before being heated to form a monolith.

As shown in FIG. 12, the cathode material defines an air passage 55 but when the tubesheets are stacked the assembly defines a fuel passage 56 such that there is a continuous path for electrons within the tube stack and layer 58. ) Is an anode material, layer 58 is an electrolyte material, and layer 59 is an interconnect material.

Another feature shown in FIG. 13 uses an irregular tube configuration in which the extruded cathode material 60 defines an air passage 61 and is coated thereon with an electrolyte and anode material 62 and interconnect material 63. . When the tube is assembled, the tube 60 defines a fuel passage 64 as shown in FIG. 14. As shown in Figures 13 and 14, the small sinusoidal ripple is increased to 1.5 times the active area for the anode so that there is no increase in material cost.

FIG. 15 shows another tube shape formed by extrusion and with 68 air passages and 69 fuel passages. This design will increase the surface area of the cathode. The tube stack has a fuel side 70 that facilitates fuel flow between the fuel cell stacks. In addition, the header 71 is connected to the fuel stack to facilitate the distribution of air through the air passage 68 and the distribution of fuel through the fuel passage groove 72.

Another method for assembling a fuel cell is the coextruded stack shown in FIGS. 16, 17 and 18, where the air passage is an extruded tube 75 and the fuel passage is a notch or groove 76. When assembled as shown in FIGS. 19 and 10, the sheet 77 causes the groove 76 and the lower surface of the next layer of the tube sheet to define the fuel cell passageway. The header can be attached by detaching, molding and " welding " the tube sheet. "Welding" is used to hold or bond parts together with a ceramic material until the bonding mixture can be heated to produce a more permanent bond. For example, inlet header 77 and fuel inlet passage 79 defining inlet space 78 may be attached to the inlet end of plate 77 and outlet branch 80 may be attached to plate 77. It is attached to the outlet end. The outlet has a matching passage hole 75 and a groove for the fuel passage 76. The discharged air and fuel will be discharged together through the opening 81 in the discharge branch 80. When electrical plates 77 are stacked, for example when 56 cell plates are stacked, branch tubes may be stacked to provide 42vDC at 0.75v / cell. Talc or powdered mica can be used in the branch seal region to reduce leakage. The stack is assembled as shown in FIG. 20 with terminals 86 and 87 between end plates 84 and 85, and ceramic electrical insulation plates 88 and 89 are end plates and base plates 92 and end plates. The powder desorption plate is separated from (93).

Clamping rods are provided by a pair of tiebars and a base plate loaded by a spring. The ceramic electrical insulating plate separates the powder desorption plate from the end plate and the base plate. The plate can be, for example, Hesterloy X casting or a long time tough alumina coated alloy. The tiebar and spring may be, for example, Inconel 716. The tieva may be extruded such that the spring is located outside the hot zone. Inconel springs have a usage limit of approximately 600 ° C. The reaction gas inlet and outlet flows through the ports in the endplates. The end plates are electrically grounded and the connections are formed by bolting or welding to the powder release plate lugs.

Another example of extruding a tube sheet and assembling a molded header is to mold the tube sheet using a fused core material. As shown in FIGS. 21, 22 and 23, a tube sheet with an integral header can be produced by a mold assembly (shown in FIG. 21), which is the lower cathode preform 100, the upper cathode preform 101. And a fuzzy core material 102 positioned between the lower cathode preform 100 and the upper cathode preform 101 to form an air passageway when the cathode material is melted to form a cathode monolith. When the core is combusted, the remaining space defines the air passage 103, the branch pipe is defined by the molded material 104, the fuel injection passage is defined by the space 105, and the fuel passage is space Defined by 106, the fuel side is defined by space 107. The space forms an air side at 108.

The upper and lower cathode preforms can be formed by compression molding or similar titration processes. Fused cores are prepared by compression or injection molding from polymer waxes, carbon powder mixtures or other materials that evaporate, vaporize, and decompose and are removed by heat without leaving any excess. The green upper and lower green cathode preforms are assembled into a fusitive core, the assembly being pressed together with the intra die cores to connect the preforms into a single green cathode cell plate surrounding the core. The assembly is then dried and heated to reinforce the cathode with the porous ceramic. The core supports the cathode material during the beginning of the heating cycle and is then removed by evaporation or pyrolysis. As a result, a complete hollow cathode with an inlet and outlet branch is formed, and subsequent processing for adding the electrolyte, interconnect and anode layer is prepared. The seat can be assembled in a similar manner as shown in FIGS. 19 and 20 to provide a complete fuel cell.

24 and 25 illustrate alternative package designs for those shown in FIGS. 19 and 20. FIG. 24 is an assembly view and FIG. 25 shows an assembly view of a packaging similar to that shown in FIGS. 1-3. As shown in FIGS. 24 and 25, the upper cover 111 and the lower plenum. The parts are clamped, welded or fixed by appropriate means to securely hold the fuel stack and remain assembled. This facilitates the use of the mesh spring pack 116 located in the bottom cover or fuel plenum 112. When the assembly including the ceramic insulators 117 and 118 is completed, the current collector plates 119 and 120 generate a current flowing through the terminal 121. Air is supplied to the housing at 122 and a fixed outlet is located at 123. Fuel is supplied to the plenum through fuel inlet 124.

