DE102021121983A1 - Ceramic component and manufacturing method therefor - Google Patents

Abstract

In at least one embodiment, the ceramic component (1) comprises a ceramic body (2) with a functional ceramic and a marking (3). The marking (3) is temperature-resistant at least up to a temperature of 600° C. and comprises a marking glass (30).

Description

A ceramic component is specified. In addition, a method for producing such a ceramic component is specified.

The publication J. Schilm et al., "Glass ceramics sealants for SOFC interconnects based on a high chromium sinter alloy", Int. J appl. Ceram Technol., 2018, pages 239 to 254, DOI: 10.1111/ijac.12811 relates to glass-ceramics for solid oxide fuel cells.

The publication D. Faidel et al., "Glass sealing materials and laser joining process development for fuel cell stack manufacturing", Mat.-wiss. and materials tech. 2010, 41, no. 11, pages 914 to 924, DOI: 10.1002/mawe.201000685, relates to joining processes for fuel cell production.

One problem to be solved is to mark a ceramic component in such a way that a marking that is still legible, preferably machine-readable, is produced even after a temperature treatment, as a result of which the ceramic component can be traced in its manufacture and use.

This object is achieved, inter alia, by a ceramic component and by a method having the features of the independent patent claims. Preferred developments are the subject matter of the dependent claims.

In at least one embodiment, the ceramic component comprises a ceramic body with at least one functional ceramic and a marking. The marking is temperature-resistant up to a temperature of at least 600° C. and comprises at least one marking glass. The terms marking and labeling can be used synonymously in the present case.

In particular, components that fulfill an electrical, magnetic, dielectric and/or optical function are assigned to the functional ceramic.

The functional ceramic is, for example, a membrane and/or an electrolyte, in particular in a solid oxide fuel cell or solid oxide electrolyzer cell, or a piezo ceramic, for example in an actuator or in a sensor. The ceramic body can also include a number of different functional ceramics, for example an electrolyte or a membrane and an electrode substrate and/or a ceramic electrode.

Functional ceramic elements usually go through comparatively complicated process chains in production. In particular, membranes for fuel cells or electrolytic cells or piezoelectric converters, such as sensors or actuators, are produced over a large area, for example by means of film casting, cut to size and processed into larger stacks. Such components are pressed, sintered and/or cast in with glasses. In this way, a large number of individual elements are combined to form an overall system. In this case, a transition from batch processes to series production usually also takes place during the transition from cell elements to stacks or solidoids.

High process temperatures can occur both in production and in use. Material fluctuations and production fluctuations may then lead to problematic failures, which should either be identified early in the process or analyzed as returns from the field. In both cases, a clear identification of the individual cell elements is already necessary in the batch process. Such a marking cannot be carried out so far. A challenge for such a marking is the small available area, the susceptibility to breakage of the generally brittle materials and the difficult material compatibility of the printing and the substrate. For example, diffusion at high temperatures and with temperature cycling in the production process and in later use should be prevented as far as possible.

Material-removing methods for creating a marking, such as laser marking, cannot be used on ceramic bodies, for example for solid oxide fuel cells, also known as SOFC or solid oxide fuel cells, or for solid oxide electrolyzer cells, also known as SOEC or solid oxide electrolyzer cells. Due to the low thickness and the high thermo-mechanical stress during use, this option is not an option, since excessive material weakening and the introduction of stress fields frequently lead to fractures. Printing with conventional inks is not effective, since such markings can no longer be read after final sintering, since high temperatures lead to loss of adhesion, evaporation or the diffusion of foreign substances into the material systems that are sensitive to trace substances.

In the case of the ceramic component described here, the ceramic body with the at least one functional ceramic is preferably printed with an ink which contains an inorganic adhesion promoter, in particular a glass powder, made from the same or a compatible material as the functional ceramic. It is also possible to use the same glass in powder form with which the following Manufacturing the cell membranes are joined to form a solidoid. A contrast between the ceramic body and the marking can be achieved, for example, by forming polycrystalline crystal structures of the adhesion promoter or by adding a contrasting pigment that is also compatible, for example cobalt blue, or an inorganic phosphor.

