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EP-4738478-A2 - METHOD FOR MANUFACTURING AN ELECTROLYTE-SUPPORTED FUEL CELL STRUCTURE

EP4738478A2EP 4738478 A2EP4738478 A2EP 4738478A2EP-4738478-A2

Abstract

A method (200) for manufacturing an electrolyte-supported fuel cell structure (100) is provided. The method (200) includes providing (210) a continuous electrolyte layer (110) with a first side (111) and a second side (112), coating (221) the first side (111) with an anode material (121) to form a continuous anode layer (120), and coating (222) the second side (112) with a cathode material (131) to form a continuous cathode layer (130). Portions of the anode layer (120) and cathode layer (130) are removed (231, 232) via laser ablation, creating separated anode and cathode sections. Through holes (113) are created (240) in the electrolyte layer (110) coinciding with areas where the anode or cathode layers have been removed. Conductive material (160) is arranged in the through holes to connect anode and cathode sections, thereby forming a serial connection between corresponding fuel cell segments.

Inventors

  • ROHR, Oliver
  • FRIEDBERGER, ALOIS

Assignees

  • Airbus S.A.S.

Dates

Publication Date
20260506
Application Date
20251009

Claims (15)

  1. Method (200) for manufacturing an electrolyte-supported fuel cell structure (100), the method (200) comprising: providing (210) a continuous electrolyte layer (110) having a first side (111) and a second side (112); coating (221) the first side (111) of the continuous electrolyte layer (110) with an anode material (121), such that a continuous anode layer (120) at least partially covers the first side (111) of the electrolyte layer (110); coating (222) the second side (112) of the continuous electrolyte layer (110) with a cathode material (131), such that a continuous cathode layer (130) at least partially covers the second side (112) of the electrolyte layer (110); removing (231) portions of the anode layer (120) via laser ablation, such that at least a first anode section (122) and a second anode section (123) that are completely separated from each other but that are neighboring each other on the first side (111) of the electrolyte layer (110) are build; removing (232) portions of the cathode layer (130) via laser ablation, such that at least a first cathode section (132) and a second cathode section (133) that are completely separated from each other but that are neighboring each other on the first side (111) of the electrolyte layer (110) are build; creating (240) through holes (113) through the electrolyte layer (110) that at least partially coincide with areas, in which the anode layer (120) and/or the cathode layer (130) has been removed; and arranging (250) a conductive material (160) within the through holes (113), such that the conductive material (160) connects the first anode section (122) with the second cathode section (133), or such that the conductive material (160) connects the second anode section (123) with the first cathode section (132), thereby building a serial connection between corresponding fuel cell segments.
  2. The method (200) of claim 1, wherein providing the continuous electrolyte layer (110) comprises providing the continuous electrolyte layer (110) in a tubular shape building a tube having an inner side (111) and an outer side (112), wherein the first side (111) of the electrolyte layer (110) is the inner side (111) of the tube and wherein the second side (112) of the continuous electrolyte layer (110) is the outer side (112) of the tube or vice versa.
  3. The method (200) of claim 2, wherein removing (231) the portions of the anode layer (120) and removing (232) the portions of the cathode layer (230) each occurs in at least one ring around the circumferential direction of the tube, such that the rings in which the anode layer (120) and the cathode layer (130) are removed are at least partially opposing each other on opposite sides of the tube.
  4. The method (200) of claim 2 or 3, wherein removing (231, 232) the portions of the corresponding one of the anode layer (120) or the cathode layer (130) that is arranged at the inner side of the tube is performed by inserting (233) a carrier (190) having a mirror (191) mounted thereon into the tube and illuminating (234) the mirror with a laser beam (193); wherein the mirror (191) is configured to direct the laser beam (193) onto the inner side of the tube at an incident angle between 5 degree and 175 degree.
  5. The method (200) of any one of the preceding claims, wherein removing (231) the portions of the anode layer (120) and/or removing (232) the portions of the cathode layer (230) by laser ablation is stopped as soon as the electrolyte layer (110) is exposed, in order to at least largely avoid removal of material of the electrolyte layer (110).
  6. The method (200) of any one of the preceding claims, wherein removing (231) the portions of the anode layer (120) and/or removing (232) the portions of the cathode layer (230) is performed for a predetermined period of time.
  7. The method (200) of any one of the preceding claims, wherein the electrolyte layer (110) and the corresponding one of the anode layer (120) and the cathode layer (130) exhibit distinct emission spectra; and wherein removing (231) the portions of the anode layer (120) and/or removing (232) the portions of the cathode layer (230), respectively, further comprises monitoring (235) the emission spectra during laser ablation and stopping the laser ablation process when a change in the detected emission spectrum indicates the ablation process has reached the electrolyte layer (110) and therefore is complete.
  8. The method (200) of any one of the preceding claims, wherein removing (231, 232) the portions of the anode layer (120) or the cathode layer (130), respectively, is performed by scanning corresponding regions of the respective one of the anode layer (120) and the cathode layer (130) with a laser beam (193).
  9. The method (200) of any one of the preceding claims, wherein creating (240) the through holes (113) through the electrolyte layer (110) is performed via laser drilling.
  10. The method (200) of any one of the preceding claims, wherein creating (240) the through holes (113) through the electrolyte layer (110) comprises: coating (241) the arrangement comprising the electrolyte layer (110), the anode layer (120), and the cathode layer (130) with a photoresist (196) by dip coating or spray coating after removing (231, 232) the portions of the anode layer (120) and the cathode layer (130); laser structuring (242) the photoresist (196) on at least one of the sides of the arrangement; and laser drilling (243) the through holes (113) on the at least one side of the arrangement that has been laser structured.
  11. The method (200) of any one of the preceding claims, wherein arranging (250) the conductive material (160) within the through holes (113) is performed by galvanic deposition and/or physical vapor deposition, PVD.
  12. The method (200) of any one of the preceding claim, wherein coating (221) the first side (111) of the electrolyte layer (120) with the anode material (121) and/or coating (222) the second side (112) of the electrolyte layer (120) with the cathode material (131) is carried out by slurry dip coating.
  13. The method (200) of any one of the preceding claims, further comprising coating (223) the first side (111) and/or the second side (112) of the electrolyte layer (110) with a barrier layer (140) prior to coating (221, 222) the corresponding one of the first side (111) and the second side (112) with the anode material (121) or the cathode material (131), respectively.
  14. The method (200) of any one of the preceding claim, wherein the laser ablation is adjusted so as to soften edges at the end of the laser ablation processes, in order to avoid or at least reduce mechanical stress in the electrolyte layer (110).
  15. The method (200) of any one of the preceding claims, wherein removing (231, 232) the portions of the anode layer (120) and/or the cathode layer (130) is carried out by directing a laser beam (193) onto the corresponding surface via an optical fiber (150) having a cleaved end and/or a micro lens arranged at its end.

