WO2003019712A2 - Gas diffusion electrode with a porous coating and corresponding production method - Google Patents

Gas diffusion electrode with a porous coating and corresponding production method Download PDF

Info

Publication number
WO2003019712A2
WO2003019712A2 PCT/DE2002/002540 DE0202540W WO03019712A2 WO 2003019712 A2 WO2003019712 A2 WO 2003019712A2 DE 0202540 W DE0202540 W DE 0202540W WO 03019712 A2 WO03019712 A2 WO 03019712A2
Authority
WO
WIPO (PCT)
Prior art keywords
gas diffusion
diffusion electrode
cathode
layer
electrode
Prior art date
Application number
PCT/DE2002/002540
Other languages
German (de)
French (fr)
Other versions
WO2003019712A3 (en
Inventor
Robert Fleck
Norbert Landgraf
Original Assignee
Siemens Aktiengesellschaft
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Siemens Aktiengesellschaft filed Critical Siemens Aktiengesellschaft
Publication of WO2003019712A2 publication Critical patent/WO2003019712A2/en
Publication of WO2003019712A3 publication Critical patent/WO2003019712A3/en

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/86—Inert electrodes with catalytic activity, e.g. for fuel cells
    • H01M4/90—Selection of catalytic material
    • H01M4/9016—Oxides, hydroxides or oxygenated metallic salts
    • H01M4/9025—Oxides specially used in fuel cell operating at high temperature, e.g. SOFC
    • H01M4/9033—Complex oxides, optionally doped, of the type M1MeO3, M1 being an alkaline earth metal or a rare earth, Me being a metal, e.g. perovskites
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/86—Inert electrodes with catalytic activity, e.g. for fuel cells
    • H01M4/88—Processes of manufacture
    • H01M4/8878—Treatment steps after deposition of the catalytic active composition or after shaping of the electrode being free-standing body
    • H01M4/8882—Heat treatment, e.g. drying, baking
    • H01M4/8885—Sintering or firing
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H01M8/10—Fuel cells with solid electrolytes
    • H01M8/12—Fuel cells with solid electrolytes operating at high temperature, e.g. with stabilised ZrO2 electrolyte
    • H01M8/1213—Fuel cells with solid electrolytes operating at high temperature, e.g. with stabilised ZrO2 electrolyte characterised by the electrode/electrolyte combination or the supporting material
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H01M8/10—Fuel cells with solid electrolytes
    • H01M8/12—Fuel cells with solid electrolytes operating at high temperature, e.g. with stabilised ZrO2 electrolyte
    • H01M8/1213—Fuel cells with solid electrolytes operating at high temperature, e.g. with stabilised ZrO2 electrolyte characterised by the electrode/electrolyte combination or the supporting material
    • H01M8/1226—Fuel cells with solid electrolytes operating at high temperature, e.g. with stabilised ZrO2 electrolyte characterised by the electrode/electrolyte combination or the supporting material characterised by the supporting layer
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/86—Inert electrodes with catalytic activity, e.g. for fuel cells
    • H01M2004/8678—Inert electrodes with catalytic activity, e.g. for fuel cells characterised by the polarity
    • H01M2004/8689—Positive electrodes
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/30—Hydrogen technology
    • Y02E60/50—Fuel cells
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Definitions

