The Nicholas group is interested in the processing-structure-performance relationships of Solid Oxide Cell (SOC) electrodes. By carefully studying these relationships, the Nicholas Group has independently, and in collaboration with the group of Dr. Kevin Huang, demonstrated that on-board getters can dramatically improve the performance and/or stability of nano-composite Solid Oxide Fuel Cell (SOFC) and Solid Oxide Electrolysis Cell (SOEC) electrodes through the removal of surface-segregated strontium. Precursor nitrate solution desiccation has also been found to produce small improvements in infiltrated electrode performance. The Nicholas Group has also developed and validated the world's most-cited Solid Oxide Cell infiltrated electrode model, the Simple Infiltrated Microstructure Polarization Loss Estimation (SIMPLE) model, in conjunction with the group of Dr. Scott Barnett. A full description of the SIMPLE Model and an Online Nano-Composite Electrode Polarization Resistance Calculator are available at: https://www.egr.msu.edu/nicholasgroup/simple.php.
For details see:
Zhang Y, Nicholas JD. Updating the Notion that Poor Cathode Performance Typically Dominates Overall Solid Oxide Fuel Cell Response. Journal of the Electrochemical Society 2021; 168, 034513. https://doi.org/10.1149/1945-7111/abed21
Zhang Y, Nicholas JD. Evidence that Surface-Segregated Sr Phases Can Be Removed in LSCF via Ceria Pre-Infiltration, Are Less Apt to Form in SSC. Journal of the Electrochemical Society 2021; 168, 024522. https://doi.org/10.1149/1945-7111/abe34e
Zhang Y, Wen Y, Huang H, Nicholas JD. Atomic Layer Deposited Zirconia Overcoats as On-Board Strontium Getters for Improved Solid Oxide Fuel Cell Nano-Composite Cathode Durability. ACS Applied Energy Materials 2020; 3: 4057-4067. https://doi.org/10.1021/acsaem.0c00558
Burye TE and Nicholas JD. Improving La0.6Sr0.4Co0.8Fe0.2O3−x Infiltrated Solid Oxide Fuel Cell Cathode Performance through Precursor Solution Desiccation. Journal of Power Sources 2015; 276: 54–61. http://dx.doi.org/10.1016/j.jpowsour.2014.11.082
Burye TE and Nicholas JD. Nano-Ceria Pre-Infiltration Improves La0.6Sr0.4Co0.8Fe0.2O3−x Infiltrated Solid Oxide Fuel Cell Cathode Performance. Journal of Power Sources 2015; 300: 402–412. http://dx.doi.org/10.1016/j.jpowsour.2015.09.080
Burye TE and Nicholas JD. Precursor Solution Additives Improve Desiccated La0.6Sr0.4Co0.8Fe0.2O3−x Infiltrated Solid Oxide Fuel Cell Cathode Performance. Journal of Power Sources 2016; 301: 287–298. http://dx.doi.org/10.1016/j.jpowsour.2015.10.012
Burye TE, Tang H, Nicholas JD. The Effect of Precursor Solution Desiccation or Nano-Ceria Pre-Infiltration on Various La0.6Sr0.4FeyCo1-yO3-x Infiltrate Compositions. Journal of the Electrochemical Society. 2016; 163: F1017–F1022. http://dx.doi.org/10.1149/2.0431609jes
Nicholas JD, Wang L, Call AV, Barnett SA. Use of the Simple Infiltration Microstructure Polarization Loss Estimation (SIMPLE) Model to Predict the Polarization Resistance of Infiltrated Nano-Composite Solid Oxide Fuel Cell Cathodes. Physical Chemistry Chemical Physics 2012; 14: 15379-15392. http://dx.doi.org/10.1039/C2CP43370B
Nicholas JD, Barnett SA. Measurements and Modeling of Sm0.5Sr0.5CoO3–x — Ce0.9Gd0.1O1.95 SOFC Cathodes Produced Using Infiltrate Solution Additives. Journal of the Electrochemical Society 2010; 157: B536. http://dx.doi.org/10.1149/1.3284519
Funding Sources: Department of Energy Solid Oxide Fuel Cell Program Award, NSF CAREER Award, Nissan North America Contract