Adhesion is promoted in the cold state, for example first by an organic binder, and then by the inorganic adhesion promoter after temperature treatment. If necessary, only one solvent can be used, without any binder at all. The temperature expansion coefficients of the marking and the component provided with the marking should also be optimally adjusted to one another, that is, their difference should be as small as possible over the temperature range. In addition, an increase in height due to the marking is preferably taken into account, so that, for example, when several cells are stacked one on top of the other, no compressive stresses are introduced into the solidoid. This can be done by a suitable process control during stacking and by avoiding an increase in height, in particular when introducing the sealing glass and/or another sealing material. The formation of compressive stresses can be avoided above all by using the sealing glass to promote adhesion of the marking.

1. 1. Herstellen eines Substrats, zum Beispiel mittels Foliengießen, das zum Beispiel aus Nickeloxid oder Zirkonoxid oder einem Metall besteht oder ein solches Material umfasst,
2. 2. Sinterung des Substrats bei mehr als 600 °C,
3. 3. Drucken einer ersten flächigen Elektrode oder eines Elektrolyten, zum Beispiel mittels Siebdruck,
4. 4. Wiederholung des Schritts 3 für alle Elektroden,
5. 5. Bau des Stapels aus einzelnen Zellen, aus Glas als Verbindungsmittel und Dichtung sowie aus bevorzugt metallischen Bipolarplatten, und
6. 6. Sintern des Stapels bei Temperaturen knapp oberhalb eines Verglasungspunktes des Verbindungsmittels.

Process steps for the production of a SOEC or a SOFC, regardless of whether they are planar or tubular, as described here, include in particular the following steps:

1. 1. Production of a substrate, for example by means of tape casting, which consists of, for example, nickel oxide or zirconium oxide or a metal or comprises such a material,
2. 2. sintering of the substrate at more than 600 °C,
3. 3. Printing a first flat electrode or an electrolyte, for example by means of screen printing,
4. 4. Repeat step 3 for all electrodes,
5. 5. Construction of the stack from individual cells, from glass as connecting means and seal and from preferably metallic bipolar plates, and
6. 6. Sintering the stack at temperatures just above a glass transition point of the fastener.

The aforementioned steps can be carried out as individual steps or so-called co-sintering of the cells takes place.

The marking described herein or a raw material for the marking is preferably applied during step 1 or between steps 1 and 2. Alternatively, the marking described here or the raw material for the marking is only applied after step 2, preferably before step 3.

With the method described here, an efficient identification of individual elements of fuel cell stacks, electrolytic cell stacks or piezoelectric converters is possible.

In particular, it is possible for foreign materials to be prevented from being introduced into the functional ceramic, since there are no functional impairments as a result of the diffusion of foreign materials. Excellent adhesion of the marking can be achieved by means of a material connection, so that the markings on the individual elements, such as the membranes, can still be read well, in particular by machine, even after they have been cast in and subsequently separated. Furthermore, excellent temperature stability with regard to adhesion and contrast can be achieved. In addition, there is no damage to a surface of the ceramic body, so that the risk of cracking or stress areas as the starting point for later cracks is significantly reduced. There are no additional thermal stresses in the marked cell in subsequent thermal process steps, since the thermal expansion coefficient of the vitreous adhesion promoter of the marking is adapted to the base material. Finally, the superelevation of the marking can be compensated for by the viscous sealing glass flowing around the raised marking points on the cell during the joining process of the solidoid.

According to at least one embodiment, the ceramic component is a solid oxide fuel cell and/or a solid oxide electrolytic cell. This means that the functional ceramic of the ceramic body is then preferably an electrolyte membrane. In other words, the ceramic component is a solid oxide cell for use as a fuel cell or an electrolytic cell.

According to at least one embodiment, the ceramic body is in the form of a plate. The plate can be flat and therefore not bent. Panel means in particular that a side length and/or a diagonal length of a main side of the panel exceeds a thickness of the panel by at least a factor of 10 or by at least a factor of 100. The plate can have plane-parallel main sides.

According to at least one embodiment, the marking is located directly on the ceramic body, in particular on an edge of the main side the plate. Alternatively or additionally, the marking is on a substrate for the ceramic body, for example a metal substrate or a ceramic substrate. This means that the ceramic body can be attached to the substrate, in particular can be firmly and permanently connected to the substrate, so that the substrate and the ceramic body cannot be detached from one another without being destroyed. In other words, after the substrate has been detached from the ceramic body, the ceramic body and/or the substrate is then destroyed.

