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College of Engineering and Computing

Graduate student works in lab

Our Research

Our research includes a number of specific areas related to fundamental knowledge, technical applications, and integrated systems.

Selected Research Projects 

Understanding of the complex electrochemical, transport, and phase-chnage phenomena in Li-S cells through the mathematical modeling to addressee the current issues and challenges facing Li-S batteries.



1. N. Kamyab, J. W. Weidner, R. E. White, Journal of Electrochemical Society, 166 (2), A334-A341 (2019).

To use multidimensional, multiscale, and multiphase polymer electrolyte membrane fuel cell (PEMFC) model to enhance understanding of water transport inside gas diffusion layer (GDL) and microporous layer (MPL) during fuel cell operations. The outcomes will facilitate the development of advanced mass transport design in order to enhance the performance and the operational robustness.



1. S. Shimpalee, P. Satjaritanun, S, Hirano, N. Tippayawong, J. W. Weidner, "Multiscale Modeling of PEMFC using Co-Simulation Approach, J. of Electrochemical Society (Submitted March, 2019)

The purpose of this work is to use the direct-modeling-based Lattice Boltzmann Method combined with in-situ flow visualization to explore the transport of liquid water inside the gas diffusion layers (GDLs) used in polymer electrolyte fuel cells. The studies include the understanding of water evolution, water saturation, and breakthrough pressure inside the GDL under different conditions and situations that could occur in fuel cells.



1. P. Satjaritanun, J. W. Weidner, S. Hirano, Z. Lu, Y. Khunatorn, S. Ogawa, S. Litster, A. D. Shum, I. V. Zenyuk, S. Shimpalee, “Micro-scale Analysis of Liquid Water Breakthrough inside Gas Diffusion Layer for PEMFC using X-ray Computed Tomography and Lattice Boltzmann Method,” J. of Electrochem. Soc., 164(11), E3359-E3371, 2017.

2. P. Satjaritanun, S. Hirano, A. D. Shum, I. V. Zenyuk, A. Z. Weber, J. W. Weidner, and S. Shimpalee, “Fundamental Understanding of Water Movement in Gas Diffusion Layer under Different Arrangements using Combination of Direct Modeling and Experimental Visualization,” J. of Electrochem. Soc., 165(13), F1115-F1126, 2018.  

A polymer electrolyte membrane water electrolyzer (PEMWE) produces hydrogen and oxygen via electrochemical oxidation of water. PEMWEs differ from conventional electrolyzers, which use an aqueous electrolyte such as KOH to conduct ions. 3D models can predict not only the curretn density output at a given cell potential, but also the locations of hotspot caused by two-phase transport. This is important to consider in the design of flow fields and porous transport layers in large, commerical PEMWEs.


The objective of this project is to investigate mass transfer in high temperature molten salt system along with corrosion in the systems. Coupling of non-isothermal experiments with CFD modeling of systems with thermal gradients and natural convection will allow enhanced evaluation of corrosion on samples.



1. H-S. Cho, J.W. Van Zee, S. Shimpalee. B. Tavakoli, J.W. Weidner, B. Garcia-Diaz, M. Martinez-Rodriguez, L. Olson, J. Gray, “Dimensionless Analysis for Predicting Fe-Ni-Cr Alloy Corrosion in Molten Salt System for Concentrated Solar Power Systems,” CORROSION, 72(6), 742-760, 2016.

2. B. Tavakoli, J. W. Weidner, B. Garcia-Diaz, M. Martinez-Rodriguez, L. Olson, S. Shimpalee, “Multidimensional Modeling of Nickel Alloy Corrosion inside High Temperature Molten Salt Systems,” J. of Electrochem. Soc., 163(4), C830-C838, 2016.

3. B. Tavakoli, J. W. Weidner, B. Garcia-Diaz, M. Martinez-Rodriguez, L. Olson, S. Shimpalee, “Modeling the Effect of Cathodic Protection on Superalloys inside High Temperature Molten Salt Systems,” J. of Electrochem. Soc., 164 (7), C171-C179, 2017.  

The development and testing of a new catalytic material to decompose sulfuric acid. A novel catalyst preparation technique, developed by USC, uses a combination of: (1) strong electrostatic adsorption (SEA), which permits formation of very small metal particles with a narrow distribution of sizes, and (2) electroless deposition (ED) to produce controlled bimetallic catalysts.  A new laboratory scale decomposition reactor will also be designed and tested. The solar driven Hybrid Sulfur (HyS) cycle will also be modeled, integrating the downselected reactor concept with the other HyS interfaced equipment. A large scale solar driven process configuration will be identified, modeled and optimized to achieve solar efficiencies.



1. C. Corgnale, S. Shimpalee, M.B. Gorensek, P. Satjaritanun, J. W. Weidner, W. A. Summers, “Numerical Modeling of a Bayonet Heat Exchanger-based Reactor for Sulfuric Acid Decomposition in Thermo-Electrochemical Hydrogen Production Processes,” Intl. J. of Hydrogen Energy, 42 (32), 20463-20472, 2017.

This Project is about the effect of the balance of plant contaminations on the fuel cell performance. In this project we are working on the impact of different contamination on the fuel cell performance and trying to develop a mathematical model that can show the effect of different contamination mechanisms on fuel cell performance.

Commercialization of polymer electrolyte membrane fuel cells requires low-cost components, materials and manufacturing processes. Specifically, bipolar plate manufacturing utilizes methods that are slow, expensive, and are inappropriate for some advanced flow field designs. It is desirable that new manufacturing technologies be developed that enable advanced designs at high volume and low cost.