  • the invention relates to a gas diffusion electrode with a porous coating.
  • gas diffusion electrodes should be applicable in particular as a cathode or anode in SOFC fuel cells.
  • the invention also relates to a manufacturing process for the electrode coating.
  • SOFC Solid Oxide Fuell Cell
  • the cathode usually consists of porous perovskites.
  • an intermediate layer consisting of a lanthanum-manganide-zirconium oxide mixed structure between the cathode and the electrolyte can lower the polarization resistance of the cathode and thus increase the cell activity by more than 100% ,
  • the latter structure enlarges the active reaction zone by means of an interlocking structure made of ionically and electronically conductive materials.
  • the porosity of the intermediate layer depends, among other things, on the sintering temperature during manufacture, the structural properties playing a role. If the zirconium electrolyte is applied to the intermediate layer by means of a thermal spray process or else wet-chemically, the electrolyte can only be thermally treated at temperatures between 1250 ° C and sintered gas-tight at 1350 ° C.
  • the latter effect is naturally greater, the higher the sintering temperature and the longer the sintering time.
  • the compression of the intermediate layer can have a negative effect on the cell performance in the form of an increased diffusion resistance of the layer, especially when operating under high current densities.
  • the object of the invention is therefore to provide an electrode coating for a gas diffusion electrode which allows sufficient oxygen diffusion.
  • a manufacturing method is to be specified with which an electrode coating with a correspondingly low diffusion resistance, in particular for oxygen, is produced.
  • a defined open porosity of the layer can be achieved, which remains even after being coated with a solid electrolyte and its sintering. This allows a sufficiently low diffusion resistance to be set and sufficient oxygen diffusion to be achieved, in particular when coating the cathode.
  • both cathode and anode layers with a high gas conductance and thus low diffusion resistance can now be produced, with a reduction due to diffusion-related aging due to resintering of the structure.
  • FIG. 1 shows a schematic cross section of a tubular fuel cell
  • FIG. 2 shows a microstructure of a cover layer produced by conventional methods on a cathode in FIG. 1,
  • Figure 3 is a microstructure of such a layer, the under
  • High-temperature fuel cells or SOFC Solid Oxide Fuel Cell
  • SOFC Solid Oxide Fuel Cell
  • a solid ceramic, tubular fuel cell 3 comprises a first electrode called cathode 4 and a second electrode called anode 6.
  • the cathode 4 and the anode 6 are designed as concentrically arranged cylinders and consist of a porous ceramic material.
  • Such a fuel cell 3 with solid ceramic electrodes is also referred to as a “SOFC fuel cell * (solid oxide fuel cell).
  • SOFC fuel cell * solid oxide fuel cell
  • the cathode 4 is also referred to as the air electrode and the anode 6 as the fuel electrode.
  • a solid electrolyte layer 8 is arranged between the cathode 4 and the anode 6.
  • the solid electrolyte layer 8 must be gas-tight in order to avoid contact of the air and the fuel via the porous electrodes 4, 6. At the same time, the solid electrolyte layer 8 must have good ion conductivity so that ions can migrate between the cathode 4 and the anode 6 during operation of the fuel cell in order to build up a voltage. In order to achieve good ion conductivity between the two electrodes 4, 6, a special intermediate layer, not shown in detail in FIG. 1, is preferably inserted between the solid electrolyte layer 8 and the cathode on the one hand and the anode 6 on the other hand.
  • Both the solid electrolyte layer 8 and the anode 6 are not completely annular. Rather, they have an annular opening in which a so-called interconnector 9 is attached and is directly connected to the cathode 4 in an electrically conductive manner.
  • the internal cathode 4 can be electrically connected to other cells via the interconnector 9.
  • the air electrode ie the cathode 4 of the SOFC, according to FIG. 1, consists of perovskite lanan strontium manganate or lanthanum callium manganate.
  • the solid electrolyte 6 based on a ceramic zirconium oxide, which is replaced by 16 to 20 atomic% of the tetravalent zirconium by a trivalent ion, is usually applied to the cathode Yttrium (Y) or scandium (Sc), which becomes oxygen ion conducting, exists.
  • the layer between the cathode 4 and electrolyte 6 be ⁇ zirconia is lanthanum manganite mixture especially from one, wherein the structure and preparation is described in detail with reference to Figures 2 to. 4
  • the zirconium oxide-based electrolyte can be applied using thermal spray processes.
  • Known processes such as atmospheric plasma spraying (APS), vacuum plasma spraying (VPS) or the so-called LPPS (Low Pressure Plasma Spraying) process are suitable for this.
  • APS atmospheric plasma spraying
  • VPS vacuum plasma spraying
  • LPPS Low Pressure Plasma Spraying
  • VSC Vacuum Slurry Coating
  • RC Roller Coating
  • WPS Wet Pow- er Spraying
  • the generated electrolyte layers must be sintered gas-tight by a thermal aftertreatment at temperatures between 1200 ° and 1400 ° C. Sintering in general and also the sintering in of the intermediate layer influences the structure of the structure.
  • FIG. 2 shows a micrograph of an HPD tube for use in an SOFC.
  • a support with a cathode or the cathode itself as a support for further functional layers with an intermediate layer which has been sintered at 1325 ° C. for 3 hours.
  • the perovskite material 1 with pores 2 on which the intermediate layer 10 is applied which after sintering has only a few pores 11 and is almost completely dense overall. This makes oxygen diffusion considerably more difficult.
  • FIG. 3 shows the same perovskite structure 1 with pores 2, on which an intermediate layer is applied using so-called pore formers.
  • the intermediate layer is designated 20, which has considerable pores 21. Adequate oxygen diffusion is possible through the pores 21.
  • Layer 20 in FIG. 2 was produced with admixtures of pore formers with a defined grain size.
  • ⁇ the cathode mixture layer consisting of zirconium oxide and lanthanum calcium manganite before sintering pore former examples game, in weight proportions of from 2 to 20 wt .-% added ⁇ sets.
  • the pore formers burn out during sintering, so that the microstructure is specifically influenced and correspondingly defined porosities can be set.
  • the porosity advantageously has average particle sizes between 3 and 10 ⁇ m. This means that in different examples there are pore distributions around these mean values, Gaussian distributions of the pore sizes around these mean values.
  • pore formers come e.g. Plastics, coal, graphite or the like question that burn out at comparatively low temperatures.
  • a targeted porosity can also be achieved through the partial use of highly sintered zirconium oxide powders with a defined grain size, for example in an amount of 5 to 80%.
  • Such a powder acts as a structure stabilizer and also forms pores in the above sense.
  • higher sintering temperatures are necessary for stabilization.
  • the aging influences during long-term operation of the fuel cell are less.
  • Both options can also be coupled with one another in order to produce suitable structural properties for the individual case.
  • the long-term stable structure structures thus defined facilitate oxygen diffusion to the cathode / electrolyte interface due to the reduction in diffusion resistance especially when operating under heavy loads. As a result, the performance of the fuel cell is increased.
  • the measures described can also be used to set defined anode microstructures.
  • the intermediate layers are generally suitable for gas-permeable electrodes.
  • Figure 3 shows the gas conductance L of planar AE (Air electro de) substrates having an intermediate layer of combined Ka ⁇ thoden- and electrolyte materials as a function of the sintering temperature, wherein the layer form added in a case with no pore, ie without pore-forming agent, and in the other case the layer was produced with a pore shape additive, ie with a pore former.
  • Characteristic curve 31 shows the dependence of the gas conductance L in the prior art.
  • the gas conductance L starts from a predetermined value and drops steeply with the sintering temperature. At usual sintering temperatures and times there is a drop of, for example, 40%.
  • the characteristic curve 32 shows the diffusion layer with added pore shape. This results in an increased initial value, which is already 15% above the conductance of the layers produced according to the prior art, and which remains largely independent of the sintering temperature. The gas diffusion is accordingly increased and corresponds to practical requirements.
  • the example specifically described as a coating of a cathode on the basis of the figures can also be implemented as a porous coating of an anode of a SOFC.
  • Layers of this type can be used as intermediate layers both in tubular and in planar high-temperature fuel cells and have proven particularly useful in HPD (high power density) cells with integrated tubes.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Electrochemistry (AREA)
  • Manufacturing & Machinery (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Sustainable Development (AREA)
  • Sustainable Energy (AREA)
  • Materials Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Inert Electrodes (AREA)
  • Fuel Cell (AREA)

Abstract

Conventionally, gas-permeable layers are particularly provided on the surfaces of the cathodes of high temperature fuel cells (SOFC) and the oxygen diffusion is significantly reduced as a result of the corresponding application of electrolyte and sintering. According to the invention, an electrode coating may be produced with which the porosity may be defined and remains at this value after sintering. The above is achieved, whereby a pore-forming agent and/or a structural stabiliser are used.