According to at least one embodiment, the ceramic body has dimensions between 2 cm×2 cm×20 μm and 0.5 m×0.5 m×0.3 mm inclusive, in particular between 5 cm×5 cm×30 μm and 0.3 inclusive m × 0.3m × 0.15mm.

According to at least one embodiment, a thickness of the marking is at most 10 μm or at most 5 μm, for example between 1 μm and 5 μm inclusive. This thickness can be a maximum thickness of the marking.

According to at least one embodiment, the ceramic component includes one or two connecting plates. In particular, the ceramic body is located between the two connection plates of the ceramic component. The at least one connection plate can also be referred to as an interconnector or bipolar plate. In the case of a connection plate which is a bipolar plate, the connection plate can in turn be located at least in part between two of the ceramic bodies. The at least one connection plate is preferably made of metal or another electrically conductive material such as graphite.

According to at least one embodiment, the connecting plates are connected to one another directly or indirectly by a connecting means. In the case of a direct connection, only the connecting means between the connection plates in question is then located in the connection areas.

According to at least one embodiment, the connecting means comprises or consists of a connecting glass. With regard to the connecting glass, no distinction is made between glasses and glass ceramics. This means that the term connecting glass includes both glasses and glass ceramics.

According to at least one embodiment, the connecting glass and the marking glass are in direct contact with one another. In particular, the marking glass can be embedded in the connecting glass, in particular seen in a sectional plane parallel to the relevant main side of the ceramic body. In this sectional plane, the connecting glass can therefore directly surround the marking glass and thus the marking all around. The connecting glass can also be in direct contact with the ceramic body.

According to at least one embodiment, the marking glass and the connecting glass have the same material composition or comprise the same material composition. That is, the marker glass and the connecting glass can be made of the same material mixture. If the marking in this case has another substance in addition to the marking glass, the marking glass makes up a weight proportion of the finished marking of preferably at least 50% or at least 75% or at least 90%.

It is possible that the marker consists of the marker glass.

According to at least one embodiment, the marking glass has a processing temperature that is at least 50° C. or at least 100° C. higher than the connecting glass. This means that the marking then withstands higher temperatures than the connecting glass. For example, the processing temperature is a melting temperature or a glass transition temperature.

According to at least one embodiment, the marking contains at least one further component in addition to the marking glass. For example, the further component is an inorganic phosphor or a pigment, where the pigment can be organic or also inorganic.

The at least one pigment is therefore a temperature-resistant, coloring material. The pigments are, for example, temperature-resistant ceramic pigments and/or metal oxide pigments, preferably with a color different from the ceramic body. For example, the ceramic pigments are white, colored or black. Prussian blue, ie iron(III) hexacyanidoferrate(II/III), can be used as a pigment, for example. Ceramic pigments can also be used. In the case of metal oxide pigments, for example, the pigments are titanium dioxide.

