JP6108724B2 - Fuel cell with improved current guidance - Google Patents

Description

  The present invention relates to a fuel cell and a fuel cell system.

  The fuel cell is configured in a tubular shape or a planar shape. The fuel cell which is the subject of the present application has a tubular structure. This is also called a tube shape, and is distinguished from a fuel cell formed into a planar shape by its geometric shape.

  It is known to use a current collector in a tubular fuel cell for the current guide along this tube. They are mainly formed from a particularly conductive material, for example to provide a suitable current guide and limit resistance losses, for example as a current collector rod, placed in the middle of a gas supply cylinder, or a layer or web Directly on the tube. In addition to good conductivity, the current collector should have chemical and thermomechanical compatibility with the other materials used (eg anode or cathode). In addition, long-term durability should be provided even at high temperatures.

  A tubular fuel cell is known from document EP 1079453. Here, the sealing structure improves the sealing properties of the cell as well as the electrical properties of the cell. In addition, the tubular cell includes a cell element film. This is formed on the surface of the substrate tube of the fuel cell by forming the firing method and the fuel electrode and air electrode as a film. Here, a solid electrolyte is inserted between the fuel electrode and the air electrode. At this time, an adhesion enhancing film having a large surface roughness is disposed on the sealed section of the tubular cell.

  Furthermore, a method for producing a solid oxide fuel cell or a solid oxide fuel cell is known from the document EP 1 624 521. The fuel cell includes a plurality of cells. Each of these cells includes a fuel electrode, an electrolyte, and an air electrode. These cells are here arranged, for example, on an insulating substrate with a tubular cross section. A plurality of adjacent cells are electrically connected to each other in series by an interconnector. Each of these interconnectors connects the fuel electrode of the first cell to the air electrode of another cell.

European Patent No. 1079453 European Patent Application No. 1624521

  To provide a fuel cell and a fuel cell system with improved current guidance.

  The above-mentioned problem has a tubular functional part with at least two segment lines that are electrically connected, each of the at least two segment lines having at least two electrode-electrolyte-segments. Each of the electrode-electrolyte-segments includes an anode, a cathode, and an electrolyte disposed between the anode and the cathode, the electrode-electrolyte in one segment line -The segments are connected in series, at least two electrodes arranged in different segment lines-the electrolyte-the segments are electrically connected via a connection part formed from the anode material or from the cathode material In particular, this allows a plurality of segment lines to be connected in series. It is solved by a fuel cell to. The above-described problem is solved by a fuel cell system including at least one fuel cell.

  A constituent element of the present invention is a fuel cell, and the fuel cell includes a tubular functional unit having at least two segment lines that are electrically connected. Here, each segment line of the at least two segment lines has at least two electrode-electrolyte-segments, and the electrode-electrolyte-segment has one anode and one cathode, one anode and one cathode. And an electrolyte disposed therebetween. These electrode-electrolyte-segments of the segment line are connected in series. Furthermore, the at least two electrode-electrolyte-segments arranged in different segment lines are electrically connected via a connection formed from the anode material or from the cathode material, in particular thereby A plurality of segment lines are connected in series. In the present invention, the functional part is an element or a part that gives a function to the fuel cell, that is, is used for supplying energy. In order to supply energy, in particular, the electrode-electrolyte-segment is used in the fuel cell according to the invention. This segment includes an anode, a cathode, and an electrolyte disposed therebetween. Such segments are supplied with energy by the electrochemical process of the anode, cathode and electrolyte in a manner known per se in fuel cells.

  In the present invention, the functional unit has at least two segment lines that are electrically connected. Here, each segment line of the at least two segment lines has at least two electrode-electrolyte-segments, and the electrode-electrolyte-segments are connected in series. Thus, the functional part has at least four electrode-electrolyte-segments. Each electrode-electrolyte segment now includes one anode, one cathode and one electrolyte disposed between the electrodes. By providing such a plurality of electrode-electrolyte segments, the functional part is appropriately adapted to each application. In particular, the current value and voltage value of the fuel cell can be adjusted as desired. By providing electrode-electrolyte-segments that are electrically connected in different lines, further expanded versatility or adjustability is obtained.

  In order to eliminate unwanted effects between at least two segment lines, the segment lines themselves can further be at least partially electrically isolated from one another. “Partially insulated from one another” means, in particular, within the framework of the invention, that the individual segment lines are only electrically connected to one another only via the intended electrical connection, for example a connection part. It means that More particularly here, the anode and cathode regions of the different segment lines or their electrode-electrolyte-segments are electrically and ionically isolated from each other, for example, thereby preventing insulation. More preferably, the different segment lines and their electrode-electrolyte-segment electrolyte regions are also isolated from one another both ionically and electronically. Thus, at least two segment lines or their electrode-electrolyte-segments are completely electronically and ionically isolated from each other, or suitable electrical insulators, ionic insulators or electrical and ionic insulators, It can be provided only where necessary. Electrical insulation means in the scope of the invention in particular that there is no electrical conductivity in this region or only a non-essential electrical conductivity. In this context, ionic insulation means, in particular, that no ionic conductivity exists in this region, or that only non-essential ionic conductivity exists.

  In the present invention, the functional part is further formed in a tubular shape, whereby a tubular or tubular fuel cell is formed. The tubular functional part here is in particular a hollow cylindrical body with a substantially circular, for example annular, elliptical or polygonal base. Furthermore, this functional part already has adequate stability. Therefore, there is no need to provide a carrier. In this way, the manufacturing method can be made particularly simple and low cost. Here, the tubular function can obtain its stability by one or two electrodes and / or by an electrolyte. In other words, the functional part can be carried by the electrode or can be carried by the electrolyte. However, basically, in the present invention, a non-self-supporting configuration of the functional unit is also possible.

