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US-20260128343-A1 - FUEL CELL FOR AIRCRAFTS

US20260128343A1US 20260128343 A1US20260128343 A1US 20260128343A1US-20260128343-A1

Abstract

A fuel cell for aircraft with a cell stack having an anode, a cathode and a proton exchange membrane. A frontal end plate is placed at one end of the cell stack and a rear end plate is placed at the other end of the cell stack. An insulating panel made from a polymer material is placed between the cell stack and one or both of the frontal end plate and the rear end plate.

Inventors

  • Alfonso DELGADO OLLERO
  • Mónica PARDO HERRERO
  • Iñigo UBIERNA HUIDOBRO
  • Manuel Silvestre Salas

Assignees

  • AIRBUS OPERATIONS S.L.U.

Dates

Publication Date
20260507
Application Date
20251106
Priority Date
20241107

Claims (13)

  1. 1 . A fuel cell for an aircraft comprising: a cell stack comprising an anode, a cathode, and a proton exchange membrane; a frontal end plate placed at one end of the cell stack; a rear end plate placed at another end of the cell stack; and, an insulating panel made from a polymer material placed between the cell stack and one or both of the frontal end plate and the rear end plate.
  2. 2 . The fuel cell according to claim 1 , wherein the insulating panel comprises a first insulation sheet, a second insulation sheet, and an insulation layer between the first insulation sheet and the second insulation sheet.
  3. 3 . The fuel cell according to claim 2 , wherein the insulating panel further comprises an additional insulation sheet in contact with the first insulation sheet between said first insulation sheet and the frontal end plate.
  4. 4 . The fuel cell according to claim 2 , wherein the insulating panel comprises seals in contact with the first insulation sheet.
  5. 5 . The fuel cell according to claim 2 , wherein the first insulation sheet and the second insulation sheet both comprise 4,4′-oxydiphenylene-pyromellitimide.
  6. 6 . The fuel cell according to claim 2 , wherein the first insulation sheet and the second insulation sheet both are attached to the insulation layer.
  7. 7 . The fuel cell according to claim 2 , wherein the insulation layer is made of polyether ether ketone or polyphenylene sulfide.
  8. 8 . The fuel cell according to claim 1 , wherein the frontal end plate comprises an interface for an entry of a fluid, or an exit of the fluid, or both, and wherein an insulating reinforcement is between the interface and the frontal end plate.
  9. 9 . The fuel cell according to claim 8 , wherein the insulating reinforcement comprises a groove in which an O-ring is housed.
  10. 10 . The fuel cell according to claim 8 , wherein the frontal end plate comprises an insulating liner in correspondence with the interface.
  11. 11 . The fuel cell according to claim 1 , wherein the insulating panel comprises a first insulation sheet, a second insulation sheet, and an insulation layer between the first insulation sheet and the second insulation sheet, and wherein the first insulation sheet and the second insulation sheet each have a thickness of less than 0.5 mm.
  12. 12 . The fuel cell according to claim 1 , wherein the proton exchange membrane comprises a catalyst.
  13. 13 . The fuel cell according to claim 1 , wherein the proton exchange membrane comprises two sides, and wherein the fuel cell further comprises: a seal on each of the two sides of the proton exchange membrane.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to European Patent Application No. 24 383 217.7, filed on Nov. 7, 2024, the entire disclosure of which is incorporated herein by way of reference. FIELD OF THE INVENTION The present invention relates to a fuel cell for aircrafts, that solves electrical insulation problems of fuel cells for aeronautical use in and allows the connection of a floating bonding network in an aircraft. BACKGROUND OF THE INVENTION A fuel cell is an electrochemical device, which by an electrochemical reaction of a fuel (hydrogen, methanol, natural gas etc.) and oxygen at the anode that produces heat and electricity, which can be used to power a vehicle or in a stationary application. The fuel cells have many advantages over traditional thermal machines, such as their performance, their size or their dynamic response capacity in the face of a transient or demand, this characteristic being highly appreciated in the aeronautical industry. However, there is still a long way to go when it comes to specific power, the weight being very critical when embarking on an aircraft. A fuel cell can be manufactured in different formats and types depending on its technology. There are low-temperature alkaline (AFC), polymeric (PEMFC), direct methanol (DMFC) and high-temperature, solid oxide (SOFC), molten carbonate (MCFC) and high-temperature polymeric (HT-PEM) fuel cells. A fuel cell comprises one or more cells installed in series to form a stack. These cells consist of an anode, where the oxidation of the fuel takes place, and a cathode where the oxygen is reduced to produce water. The anode and cathode are separated by a membrane, or ceramic, which is usually conductive, allowing the ions to diffuse freely from the anode to the cathode. On this membrane, the catalyst particles are deposited on both sides. To improve gas diffusion on both sides of the membrane, a carbon cloth or mesh is added to make it electrically conductive, improving the contact between the phases and providing a larger possible diffusion area. This part is called gas diffusion layer or GDL. Between both sides of the assembled membrane, catalyst membrane and GDL, several polymeric gaskets are placed in order to seal the membrane on both sides with the bipolar or mono-polar plates placed at the ends of the stack. Bi-polar plates are plates made of any electrically conductive material with channels of a certain morphology through which H2 or fuel passes to the anode or oxygen or air to the cathode, distributing the reagents homogeneously on both sides of the membrane and efficiently evacuating the reaction products such as the water formed, avoiding the formation of hotspots on the membrane. Bi-polar plates are so called because they act as both cathode and anode, i.e. one side is the cathode of one cell and the other side is the anode of the adjacent cell. Inside the bi-polar plates, which generally consist of two parts separated by a seal, circulates the coolant that cools the fuel cell, if necessary and depending on the type of fuel cell, as if it were a casing. At the ends of the stack, the monopolar plates are located, i.e., they are simple in that they have only one side through which the air or fuel circulates and are the cathode or the final anode, depending on the cell arrangement of the stack. Next to the monopolar plates, there are current collector plates made of copper or other electrically conductive material, these being the fuel cell terminals where the external electrical connection is made. To close the stack, the end or closure plates are placed with the external interfaces. These plates are external to the stack and their function is to provide sufficient mechanical integrity to prevent the “sandwich” from disassembling. These plates can be made of different insulating materials such as thermoplastic (e.g. polyphenylene sulfide) or metal (e.g. anodized aluminum, stainless steel etc.). On these plates, there is a nominal current leakage which, depending on the quality of the internal stack insulation, can be higher or lower. On these plates are placed mechanical interfaces, which can also be made of the same material as the end plates. These interfaces are responsible for interconnecting the different ports of the stack, 02 or air, H2 or fuel and coolant to the balance of plant, which allows the stack to work. These interfaces are communicated with all the cells inside them, and their insulation is very important because, depending on this, there will be a greater or lesser leakage of current towards the air and fuel supply and exhaust pipes, which should also be insulated and grounded. On these collector plates, an insulation layer or piece composed of a polymer or oxide is introduced in the form of a piece or coating, such as mentioned in U.S. Pat. No. 6,773,841B2, which proposes to use an electrolytically deposited coating by a PVD or CVD technique, which consists of physical (PVD) o