The phosphor or one of the phosphors or some of the phosphors or all phosphors are preferably selected from the following group: Eu ²⁺ -doped nitrides such as (Ca,Sr)AlSiN ₃ :Eu ²⁺ , Sr(Ca,Sr)Si ₂ Al ₂ N ₆ :Eu ²⁺ , (Sr,Ca)AlSiN ₃ *Si ₂ N ₂ O:Eu2 ⁺ , (Ca,Ba,Sr) ₂ Si ₅ N ₈ :Eu ²⁺ , (Sr,Ca)[LiA1 ₃ N ₄ ]: Eu ²⁺ ; Garnets from the general system (Gd,Lu,Tb,Y) ₃ (Al,Ga,D) ₅ (O,X) ₁₂ :RE with X = halide, N or divalent element, D = trivalent or tetravalent element and RE = rare earth metal, such as Lu ₃ (Al _1x Ga _x ) ₅ O ₁₂ :Ce ³⁺ , Y ₃ (Al _1-x Ga _x ) ₅ O ₂₂ :Ce ²⁺ ; Eu ²⁺ -doped sulfides such as (Ca,Sr,Ba)S:Eu ²⁺ ; Eu ²⁺ -doped SiONs such as (Ba,Sr,Ca)Si ₂ O ₂ N ₂ :Eu ²⁺ ; SiAlONe for example from the system Li _x M _y Ln _z Si ₁₂ - _(m+n) Al _(m+n) O _n N _16-n ; beta-SiAlONe from the system Si _6-x Al _z O _y N _8-y :RE _z ; nitrido-orthosilicates such as AE _2-xa RE _x Eu _a SiO _4-x N _x , AE _2-xa RE _x Eu _a Si _1-y O _4-x-2y N _x with RE=rare earth metal and AE=alkaline earth metal; orthosilicates such as (Ba,Sr,Ca,Mg) ₂ SiO ₄ :Eu ²⁺ ; chlorosilicates such as Ca ₈ Mg(SiO ₄ ) ₄ Cl ₂ :Eu ²⁺ ; chlorophosphates such as (Sr,Ba,Ca,Mg) ₁₀ (PO ₄ ) ₆ Cl ₂ :Eu ²⁺ ; BAM phosphors from the BaO-MgO-Al ₂ O ₃ system such as BaMgAl ₁₀ O ₁₇ :Eu ²⁺ ; Halophosphates such as M ₅ (PO ₄ ) ₃ (Cl,F): (Eu ²⁺ , Sb ³⁺ , Mn ²⁺ ); SCAP phosphors such as (Sr,Ba,Ca) ₅ (PO ₄ ) ₃ Cl:Eu ²⁺ ; KSF phosphors based on potassium, silicon and fluorine such as K ₂ SiF ₆ :Mn ⁴⁺ .

Furthermore, the phosphor can have a quantum well structure and in particular be formed from semiconductor nanoparticles, for example from a II-VI material such as CdSe. Such semiconductor nanoparticles have a diameter of at most 20 nm or at most 12 nm, for example.

The phosphor can be set up to shorten the wavelength of an excitation radiation, also referred to as upconversion, and convert infrared light into visible light, for example. Alternatively, the phosphor can convert short-wavelength light into long-wavelength light. The phosphor is excited in the near-ultraviolet, in the visible and/or in the near-infrared spectral range. The phosphor is preferably read out in the visible or in the near-ultraviolet spectral range. In contrast, the pigments are not equipped for wavelength conversion.

According to at least one embodiment, the at least one phosphor and the at least one type of pigment are present as particles. An average diameter of the particles, in particular a D ₅₀ diameter, is preferably at least 50 nm or at least 300 nm and/or at most 10 μm or at most 5 μm or at most 2 μm. In particular, the mean diameter can be between 50 nm and 500 nm inclusive in order to reduce mechanical stresses, or between 0.5 μm and 5 μm inclusive in order to obtain a high thermal resistance of the particles.

According to at least one embodiment, the marking and/or the marking glass contains a number of crystalline partial areas. That is, the marker glass is polycrystalline. As a result, the marking glass can have a light-scattering effect and appear white, for example. If the marking glass includes such crystalline partial areas, then the marking can consist of the marking glass or have at least one further component.

Mixtures of one or more phosphors, of one or more pigments and/or of crystalline subregions can also be present. In addition, there can be several partial areas of the marking that have different colors in order to ensure increased contrast within the marking. These sub-areas can have different phosphors, pigments or mixtures thereof or differently designed crystalline sub-areas, for example crystalline sub-areas of different sizes, so that an optical scattering behavior can be differently pronounced locally.

According to at least one embodiment, the ceramic component also includes a first electrode. The first electrode is preferably applied flat to the ceramic body. This can mean that the first electrode covers at least 50% or at least 80% or at least 90% of the relevant main side of the ceramic body.

In accordance with at least one embodiment, the first electrode and the marking are located on the same side of the ceramic body and are arranged next to one another without overlap when viewed from above on this side. This means that the marking and the first electrode then do not overlap.

In accordance with at least one embodiment, the first electrode protrudes beyond the marking in the direction away from the ceramic body. That is, the first electrode is thicker than the mark.

According to at least one embodiment, the ceramic component also includes a second electrode. The second electrode is preferably also applied areally to the ceramic body, so that the second electrode can cover at least 50% or at least 80% or at least 90% of the relevant main side of the ceramic body. The second electrode is preferably located directly on a main side of the ceramic body opposite the first electrode.