  The fuel cell of the present invention further has a particularly advantageous electrical connection of at least two electrode-electrolyte-segments arranged in different segment lines. In particular, in the present invention, at least two electrode-electrolyte-segments arranged in different segment lines are electrically connected to each other via a connection formed from an anode material or from a cathode material. It is connected to the. Here, this electrical connection is realized within the scope of the invention, for example, by a connection part configured as one part with the anode or the cathode. Thereby, this connecting part is formed as part of the anode or cathode. Or a corresponding electrode is conductively connected to this connection. Here, in particular, the connection area is the following area. That is, although it is formed from an anode or cathode material, it does not contribute or substantially contribute to the generation of electrical energy, and the main task is to electrically connect the two electrodes-electrolytes-segments. This is a region having a good connection. For example, in the present invention, the corresponding region is not disposed opposite the complementary region, i.e., for example, the cathode material is not provided directly adjacent to the anode material, or vice versa. The above can be read. Or, for example, in the region of the connecting portion, the above can be read in the present invention from the fact that the surface and / or volume of the anode material is larger compared to the cathode material and vice versa. Here, in particular, a series connection of at least two segment lines is realized here.

  Here, the electrical connection is not particularly limited to the electrode material. Rather, in the present invention, the electrical connection that electrically connects the two electrode-electrolyte units to each other is the material or the material from which at least one electrode of the two electrode-electrolyte units to be connected is formed. Formed from substance or mixed substance.

  The anode material here is, for example, gas permeable or gas impermeable. Here, this gas permeability is adjusted by adjusting the appropriate porosity of the anode material. Particularly suitable anode materials are materials that are both conductive and ionically conductive. The advantage of an anode material that is ion-conductive is the formation of a two-dimensional reaction space. This causes a reaction on the entire surface of the anode material and this reaction is not limited to a three-phase interface. An example of a conductive and ion non-conductive material that forms or can be included in the anode is, for example, nickel. An example of a conductive and ionically conductive material that forms or can include the anode is, for example, nickel mixed with yttria stabilized zirconia (YSZ).

  The cathode material here is, for example, gas permeable or gas impermeable. Here, this gas permeability is adjusted by adjusting the appropriate porosity of the cathode material. Particularly suitable as the cathode material is a material that is both conductive and ionically conductive. The advantage of the ion conductive cathode material is the formation of a two-dimensional reaction space. This causes a reaction on the entire surface of the cathode material and this reaction is not limited to a three-phase interface. An example of a conductive and non-ionically conductive material that forms or can be included in the cathode is, for example, lanthanum strontium manganite (LaSrMn, LSM). An example of a conductive and ionically conductive material that forms or can be included in the cathode is, for example, lanthanum strontium cobalt ferrite (LSCF).

  The formation of the connecting part from the anode material or the cathode material here means in particular: This means that the connecting part is formed from a corresponding chemical material, substance or mixture. The porosity, in particular the gas permeability, can be different here, for example, when the anode or cathode material is used as an electrode and when used as a connection.

  In the present invention, it is not excluded that another electrical connection unit is arranged, for example, between the anode and the connection part or between the cathode and the connection part. In the latter case, the corresponding electrode-electrolyte-segments are indirectly connected to each other by connecting parts.

  By electrically connecting the two electrode-electrolyte segments as described above, the current guide or current flow in the fuel cell according to the present invention is significantly improved compared to conventional fuel cells. The anode material or cathode material is used to electrically connect the two electrode-electrolyte-segments in addition to the anode function, and thus by taking on substantially the function of a current collector, thereby allowing current flow. However, it is often achieved without providing a costly current collector. Furthermore, a particularly easy manufacturing method is realized, for example, by a printing process. This electrical connection is here made in a step involving the deposition of electrode material, for example during the printing process.

  Moreover, thermomechanical problems are reduced or completely prevented by relatively simple geometries and a reduced boundary layer of various materials.

  In some embodiments, the at least two segment lines are at least partially ionized by an airtight joint that is axially oriented with respect to the axis of the tubular feature and extends axially with respect to the axis of the tubular feature. And electrically isolated from each other. In this form, the division of the functional layer or the functional part along the tube is realized, so that substantially two half tubes are produced. In particular, a parallel current flow direction is thus obtained in each segment line. This parallel current flow direction extends in the axial direction in the present invention, in particular without an axial current collector. Therefore, in this configuration, in particular, a current direction extending along the axial direction of the tubular functional part is realized. Here, the fuel cell of the present invention is particularly suitable because the path through which current flows is short.

  Here, the directions in which the currents flow are mutually reversed in at least two segment lines. In this configuration, the current is guided or flows particularly upward in one half tube and is guided or flows downward in the other half tube. In this way, in particular, the electrical connection of the fuel cells according to the invention is facilitated. This further expands the application range. Therefore, in this embodiment, the positioning of the connection portion can be selected in a wider area. Therefore, a great degree of freedom occurs in the structure of the fuel cell of the present invention.

  In another form, the electrical connections between the different segment lines include connectors in addition to the connection portions, and / or one electrode-electrolyte-segment anode of the same segment line is another The electrode-electrolyte-segment cathode is electrically connected by a connector. Such connectors are kept very small in size and form only spatially limited connections. This saves costs when manufacturing the fuel cell according to the invention. The achievable cost savings are further expanded by: That is, the electrode-electrolyte-segment is expanded by only comprising an anode, a cathode, an electrolyte, and a connector as a connecting element. In this way, further components are omitted. Moreover, the capacity of the fuel cell according to the present invention is not reduced. Furthermore, the manufacturing method becomes simpler by reducing the number of members required. Thus, in the first case of electrode-electrolyte-segment connection of different segment lines, the connector is used as an additional member of the connection part formed from the anode material or the cathode material. This realizes, for example, a series connection. In the case of connecting a plurality of electrode-electrolyte-segments of the same segment line, the connector is used as a sole member for connecting the corresponding electrode-electrolyte units in series. Here, the connector particularly preferably has the same structure. This makes the manufacturing method particularly easy.

