Joel Kuhn

Joel Kuhn

Research Interests

Plasma spraying is a manufacturing technique that has demonstrated the capacity to manufacture solid oxide fuel cells (SOFCs) on metal supports with good power densities and high thermal and redox cycle stabilities. One particular challenge with plasma spraying SOFCs is to produce dense, thin (<15 μm) electrolytes that are gas tight. High quality electrolytes result in high open circuit voltages (OCVs), reduced ohmic losses, minimized gas crossover & combustion, minimized metal support degradation, and minimized long-term performance degradation. High quality electrolytes also aid in the characterization of new electrode material sets by improving the repeatability of polarization and impedance measurements. With this in mind, my work aims to improve upon prior plasma sprayed electrolyte work, and create manufacturing techniques/processes that integrate prior work of all SOFC components such that a plasma sprayed metal-supported SOFCs can be generated with repeatable OCVs and performance.


PhD Research

PhD work focused on the effect of solid oxide fuel cell (SOFC) operating conditions on carbon deposition in nickel/yttria-stabilized-zirconia (Ni/YSZ) anodes and the effect of carbon deposition on impedance spectra of polarized SOFCs. The operating conditions investigated were temperature, molar steam:carbon ratio (SC), fuel utilization (Uf), current density, and mole fraction of ethane in the fuel. A method for measuring deposited carbon (quantification of gasified carbon method) was developed and validated using a thermogravimetric analyzer. Constituent concentrations of CH4 reformate gas mixtures were also developed for different SC and Uf. The coking thresholds at open circuit with respect to fuel utilization and molar steam:carbon ratio were measured at 600 and 700 °C, respectively. At 700 °C, coking thresholds agreed well with thresholds predicted by thermodynamic equilibrium calculations. At 600 °C, coking thresholds agreed well with thresholds predicted by thermodynamic equilibrium calculations only when the Gibbs free energy of solid carbon was greater than that of graphite. Experiments with nonzero current density further validated the carbon thresholds measured at open circuit. Impedance spectroscopy was found to minimally detect the presence of carbon deposited in the anode.


Publications

  1. Kuhn, J., Gupta, M., Kesler, O., Björklund, S. The effect of fuel electrode roughness on the properties of plasma sprayed solid oxide cells (2018) Journal of the Electrochemical Society, 165 (9), pp. F693-F701.

  2. Aicart, J., Kuhn, J., Kesler, O. Performance of Non-Destructive Compressive Seals for Reversible Solid Oxide Cells(2017) Fuel Cells, 17 (1), pp. 90-99.

  3. Harris, J., Kuhn, J., Kesler, O. Atmospheric plasma-sprayed metal-supported solid oxide fuel cells with varying cathode microstructures (2017) Journal of the Electrochemical Society, 164 (4), pp. F441-F447.

  4. Fan, E.S.C., Kuhn, J., Kesler, O. Suspension plasma spraying of La0.6Sr0.4Co0.2Fe0.8O3-δ cathodes: Influence of carbon black pore former on performance and degradation (2016) Journal of Power Sources, 316, pp. 72-84.

  5. Kuhn, J., Kesler, O. Carbon deposition thresholds on nickel-based solid oxide fuel cell anodes I. Fuel utilization (2015) Journal of Power Sources, 277, pp. 443-454.

  6. Kuhn, J., Kesler, O. Carbon deposition thresholds on nickel-based solid oxide fuel cell anodes II. Steam:carbon ratio and current density (2015) Journal of Power Sources, 277, pp. 455-463.

  7. Kuhn, J., Kesler, O. Method for in situ carbon deposition measurement for solid oxide fuel cells (2014) Journal of Power Sources, 246, pp. 430-437.

  8. Marr, M., Kuhn, J., Metcalfe, C., Harris, J., Kesler, O. Electrochemical performance of solid oxide fuel cells having electrolytes made by suspension and solution precursor plasma spraying (2014) Journal of Power Sources, 245, pp. 398-405.

  9. Metcalfe, C., Kuhn, J., Kesler, O. Characterization of Ni-YSZ anodes for solid oxide fuel cells fabricated by suspension plasma spraying with axial feedstock injection (2013) Journal of Power Sources, 243, pp. 172-180.

  10. Cuglietta, M., Kuhn, J., Kesler, O. A novel hybrid axial-radial atmospheric plasma spraying technique for the fabrication of solid oxide fuel cell anodes containing Cu, Co, Ni, and samaria-doped ceria (2013) Journal of Thermal Spray Technology, 22 (5), pp. 609-621.

  11. Metcalfe, C., Harris, J., Kuhn, J., Marr, M., Kesler, O. Progress in metal-supported axial-injection plasma sprayed solid oxide fuel cells using Nanostructured NiO-Y0.15Zr0.85O 1.925 dry powder anode feedstock (2013) Journal of Thermal Spray Technology, 22 (5), pp. 599-608.

  12. Harris, J., Metcalfe, C., Marr, M., Kuhn, J., Kesler, O. Fabrication and characterization of solid oxide fuel cell cathodes made from nano-structured LSCF-SDC composite feedstock (2013) Journal of Power Sources, 239, pp. 234-243.


Conference Papers

  1. Kuhn, J., Gupta, M., Kesler, O., Björklund, S. The effect of fuel electrode roughness on the properties of plasma sprayed solid oxide cells (2017) ECS Transactions, 78 (1), pp. 1477-1487.

  2. Kesler, O., Cuglietta, M., Harris, J., Kuhn, J., Marr, M., Metcalfe, C. Progress in metal-supported SOFCs using hydrogen and methane fuels (2013) ECS Transactions, 57 (1), pp. 491-501.


Teaching Assistantships

  • Dynamics (MIE100)-Winter '08
  • Heat and Mass Transfer (MIE313)-Winter '08, '09, '10, &'11
  • Circuits with Application to Mechanical Engineering Systems (MIE342)-Fall '08, '09, &'10
  • Fuel Cell Systems (MIE517)-Fall '08

Professional Experience

  • Engineering Technologist, Toronto, ON, Canada (May '10 - Sep '12)
  • Industrial Refrigeration Consortium, Madison, WI, USA (May '07 - July '07)
  • Forschungszentrum Jülich, Jülich, Germany (May '06 - Aug '06)
  • Hamilton Sundstrand (UTC), Rockford, IL, USA (Aug '04 - May '06)
  • Oshkosh Truck Corporation, Oshkosh, WI, USA (May '04 - Aug '04)

Education

  • PhD University of Toronto (2008-2013), Toronto, ON, Canada
  • BS University of Wisconsin-Madison (2001-2006), Madison, WI, USA

Contact

joel DOT kuhn AT mail DOT utoronto DOT ca

Mailing and Shipping Address:
University of Toronto
Department of Mechanical & Industrial Engineering
5 King's College Road
Toronto ON. M5S 3G8