According to at least one embodiment, the marking is a point code. In this case, the mark is formed of a plurality of islands spaced from each other. When viewed from above, the islands preferably have a circular, elliptical or polygonal shape. As an alternative to a dot code, a bar code or a QR code or a character code can also be used for the marking.

According to at least one embodiment, a diameter of the islands is at most 2 mm or at most 1 mm. It is possible that this diameter is at least 0.1 mm or at least 0.3 mm. All islands are preferably of the same size, within the scope of manufacturing tolerances.

In addition, a method for producing a ceramic component, as described in connection with one or more of the above-mentioned embodiments, is specified. Features of the ceramic component are therefore also disclosed for the method and vice versa. In particular, the method generates a marking which is designed as described above.

1. A) Bereitstellen des Keramikkörpers, der die Funktionskeramik umfasst oder der die Funktionskeramik ist, und
2. B) Aufbringen der Markierung, insbesondere direkt auf den Keramikkörper.

In at least one embodiment, the method comprises the following steps, in particular in the order given:

1. A) providing the ceramic body which comprises the functional ceramic or which is the functional ceramic, and
2. B) Applying the marking, in particular directly to the ceramic body.

After step B), the marking preferably runs through at least one further process step at a temperature of at least 600° C. and after this at least one further process step is legible, in particular machine-readable.

A ceramic component described here and a method described here are explained in more detail below with reference to the drawing using exemplary embodiments. The same reference symbols indicate the same elements in the individual figures. However, no references to scale are shown here; on the contrary, individual elements may be shown in an exaggerated size for better understanding.

• 1 eine schematische perspektivische Darstellung eines Ausführungsbeispiels eines hier beschriebenen Keramikbauteils,
• 2 bis 4 schematische Schnittdarstellungen von Ausführungsbeispielen von hier beschriebenen Keramikbauteilen,
• 5 eine schematische Schnittdarstellung eines Ausführungsbeispiels eines hier beschriebenen Keramikbauteils, das eine Festoxidbrennstoffzelle ist,
• 6 und 7 schematische Blockdiagramme von Ausführungsbeispielen von Verfahren zur Herstellung von hier beschriebenen Keramikbauteilen, und
• 8 bis 10 schematische Schnittdarstellungen von Markierungen in Ausführungsbeispielen von hier beschriebenen Keramikbauteilen.

Show it:

• 1 a schematic perspective view of an embodiment of a ceramic component described here,
• 2 until 4 schematic sectional views of exemplary embodiments of ceramic components described here,
• 5 a schematic sectional view of an embodiment of a ceramic component described here, which is a solid oxide fuel cell,
• 6 and 7 schematic block diagrams of exemplary embodiments of methods for producing ceramic components described here, and
• 8th until 10 schematic sectional representations of markings in exemplary embodiments of ceramic components described here.

In 1 an exemplary embodiment of a ceramic component 1 is shown. The ceramic component 2 comprises a plate-shaped ceramic body 2 with a main side 20. A marking 3 is located directly on the main side 20. The marking 3 is designed as a dot code, so that the marking 3 is composed of a large number of separate islands 31.

The marking 3 preferably extends along an edge 22 of the main side 20. The edge 22 has a width of at least 2 mm and/or at most 5 mm, for example. Alternatively or additionally, the edge 22 has a width of at least 1% and/or at most 5% of an edge length of the ceramic body 2 .

In terms of their optical properties, the islands 31 stand out from the ceramic body 2 on which they are applied. In this case, all the islands 31 can be of the same construction and thus have the same optical properties. For example, the marking 3 faces the component to which it is applied 1 i.e. compared to the ceramic body, at least in part of the near-ultraviolet, the visible and/or the near-infrared spectral range, there is a difference in reflectance and/or a difference in reflectance and/or an albedo difference of at least 10 percentage points or at least 20 percentage points or at least 30 percentage points.

The ceramic body 2 is in particular a functional ceramic. For example, the ceramic body 2 is then an electrolyte membrane for a solid oxide fuel cell, SOFC for short, or for a solid oxide electrolytic cell, SOEC for short, or is a piezo ceramic, for example in an actuator or in a sensor.