The connector or connectors are in particular formed from or comprise a material that is electrically conductive and ion-insulating. Furthermore, the connector in particular is formed from or contains an airtight material. For example, the connector is formed from or includes lanthanum chromite (LaCro ₃ ), zinc oxide (ZnO), platinum (Pt), or an ion non-conductive anode or cathode material.

  Accordingly, the connector or connectors are made of a conductive material, such as an anode material or a cathode material. Here this material is hermetic and non-ionic. In this way, suitable connections are provided between each electrode of the electrode-electrolyte-segment. Here in particular, ionic connections between the corresponding electrolytes of the electrode-electrolyte-segment are thus prevented. This prevents the electrode-electrolyte-segment noise flow. Furthermore, a particularly easy manufacture is realized by the connector being formed from an anode material or a cathode material. Here, the corresponding components of the electrode-electrolyte-segment are suitably ionically insulated from one another or left insulated. Gas permeability or gas tightness is here achieved, for example, by appropriately adjusting the porosity of the same material or the same chemical substance or mixed substance.

  In another form, the fuel cell has a layer assembly comprising an anode layer, a cathode layer, and an electrolyte layer. This is a particularly easily manufacturable assembly for producing electrode-electrolyte-segments or functional parts of fuel cells. In particular, it is possible to form a structure consisting of an anode, a cathode and an electrolyte disposed between them. This can be provided in a tubular or tube form without any problem. Furthermore, conventional manufacturing methods, such as printing methods, can be used to manufacture the fuel cell of the present invention. Here, suitably, the individual layers are only deposited adjacently. Here, depending on the case, an appropriate insulating part is added.

  In another form, an anode region is formed in the anode layer. This forms the anode of the electrode-electrolyte-segment. Here, one anode region is separated from another anode region by an electrically insulating and ionic insulating region.

  In another form, a cathode region is formed in the cathode layer. This cathode region forms the cathode of the electrode-electrolyte-segment. Here, one cathode region is separated from another cathode region by an electrically insulating and ionic insulating region.

  In another form, an electrolyte region is formed in the electrolyte layer. This electrolyte region forms an electrode-electrolyte-segment electrolyte. Here, one electrolyte region is separated from another electrolyte region located in the same segment line by an ionic insulating region and / or one electrolyte region is located in a different segment line. It is separated from another electrolyte region of the electrolyte region by an electrically and ionically insulating, gas tight region.

  In this form, the electrode-electrolyte-segment is advantageously manufactured particularly easily and at low cost. Here, a particularly great consistency for the desired application is obtained, in particular by adjusting the number, size and shape of the individual anode regions, cathode regions or electrolyte regions. Further, in this way, a complicated structure can be realized by a simple manufacturing method, for example, a printing method.

  Here, electrically and ionically insulating regions for separating the anode and / or cathode regions are formed by air or air filled cavities and / or arranged in different segment lines. The electrically and ionically insulating regions for separating the separated electrolyte regions are formed by solid insulators, in particular aluminum oxide, and / or separated electrolyte regions arranged in the same segment line. The ion-insulating region to be further conductive is formed by the connector. Air, on the one hand, is a good electrical insulator, where it has no requirement for proper manufacturing or geometric shape. Furthermore, a partially costly insulator can be omitted. As a result, the fuel cell according to the present invention is formed at a particularly low cost. Further, for example, aluminum oxide is a low cost insulator. This provides both electrical and ionic insulation or has the desired electrical and ionic insulation. In this configuration, only one insulating material that is ionically and electrically insulative is used. This saves costs. Further, the fuel cell of the present invention can be easily manufactured, for example, with the above-described layer structure, even in this configuration including the solid insulator, by the manufacturing steps known per se as described above. This manufacturing is further facilitated when the connector is used as an ion insulating region. This is because, in particular, the materials used in any case can be used in the processing steps, and further materials and processing steps are omitted.

  In another form, the anode region of the electrode-electrolyte-segment disposed in the anode layer and the cathode region of another electrode-electrolyte-segment disposed in the cathode layer partially overlap. Be placed. Here, the connector in the electrolyte layer is disposed in the overlapping region. Here, in particular, the connector is constructed mainly in the electrolyte layer and / or does not protrude into the anode layer and / or the cathode layer. In this way, the individual electrode-electrolyte-segment connections are constructed in a particularly compact manner, thereby saving space. Furthermore, a connector is arrange | positioned only in an electrolyte layer, for example. This saves material and thus costs. Here, this arrangement is preferably easily formed by a coating method, for example a printing method.

  Further, a configuration in which a current collector for electrically contacting and connecting an electrode made of a conductive material different from the anode material and the cathode material is not attached to the outer surface of the electrode of the electrode-electrolyte-segment, and / or the fuel cell is provided. A configuration without a longitudinal current collector for connecting a plurality of electrode-electrolyte-segments is possible. It is arranged axially with respect to the axis of the functional part and is made of a conductive material different from the anode material and the cathode material. The fuel cell according to the invention therefore does not have an axial current collector, in particular with respect to the tube axis. As a result, a short current guide path according to the present invention can be realized, and the fuel cell manufacturing method of the present invention becomes easier and less expensive. Some of the costly extra steps of connecting the current collector and connecting the contacts can be omitted. Furthermore, the material of the current collector can be omitted, which is particularly advantageous. This is because high demands are placed on the material of this current collector or collectors. Rather, in the present invention, current flows through an assembly that includes or consists of an anode, a cathode, an electrolyte, and a connector.