Description

Beschreibungdescription
Gasdiffusionselektrode mit einer porösen Beschichtung und zugehöriges HerstellungsverfahrenGas diffusion electrode with a porous coating and associated manufacturing process
Die Erfindung bezieht sich auf eine Gasdiffusionselektrode mit einer porösen Beschichtung. Derartige Gasdiffusionselektroden sollen insbesondere als Kathode bzw. Anode bei SOFC- BrennstoffZeilen anwendbar sein. Daneben bezieht sich die Er- findung auch auf ein Herstellungsverfahren für die Elektrodenbeschichtung .The invention relates to a gas diffusion electrode with a porous coating. Such gas diffusion electrodes should be applicable in particular as a cathode or anode in SOFC fuel cells. In addition, the invention also relates to a manufacturing process for the electrode coating.
Als SOFC (Solid Oxide Fuell Cell) werden Hochtemperatur- Brennstoffzellen bezeichnet, die mit einem festen Elektroly- ten arbeiten. Derartige Brennstoffzellen werden beispielsweise in „VIK-Berichte*, Nr. 214 (1999), Seiten 49 ff. für das sogenannte Röhrenkonzept und Seiten 54 ff. für planare Ausführungen beschrieben.High-temperature fuel cells that work with a solid electrolyte are referred to as SOFC (Solid Oxide Fuell Cell). Fuel cells of this type are described, for example, in “VIK reports *, No. 214 (1999), pages 49 ff. For the so-called tube concept and pages 54 ff. For planar designs.
Bei letzteren Hochtemperatur-Brennstoffzellen besteht die Kathode üblicherweise aus porösen Perowskiten. Speziell bei der kathodengestützten, röhrenförmigen Zelle entsprechend vorstehend zitierter Veröffentlichung kann durch eine Zwischenschicht, die aus einem Lanthan-Manganid-Zirkonoxid-Misch- gefüge zwischen Kathode und Elektrolyt besteht, der Polarisationswiderstand der Kathode gesenkt und damit die Zellaktivität bis zu über 100 % gesteigert werden.In the latter high-temperature fuel cells, the cathode usually consists of porous perovskites. Particularly in the case of the cathode-supported, tubular cell in accordance with the publication cited above, an intermediate layer consisting of a lanthanum-manganide-zirconium oxide mixed structure between the cathode and the electrolyte can lower the polarization resistance of the cathode and thus increase the cell activity by more than 100% ,
Letzterer Aufbau vergrößert die aktive Reaktionszone durch einen ineinander verzahnten Aufbau aus ionisch und elektronisch leitenden Materialien. Die Porosität der Zwischenschicht ist dabei unter anderem von der Sintertemperatur bei der Herstellung abhängig, wobei die Gefügeeigenschaften eine Rolle spielen. Wird auf die Zwischenschicht der Zirkon-Elek- trolyt mittels thermischer Spritzverfahren oder aber nasschemisch aufgebracht, so kann der Elektrolyt nur durch eine thermische Nachbehandlung bei Temperaturen zwischen 1250°C und 1350°C gasdicht gesintert werden. Eine solche anschlie¬ ßende Sinterung und auch das Einsintern der Zwischenschicht beeinflusst aber auch die Gefügestruktur der teilweise aus Zirkonoxid bestehenden Zwischenschicht dahingehend, dass de- ren Gefügeporosität sinkt und damit die Sauerstoffdiffusion behindert werden kann.The latter structure enlarges the active reaction zone by means of an interlocking structure made of ionically and electronically conductive materials. The porosity of the intermediate layer depends, among other things, on the sintering temperature during manufacture, the structural properties playing a role. If the zirconium electrolyte is applied to the intermediate layer by means of a thermal spray process or else wet-chemically, the electrolyte can only be thermally treated at temperatures between 1250 ° C and sintered gas-tight at 1350 ° C. However, such a subsequent sequent ¬ sintering and also the Sintering of the intermediate layer also affects the microstructure of the partially consisting of zirconium oxide intermediate layer in that de- ren Gefügeporosität decreases and thus the oxygen diffusion can be obstructed.
Letzterer Effekt ist naturgemäß um so größer, je höher die Sintertemperatur und je länger die Sinterzeit ist. Die Ver- dichtung der Zwischenschicht kann sich speziell beim Betrieb unter hohen Stromdichten negativ auf die Zellleistung in Form eines erhöhten Diffusionswiderstandes der Schicht auswirken.The latter effect is naturally greater, the higher the sintering temperature and the longer the sintering time. The compression of the intermediate layer can have a negative effect on the cell performance in the form of an increased diffusion resistance of the layer, especially when operating under high current densities.
Aufgabe der Erfindung ist es daher, eine Elektrodenbeschich- tung für eine Gasdiffusionselektrode zu schaffen, die eine hinreichende Sauerstoffdiffusion erlaubt. Daneben soll ein Herstellungsverfahren angegeben werden, mit dem eine Elektrodenbeschichtung mit einen entsprechend niedrigen Diffusionswiderstand, insbesondere für Sauerstoff, erzeugt wird.The object of the invention is therefore to provide an electrode coating for a gas diffusion electrode which allows sufficient oxygen diffusion. In addition, a manufacturing method is to be specified with which an electrode coating with a correspondingly low diffusion resistance, in particular for oxygen, is produced.
Die Aufgabe ist bei einer Gasdiffusionselektrode der eingangs genannten Art durch die Merkmale des Patentanspruches 1 gelöst. Ein Herstellungsverfahren insbesondere der Elektrodenbeschichtung ist Gegenstand des Patentanspruches 6. Weiter- bildungen der Elektrodenbeschichtung und des zugehörigen Herstellungsverfahrens sind in den Unteransprüchen angegeben.The object is achieved in a gas diffusion electrode of the type mentioned by the features of claim 1. A manufacturing method, in particular the electrode coating, is the subject of patent claim 6. Further developments of the electrode coating and the associated manufacturing method are specified in the subclaims.