A first electrode 51 is optionally located directly on the main side 20. The first electrode 51 covers, for example, at least 80% of the main side and in particular only leaves the edge 22 free. The edge 22 can run around the first electrode 51 in the shape of a frame.

In the embodiment of 2 the ceramic component 1 is intended for an SOFC. For this purpose, the ceramic component 1 has a substrate 53, for example made of Ni-YSZ, where YSZ stands for yttrium-stabilized zirconium oxide. A thickness of the substrate 53 is, for example, between 0.1 mm and 0.5 mm inclusive. Especially right on that A second electrode 52 is located on the substrate 53. The second electrode 52 is made, for example, of LSM, that is to say of lanthanum strontium manganite, (La,Sr)MnO ₃ . A thickness of the second electrode 52 is, for example, between 5 μm and 50 μm inclusive.

In particular, the ceramic body 2 is located directly on the second electrode 52. For example, the ceramic body 2 is made of a doped zirconium oxide or of a doped cerium oxide. A dopant is, for example, Sc, Y, Yb, Gd or another rare earth, with a dopant concentration preferably being between 2 mol % and 10 mol % inclusive. It is possible for the ceramic body 2 to be made from YSZ or from SSZ, ie from zirconium oxide stabilized with scandium oxide. The first electrode 51 , which protrudes beyond the marking 3 , is located on a side of the ceramic body 2 opposite the second electrode 52 . The first electrode 51 is made of Ni:YSZ, for example. A thickness of the first electrode 51 is, for example, between 5 μm and 50 μm inclusive.

Alternatively, see the in 2 in parentheses, the ceramic body 2 serves as a support for the structure and is, for example, made of YSZ with a thickness of between 0.1 mm and 0.5 mm inclusive. The first electrode 51 is then located on the ceramic body 2, for example made of LSM with a thickness between 5 μm and 50 μm inclusive. Optionally, an intermediate layer 54 and a barrier layer 53 may be present, for example each having a thickness between 2 µm and 50 µm inclusive.

Further alternatively, see the in 2 reference numerals placed in square brackets, the first electrode 51 serves as a carrier, it being possible for the first electrode 51 to be regarded as part of the ceramic body 2 . The first electrode 51 is then, for example, made of Ni:YSZ with a thickness between 0.1 mm and 1 mm inclusive. The ceramic body 2 serving as the electrolyte membrane is made of YSZ or SSZ, for example, with a thickness of between 2 μm and 10 μm inclusive. The intermediate layer 54 is in particular made of CGO, cerium gadolinium oxide, for example with a thickness between 5 μm and 50 μm inclusive. The second electrode 52 is, for example, a lanthanum-strontium-cobaltite-iron layer, LSCF for short, for example with a thickness between 5 μm and 50 μm inclusive.

In particular, the ceramic component 1 according to 2 thus an electrolyte-supported cell, also referred to as ESC or electrolyte supported cell. Alternatively, the ceramic component 1 according to 2 an anode supported cell, also called ASC or anode supported cell.

Otherwise, the statements apply 1 in the same way for 2 and vice versa.

In 3 It is illustrated that the ceramic body 2 is provided with the electrodes 51, 52 on both sides. Optionally, the marking 3 can also be located on both main sides of the ceramic body 2. As a further option, not shown, it is alternatively or additionally possible for the marking 3 to be located on an end face of the ceramic body 2 .

Otherwise, the comments on the 1 and 2 in the same way for 3 and vice versa.

In the embodiment of 4 the ceramic component is designed as a metal-supported cell, MSC for short or metal supported cell. A metal plate or metal foil, for example made of FeCr with a thickness between 0.1 mm and 1 mm inclusive, then serves as the substrate 53 . On the substrate 53 is the barrier layer 55 over which is placed the second electrode 52, such as Ni-YSZ, followed by the electrolytic membrane ceramic body 2, such as YSZ or SSZ, followed in turn by the intermediate layer 54, e.g CGO, and the first electrode 51, such as LSCF.

According to 4 the marking 3 is located on the ceramic body 2 in areas which are left free by the intermediate layer 54 and the first electrode 51 . Alternatively, however, the marking 3 can also be attached to the metallic substrate 53, either on a main side or also on a front side.

Otherwise, the comments on the 1 until 3 in the same way for 4 and vice versa.