  In another form, the functional part is formed as a tube closed on one side. In this embodiment, appropriate separation between the fuel side and the air side is realized. In a particularly advantageous shape here, the fuel side is formed inside the tube. In particular, if the tube closed at one end is arranged on the carrier substrate on its open side, air easily flows along the outside or air side. On the other hand, for example, hydrogen flows along the inner side or the fuel side. This reduces the risk, even if it uses a potentially safe critical material, such as hydrogen, as a fuel, but rather eliminates it completely. Here, the tube can be sealed either by the functional part itself or by another material, for example glass.

  In another form, the functional part is arranged on a tubular carrier. This further improves the stability of the fuel cell. In this case, great variability with respect to the electrode material and electrolyte material or its thickness and configuration is obtained. This stability of the fuel cell or tube is here particularly based on the support. The support can for example comprise or be formed from one, in particular inert, ceramic material and / or glass material. In the context of the present invention, inert materials are in particular materials that do not participate in electrochemical reactions, for example by ion guides of electrolytes, and / or materials that are not used as electrodes. In this case, the fuel cell is also referred to as an inter-support fuel cell. The material of the carrier is in particular ion-insulating, in particular ion-insulating and electrically insulating.

In particular, the support contains or is formed from magnesium olivine (Mg ₂ SiO ₄ ), in particular forsterite.

  The arrangement of the functional parts on the tubular carrier is arranged within the framework of the invention, in which the functional parts are arranged in the carrier or inside the carrier and / or outside or outside the carrier, in particular in contact with it. It means that. In particular, the cathode layer of the functional part is in contact with the carrier. The anode layer of the functional part here is in particular accessible from the inner space or the outer side of the carrier.

  In particular, the carrier has pores and / or openings, in particular pores, through which the gas passes in one or more parts in contact with the functional part. In one or more parts that are not provided with one or more electrode-electrolyte-segments or are not covered by a functional part, the carrier is formed in a particularly gastight manner.

  For example, the carrier has at least one open tube end, in particular a tube end open on one or both sides, and has a base for fixing the fuel cell to the support substrate. This is also referred to as a mounting flange or a gas connection flange. Here, in particular, the base is configured to be airtight.

  In addition to this, in particular when the open tube end is formed as a base, the carrier is sealed off by the cap part at one (other) tube end. Here, the cap part is formed in a particularly gastight manner.

  In this case, the production of, for example, a tubular carrier from the material forsterite, for example with a hollow cylindrical wall, results in a highly porous region. On the bottom side, for example, a base, also called a mounting flange, is arranged on the carrier. On the top side, an airtightly formed cap portion, also called a tube cap, is arranged for the airtight sealing of the carrier. This functional part is positioned at the height of the porous region inside the tube. In this form, the carrier functions as a so-called electrochemically inert carrier for the functional layer or functional part. This is because this material does not participate in electrochemical reactions. This achieves a very thin layer. This means a saving of material in the individual functional areas. This saves in particular costs. Based on this carrier, the functional part is produced in this form in a layer thickness with fewer systems. In particular, the layer thickness of the electrolyte layer is reduced here. For example, the electrolyte layer has a layer thickness in the range of 10 μm to 20 μm, for example, 15 μm. This results in a continuous operating temperature of only about 750 ° C.

  To start operation, the combustion gas is guided into the tube or carrier where it hits the anode. The reaction partner air reaches the cathode through a porous support, in particular a forsterite tube. In this concept, all functional layers of the functional part are located on the combustion gas side.

  This functional part is, for example, directly connected via a film back injection molding method or connected to a carrier substrate made of forsterite, for example, or fixed to the carrier substrate during the injection molding process. Therefore, the manufacturing step can be omitted.

Forsterite is advantageously electrically highly insulating, with specific resistances of 10 ¹¹ Ωm (20 ° C.) and 10 ⁵ Ωm (600 ° C.). Therefore, when the functional unit is configured, an electrical short circuit or an ionic short circuit is not expected, and an additional insulating layer can be omitted.

Forsterite is further tailored to the functional material in terms of firing behavior, such as shrinkage or firing kinetics, and in terms of thermal elongation properties (about 10-11 ^{* 10-6} K- ¹ ). This allows simultaneous firing of the entire compound. Thus, instead of the two firing steps normally required, only one firing step is required to produce the cell. This provides further cost savings.

  High-purity forsterite is further produced from talc and one or more magnesium compounds, in particular magnesium salts (eg magnesium oxide), via reaction calcination, thereby contributing to cost savings in cell production. .

In detail, forsterite is first obtained from talc (Mg ₃ Si ₄ O ₁₀ (OH) ₂ ) and a magnesium compound, for example magnesium oxide (MgO), according to the following reaction, in order to produce a support. Is:
Mg ₃ Si ₄ O ₁₀ (OH) ₂ + 5MgO → 4Mg ₂ SiO ₄ + H ₂ O
This is achieved in particular through a common grinding process of the two raw material components in high energy grinding. Thereby, for example, particle sizes of 4 μm or less, in particular 3 μm or less, are adjusted in order to form intact forsterite and to allow subsequent co-firing. Forsterite formation takes place here in particular by calcination of the ground material. This advantageously allows the raw material to be processed into injection molded components.

