Investigation of Fe-Cr-Al Alloy for Metal Supported SOFC

Abstract

Porous Fe-Cr-Al alloy was investigated for the support material of solid oxide fuel cells. Interfacial resistance at 700 o C in 3% H 2 O -97% H 2 atmosphere between the porous alloy and Ni coating was stable at around 10 mΩcm 2 . Interfacial resistance at 700 o C in air between the porous alloy and LSCF coating was stable at around 20 mΩcm 2 . The surface oxide layer on the Fe-Cr-Al alloy consists of nano-sized γ-Al 2 O 3 columns growing outward in the same direction, containing 4 at.% of Sr, which may contribute electronic conduction. It is expected that the negligible Cr content in the surface oxide layer can solve the Cr contamination problem, generally known in SOFC. We are also developing a cell using the porous Fe-Cr-Al alloy by a co-sintering process.

Characterization of thin metal‐supported solid oxide fuel cells fabricated through atmospheric Plasma spraying

“…Currently, research attention on SOFCs has shifted from ceramic-supported SOFCs to metalsupported SOFCs (MS-SOFCs) because of the potential benefits of MS-SOFCs, including high strength, suitable workability, relatively low operating temperatures, high thermal conductivity, low cost, and rapid start-up. MS-SOFCs in which the supporting component for the ceramic anode, electrolyte, and cathode layers is composed of a porous metal substrate are referred to as third-generation SOFCs and have received considerable research attention because they have high potential for use in mobile applications owing to their suitable thermal and mechanical properties [1][2][3][4][5][6][7]. Metal substrates must meet several criteria for SOFC applications, including criteria related to the coefficient of thermal expansion (CTE), electrical conductivity, oxidation behavior, and porosity.…”

“…When MS-SOFCs are operated under a hydrogen atmosphere and high temperature, the metal substrate must be able to maintain phase stability for a prolonged period, and it must not undergo a mutual diffusion reaction with the metal catalyst on the anode side in order to prevent catalyst poisoning and the formation of an insulation phase. Studies have investigated several alloys used for metal supports, such as Ni [4], Ni-Fe [5], Fe-Cr [6], and Fe-Cr-Al [7]. Stainless steels (STSs) are often used as supporting metal because of their low cost and because their CTE value adequately matches those of commonly used electrolytes.…”

Development and Evaluation of Thin Flexible Metal-Supported Solid Oxide Fuel Cells

“…Metal-supported solid oxide fuel cells (MS-SOFCs), the supporting component for the ceramic anode, electrolyte and cathode layers of the cell is made of porous alloy substrate and is referred to as the third generation of SOFCs. In comparison to traditional all ceramic SOFCs, MS-SOFCs have been obtaining popularity in the recent years (1)(2)(3)(4)(5)(6)(7)(8). There were several types of alloys investigated for the metal supports, such as Ni (4), Ni-Fe (5), or Fe-Cr (6) and Fe-Cr-Al (7).…”

“…In comparison to traditional all ceramic SOFCs, MS-SOFCs have been obtaining popularity in the recent years (1)(2)(3)(4)(5)(6)(7)(8). There were several types of alloys investigated for the metal supports, such as Ni (4), Ni-Fe (5), or Fe-Cr (6) and Fe-Cr-Al (7). In our previous studies, we have used porous Ni substrates (8; 9), porous Ni-Fe substrates (10;11) and porous Ni-Mo substrates (12;13) to support functional layers of SOFC.…”

Semiconductive α-Al2O3/Sr3Al2O6 Oxide Layer Formed on Fe–Cr–Al Alloy

“…The columnar structure also appeared when the alloy was coated with NiO and used in a fuel atmosphere. 19 However, the growth rate was relatively high for columnar γ-Al 2 O 3 /Sr 3 Al 2 O 6 ; it was estimated that the thickness of the oxide layer exceeds 1 μm after 6,000 h at 700 °C. If the alloy is used for a longer time, the thickness increases with time, involving the growth of a Cr 2 O 3 layer on the inner side.…”