High Temperature Brazes, Circuits, and Seals
Metal-to-ceramic and ceramic-to-ceramic seals/electrical contacts often suffer from high porosity and/or low adhesion strength, especially after long-term, elevated-temperature operation. For instance, traditional SOFC/SOEC Ag-CuO brazes exhibit detrimental pore formation caused by wetting problems during manufacturing and the reduction of CuO by SOFC/SOEC fuel gases. Hence, with support from the Dr. Thomas Bieler, Dr. Tim Hogan, Dr. Yue Qi and Dr. Hui-Chia Yu research groups, the Nicholas Group has developed a new Ag-Ni joining/electrical circuit fabrication technique. A movie illustrating this technology (where molten silver defies gravity as it spreads into a porous nickel layer at ~1025oC to produce a "self-assembled", 97% dense, well-adhered patterned circuit on sapphire) is available here:
For details see:
Hu G, Hogan T, & Nicholas JD. Porous Interlayers that Getter Surface-Segregating Species for Improved Silver Wetting, Adhesion, and Electrical Contact on Stainless Steel SOFC Components. Journal of the Electrochemical Society, 2025; 172, 014513. https://doi.org/10.1149/1945-7111/adad48
Termuhen R, Hu G, Nicholas JD & Yu H-C. Spontaneous Imbibition Velocities in Porous Metal Layers on Ceramic Substrates Calculated Using Microstructural Analyses. Materialia, 2023; 28, 101779. https://doi.org/10.1016/j.mtla.2023.101779
Hu G, Zhou Q, Bhatlawande A, Park J, Termuhlen R, Ma Y, Bieler TR, Yu HC, Qi Y, Hogan T, and Nicholas JD, Patterned Nickel Interlayers for Enhanced Silver Wetting, Spreading and Adhesion on Ceramic Substrates. Scripta Materialia, 2021; 196, 113767. https://doi.org/10.1016/j.scriptamat.2021.113767
Park J, Phongpreecha T, Nicholas JD, and Qi, Y, Enhanced Liquid Metal Wetting on Oxide Surfaces via Patterned Particles. Acta Materialia, 2020; 199, 551. https://doi.org/10.1016/j.actamat.2020.08.037
Zhou Q, Bieler TR and Nicholas JD. Dual Atmosphere Isothermal Aging and Rapid Thermal Cycling of Ag-Ni and Ag-CuO Stainless Steel to Zirconia Braze Joints. Journal of the Electrochemical Society 2019; 166: F594-F603. http://dx.doi.org/10.1149/2.0911910jes
Zhou Q, Bieler TR, and Nicholas JD. Transient Porous Nickel Interlayers for Improved Silver-Based Solid Oxide Fuel Cell Brazes. Acta Materialia. 2018; 148: 156-162. http://dx.doi.org/10.1016/j.actamat.2018.01.061
Phongpreecha T, Nicholas JD, Bieler TR, Qi Y. Computational Design of Metal Oxides to Enhance the Wetting and Adhesion of Silver-based Brazes on Yttria-Stabilized-Zirconia. Acta Materialia. 2018; 152: 229-238. http://dx.doi.org/10.1016/j.actamat.2018.04.024
Nicholas JD, Zhou Q, Bieler TR. Controlled Wetting and Spreading of Metals on Substrates Using Porous Interlayers and Related Articles. Patent US2019/0320528 A1 (2019). Click here for the patent
Nicholas JD, Zhou Q, Bieler TR, Kerr RD. Brazing Methods Using Porous Interlayers and Related Articles. Patent US2018/0326524 A1 (2018). Click here for the patent
Funding Sources:
Department of Energy Solid Oxide Fuel Cell Program Award, Delphi Solid Oxide Fuel Cell Collaboration, Nissan North America Contract
Electro-Chemo-Mechanics