In order to avoid the formation of free SiO ₂ , which can cause chemical reactions with the cathode during cofiring and cause functional loss, it is particularly advantageous for 0.25% to 0.75%, for example 0%. A magnesium oxide with a mass ratio higher than the stoichiometric ratio of 0.5% is adjusted. In addition to magnesium oxide, other magnesium raw materials such as magnesium hydroxide (Mg (OH) ₂ ) and / or magnesium carbonate (MgCO ₃ ) can also be used. This calcination destroys the mineral plate structure of talc and initiates regeneration into forsterite. The resulting, for example, spherical particle shape allows a variable solids content in the component. As a result, the contraction of the contraction to the functional unit can be performed. In order to produce a hermetic carrier part, hermetic fired (injection molded) components (compounds) are used. This may contain organic components, binders and / or plasticizers, in particular 25% to 75% by volume, for example 56% by volume of forsterite component. In contrast to this, porous fired (injection molded) components can be used to produce a porous carrier part. This is admixed with one or more, in particular organic pore formers. This is baked by ceramic injection molding (CIM) during the post-molding thermal process, leaving an infiltration hollow space.

  The pore forming agent includes, for example, a phenol resin-short fiber having a size of 100 μm × 10 μm to 300 μm × 30 μm, for example, a size of 200 μm × 20 μm. Therefore, advantageously, an infiltration pore network with a passage section of 2.5 μm to 7.5 μm, for example 5 μm, is obtained. Based on such a pore passage section, free gas diffusion is achieved in particular without Knudsen action. Another fibrous pore former is cellulose. However, spherical pore formers made of starch, thermosetting powder or glassy carbon are also possible.

  The formation of the entire combined body is performed through injection molding of a plurality of components. Here, first, a porous fired component is formed into a geometrically defined tube. In this step, the functional part (in-mold label) is placed in the tool in advance, and then the porous fired component is flowed. Here, the functional unit and the component are closely connected. Next, in a second step, the cap portion and / or one or more bases of the component to be hermetically fired are injection molded. In order to avoid separation of the two materials in the form of cracks, etc. during the thermal process or subsequent operation, a connection profile according to shape is advantageously provided in the connection region of the two materials. This is achieved without problems using ceramic injection molding. There are wavy or profiles using grooves and sun. However, undercutting that can be freely structured is also possible. In this way, the functional layer is incorporated into the cell after the injection molding process.

  Subsequent release and co-firing of the entire tube is performed at a temperature of 1200 ° C. or lower. Here, first all organic components are separated from the injection molded body and the functional layer, and the desired porosity is adjusted in the carrier. Thereafter, the material is ceramicized. A curing time of at least 5 hours is advantageous in order to completely fire all components.

  As an alternative or in addition to this, first the part produced from the porous fired component is sealed with an airtight material. As an alternative or in addition, the carrier, in particular the cap part, is formed as follows. That is, the guide element for stabilizing the gas supply cylinder is formed. A base is formed on the opposite side. This allows an airtight connection without additional sealing of the airtight material. Here, the entire tube tube is fired simultaneously.

  In another form, the connecting portion is disposed at the terminal portion of the functional unit. Thereby, the segment lines in particular extend over the entire axial length of the fuel cell and are interconnected only at the head end, in particular by a series connection. In this configuration, particularly when the current flow is opposite in the plurality of segment lines, the full length or the entire axial surface of the fuel cell is preferably utilized, whereby the power supplied from the fuel cell is increased. Is maximized.

  If the connecting part is formed as an annular conductor, the resistance drop is minimized at the connecting part. This is because it is constituted by a large track section. Furthermore, the annular conductor can be incorporated in the tubular or tubular functional part without any problem. This is especially the case with the layer structure described above. By forming the connecting part or the annular conductor from a cathode material or an anode material, these are easily formed during the formation of the anode region or the cathode region, for example incorporated into a layer structure. This further facilitates the production of the fuel cell of the present invention.

  The invention further relates to a fuel cell system. This includes at least one fuel cell according to the invention. Here, the at least one fuel cell is advantageously arranged on a carrier substrate. In this configuration, the fuel cell system in particular has a plurality of fuel cells. Through various forms of fuel cells, in particular, the desired power characteristics of the fuel cell system are adjusted. This allows for great variability in application. The carrier substrate is formed, for example, from an inert material. Furthermore, the carrier substrate forms, for example, a bottom plate.

  Further advantages and preferred embodiments of the object according to the invention are illustrated by the drawings and explained in the following description. It should be noted, however, that the drawings are for illustrative purposes only and are not intended to limit the invention in any way.

Schematic of an embodiment of a fuel cell according to the invention Schematic showing the layer structure of an embodiment of a fuel cell system according to the present invention Schematic of another embodiment of a fuel cell according to the present invention Schematic of another embodiment of a fuel cell according to the present invention Schematic of another embodiment of a fuel cell according to the present invention

  FIG. 1 shows a schematic diagram of an embodiment of a fuel cell 1 according to the invention. This fuel cell 1 is used, for example, for obtaining energy as the only fuel cell. However, it may be combined into a single fuel cell system, for example on a carrier substrate, together with other fuel cells 1 that are formed in the same way.

  The fuel cell 1 includes a tubular functional part 2. This functional part includes at least two electrically connected segment lines 3 and 4. Particularly advantageously, these at least two segment lines 3, 4 are at least partially electrically and ionically isolated from one another. This avoids unwanted buffering between the functions of the segment lines 3 and 4. In the present invention, each of the at least two segment lines 3, 4 has at least two electrode-electrolyte-segments 5, 6 or 7, 8. Each electrode-electrolyte-segment 5, 6 or 7, 8 is in particular connected in series. The exact number of electrode-electrolyte-segments 5, 6, 7, 8 is not limited in the present invention, but rather can be freely selected depending on the application and capacity. The exact number is chosen in particular depending on the desired performance characteristics, i.e. on the strength of the current to be provided or on the voltage.