Mit der Erfindung lässt sich eine definierte offene Porosität der Schicht erreichen, die auch nach Belegung mit einem Fest- körperelektrolyten und dessen Sinterung bestehen bleibt. Damit lässt sich ein hinreichend niedriger Diffusionswiderstand einstellen und insbesondere bei der Beschichtung der Kathode eine genügende Sauerstoffdiffusion erreichen.With the invention, a defined open porosity of the layer can be achieved, which remains even after being coated with a solid electrolyte and its sintering. This allows a sufficiently low diffusion resistance to be set and sufficient oxygen diffusion to be achieved, in particular when coating the cathode.
Vom Stand der Technik ist es zwar bekannt, dass man bei keramischen Pulvern vor der Formgebung speziell organische Zuschlagsstoffe zusetzt, um dort die Porosität des fertigen Teiles zu beeinflussen. Die Verwendung solcher Porenbildner bei Diffusionsschichten für BrennstoffZellenanwendungen ist aber bisher nicht vorgeschlagen.It is known from the prior art that, in the case of ceramic powders, special organic additives are added before shaping in order to increase the porosity of the finished product To influence part. However, the use of such pore formers in diffusion layers for fuel cell applications has not previously been proposed.
Vorteilhafterweise können nunmehr sowohl Kathoden- als auch Anodenschichten mit hohem Gasleitwert und damit geringem Diffusionswiderstand hergestellt werden, wobei gleichermaßen um eine diffusionsbestimmte Alterung aufgrund einer Nachsinterung des Gefüges reduziert wird.Advantageously, both cathode and anode layers with a high gas conductance and thus low diffusion resistance can now be produced, with a reduction due to diffusion-related aging due to resintering of the structure.
Weitere Einzelheiten und Vorteile der Erfindung ergeben sich aus der nachfolgenden Figurenbeschreibung anhand von Ausführungsbeispielen in Verbindung mit den Patentansprüchen. Es zeigenFurther details and advantages of the invention result from the following description of the figures using exemplary embodiments in conjunction with the patent claims. Show it
Figur 1 einen schematischen Querschnitt einer röhrenförmigen Brennstoffzelle,FIG. 1 shows a schematic cross section of a tubular fuel cell,
Figur 2 ein Gefügebild einer nach herkömmlichen Verfahren hergestellten Deckschicht auf einer Kathode bei Figur 1,FIG. 2 shows a microstructure of a cover layer produced by conventional methods on a cathode in FIG. 1,
Figur 3 ein Gefügebild einer derartigen Schicht, die unterFigure 3 is a microstructure of such a layer, the under
Verwendung eines Porenbildners hergestellt wurde, undWas made using a pore former, and
Figur 4 Ergebnisse von experimentellen Messungen des Gasleitwertes speziell an Kathodenschichten mit und ohne Zwischenschicht.Figure 4 Results of experimental measurements of the gas conductance, especially on cathode layers with and without an intermediate layer.
Hochtemperatur-Brennstoffzellen bzw. SOFC (Solid Oxide Fuel Cell) sind gemäß der eingangs zitierten Literatur in unterschiedlicher Ausführungsform bekannt. Insbesondere in tubula- rer Ausführung ergibt sich vorteilhafterweise das Konzept der sog. HPD (High Power Density) -Zellen mit integrierten Röhren.High-temperature fuel cells or SOFC (Solid Oxide Fuel Cell) are known in different embodiments according to the literature cited at the beginning. The tubular HPD (high power density) cell concept with integrated tubes advantageously results, in particular, in a tubular design.
Gemäß FIG 1 umfasst eine festkeramische, röhrenförmige Brennstoffzelle 3 eine erste als Kathode 4 bezeichnete Elektrode und eine zweite als Anode 6 bezeichnete Elektrode. Die Kathode 4 und die Anode 6 sind als konzentrisch zueinander angeordnete Zylinder ausgebildet und bestehen aus einem porösen keramischen Werkstoff. Eine derartige Brennstoffzelle 3 mit festkeramischen Elektroden wird auch als „SOFC-Brennstoff- zelle* (Solide Oxide Fuel Cell) bezeichnet. Durch die innere röhrenförmige Kathode 4 wird Luft bzw. Sauerstoff geleitet, während an der die Kathode 4 umgebenden Anode 6 ein Brenn¬ stoff, beispielsweise Wasserstoff, vorbeigeführt wird. Die Kathode 4 wird auch als Luftelektrode und die Anode 6 als Brennstoffelektrode bezeichnet. Zwischen der Kathode 4 und der Anode 6 ist eine Festelektrolytschicht 8 angeordnet.According to FIG. 1, a solid ceramic, tubular fuel cell 3 comprises a first electrode called cathode 4 and a second electrode called anode 6. The cathode 4 and the anode 6 are designed as concentrically arranged cylinders and consist of a porous ceramic material. Such a fuel cell 3 with solid ceramic electrodes is also referred to as a “SOFC fuel cell * (solid oxide fuel cell). Through the inner tubular cathode 4 air or oxygen is passed while at the cathode 4 surrounding anode 6 ¬ a fuel material, for example hydrogen, is passed. The cathode 4 is also referred to as the air electrode and the anode 6 as the fuel electrode. A solid electrolyte layer 8 is arranged between the cathode 4 and the anode 6.
Die Festelektrolytschicht 8 muss einerseits gasdicht sein, um einen Kontakt der Luft und des Brennstoffes über die porös ausgebildeten Elektroden 4, 6 zu vermeiden. Gleichzeitig muss die Festelektrolytschicht 8 eine gute Ionenleitfähigkeit auf- weisen, damit beim Betrieb der Brennstoffzelle Ionen zwischen der Kathode 4 und der Anode 6 wandern können, um eine Spannung aufzubauen. Um eine gute Ionenleitfähigkeit zwischen den beiden Elektroden 4, 6 zu erreichen, ist vorzugsweise zwischen der Festelektrolytschicht 8 und der Kathode einerseits sowie der Anode 6 andererseits eine spezielle, in Figur 1 nicht im Einzelnen dargestellte Zwischenschicht eingefügt.On the one hand, the solid electrolyte layer 8 must be gas-tight in order to avoid contact of the air and the fuel via the porous electrodes 4, 6. At the same time, the solid electrolyte layer 8 must have good ion conductivity so that ions can migrate between the cathode 4 and the anode 6 during operation of the fuel cell in order to build up a voltage. In order to achieve good ion conductivity between the two electrodes 4, 6, a special intermediate layer, not shown in detail in FIG. 1, is preferably inserted between the solid electrolyte layer 8 and the cathode on the one hand and the anode 6 on the other hand.