The Nicholas Group seeks to demonstrate that mechanical measurements can be used to measure and engineer the properties of electrochemically active materials. For instance, to measure oxygen surface exchange rate coefficients, the Nicholas Group has tailored a Multibeam Optical Stress (MOS) sensor available from (k-Space Associates, Inc.) to study the curvature change of a mechano-chemical active film atop an inert substrate. Using this technique, the Nicholas Group has shown that a variety of thermal, mechanical, and electrochemical properties (specifically the biaxial modulus, Young’s Modulus, thermal expansion coefficient, thermo-chemical expansion coefficient, oxygen nonstoichiometry, chemical oxygen surface exchange coefficient, and oxygen surface exchange resistance) can all be determined in situ under simultaneously-measured biaxial film stress, without the need for current collectors that can alter film properties through alteration of the film stress state or via unintentional catalytic enhancement/supression of the oxygen surface exchange reaction. Additional experiments to evaluate current collector effects, quantify surface impurity effects, and engineer electrocatalyst oxygen exchange performance are underway. For details see:
Ma Y, Zhou Q, and Nicholas JD. High Temperature Thermo-Mechanical Properties of Praseodymium Doped Ceria Thin Films Measured Two Ways. Materials Advances. 2022; 3: 1574. https://doi.org/10.1039/d1ma00842k
Ma Y, Burye TE, and Nicholas JD. Pt Current Collectors Artificially Boosting Praseodymium Doped Ceria Oxygen Surface Exchange Coefficients. Journal of Materials Chemistry A. 2021; 9: 24406. https://doi.org/10.1039/D1TA06237A
Ma Y and Nicholas JD. Silicon Contamination of the Praseodymium Doped Ceria Oxygen Surface Exchange Coefficient. Journal of the Electrochemical Society. 2021; 168: 104518. https://doi.org/10.1149/1945-7111/ac2e1d
Ma Y and Nicholas JD. Mechanical, Thermal, and Electrochemical Properties of Pr Doped Ceria from Wafer Curvature Measurements. Physical Chemistry Chemical Physics. 2018; 20: 27350-27360. http://dx.doi.org/10.1039/c8cp04802a
Nicholas JD. Practical Considerations for Reliable Stress and Oxygen Surface Exchange Coefficients from Bilayer Curvature Relaxation Measurements. Extreme Mechanics Letters. 2016; 9 (3): 405-421. http://dx.doi.org/10.1016/j.eml.2016.04.006
Yang Q and Nicholas JD. Porous Thick Film Lanthanum Strontium Ferrite Stress and Oxygen Surface Exchange Bilayer Curvature Relaxation Measurements. Journal of the Electrochemical Society 2014; 161: F3025-F3031. http://dx.doi.org/10.1149/2.0051411jes
Yang Q, Burye TE, Lunt RR, and Nicholas JD. In Situ Oxygen Surface Exchange Coefficient Measurements on Lanthanum Strontium Ferrite Thin Films via the Curvature Relaxation Method. Solid State Ionics 2013; 249-250: 123-128. http://dx.doi.org/10.1016/j.ssi.2013.07.025
Funding Sources:
NSF CAREER Award, Army Research Office STIR Award, U.S. Department of Energy Solid Oxide Fuel Cell Program Award
Density Functional Theory Simulations of Oxygen Exchange Catalysts
The Nicholas Group is facilitating Dr. Yue Qi and her group as they seek to understand the properties of highly defective materials for ionic conductor, electrostrictor, memristor, ion exchange, and other applications. For details see:
Park J, Nicholas JD & Qi Y. Surface Gibbs Free Energy Analyses of Sr Segregation in Lanthanum Strontium Iron Oxide. Surface Science, 2023; 732, 122268. https://doi.org/10.1016/j.susc.2023.122268
Das T, Nicholas JD, Qi Y. Composition, Crystallography, and Oxygen Vacancy Ordering Impacts on the Oxygen Ion Conductivity of Lanthanum Strontium Ferrite. Physical Chemistry Chemical Physics. 2020; 22: 9723-9733. http://dx.doi.org/10.1039/C6TA10357J