In 5 1 is illustrated that the ceramic component 1 forms part of a solid oxide fuel cell 10, alternatively a SOEC. The ceramic component 1 can also be the cell 10 . For example, the actual ceramic component 1 is constructed as in connection with the 1 until 4 described.

Optionally, there is a contact layer 56 on the ceramic component 1, for example a network based on Ni.

The cell 10 also has two connection plates 41 , 42 , also referred to as an interconnector or bipolar plate, one of the connection plates also being part of an adjacent cell 10 . Furthermore, a cell frame 43 is optionally present, which lies in the same plane as the ceramic component 1.

The connecting plates 41, 42, the cell frame 43 and the ceramic component 1 are connected to one another by means of a connecting means 44. The connecting means 44 is preferably made of connecting glass. The marking 3 is embedded in the connecting means 44 . The connecting glass is, for example, a glass based on the components BaO, CaO, SiO ₂ and/or Al ₂ O ₃ .

Otherwise, the comments on the 1 until 4 in the same way for 5 and vice versa.

In 6 a manufacturing method for ceramic components 1 is described schematically as a block diagram. In a method step S1, the substrate 53 and/or the ceramic body 2 is produced, in particular by means of tape casting, also known as tape casting, in particular from nickel oxide or from zirconium oxide or from a metal. That is, the substrate 53 and/or the ceramic body 2 are preferably cast, cut and dried.

A raw material 3' for the marking 3 is then applied in step S7. In this case, a shape and an information content of the marking 3 are preferably defined.

Then, in step S2, the substrate 53 and/or the ceramic body 2 is sintered, together with the raw material 3' for the marking 3. This sintering, during which the marking 3 is also finally created, takes place, for example, at a temperature of at least 1000 °C

In the next step S3, the first electrode is produced, in particular in the case of cells of the ESC type, or in particular the electrolyte membrane in the case of cells of the ASC or MSC type. This is done, for example, by means of printing, such as screen printing.

In step S4, analogously to step S3, all other missing layers are produced, such as the second electrode.

A stack is then built in step S5, comprising several of the ceramic bodies and the connection plates and the optional cell frame and also the connecting means. In this case, the connecting means is present, for example, as glass paste or frit. That is, in step S5, the components of the stack are arranged but are not yet firmly connected to each other.

Finally, in step S6, the stack is assembled. This preferably takes place at a temperature just above a glass transition point of the connecting glass, for example at approximately 900°C. This temperature is thus lower than the sintering temperature in step S2. The marking 3 thus survives the step S6 undamaged.

Otherwise, the comments on the 1 until 5 in the same way for 6 and vice versa.

In the process of 7 the sintering of step S2 takes place first, before the raw material 3' for the marking 3 is applied in step S7. In this step S7, the raw material 3′ can optionally be sintered to form the marking 3, for example by means of laser radiation.

The remaining process steps are carried out according to 6 .

Since the process of 7 the high-temperature sintering step S2 is carried out before step S7, the same material can be used for the marking 3 as the marking glass 30 as for the connecting glass of the connecting means 44. This means that no significant thermal stresses then occur between the marking 3 and the connecting means 44 during temperature cycles.

In the 8th and 9 individual islands 31 of the marking 3 are illustrated schematically. In 8th it is shown that the marker 3 consists of the marker glass 30 . A plurality of crystalline partial areas 33 are present in the marking glass 30, so that the island 31 has a light-scattering effect. Such crystalline partial regions 33 can be produced, for example, by laser treatment and/or by adjusting an ambient temperature, for example by comparatively rapid cooling of the islands 31 after heating.

On the other hand is in 9 illustrates that the marking 3 additionally comprises at least one further component 32 . The further component 32 is, for example, phosphor particles or at least one pigment. This means that the marking 3 can be colored in a targeted manner by the at least one further component 32 .

In order to reduce or prevent thermal stresses between the marker 3 and the ceramic body 2, the islands 31 are preferably relatively small, for example with a diameter of at most 0.5 mm and a height of at most 10 μm. In addition, a difference in the temperature expansion coefficients of the ceramic body 2 and the marking glass 30 is preferably at most 1 × 10 ^-6 K ^-1 or at most 0.5 × 10 ^-6 K ^-1 , preferably over the entire relevant temperature range, i.e. at Tem temperatures that occur during manufacture and operation of the ceramic body 2.