Description

TECHNICAL FIELD The present disclosure relates to method for manufacturing fuel cell structures in general, and in particular to a method for manufacturing an electrolyte-supported fuel cell structure comprising multiple fuel cells that are supported by a common electrolyte layer and connected in series with each other. TECHNICAL BACKGROUND Because of the technical progress, and because of their environmentally friendly creation of electrical energy, fuel cells are becoming increasingly popular as alternative energy sources. However, planar solid oxide fuel cells (SOFCs), for example, offer a relatively low gravimetric power density and are as such currently mainly developed for stationary applications. In mobile applications, and for aircrafts in particular, reduction of weight is of paramount importance. Therefore, in order to keep the weight low while still providing the necessary power, increasing the gravimetric power density (being the power per weight unit) is desired. In typical planar SOFCs having an oxide conducting ceramic electrolyte covered with a negative electrode (anode) on the fuel side and with a positive electrode (cathode) on the oxidizer side, metallic interconnectors at the outsides of each cell are used to electrically connect each cell to a neighboring cell and to separate the fuel from the oxidizer channel (air gas channel) of two neighboring cells, in order to build a fuel cell stack. The electrical current thereby is transferred in a perpendicular direction of the cell area. The interconnectors can take up to 70% of the total weight of such a planar stack. Although known tubular cell designs, for example, do not rely on such heavy interconnectors and therefore offer optimization potential with regard to the gravimetric power density, such solutions implement current collection in the longitudinal or circular direction and along the in-plane cross section of the cell. This current collection mechanism causes higher current losses compared to planar concepts (partly because of the long distances the electrons have to travel) and with this low gravimetric power densities. Also, integrated planar SOFC concepts are known in the art, in which single cell strips are arranged in a common plane onto a porous support substrate and interconnected in series by electrical interconnectors. Such solutions offer advantages with regard to the gravimetric power density because heavy interconnector plates can be avoided. However, the manufacturing process of the integrated planar SOFC concepts requires that the porous support layer is produced prior to the functional layers, which results in difficulties with respect to applying the appropriate sintering temperatures, which furthermore can reduce the performance and durability of the cell. Further, the thermal expansion of the different layers result in an increased risk of delamination and cracking at the interface between two cell segments. DESCRIPTION It is an objective to provide a method for manufacturing an integrated electrolyte-supported fuel cell structure that increases manufacturing precision, is cost efficient, leads to low mechanical degradation and increases lifetime of the fuel cell structure, and that is highly reproducible. This objective is solved by the subject matter of the independent claims. Further embodiments are described in the dependent claims as well as in the following description. According to a first aspect, a method for manufacturing an electrolyte-supported fuel cell structure is provided. The method comprises providing a continuous electrolyte layer having a first side and a second side. The method further comprises coating the first side of the continuous electrolyte layer with an anode material, such that a continuous anode layer at least partially covers the first side of the electrolyte layer, and coating the second side of the continuous electrolyte layer with a cathode material, such that a continuous cathode layer at least partially covers the second side of the electrolyte layer. The method then comprises removing portions of the anode layer via laser ablation, such that at least a first anode section and a second anode section that are completely separated from each other but that are neighboring each other on the first side of the electrolyte layer are build, and removing portions of the cathode layer via laser ablation, such that at least a first cathode section and a second cathode section that are completely separated from each other but that are neighboring each other on the first side of the electrolyte layer are build. The method further comprises creating through holes through the electrolyte layer that at least partially coincide with areas, in which the anode layer and/or the cathode layer has been removed, and arranging a conductive material within the through holes, such that the conductive material connects the first anode section with the second cathode section, or such that the conductive mat