iScience
Volume 25, Issue 9, 16 September 2022, 105009
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Article
A comprehensive investigation of direct ammonia-fueled thin-film solid-oxide fuel cells: Performance, limitation, and prospects

https://doi.org/10.1016/j.isci.2022.105009Get rights and content
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Highlights

  • Thin-film SOFCs and a commercial SOFC are tested for direct-ammonia and H2 operation

  • Record-high performance for direct-ammonia operation achieved with thin-film SOFC

  • 2D multi-physics modeling explained the performance gap between NH3 and H2 fuel

  • NH3 decomposition activity and gas transport are the main causes of the performance gap

Summary

Ammonia is a promising carbon-free hydrogen carrier. Owing to their nickel-rich anodes and high operating temperatures, solid oxide fuel cells (SOFCs) can directly utilize NH3 fuel—direct-ammonia SOFCs (DA-SOFCs). Lowering the operating temperature can diversify application areas of DA-SOFCs. We tested direct-ammonia operation using two types of thin-film SOFCs (TF-SOFCs) under 500 to 650°C and compared these with a conventional SOFC. The TF-SOFC with a nickel oxide gadolinium-doped ceria anode achieved a peak power density of 1330 mW cm−2 (NH3 fuel under 650°C), which is the best performance reported to date. However, the performance difference between the NH3 and H2 operations was significant. Electrochemical impedance analyses, ammonia conversion quantification, and two-dimensional multi-physics modeling suggested that reduced ammonia conversion at low temperatures is the main cause of the performance gap. A comparative study with previously reported DA-SOFCs clarified that incorporating a more active ammonia decomposition catalyst will further improve low-temperature DA-SOFCs.

Subject areas

Chemistry
electrochemistry
electrochemical energy conversion
engineering
materials science

Data and code availability

  • All data reported in this paper will be shared by the lead contact upon request.

  • This paper does not report original code.

  • Any additional information required to reanalyze the data reported in this paper is available from the lead contact upon request

Cited by (0)

6

These authors contributed equally

7

Lead contact