  The electrode-electrolyte-segments arranged in the segment lines 3, 4 are at least partly separated by electrically and ionically insulating regions 24. In addition, each electrode-electrolyte-segment 5, 6, 7, 8 includes an anode, a cathode, and an electrolyte disposed between the anode and the cathode. This is shown in detail in FIG. 2 and will be described in detail later.

  FIG. 1 further shows the following. That is, at least two electrode-electrolyte-segments 5, 7 arranged in different segment lines 3, 4 are electrically connected via a connecting part 9 formed from an anode material or from a cathode material. It shows that it is connected. Particularly advantageously, the electrode-electrolyte-segments 5, 7 are connected in series.

  In an advantageous embodiment, at least two segment lines 3, 4 are axially oriented with respect to the axis of the tubular function part 2. In order to achieve a proper insulation between the individual segment lines 3, 4, they are at least partly ionic by a gastight joint 10 extending axially with respect to the axis of the tubular function part 2. And electrically isolated from each other. In this way, the joint 10 divides the tube constituted by the tubular functional unit 2 into, for example, two half tubes. Here, each half tube is formed by one segment line 3, 4. However, within the framework of the present invention, the functional unit 2 may be integrally formed in this configuration, and is not necessarily divided into two functional units 2.

  Regarding the function of the fuel cell 1, currents flow in opposite directions in at least two segment lines 3, 4. For this purpose, for example, current flows in one direction along the segment line 3 and in the opposite direction along another segment line 4. Here, this current flows in particular through the connecting part 9. The reverse current flow is shown in FIG. The current flow in the reverse direction is particularly advantageous when the connecting part 9 is arranged at the end of the functional part 2. This is illustrated in FIG. In this way, substantially the entire length of the functional unit 2 is used for energy acquisition. Here it is also possible for the connecting part 9 to be configured as a tubular conductor in order to provide a suitable electrical connection.

  FIG. 1 further shows that the functional part 2 is formed as a tube closed at one end. In this way, the fuel side and the air side can be easily separated. Here, advantageously, air flows along the outside of the tubular function part 2 and combustion gas flows along the inside of the wall part of the function part 2.

  This is a particularly safe operation of the fuel cell 1 according to the invention. Because the combustion gas, for example hydrogen, can be easily controlled inside the tubular functional part 2 or inside the fuel cell, in this way there is a clear danger of starting the combustion gas, for example in the form of an explosion This is because it is reduced. Therefore, in this configuration, the anode is disposed inside the functional unit 2 and the cathode is disposed outside the functional unit 2.

  In order to increase the stability, the functional part 2 can be further arranged on a tubular carrier. Although not shown in detail, the carrier is arranged outside or inside the functional part 2, for example, in a tubular cross section.

  FIG. 2 shows in detail an embodiment of the fuel cell 1 or, in particular, its functional part 2. FIG. 2 a shows here a longitudinal section of the functional part 2, whereas FIG. 2 b) shows a plan view of the three layers at the joint 10.

  FIG. 2 shows that the fuel cell 1 according to the invention in particular has a layer assembly comprising an anode layer 12, a cathode layer 13 and an electrolyte layer 14. Here, anode regions 15, 16, 17, and 18 are formed in the anode layer 12. These form the anode of the electrode-electrolyte-segments 5, 6, 7, 8 and are airtight or gas permeable. Further, the anode has only conductivity, or has both conductivity and ion conductivity. The anode regions 15, 17 are here separated from the other anode regions 16, 18 by an electrically and ionically insulating region 19. This can be gas tight or gas permeable. Correspondingly, cathode regions 20, 21, 22 and 23 are formed in the cathode layer 13. This forms the cathode of the electrode-electrolyte-segments 5, 6, 7, 8 and can be gas tight or gas permeable. In addition, the cathode can be conductive only, or it can be conductive and ionic conductive. The cathode regions 20, 22 are here separated from the other cathode regions 21, 23 by an electrically and ionically insulating region 24. This can be gas tight or gas permeable. Further, electrolyte regions 25, 26, 27, and 28 are formed in the electrolyte layer 14. These electrolyte regions form an electrode-electrolyte-segment 5, 6, 7, 8 electrolyte and are airtight. Further, this electrolyte is electrically insulating, but may be ionically conductive. For example, the electrolyte comprises or consists of yttrium stabilized zirconia (YSZ). Here, the electrolyte regions 25, 27 are separated from other electrolyte regions 26, 28 arranged in the same segment line by ionically insulating and airtight regions, in particular by connectors 29. Furthermore, the electrolyte regions 25, 26 are separated from other electrolyte regions 27, 28 located in the same segment line by an electrically and ionically insulating, airtight region 30.

  From the above description, it is clear that, for example, the anode region 15, the cathode region 20 and the electrolyte region 25 form the electrode electrolyte segment 5. Similarly, the electrode-electrolyte-segment 6 has an anode region 16, a cathode region 21 and an electrolyte region 26, and the electrode-electrolyte-segment 7 has an anode region 17, a cathode region 22 and an electrolyte region 27. The electrode-electrolyte-segment 8 has an anode region 18, a cathode region 23 and an electrolyte region 28.

  Within the framework of the invention, it is further advantageous that the electrically and ionically insulative regions 19, 24 separating the anode region and / or the cathode region are constituted by cavities filled with air or air. Furthermore, preferably, regions 30 that electrically and ionicly isolate the electrolyte regions arranged in the various segment lines 3, 4 are formed by a solid insulator, in particular aluminum oxide. .

  With regard to the connector 29, it is further advantageous that it consists of an anode material or a cathode material. Here, this material is particularly conductive, but not ionically conductive. In particular, in this case, the electrical connection 9 has a connector 29 between the various segment lines 3 and 4 in addition to the connection 9. Correspondingly, the anode of the electrode-electrolyte-segments 5, 7 is electrically connected by a connector 29 to the cathode of another electrode-electrolyte-segment 6, 8 on the same segment line 3, 4.

