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WO-2026090674-A1 - IMPROVED FUEL AND ELECTROLYSER CELL ASSEMBLIES

WO2026090674A1WO 2026090674 A1WO2026090674 A1WO 2026090674A1WO-2026090674-A1

Abstract

Described herein is an assembly for a solid oxide fuel or electrolyser cell, comprising a fuel electrode, an air electrode, and a solid-state electrolyte sandwiched therebetween, wherein the assembly further comprises a fuel side interlayer between the fuel electrode and the solid-state electrolyte, as well as methods for producing same and uses thereof.

Inventors

  • GIDDEY, Sarbjit
  • BISWAS, Saheli
  • KAUR, GURPREET

Assignees

  • COMMONWEALTH SCIENTIFIC AND INDUSTRIAL RESEARCH ORGANISATION

Dates

Publication Date
20260507
Application Date
20251031
Priority Date
20241101

Claims (20)

  1. 1 . An assembly for a solid oxide fuel or electrolyser cell, comprising: a fuel electrode, an air electrode, and a solid-state electrolyte (SSE) sandwiched therebetween, wherein the assembly further comprises: a fuel side interlayer between the fuel electrode and the SSE.
  2. 2. The assembly of claim 1 , further comprising an air side interlayer between the air electrode and the SSE.
  3. 3. The assembly of claim 1 or claim 2, wherein the fuel electrode and/or the air electrode comprises a fluorite material.
  4. 4. The assembly of claim 3, wherein the fluorite material is a metal oxide-doped ceria.
  5. 5. The assembly of claim 3 or claim 4, wherein the fluorite material is a metal oxide-doped ceria selected from gadolinium oxide-doped ceria (GDC), samarium oxide-doped ceria (SDC), and yttrium oxide-doped ceria (YDC), or a combination thereof.
  6. 6. The assembly of any one of the preceding claims, wherein the fuel electrode and/or the air electrode comprises a perovskite material.
  7. 7. The assembly of claim 6, wherein the perovskite material is an LST material of formula La x Sri. x TiO3, a BSCF material of formula Ba x Sri.xCo y Fei.y03-6, an LSCF material of formula La x Sri.xC0yFei.yO3-6 or an LSCM of formula La x Sri.xCryMni. y O3-6, or a combination of any two or more of these.
  8. 8. The assembly of claim 6 or claim 7, wherein perovskite material is Bao.sSro.sCoo.sFeo^Os-a, Lao.6Sro.4Coo.2Feo.803-6, or Lao.75Sro.25Cro.5M no.5O3-0, or a combination of any two or more of these.
  9. 9. The assembly of any one of the preceding claims, wherein the fuel electrode and/or the air electrode comprises a hybrid material.
  10. 10. The assembly of claim 9, wherein the fuel electrode comprises a hybrid material.
  11. 1 1 . The assembly of claim 9 or claim 10, wherein the air electrode and the fuel electrode each comprise a hybrid material.
  12. 12. The assembly of any one of claims 9 to 1 1 , wherein the hybrid material is a metal-metal oxide composite.
  13. 13. The assembly of any one of claims 9 to 12, wherein the hybrid material comprises a metallic phase transition metal, optionally wherein the transition metal is selected from copper, silver, gold, iron, cobalt, nickel and molybdenum, or an alloy of any two or more of these.
  14. 14. The assembly of any one of claims 9 to 13, wherein the hybrid material comprises a metallic phase transition metal selected from copper, silver and gold, or an alloy thereof, optionally wherein the hybrid material is selected from Ag-GDC, Cu-GDC, Au/Mo-GDC, Ag/Fe-GDC, Ag/Ni-GDC, Ni/Cu/Co-GDC, Co/Ag-GDC, Ni/Ag/Fe-GDC, and Ag-LSCF.
  15. 15. The assembly of any one of claims 9 to 14, wherein the hybrid material comprises from 10 wt% to 90 wt% of a metallic phase metal and from 10 wt% to 90 wt% of a metal oxide, optionally from 60 wt% to 80 wt% of a metallic phase metal and from 20 wt% to 40 wt% of a metal oxide.
  16. 16. The assembly of any one of claims 9 to 15, wherein both the fuel electrode and the air electrode comprise the same hybrid material.
  17. 17. The assembly of any one of claims 9 to 15, wherein the fuel electrode and the air electrode comprise each comprise a different hybrid material.
  18. 18. The assembly of any one of claims 9 to 17, wherein the hybrid material does not comprise the same material as the SSE.
  19. 19. The assembly of any one of the preceding claims, wherein the fuel side interlayer comprises a metal oxide-doped ceria, optionally selected from: gadolinium oxide-doped ceria (GDC), samarium oxide-doped ceria (SDC), and yttrium oxide-doped ceria (YDC).
  20. 20. The assembly of any one of the preceding claims, wherein the fuel side interlayer has a thickness of from 50 nm to 10 pm, optionally of about 100 nm to 5 pm.