Sowohl die Festelektrolytschicht 8 als auch die Anode 6 sind nicht vollständig ringförmig ausgebildet. Sie weisen vielmehr eine Ringöffnung auf, in der ein sogenannter Interkonnektor 9 angebracht und unmittelbar mit der Kathode 4 elektrisch leitend verbunden ist. Über den Interkonnektor 9 ist die innenliegende Kathode 4 elektrisch mit anderen Zellen verbindbar.Both the solid electrolyte layer 8 and the anode 6 are not completely annular. Rather, they have an annular opening in which a so-called interconnector 9 is attached and is directly connected to the cathode 4 in an electrically conductive manner. The internal cathode 4 can be electrically connected to other cells via the interconnector 9.
Üblicherweise besteht speziell die Luftelektrode, d.h. die Kathode 4 der SOFC, gemäß Figur 1 aus perowskitischem Lan- than-Strontium-Manganat oder Lanthan-Callium-Manganat . Zur Erzielung bestimmter Eigenschaften können weitere Elemente in unterschiedlichen Konzentrationen zugesetzt werden. Auf die Kathode wird der feste Elektrolyt 6 auf der Basis eines keramischen Zirkonoxides, das durch Ersatz von 16 bis 20 Atom-% des vierwertigen Zirkoniums durch ein dreiwertiges Ion, meist Yttrium (Y) oder Scandium (Sc) , Sauerstoffionenleitend wird, besteht. Die Schicht zwischen Kathode 4 und Elektrolyt 6 be¬ steht insbesondere aus einer Lanthanmanganit-Zirkonoxid- Mischung, wobei deren Struktur und Herstellung im Einzelnen anhand der Figuren 2 bis 4 beschrieben wird.Usually, the air electrode, ie the cathode 4 of the SOFC, according to FIG. 1, consists of perovskite lanan strontium manganate or lanthanum callium manganate. To achieve certain properties, other elements can be added in different concentrations. The solid electrolyte 6 based on a ceramic zirconium oxide, which is replaced by 16 to 20 atomic% of the tetravalent zirconium by a trivalent ion, is usually applied to the cathode Yttrium (Y) or scandium (Sc), which becomes oxygen ion conducting, exists. The layer between the cathode 4 and electrolyte 6 be ¬ zirconia is lanthanum manganite mixture especially from one, wherein the structure and preparation is described in detail with reference to Figures 2 to. 4
Der zirkonoxidbasierte Elektrolyt kann mittels thermischer Spritzverfahren aufgebracht werden. Hierfür kommen bekannte Verfahren wie Atmosphärisches Plasmaspritzen (APS) , Vakuum- Plasmaspritzen (VPS) oder das sog. LPPS (Low Pressure Plasma Spraying) -Verfahren in Frage. Alternativ ist aber auch ein Aufbringen des Elektrolyts nasschemisch möglich, wozu sich Vakuumschlickerguss (VSC = Vacuum Slurry Coating) , Siebdrucken (RC = Roller Coating) oder Nasspulverspritzen (WPS = Wet Pow- der Spraying) eignen. In allen Fällen müssen allerdings die erzeugten Elektrolytschichten durch eine thermische Nachbehandlung bei Temperaturen zwischen 1200° und 1400°C gasdicht gesintert werden. Das Sintern allgemein und auch das Einsintern der Zwischenschicht beeinflusst aber die Gefügestruktur.The zirconium oxide-based electrolyte can be applied using thermal spray processes. Known processes such as atmospheric plasma spraying (APS), vacuum plasma spraying (VPS) or the so-called LPPS (Low Pressure Plasma Spraying) process are suitable for this. Alternatively, it is also possible to apply the electrolyte using wet chemistry, for which vacuum slip casting (VSC = Vacuum Slurry Coating), screen printing (RC = Roller Coating) or wet powder spraying (WPS = Wet Pow- er Spraying) are suitable. In all cases, however, the generated electrolyte layers must be sintered gas-tight by a thermal aftertreatment at temperatures between 1200 ° and 1400 ° C. Sintering in general and also the sintering in of the intermediate layer influences the structure of the structure.
Figur 2 zeigt ein Gefügebild einer HPD-Röhre zur Verwendung bei einer SOFC. Entsprechend Figur 1 ist ein Träger mit einer Kathode oder die Kathode selbst als Träger weiterer Funktionsschichten vorhanden mit einer Zwischenschicht, die bei 1325°C für 3 h gesintert wurde. Man erkennt das perowskiti- sche Material 1 mit Poren 2, auf der die Zwischenschicht 10 aufgebracht ist, die nach der Sinterung nur noch einzelne wenige Poren 11 hat und insgesamt fast dicht ist. Dadurch wird eine Sauerstoffdiffusion wesentlich erschwert.Figure 2 shows a micrograph of an HPD tube for use in an SOFC. According to FIG. 1, there is a support with a cathode or the cathode itself as a support for further functional layers with an intermediate layer which has been sintered at 1325 ° C. for 3 hours. One recognizes the perovskite material 1 with pores 2 on which the intermediate layer 10 is applied, which after sintering has only a few pores 11 and is almost completely dense overall. This makes oxygen diffusion considerably more difficult.
In der Figur 3 ist die gleiche Perowskitstruktur 1 mit Poren 2 dargestellt, auf der eine Zwischenschicht unter Verwendung von sogenannten Porenbildnern aufgebracht ist. Im Einzelnen ist die Zwischenschicht mit 20 bezeichnet, welche beachtliche Poren 21 aufweist. Durch die Poren 21 ist eine hinreichende Sauerstoffdiffusion möglich. Die Schicht 20 in Figur 2 wurde unter Beimischungen von Porenbildnern mit definierter Korngröße hergestellt. Dafür wer¬ den der Kathodenmischschicht bestehend aus Zirkonoxid und Lanthan-Calcium-Manganit vor der Sinterung Porenbildner bei- spielsweise in Gewichtsanteilen von 2 bis 20 Gew.-% zuge¬ setzt. Beim Sintern brennen die Porenbildner aus, so dass die Gefügestruktur gezielt beeinflusst wird und entsprechend definierte Porositäten eingestellt werden können. Wesentlich ist, dass eine offenporige Struktur mit Porositäten zwischen 20 und 40 % vorliegt und somit eine gute Gasdurchlässigkeit gewährleistet. Die Porosität hat vorteilhafterweise mittlere Teilchengrößen zwischen 3 und 10 μm. Dies bedeutet, dass sich in unterschiedlichen Beispielen Porenverteilungen um diese Mittelwerte ergeben, wobei im Einzelnen Gaußverteilungen der Porengrößen um diese Mittelwerte ergeben.FIG. 3 shows the same perovskite structure 1 with pores 2, on which an intermediate layer is applied using so-called pore formers. In detail, the intermediate layer is designated 20, which has considerable pores 21. Adequate oxygen diffusion is possible through the pores 21. Layer 20 in FIG. 2 was produced with admixtures of pore formers with a defined grain size. For ¬ the cathode mixture layer consisting of zirconium oxide and lanthanum calcium manganite before sintering pore former examples game, in weight proportions of from 2 to 20 wt .-% added ¬ sets. The pore formers burn out during sintering, so that the microstructure is specifically influenced and correspondingly defined porosities can be set. It is essential that there is an open-pore structure with porosities between 20 and 40%, thus ensuring good gas permeability. The porosity advantageously has average particle sizes between 3 and 10 μm. This means that in different examples there are pore distributions around these mean values, Gaussian distributions of the pore sizes around these mean values.