Taking a fuel cell stack as shown in FIG. 3 and combining them end to end using a coupling header to provide an assembly having a lower section for low temperature treatment and a second section for high temperature treatment. In addition, several units can be combined into a single package module by connecting modules in series with electrical connections to form metal felt pads and / or large packages.

The fuel cell operates by flowing air and gas through parallel spaced passages. Fuel flows from each side through fuel inflow passages between the cell plates. It then flows through the fuel metering slot and between the cell plates to the discharge end of the cell stack. The fuel reacts with the air flowing through the internal air passages to generate power. The fuel side provides an extended reactive surface area and an electrical connection between the upper and lower sides of the selpan. The air side improves the access of air to the reactive layer compared to a single straight synchronous passage. These facilitate the processing of the fused cores. The fuel and air passages are quenched and mixed into the exhaust branch (i.e., the inner branch similar to the air inlet branch).

The foregoing embodiments of the present invention have been provided for purposes of illustration and description. These descriptions and examples do not limit the invention to the forms described, but many modifications and variations are possible in light of the above teachings. The embodiments are chosen to best illustrate the principles of the invention and its practical application, and thus enable those skilled in the art to make the best use of the invention in various embodiments and that other modifications suitable for a particular use are possible. The invention is defined by the following claims.

Claims (16)

A. A parallel cell passage stack defining an air and fuel passage and comprising a cathode layer, an electrolyte layer and an anode layer; B. Manifold means attached to the input end of the fuel cell stack and distributing air and fuel to the air and fuel passages; C. current collecting means for electrons generated in the fuel cell stack; D. terminal means for drawing said electrons as current from said current collecting means; E. drawing means for supplying fuel to said manifold means; F. drawing means for supplying air to said manifold means; G. discharge manifold means for collecting and emptying discharge from said stack; H. discharge means for removing emissions from said fuel cell system; I. A solid oxide fuel cell system comprising housing means for sealing said fuel cell and defining said outer wall of said input manifold means to maintain said stack under tension. The solid oxide fuel cell system of claim 1, wherein the parallel cell passage stack has a sintered honeycomb structure. 2. The solid oxide fuel cell system of claim 1, wherein the parallel cell passage stack is a honeycomb monolith, the monolith having internal means for distributing the air and gas through the monolith. 2. The solid oxide fuel cell system of claim 1, wherein the housing means is a metal shell having at least two pieces joined together by welding. 2. The solid oxide fuel cell system of claim 1, wherein the cell stack is supported by elastic means, so that the cell stack can extend within the range of the housing. The method of claim 1, wherein the parallel cell passage is made by pushing the cathode material to create the air passage through the cathode material, wherein the seat defines an air and fuel passage for operating the fuel cell. Solid oxide fuel cell system. The method of claim 1, wherein the parallel cell passage stack is made by a positive core molding process, wherein the positive core vaporizes or disassembles to leave an air passage, and when the stack is assembled, the assembly defines a fuel passage and is porous. And heated to integrate the cathode into the ceramic. 8. The solid oxide fuel cell system of claim 7, wherein the stack of parallel cell passageways is made by a positive core molding process, wherein the molding process results in an integral inlet manifold and outlet manifold structure. 8. The solid oxide fuel of claim 7, wherein the parallel cell passage stack is made by molding each half of the stack and then combining the half to generate a full cell stack with integral inlet and outlet manifolds. Cell system. 10. The solid oxide fuel cell system of claim 1, wherein the parallel cell passage stack is made by extruding a ceramic composition to form a parallel cell passage sheet and then welding the inlet and outlet manifolds to the extruded cell stack. . The solid oxide fuel cell system of claim 1, wherein the nickel felt layer is disposed above and below the monolithic stack to generate an elastic conductive layer. 2. The solid oxide fuel cell system of claim 1, wherein the parallel cell passageway has a geometry and the anode coating increases thickness in the direction of current flow while the cathode decreases in thickness. The method of claim 1, wherein the parallel cell passage includes current path means for traversing the cathode, electrolyte, and anode layers, and the electrons move through the cell to facilitate the flow of electrons in the direction of the current path. Solid oxide fuel cell system, characterized in that. The solid oxide fuel cell system of claim 1, wherein the parallel cell passageway defines a tube having a cross section of a geometric shape selected from the group consisting of circular, octagonal, hexagonal, rectangular and triangular. The solid oxide fuel cell system of claim 1, wherein the cell passageway defines a tube having a cross section of an asymmetric polygonal geometry. The solid oxide fuel cell system of claim 1, wherein the stack of parallel cell passageways comprises means for interconnecting the layers of the stack, such that current can flow between the layers of the stack.