Description

IMPROVED FUEL AND ELECTROLYSER CELL ASSEMBLIES [001] The present application claims priority to Australian provisional patent application no. 2024903568, filed on 1 November2024, the entire contents of which are incorporated herein by crossreference. Technical Field [002] The disclosure herein relates to improved fuel and electrolyser cell assemblies. More particularly, the disclosure herein relates to improved solid oxide fuel and electrolyser cell assemblies comprising one or more interlayers, which find utility in the energy generation and storage sector, amongst other applications. Background of Invention [003] Solid oxide fuel cells (SOFCs) and solid oxide electrolyser cells (SOECs) comprise a cathode, an anode, and an electrolyte. Depending on the configuration, one of the cathode or anode functions as the fuel electrode, being the electrode that comes into contact with the hydrogen or hydrocarbon fuel that is oxidised to form water and optionally oxides of carbon (SOFC mode), or with water/steam fuel that is reduced to form hydrogen gas and oxygen ions (SOEC mode). The other electrode functions as the air electrode, being the electrode that comes into contact with oxygen molecules and that is reduced to form oxygen ions that travel to the fuel electrode (SOFC mode), or with oxygen ions that are oxidised to form oxygen gas (SOEC mode). In electrolysis mode (SOECs), electrical energy is converted to chemical energy (in the form of hydrogen and other hydrogen carriers like methane, methanol, etc.), and in fuel cell mode (SOFCs), chemical energy is converted directly to electrical power. [004] In cells that operate with a solid electrolyte, such as SOFCs and SOECs, certain challenges are present. The most common solid electrolyte in current usage is yttria-stabilised zirconia (YSZ), which is a dense ionic conductor consisting of ZrO2 doped with Y2O3. This electrolyte has good thermal stability and the ability operate at high temperatures (>1000 °C) in current generation SOFCs/SOECs. Common electrode materials paired with YSZ in SOFC/SOEC applications include nickel-doped YSZ (Ni-YSZ), lanthanum strontium manganate (LSM), and strontium and cobalt codoped lanthanum ferrite (LSCF). However, air side electrode materials can react with the YSZ electrolyte to form insulating zirconate phases or oxidised metal phases at the electrode-electrolyte boundaries in use that affect performance of the cells. Further, electrode delamination is widely reported, especially for perovskite air electrodes, as a result of chemical and/or thermal instability of the electrode-electrolyte interface. [005] Chemical instability occurs when the electrode has cations with much different mobility, leading to component separation, commonly known as “kinetic demixing”. Perovskites like lanthanum strontium ferrites, manganites, cobaltites, and the like experience strontium segregation under anodic/cathodic currents. This strontium then diffuses to the electrode-electrolyte interface, reacts with the electrolyte and forms a non-conducting oxide phase. Sometimes, cobalt also evaporates from the lattice, diffuses to the electrode-electrolyte interface, and forms cobalt oxide. In the case of air electrodes, formation of these low porosity oxide layers hinders diffusivity of the oxide ions transported across the electrolyte, leading to oxygen build-up at the air electrode/electrolyte interface. Such accumulated oxygen gradually weakens the bonding between the oxide layer and the electrolyte, resulting in complete delamination. [006] Thermal instability occurs due to thermal expansion coefficient (TEC) mismatch between the electrode and the electrolyte and/or by lattice strain generated from oxygen non-stoichiometry in the electrode. Electrode materials such as perovskites (lanthanum strontium ferrites, manganites, cobaltites, etc.) have naturally different TECs to fluorite solid electrolytes like YSZ, gadolinium oxidedoped ceria (GDC) and scandium stabilised zirconia (ScSZ). However, the formation of oxygen vacancies in electrode lattices can also contribute to TCE mismatch, as neighbouring cations are reduced and their ionic radius increases, causing lattice expansion. If the overall TCE mismatch becomes too large, the applied thermal stress during the operation of the SOFC/SOEC can result in electrode delamination (see Fig. 1 (a)). [007] SOECs guarantee green hydrogen production at a lower cost compared to other state-of-the- art electrolysers and at a higher efficiency (~90%), and operate at temperatures between 600 to 1000 °C. These high temperatures allow the integration of industrial waste heat into the system that helps reduce the electrical energy requirements, and thus the levelised cost of fuel production, but one of the major bottlenecks of SOEC technology is the cell lifetime. As described above, electrode delamination is a phenomenon that directly and adversely affects cell lifetime. [008] Previous attempts in the art to solve