Als Porenbildner kommen z.B. Kunststoffe, Kohle, Graphit od. dgl . in Frage, die bei vergleichsweise niedrige Temperaturen ausbrennen. Eine gezielte Porosität lässt sich aber auch durch die teilweise Verwendung von hochgesinterten Zirkon- oxidpulvern mit definierter Korngröße, beispielsweise in einer Menge von 5 bis 80 %, erreichen. Ein solches Pulver wirkt als Gefügestabilisierer und bildet in obigem Sinne ebenfalls Poren. Allerdings sind zur Stabilisierung hier höhere Sinter- temperaturen notwendig. Es resultiert daraus aber ein geringerer Sinterschwund und das Zirkonoxidgefüge ist stabiler. Weiterhin sind die Alterungseinflüsse beim Langzeitbetrieb der Brennstoffzelle geringer.As pore formers come e.g. Plastics, coal, graphite or the like question that burn out at comparatively low temperatures. A targeted porosity can also be achieved through the partial use of highly sintered zirconium oxide powders with a defined grain size, for example in an amount of 5 to 80%. Such a powder acts as a structure stabilizer and also forms pores in the above sense. However, higher sintering temperatures are necessary for stabilization. However, this results in less sintering shrinkage and the zirconium oxide structure is more stable. Furthermore, the aging influences during long-term operation of the fuel cell are less.
Beide Möglichkeiten können auch miteinander gekoppelt werden, um für den Einzelfall geeignete Gefügeeigenschaften herzustellen.Both options can also be coupled with one another in order to produce suitable structural properties for the individual case.
Die so definierten langzeitstabilen Gefügestrukturen erleich- tern die Sauerstoffdiffusion zur Grenzfläche Kathode/Elektrolyt aufgrund der Reduzierung des Diffusionswiderstandes insbesondere beim Betrieb unter großer Last. Damit wird im Ergebnis die Leistung der Brennstoffzelle gesteigert.The long-term stable structure structures thus defined facilitate oxygen diffusion to the cathode / electrolyte interface due to the reduction in diffusion resistance especially when operating under heavy loads. As a result, the performance of the fuel cell is increased.
Die beschriebenen Maßnahmen können auch zur Einstellung von definierten Anodengefügestrukturen eingesetzt werden. Im ver¬ allgemeinerten Sinne sind die Zwischenschichten allgemein für gasdurchlässige Elektroden geeignet.The measures described can also be used to set defined anode microstructures. In the generalized sense, the intermediate layers are generally suitable for gas-permeable electrodes.
Figur 3 zeigt den Gasleitwert L von planaren AE (Air Electro- de) -Substraten mit einer Zwischenschicht aus kombinierten Ka¬ thoden- und Elektrolytmaterialien in Abhängigkeit von der Sintertemperatur, wobei in einem Fall die Schicht ohne Poren- formzusatz, d.h. ohne Porenbildner, und im anderen Fall die Schicht mit Porenformzusatz, d.h. mit Porenbildner, herge- stellt wurde. Kennlinie 31 zeigt die Abhängigkeit des Gasleitwertes L beim Stand der Technik. Der Gasleitwert L geht von einem vorgegebenen Wert aus und fällt mit der Sintertemperatur steil ab. Bei üblichen Sintertemperaturen und -Zeiten ergibt sich ein Abfall von beispielsweise 40 %.Figure 3 shows the gas conductance L of planar AE (Air electro de) substrates having an intermediate layer of combined Ka ¬ thoden- and electrolyte materials as a function of the sintering temperature, wherein the layer form added in a case with no pore, ie without pore-forming agent, and in the other case the layer was produced with a pore shape additive, ie with a pore former. Characteristic curve 31 shows the dependence of the gas conductance L in the prior art. The gas conductance L starts from a predetermined value and drops steeply with the sintering temperature. At usual sintering temperatures and times there is a drop of, for example, 40%.
Die Kennlinie 32 zeigt die Diffusionsschicht mit Porenformzu- satz. Hier ergibt sich ein erhöhter Ausgangswert, der bereits 15 % über dem Leitwert der nach dem Stand der Technik hergestellten Schichten liegt, und der weitestgehend unabhängig von der Sintertemperatur konstant bleibt. Die Gasdiffusion ist somit entsprechend erhöht und entspricht den Anforderungen der Praxis.The characteristic curve 32 shows the diffusion layer with added pore shape. This results in an increased initial value, which is already 15% above the conductance of the layers produced according to the prior art, and which remains largely independent of the sintering temperature. The gas diffusion is accordingly increased and corresponds to practical requirements.
Das anhand der Figuren speziell als Beschichtung einer Katho- de beschriebene Beispiel kann auch als poröse Beschichtung einer Anode einer SOFC realisiert werden. Derartige Schichten sind als Zwischenschichten sowohl bei tubularen als auch bei planaren Hochtemperatur-Brennstoffzellen einsetzbar und haben sich insbesondere bei HPD (High Power Density) -Zellen mit in- tegrierten Röhren bewährt. The example specifically described as a coating of a cathode on the basis of the figures can also be implemented as a porous coating of an anode of a SOFC. Layers of this type can be used as intermediate layers both in tubular and in planar high-temperature fuel cells and have proven particularly useful in HPD (high power density) cells with integrated tubes.

