Co₃O₄/Sm-Doped CeO₂/Co₃O₄ Trilayer Coating on AISI 441 Interconnect for Solid Oxide Fuel Cells

Abstract

In this work, a novel Co/Sm-doped CeO (SDC)/Co trilayer of ∼6 μm is deposited by alternating electrodeposition and electrophoresis and oxidized to a CoO/SDC/CoO trilayer structure. This coating is unique and effective in the following aspects: (1) The area specific resistance of the coated interconnect is more stable and lower than that of the uncoated interconnect after thermal treatment at 800 °C for 400 h. (2) The CoO/SDC/CoO coating layer can effectively inhibit Cr diffusion and evaporation and significantly slow the oxidation rate of the interconnect. (3) The SmSrCoFeO cathode in the electrolyte/cathode/interconnect half-cell retains its initial stoichiometry after 100 h of the thermal treatment. Subsequently, the ohmic resistance R, high frequency polarization resistance R, and low frequency polarization resistance R of the half-cell with the CoO/SDC/CoO coated interconnect are all smaller than those of the half-cell with the bare interconnect. The CoO/SDC/CoO coating layer has great advantages to be used as a protective layer for the metallic interconnect in solid oxide fuel cells to improve cell performance, stability, and durability.

Long term durability test and post mortem for metal-supported solid oxide electrolysis cells

“…Post-mortem analysis demonstrated that a primary degradation mode is fuel electrode catalyst coarsening. In contrast, the air electrode catalyst 22 does not coarsen, which is contrary to previous results for long-term fuel cell mode operation of infiltrated MS-SOFCs. An additional primary degradation mode is Cr poisoning on the air electrode catalyst.…”

“…Chromium poisoning has been reported to massively degrade the performance of anode-supported SOFCs (ASC) with chromium-containing stainless steel interconnects. [22,23,40] Due to the metal support, both fuel and air electrodes of MS-SOEC are exposed to chromium. On the fuel electrode, chromium poisoning is negligible during long term running due to the extremely low oxygen partial pressure, which prevents formation of volatile chromium-oxide or -oxyhydroxide species.…”

“…Electrolyte reduction, [11,12] delamination, [13,14] intergranular fracture and void formation along the grain boundaries of the electrolyte, [15] structure damage in thick yttria-stabilized zirconia (YSZ) electrolyte, [16] and formation of an insulating layer between the buffer layer and the electrolyte [17] all have been reported to degrade the electrolyte. Microstructure changes and cation interdiffusion, [18,19] formation of nanoparticle clusters, [20] phase change, [17] SrO segregation on the surface, [21] and contaminants from iron-chromium (Fe-Cr) stainless steel [22,23] have been reported to degrade perovskite air electrodes. Microstructure instability, [24,25] agglomeration, [26] nickel (Ni) coarsening, [26] and contaminants from glass sealant and raw materials [15,27] have been reported to degrade Ni-based hydrogen electrodes.…”

Defect Engineering on CeO2‐Based Catalysts for Heterogeneous Catalytic Applications

“…Some studies have focused on the preparation of coatings to improve the charge separation. [ 109 ] For instance, Xing et al developed a novel composite oxide material for the electrolyte membrane of fuel cells, which was coated with CeO 2 to form a core–shell structure NaFeO 2 –10CeO 2 . The ultimate fuel cell efficiency could be up to 727 mW cm −2 maximum power output at 550 °C, as shown in Figure 11e.…”

Nanostructured Iron Fluoride Derived from Fe-Based Metal–Organic Framework for Lithium Ion Battery Cathodes

“…MOFs with porous structures can be built via several methods, such as a hydrothermal (solvent) reaction, 31 a microwave-assisted technology, 32 a and sol−gel method. 33 In recent decades, MOFs have been suggested as templated precursors to obtain tailorable and shape-preserving functional porous materials (such as metal oxide, 34 metal sulfide, 35 and their carbon composites 36 ). When compared to other templates, MOFs can reveal unique features due to their adjustable functionality, large surface areas, and interconnected porous network, 37−46 in turn exhibiting enhanced electrochemical performance when evaluated as anodes or cathodes for energy storage in many fields.…”