Route to High-Performance Micro-solid Oxide Fuel Cells on Metallic Substrates

TL;DR

This paper demonstrates the first successful growth of epitaxial cathode materials on metallic substrates for micro-solid oxide fuel cells, achieving high performance and paving the way for portable power device commercialization.

Contribution

It introduces a novel method for growing epitaxial cathodes on metal substrates, overcoming previous stability and performance challenges.

Findings

Epitaxial cathodes grown on stainless steel substrates show high performance.

Area specific resistance of 100 ohm·cm² at 500°C achieved.

Epitaxial growth on metals enables portable micro-SOFC development.

Abstract

Micro-solid oxide fuel cells based on thin films have strong potential for use in portable power devices. However, devices based on silicon substrates typically involve thin-film metallic electrodes which are unstable at high temperatures. Devices based on bulk metal substrates overcome these limitations, though performance is hindered by the challenge of growing state-of-the-art epitaxial materials on metals. Here, we demonstrate for the first time the growth of epitaxial cathode materials on metal substrates (stainless steel) commercially supplied with epitaxial electrolyte layers (1.5 {um (Y2O3)0.15(ZrO2)0.85 (YSZ) + 50 nm CeO2). We create epitaxial mesoporous cathodes of (La0.60Sr0.40)0.95Co0.20Fe0.80O3 (LSCF) on the substrate by growing LSCF/MgO vertically aligned nanocomposite films by pulsed laser deposition, followed by selectively etching out the MgO. To enable valid comparison with the literature, the cathodes are also grown on single-crystal substrates, confirming state-of-the-art performance with an area specific resistance of 100ohmegacm2 at 500dC and activation energy down to 0.97 eV. The work marks an important step toward the commercialization of high-performance micro-solid oxide fuel cells for portable power applications.