Das T, Nicholas JD, Sheldon BW, Qi Y. Anisotropic Chemical Strain in Cubic Ceria Due to Oxygen-vacancy-induced Elastic Dipoles. Physical Chemistry Chemical Physics. 2018; 20: 15293-15299. http://dx.doi.org/10.1039/c8cp01219a
Das T, Nicholas JD, Qi Y. Polaron Size and Shape Effects on Oxygen Vacancy Interactions in Lanthanum Strontium Ferrite. Journal of Materials Chemistry A. 2017; 5: 25031-25043. http://dx.doi.org/10.1039/C7TA06948K
Das T, Nicholas JD, Qi Y. Long-Range Charge Transfer and Oxygen Vacancy Interactions in Strontium Ferrite. Journal of Materials Chemistry A. 2017; 5: 4493-4506. http://dx.doi.org/10.1039/C6TA10357J
Funding Sources:
NSF CAREER Award, NSF Catalysis Program Award, U.S. Department of Energy Solid Oxide Fuel Cell Program Award
Sintering Studies
Solid state sintering is widely used to produce a variety of ceramic and refractory metal parts. Although it has been used for thousands of years, scientists are still discovering critically important details about how minor impurities impact the sintering of common materials. In fact, the Nicholas Group has produced the world's most highly cited cerium oxide sintering aid paper and, as shown below, has performed similar analyses on other ion-conducting materials. The Nicholas Group is also supporting the efforts of Dr. Hui-Chia Yu and his group as they seek to develop phase field computer simulation methods that can accurately predict the microstructural changes accompanying sintering. For details see:
Termuhlen, R., Chatzistavrou, X., Nicholas, J. D. & Yu, H.C. Three-Dimensional Phase Field Sintering Simulations Accounting for the Rigid-Body Motion of Individual Grains. Computational Materials Science, 2020; 186, 109963. https://doi.org/10.1016/j.commatsci.2020.109963
Flegler AJ, Burye TE, Yang Q, Nicholas JD. Cubic Yttria Stabilized Zirconia Sintering Additive Impacts: A Comparative Study. Ceramics International 2014; 40: 16323–16335. http://dx.doi.org/10.1016/j.ceramint.2014.07.071
Nicholas JD, DeJonghe LC. Prediction and Evaluation of Sintering Aids for Cerium Gadolinium Oxide. Solid State Ionics 2007; 178: 1187–1194. http://dx.doi.org/10.1016/j.ssi.2007.05.019
Funding Sources:
U.S. Department of Energy Solid Oxide Fuel Cell Program Award, Michigan State Center for Research Excellence in Complex Materials Award, California Energy Commission PIER Grant.
Thin Film - Diamond Anvil Cell Studies
In conjunction with the research groups of Dr. Jie (Jackie) Li, Dr. Bin Chen, formerly Dr. Susannah Dorfman, and others, the Nicholas Group is using pulsed-laser-deposited thin films placed inside diamond anvil cells to understand how grain size, deviatoric stress, and other variables affect geologically-relevant phase transformations. As part of this work, the room temperature response of ruby thin films for on-board pressure sensor measurement has also been calibrated. For details see:
Berrada, M., Hu, G., Zhou, D., Wang, S., Nguyen, P. Q. H., Zhang, D., Prakapenka, V., Chariton, S., Chen, B., Li, J. & Nicholas, J. D. Detection of Thin Film Phase Transformations at High-Pressure and High-Temperature in a Diamond Anvil Cell. Communincations Earth and Environment, 2024; 5, 73. https://doi.org/10.1038/s43247-024-01234-9
Straley EM, Dorfman SM, Nicholas JD. Correlation between the wafer curvature and fluorescence of pulsed laser deposited ruby thin films stressed to ∼2 GPa. Journal of Applied Physics. 2019; 125: 245904. https://doi.org/10.1063/1.5094141
Funding Sources:
NSF CAREER Award, NSF Geophysics EAGER Award