  FIG. 2 further shows an anode region 16 of the electrode-electrolyte-segment 6 disposed in the anode layer 12 and a cathode region 20 of another electrode-electrolyte-segment 5 disposed in the cathode layer 13. Indicates that they are partially overlapped. Here, the connector 29 is disposed in this overlapping region. This connector 29 is particularly preferably arranged mainly in the electrolyte layer 14.

  The connecting part 9 is further at least partially covered by an electrolyte material. This is disposed in the anode layer 12, the cathode layer 13, and the electrolyte layer 14 depending on the position. In each case, the connection part 9 contains a gas-tight material or is covered with a gas-tight material, which prevents gas from entering the connection part.

  In the present invention, the outer surface of the electrode of the electrode-electrolyte-segment 5, 6, 7, 8 is made of a conductive material different from the anode material and the cathode material for electrical contact connection of the electrode. It is possible not to deposit the collector. Correspondingly, the fuel cell 1 is particularly advantageously arranged axially with respect to the axis of the functional part for grouping a plurality of segments and is made of a conductive material different from the anode material and the cathode material. It is possible not to have a longitudinal current collector.

  Thus, the functional part 2 simply consists of electrode-electrolyte-segments 5, 6, 7, 8, which are connected in a preferred embodiment by a connection part 9 or a connector 29. These electrode-electrolyte-segments consist of anode regions 15, 16, 17, 18, cathode regions 20, 21, 22, 23 and electrolyte regions 25, 26, 27, 28, respectively.

  FIG. 3 shows an embodiment of a fuel cell 1 according to the invention comprising a support 30 formed from one or more tubular ceramic and / or glassy materials. The functional part 2 is attached to the inner surface of the carrier. Although not shown in the figure, the functional part 2 can be arranged on the outer surface of the tubular carrier 30 within the frame of another alternative embodiment.

  FIG. 3 shows that the tubular carrier 30 has pores through which a gas passes in the portion (s) or the porous region 30a in contact with the functional unit 2. In other words, the functional part 2 is accurately positioned at the height of the porous portion 30 a inside the tubular carrier 30. FIG. 3 further shows that the tubular carrier 30 is further sealed at one tube end by a cap portion 30b, and a base 30c, a so-called mounting flange, is fixed at the other tube end to fix the fuel cell 1 to the carrier substrate. It shows that it has. Advantageously, the base 30c is configured as follows. In other words, the fuel cell 1 is hermetically fixed to the carrier substrate with a glassy material without additional sealing. Here, the cap portion 30a and the base portion 30c are formed to be airtight.

  FIG. 3 further shows that the central hollow cylindrical gas-permeable porous part 30a, which is responsible for the function part 2 here, is in contact with the cap part 30b on the one hand in the connection region 31 and in contact with the base part 30c on the other hand. It is shown that. Here, these parts are interconnected by material. In order to increase the mechanical stability in the connection region 31, the connection region 31 of the tubular carrier 30 can further have an interlock part for connection using a shape. This one end of the tube or carrier 30 is further sealed by an airtight material.

  The tubular carrier 30 is composed in particular of an ionic and electrically insulating ceramic and / or glass material. Advantageously, the tubular carrier 30 is formed from forsterite. The function part 2 furthermore has a very thin layer system thickness, for example of 50 μm or less. Here, the electrolyte may have a layer thickness of about 15 μm.

  Further, in FIG. 3, it can be seen that the fuel cell 1 has a layer assembly including an anode layer 12, a cathode layer 13, and an electrolyte layer 14. Furthermore, it is shown that the functional part 2 has at least two electrically connected segment lines 3, 4.

  FIG. 4 shows that the end of the tube is further formed as follows. That is, it is shown that at least one, in particular, a plurality of guide members 32 are formed so as to exist in order to stabilize the gas supply cylinder 33. 4a and 4b are cross-sectional views schematically showing the guide member 32. FIG.

  In the embodiment shown in FIG. 4a, in particular, at least one strut 34 can be arranged by means of an additional material in the cap part 30b. In particular, three struts 34 are provided. Only one of these struts can be seen in FIG. 4a. The strut 34 is similar to that of the Kreuzgangs. This in particular extends inward and thus supports the gas supply tube 33. Separate support members 34 (not shown) support the gas supply cylinders 33 in different directions. Accordingly, as a whole, the gas supply cylinder 33 can be stably fixed.

  In the embodiment shown in FIG. 4b in particular, at least one, preferably a plurality of indentations 35 are provided in the cap part 30b. For example, only one of these three indentations 35 can be seen in FIG. 4b. One or more indentations 35 are likewise arranged analogously to the corridor or extend inward. This therefore forms a support for the gas supply tube 33. Other indentations 35 (not shown) support the gas supply cylinders 33 in different directions. Therefore, as a whole, stable fixation of the gas supply cylinder is realized.

  A gas connection flange is formed on the opposite side, in particular in the region of the base 30c. This allows an airtight connection without additional sealing of the glassy material. In this case, the entire tube is fired simultaneously.