Claims

Patentansprüche claims
1. Gasdiffusionselektrode mit einer porösen Beschichtung, insbesondere als Elektrode einer Hochtemperatur-Brennstoff- zelle, wobei die Porosität einen Wert hat, der nach Belegung mit einem Elektrolyten und anschließender Sinterung den vorgegebenen Wert beibehält.1. Gas diffusion electrode with a porous coating, in particular as an electrode of a high-temperature fuel cell, the porosity having a value which, after being coated with an electrolyte and subsequent sintering, maintains the predetermined value.
2. Gasdiffusionselektrode nach Anspruch 1, d a d u r c h g e k e n n z e i c h n e t , dass eine offene Porosität im Bereich von 20 bis 40 % vorliegt.2. The gas diffusion electrode as claimed in claim 1, which has an open porosity in the range from 20 to 40%.
3. Gasdiffusionselektrode nach Anspruch 1, d a d u r c h g e k e n n z e i c h n e t , dass eine offene Porosität mit einer mittleren Porengröße von 3 bis 10 μm vorliegt.3. The gas diffusion electrode as claimed in claim 1, so that an open porosity with an average pore size of 3 to 10 μm is present.
4. Gasdiffusionselektrode nach einem der Ansprüche 1 bis 3, g e k e n n z e i c h n e t in der Anwendung bei einer Kathode einer Hochtemperatur-Brennstoffzelle.4. Gas diffusion electrode according to one of claims 1 to 3, g e k e n n z e i c h n e t in use with a cathode of a high temperature fuel cell.
5. Gasdiffusionselektrode nach einem der Ansprüche 1 bis 3, g e k e n n z e i c h n e t in der Anwendung bei der Anode einer Hochtemperatur-Brennstoffzelle .5. Gas diffusion electrode according to one of claims 1 to 3, g e k e n n z e i c h n e t in use in the anode of a high-temperature fuel cell.
6. Verfahren zur Herstellung einer Gasdiffusionselektrode mit einer porösen Beschichtung nach Anspruch 1 oder einem der Ansprüche 2 bis 5, mit folgenden Maßnahmen: es wird eine poröse Elektrode als Träger wenigstens einer weiteren Schicht verwendet, - bei der Herstellung der Schicht werden in das Schichtmaterial ein Porenbildner, der nachfolgend durch eine Tempera¬ turbehandlung ausgebrannt wird, und/oder ein Gefügestabi- lisierer eingebracht, womit definierte Poren in der Schicht erzeugt werden.6. A method for producing a gas diffusion electrode with a porous coating according to claim 1 or one of claims 2 to 5, with the following measures: a porous electrode is used as a carrier of at least one further layer, - in the production of the layer are in the layer material pore formers, the below by a tempera ¬ turbehandlung is burned, and / or lisierer introduced a Gefügestabi-, thus defined pores are produced in the layer.
7. Verfahren nach Anspruch 6, d a d u r c h g e k e n n z e i c h n e t , dass Porenbildner und/oder Gefügestabili- sator definierter Korngrößenverteilungen mit mittlerem Korndurchmesser zwischen 3 und 10 μm verwendet werden.7. The method according to claim 6, characterized in that pore formers and / or microstructural defined grain size distributions with an average grain diameter between 3 and 10 μm can be used.
8. verfahren nach Anspruch 7, d a d u r c h g e k e n n z e i c h n e t , dass als Porenbildner organische Zusatzstoffe in einer Menge von 5 bis 50 Gew.-% verwendet werden.8. The method according to claim 7, d a d u r c h g e k e n n z e i c h n e t that organic additives are used as pore formers in an amount of 5 to 50 wt .-%.
9. Verfahren nach Anspruch 7, d a d u r c h g e k e n n z e i c h n e t , dass als Gefügestabilisator keramische Zusatzstoffe verwendet werden.9. The method according to claim 7, d a d u r c h g e k e n n z e i c h n e t that ceramic additives are used as a structure stabilizer.
10. Verfahren nach Anspruch 9, d a d u r c h g e k e n n z e i c h n e t , dass der keramische Zusatzstoff Zirkonoxid in einer Menge von 5 bis 80 Gew.-% ist. 10. The method according to claim 9, and that the ceramic additive is zirconium oxide in an amount of 5 to 80% by weight.
PCT/DE2002/002540 2001-07-13 2002-07-11 Gas diffusion electrode with a porous coating and corresponding production method WO2003019712A2 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE10134129A DE10134129A1 (en) 2001-07-13 2001-07-13 Coating used for a gas diffusion electrode, especially for an anode or cathode of a high temperature fuel cell, has a porosity which maintains its value after applying an electrolyte and subsequently sintering
DE10134129.6 2001-07-13