The same preferably applies with regard to the connecting glass and/or with regard to the at least one further component 32.

Otherwise, the comments on the 1 until 7 in the same way for the 8th and 9 and vice versa.

In 10 the raw material 3 ′ for the marking 3 is illustrated as an example. For example, the raw material 3 ′ is made up of particles of the marking glass 30 and a binder 34 . The binding agent 34 is optional. An optional at least one further component 32 is to simplify the illustration in 10 not drawn.

If a binder 34 is present, the binder 34 can be formed by a solvent which evaporates during the sintering of the raw material 3', or already beforehand. Alternatively, the binder 34 consists of at least one organic material and is in particular an acrylate-based material.

Otherwise, the comments on the 1 until 9 in the same way for 10 and vice versa.

The components shown in the figures preferably follow one another in the specified order, in particular directly one after the other, unless otherwise described. Components that are not touching in the figures are preferably at a distance from one another. If lines are drawn parallel to one another, the associated areas are preferably also aligned parallel to one another. In addition, the relative positions of the drawn components in the figures are correctly represented unless otherwise indicated.

The invention described here is not limited by the description based on the exemplary embodiments. Rather, the invention encompasses every new feature and every combination of features, which in particular includes every combination of features in the patent claims, even if this feature or this combination itself is not explicitly stated in the patent claims or exemplary embodiments.

Reference List

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ceramic component

2

ceramic body

20

main page

22

edge

3

mark

3'

Raw material for marking

30

marker glass

31

Island

32

fluorescent

33

crystalline part

34

binder

41

first connection plate (interconnector)

42

second connection plate

43

cell frame

44

lanyard

51

first electrode

52

second electrode

53

substrate

54

intermediate layer

55

barrier layer

56

contact layer

10

solid oxide cell

S.

process step

Claims (10)

Ceramic component (1) with - A ceramic body (2) comprising a functional ceramic, and - a marking (3), the marking (3) being temperature-resistant at least up to a temperature of 600° C. and comprising a marking glass (30). Ceramic component (1) according to the preceding claim, which is a solid oxide cell for use as a fuel cell or electrolysis cell (10), the functional ceramic of the ceramic body (2) being an electrolyte membrane. A ceramic component (1) according to any one of the preceding claims, wherein the ceramic body (2) is in the form of a sheet and the marking (3) is located directly on the ceramic body (2) at an edge (22) of a major face (20) of the sheet . Ceramic component (1) according to one of the preceding claims, further comprising two connection plates (41, 42), between which the ceramic body (2) is located, the connection plates (41, 42) being connected to one another at least indirectly by a connecting means (44). are connected, wherein the connecting means (44) comprises or consists of a connecting glass, and wherein the connecting glass and the marking glass (30) are in direct contact with one another. Ceramic component (1) according to the preceding claim, in which the marking glass (30) and the connecting glass have the same material composition. Ceramic component (1) after claim 4 , in which the marking glass (30) has a processing temperature that is at least 50 °C higher than the connecting glass. Ceramic component (1) according to one of the preceding claims, in which the marking (3) comprises, in addition to the marking glass (30), at least one inorganic phosphor (32) or at least one inorganic pigment and/or the marking glass (30) comprises a plurality of crystalline partial regions (33 ) contains. Ceramic component (1) according to one of the preceding claims, further comprising a first electrode (51) which is applied over a large area to the ceramic body (2), wherein the first electrode (51) and the marking (3) are located on the same side of the ceramic body (2) and are arranged next to one another without overlapping when viewed from above on this side, the first electrode (51) protruding beyond the marking (3) in the direction away from the ceramic body (2). Ceramic component (1) according to one of the preceding claims, wherein the mark (3) is a dot code, such that the mark (3) is formed of a plurality of islands (31) spaced from each other, a diameter of the islands (31) being at most 2 mm. Method with which a ceramic component (1) according to one of the preceding claims is produced, with the steps: A) providing the ceramic body (2), which includes the functional ceramic, and B) application of the marking (3), the marking (3) after step B) comprising at least one further process step at a temperature of at least 600° C. and after this at least one further process step being legible.

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