  DESCRIPTION OF SYMBOLS 1 Fuel cell, 2 Functional part, 3, 4 Segment line, 5, 6, 7, 8 Electrode-electrolyte-segment, 9 Connection part, 10 Joint location, 11 Arrow, 12 Anode layer, 13 Cathode layer, 14 Electrolyte layer, 15, 16, 17, 18 Anode region, 20, 21, 22, 23 Cathode region, 25, 26, 27, 28 Electrolyte region, 29 Connector, 30 Carrier, 30b Cap part, 30c Base

Claims (15)

A fuel cell,
Having a tubular function part (2) with at least two segment lines (3, 4) electrically connected;
Each of the at least two segment lines (3, 4) has at least two electrode-electrolyte-segments (5, 6, 7, 8), each of the electrode-electrolyte-segments being one anode. And one cathode, and one electrolyte disposed between the anode and the cathode,
The electrode-electrolyte-segments (5, 6, 7, 8) of one segment line (3, 4) are connected in series,
One electrode-electrolyte-segment (5, 7) arranged in different segment lines (3, 4) is connected to the anode so that a plurality of the segment lines (3, 4) are connected in series. Electrically connected via a connecting part (9) formed from a material or from a cathode material ,
The at least two segment lines (3, 4) are axially oriented with respect to the axis of the tubular function part (2), and the tubular function part between the at least two segment lines (3, 4) The at least two segment lines (3, 4) are at least partly ionic and electrically isolated from each other by an airtight joint (10) extending axially with respect to the axis of (2) fuel cell according to claim to have, that is. Direction of current flow is in the opposite directions in said at least two segment lines (3,4), the fuel cell according to claim 1 Symbol placement. The electrical connection between the different segment lines (3, 4) includes, in addition to the connection part (9), a connector (29) and / or one in the same segment line (3, 4). The anode of one electrode-electrolyte-segment (5, 6, 7, 8) is electrically connected by the connector (29) with the cathode of another electrode-electrolyte-segment (5, 6, 7, 8). The fuel cell according to claim 1 or 2 . The fuel cell according to claim 3 , wherein the connector (29) is made of a conductive material, for example an anode material or a cathode material, which is hermetic and non-ionically conductive. The fuel cell (1) according to any one of claims 1 to 4 , comprising a layer assembly comprising an anode layer (12), a cathode layer (13) and an electrolyte layer (14). Fuel cell. An anode region (15, 16, 17, 18) is formed in the anode layer (12), and the anode region (15, 16, 17, 18) is the electrode-electrolyte-segment (5, 6, 7). 8), one anode region (15, 16, 17, 18) is electrically and ionically insulative region (19) with another anode region (15, 16, 17, 18). And / or a cathode region (20, 21, 22, 23) is formed in the cathode layer (13), and the cathode region (20, 21, 22, 23) is formed by the electrode. Electrolyte—forms the cathode of the segment (5, 6, 7, 8), one cathode region (20, 21, 22, 23) is electrically connected to another cathode region (20, 21, 22, 23) And ions Are separated by an electrically insulating region (24) and / or an electrolyte region (25, 26, 27, 28) is formed in the electrolyte layer (14), and the electrolyte region (25, 26) 27, 28) form the electrolyte of the electrode-electrolyte-segment (5, 6, 7, 8), and one electrolyte region (25, 27) is arranged in the same segment line (3, 4). Are separated by another electrolyte region (26, 28) and an ionically insulating region (29) and / or one electrolyte region (25, 26) is a different segment line (4) 6. The fuel cell according to claim 5 , wherein the fuel cell is separated by another electrolyte region (27, 28) disposed therein and an electrically and ionically insulating hermetic region (30). The electrically and ionically insulating regions (19, 24) for the division of the anode region (15, 16, 17, 18) and / or the cathode region (20, 21, 22, 23) are: Due to the separation of the electrolyte regions (27, 25 from 27, 28) formed by air or by cavities filled with air and / or arranged in different segment lines (3, 4) Said electrically and ionically insulating regions (30) of the electrolyte region (26, 28) formed by solid insulators and / or arranged in the same segment line (3, 4) 7. The fuel cell according to claim 6 , wherein the ionically insulating region for severing 25, 27) is electrically conductive and formed by a connector (29). An anode region (15, 16, 17, 18) of one electrode-electrolyte-segment (5, 6, 7, 8) disposed in the anode layer (12), and in the cathode layer (13) Are arranged in a partially overlapping manner with the cathode region (20, 21, 22, 23) of another electrode-electrolyte-segment (5, 6, 7, 8),
The fuel cell according to any one of claims 5 to 7 , wherein a connector (29) is arranged in the electrolyte layer (14) in the overlapping region. The outer surface of the electrode of the electrode-electrolyte-segment (5, 6, 7, 8) is covered with a current collector made of a conductive material different from the anode material and the cathode material for electrical contact connection of the electrode. Unattached and / or the fuel cell (1) is arranged axially with respect to the axis of said functional part (2) for grouping a plurality of electrode-electrolyte-segments (5, 6, 7, 8) cage, and the do not have a longitudinal current collector made of a different conductive material than the anode and cathode materials, fuel cell according to any one of claims 1 to 8. The fuel cell according to any one of claims 1 to 9 , wherein the functional part (2) is configured as a tube sealed at one end. The functional part (2) is arranged on the tubular carrier (30);
And / or the carrier (30) has gas-permeable pores and / or openings in the part (30a) in contact with the functional part (2), and / or the carrier (30). Has a base (30c) for fixing the fuel cell (1) to the carrier substrate at at least one open pipe end, the base being configured to be airtight, and / or the carrier The fuel cell according to any one of claims 1 to 10 , wherein (30) is a tube end portion and is sealed by a cap portion (30b), and the cap portion is configured to be airtight. The fuel cell according to claim 11 , wherein the tubular support (30) contains forsterite. The connecting portion (9) is disposed at the end portion of the functional unit (2), the fuel cell of any one of claims 1 to 12. The connecting portion (9) is formed as an annular conductor, the fuel cell of any one of claims 1 to 13. The fuel cell (1) described in any one of claims 1 to 14 containing at least one,
A fuel cell system.

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