Publications (2)

Publication Number Publication Date
WO2003019712A2 true WO2003019712A2 (en) 2003-03-06
WO2003019712A3 WO2003019712A3 (en) 2003-05-30

Family

ID=7691698

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/DE2002/002540 WO2003019712A2 (en) 2001-07-13 2002-07-11 Gas diffusion electrode with a porous coating and corresponding production method

Country Status (2)

Country Link
DE (1) DE10134129A1 (en)
WO (1) WO2003019712A2 (en)

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4598467A (en) * 1984-10-05 1986-07-08 Westinghouse Electric Corp. Protective interlayer for high temperature solid electrolyte electrochemical cells
US5516597A (en) * 1994-11-07 1996-05-14 Westinghouse Electric Corporation Protective interlayer for high temperature solid electrolyte electrochemical cells
US5629103A (en) * 1993-04-30 1997-05-13 Siemens Aktiengesellschaft High-temperature fuel cell with improved solid-electrolyte/electrode interface and method of producing the interface
US6139985A (en) * 1998-07-24 2000-10-31 Siemens Westinghouse Power Corporation Electrode electrolyte interlayers containing cerium oxide for electrochemical fuel cells

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19626342A1 (en) * 1996-07-01 1998-01-08 Forschungszentrum Juelich Gmbh Procedure for making solid electrolyte as thin layer on porous electrode for fuel-cell
DE19730003B4 (en) * 1997-07-12 2007-06-21 Mtu Cfc Solutions Gmbh An electrically conductive high temperature fuel cell component and use of a metal-ceramic composite material to manufacture a high temperature fuel cell component

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4598467A (en) * 1984-10-05 1986-07-08 Westinghouse Electric Corp. Protective interlayer for high temperature solid electrolyte electrochemical cells
US5629103A (en) * 1993-04-30 1997-05-13 Siemens Aktiengesellschaft High-temperature fuel cell with improved solid-electrolyte/electrode interface and method of producing the interface
US5516597A (en) * 1994-11-07 1996-05-14 Westinghouse Electric Corporation Protective interlayer for high temperature solid electrolyte electrochemical cells
US6139985A (en) * 1998-07-24 2000-10-31 Siemens Westinghouse Power Corporation Electrode electrolyte interlayers containing cerium oxide for electrochemical fuel cells

Also Published As

Publication number Publication date
WO2003019712A3 (en) 2003-05-30
DE10134129A1 (en) 2003-02-13

Similar Documents

Publication Publication Date Title
DE69430634T2 (en) ELECTROCHEMICAL APPARATUS
EP2050155B1 (en) Electrode for a molten carbonate fuel cell and process for its production
EP1343215B1 (en) Structured body used as anode in fuel cell
DE112012004306B4 (en) Fuel cell
EP1587969B1 (en) Method for producing metallic moulded bodies comprising a ceramic layer, metallic moulded body, and the use of the same
DE19963882A1 (en) Electrode for high temperature fuel cell and method of manufacturing the same
DE10031102C2 (en) Process for producing a composite body, in particular an electrode with temperature-resistant conductivity
EP1261057B1 (en) Production process of a membrane-electrode assembly and membrane-electrode assembly obtained by this process
EP1246288B1 (en) Porous gas-permeable substructure layer of a thin gas impervious layer for use as functional component in high temperature fuel cells
EP3670703A1 (en) Gas diffusion body
WO2013026647A1 (en) Tubular fuel cell supported in an inert manner
WO2005045979A2 (en) Cathode material for a high-temperature fuel cell (sofc) and a cathode that can be produced therefrom
DE60123839T2 (en) STACKED MICROSTRUCTURES OF LEADING, CERAMIC OXIDION MEMBRANES; USE FOR THE SEPARATION OF OXYGEN FROM AIR
EP1513214A1 (en) High temperature fuel cell with stabilized cermet structure
DE102011081540A1 (en) Fuel cell for production of energy, has functional body i.e. one-sided closed tube, including two electrical interconnected segment strands aligned in axial direction with respect to axis of functional body
DE10052189B4 (en) A multilayer gas diffusion electrode of a polymer electrolyte membrane fuel cell, a membrane electrode assembly, a method of manufacturing a gas diffusion electrode and a membrane electrode assembly, and use of the membrane electrode assembly
EP2669984B1 (en) Layered anode system for electrochemical applications and process of manufacturing the same
DE102004024844A1 (en) Electrode paste for producing a catalyst layer for an electrochemical cell and method for producing a catalyst layer
WO2003019712A2 (en) Gas diffusion electrode with a porous coating and corresponding production method
DE10031123A1 (en) Making porous planar anode substrate for high temperature fuel cell by ceramic slip film casting, involves adding combustible filler to coarse and fine powder mixture
EP2850676B1 (en) Storage structure of an electrical energy storage cell
DE19943523B4 (en) Long-term stable high-temperature fuel cells (SOFC) and process for their production
WO2018096022A1 (en) Anode for an electrochemical cell and method for producing an electrochemical cell comprising such an anode
EP1658653A1 (en) Solid-oxide fuel cell and method for producing the same
DE102017206693A1 (en) Method for producing a functional layer

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A2

Kind code of ref document: A2

Designated state(s): US

AL Designated countries for regional patents

Kind code of ref document: A2

Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR IE IT LU MC NL PT SE SK TR

Kind code of ref document: A2

Designated state(s): AT BE BG CH CY CZ DE DK EE ES FR GB GR IE IT LU MC NL PT SE SK TR

DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
121 Ep: the epo has been informed by wipo that ep was designated in this application
122 Ep: pct application non-entry in european phase