# Engineering Lamellar Stainless Steel 410S Porous Supports via a Water-Based Tape Casting Method: A Scalable Path for MS-SOFCs

## TL;DR

A scalable water-based method is developed to create porous stainless steel supports for solid oxide fuel cells, improving their performance and manufacturability.

## Contribution

A reproducible water-based tape casting method for fabricating oxidation-resistant, high-permeability porous stainless steel supports for MS-SOFCs.

## Key findings

- A lamellar microstructure and interconnected porosity were achieved in sintered PMS, enhancing gas permeability.
- Argon sintering preserved metallic structure and chromium content, while air sintering caused oxidation and phase destabilization.
- The PMS showed a permeability of 5.85–8.36 × 10–12 m² and resistivity of 2.45 ± 0.28 Ω·cm.

## Abstract

Metal-supported solid oxide fuel cells (MS-SOFCs) have
garnered
increasing attention for advancing energy converter devices owing
to their mechanical robustness, fast thermal cycling, and ability
to operate with a wide range of fuels such as hydrocarbons and biofuels
without contaminations. However, the manufacturing of porous metallic
supports (PMSs), a critical component of these cells, still presents
significant challenges, particularly regarding oxidation resistance,
mismatch in thermal expansion coefficients (CTEs), gas diffusion issues,
and synthesis reproducibility. In this work, we report a reproducible
water-based tape casting methodology for PMS fabrication using commercially
available 410S stainless steel powder. This alloy was selected due
to their CTE compatibility with MS-SOFC ceramic layer components and
due to its excellent chromium content (11.5–14.5%) to improve
corrosion resistance. The optimized slurry formulation, containing
tailored amounts of water-soluble binders and plasticizers, offers
flexible and defect-free green tapes. Rheological characterization
confirmed pseudoplastic and thixotropic behavior with high recovery
(91.5%) after shear, ensuring stability during casting. Thermal gravimetric
analysis (TGA) guided the debinding profile to prevent structural
damage, and sintering was conducted under air and argon atmospheres.
Argon sintering preserved the metallic structure and chromium content,
while air sintering led to severe oxidation and phase destabilization.
Precalcined ZrO2 nonstick coarse powder at 1600 °C
for 2 h was used during sintering to prevent contamination from Al2O3. A well-developed lamellar microstructure and
peculiar interconnected porosity were observed in the sintered PMS,
both of which are fundamental for ensuring gas permeability in MS-SOFC
applications. The permeability of the PMS was tested for H2, obtaining a result of 5.85 to 8.36 × 10–12 m2. Additionally, the PMSs showed an average resistivity
of 2.45 ± 0.28 Ω·cm. This process addresses several
obstacles in PMS fabrication pathway for integrating PMSs into next-generation
SOFC architectures.