1. S. Shimpalee, V. Lilavivat, H. McCrabb, A. Lozano-Morales, J.W. Van Zee, "Understanding the effect of channel tolerances on performance of PEMFCs," Intl. J. of Hydrogen Energy, 36/19, 12512-12523, 2011.

2. S. Shimpalee and V. Lilavivat,” Study of Water Droplet Removal on Etched-Metal Surfaces for Proton Exchange Membrane Fuel Cell Flow Channel,” ASME-Journal of Electrochemical Energy Conversion and Storage, 13, 011003-1 – 011003-7, 2016. 

3. S. Shimpalee, V. Lilavivat, H. McCrabb, J.W. Weidner, Y. Khunatorn, H-K. Lee, and W-K. Lee, “Investigation of Bipolar Plate Materials for Proton Exchange Membrane Fuel Cells,” Intl. Journal of Hydrogen Energy, 41, 13688-13696, 2016. 


The overall objective of this project is to develop a better understanding of transport phenomena in current H2 Air polymer electrolyte membrane fuel cells. Water transport and its role in fuel cell performance is the main focus of this project. The project objectives have been achieved by generating custom materials; membranes, catalyst layers, diffusion media and flow fields and characterizing them ex situ, followed by operation in a fuel cell and modeling of the results.

 Transport PEMFC


1. V. Lilavivat, S. Shimpalee, J.W. Van Zee, H. Xu, and C.K. Mittlesteadt, “Current Distribution Mapping for PEMFC,” Electrochimica Acta,174,1253–1260, 2015.

2. J.R. Rowlett, V. Lilavivat, A.S. Shaver, Y. Chen, A. Daryaei, H. Xu, C. Mittelsteadt, S. Shimpalee, J.S. Riffle, J. E. McGrath, “Multiblock Poly(arylene ether nitrile) Disulfonated Poly(arylene ether sulfone) Copolymers for Proton Exchange Membranes: Part 2 Electrochemical and H2/Air Fuel Cell Analysis,” Polymer, 122, 296-302, 2017.

3. S. Shimpalee, V. Lilavivat, H. Xu, J. R. Rowlett, C. Mittelsteadt, and J. W. Van Zee, “The Effect of Membrane Properties on Performance and Transports inside Polymer Electrolyte Membrane Fuel Cells,” J. of Electrochem. Soc. 165 (11), F1019-F1026, 2018.  

In this project we want to see the effect of bimetallic electrocatalyst on different metal oxide supports towards methanol electrooxidation reaction.

The objective of this project is to describe polymer electrolyte membrane fuel cell (PEMFC) behavior resulting from changes in the fundamental properties of GDLs. This objective is being accomplished by measuring the GDL properties, including micro and macro porous layers, fuel cell performance under a variety of operating conditions, and by developing a mathematical model.




1. M. Martinez, S. Shimpalee, and J. W. Van Zee, “Measurement of MacMullin numbers for PEMFC gas diffusion media," J. of Electrochem. Soc.,156/1, B80-B85, 2009.

2. M. Martinez, S. Shimpalee, and J. W. Van Zee, “Assessing methods and data for pore size distribution of PEM fuel cell gas diffusion media,” J. of Electrochem. Soc., 156/5, B558-B564, 2009.

3. J. Farmer, M. Martinez, S. Shimpalee, B. Duong, S. Seraphin, J.W. Van Zee, "Assessing porosity of PEM fuel cell gas diffusion layers by SEM image analysis," J. of Power Sources, 197C, 1-11, 2011.

4. M. Martinez, S. Shimpalee, T. Cui, B. Duong, S. Seraphin, J.W. Van Zee, "Effect of microporous layer on MacMullin number of carbon paper gas diffusion layer," J. of Power Sources, 207, 91-100, 2012. 

5. S. Shimpalee, V. Lilavivat, H. Xu, C. K. Mittlesteadt, Y. Khunatorn, “Experimental Investigation and Numerical Determination of Custom Gas Diffusion Layers on PEMFC Performance,” Electrochimica Acta, 222,1210-1219, 2016. 

In this project we are study the operation of a twin-cell electrochemical filter for removing carbon monoxide (CO) from reformate hydrogen by periodically adsorbing and then electrochemically oxidizing CO on the electrode. During the adsorption step, the effects of various operating parameters (e.g., feed CO concentration, flow rate, electrode catalyst loading, type of feeder gas, temperature) on CO breakthrough are measured. Finally steady-state filter operation is implemented to decrease the CO concentration from 10,000 to 10 ppm.

We are developing our patented gas-fed SO2-depolarized electrolyzer (SDE) for use in the hybrid-sulfur (HyS) process, the only practical, all-fluid, two-step thermochemical cycle for producing hydrogen on a large scale. We have tested our SDE over a range of operating conditions (e.g., current, temperature, SO2 flow rate) and design variations (e.g., catalyst type and loading, membrane type and thickness). A key insight from our work is that the concentration of sulfuric acid increases with current density, which dehydrates perfluorinated sulfonic acid membranes like Nafion and increases cell resistance. We have recently shown that acid-doped polybenzimidazole (PBI) membranes represent an alternative to Nafion because they do not rely on water for their proton conductivity, and therefore they offer the possibility of operating at high acid concentrations and/or elevated temperatures to minimize voltage losses (e.g., kinetic and ohmic resistances).

Currently, the United States has more than 2,200 sites producing biogas, with high growth potential. DOE estimates nearly 14,000 additional sites can be developed. Together these new biogas systems could produce enough energy to power 3.5 million American homes and reduce emissions equivalent to             removing 15.4 million passenger vehicles from the road. Our research is directed at reducing investor risk by enhancing in-situ, on-line monitoring techniques and thereby improving the  chances for long-term process success.



1. A. L. Martin, P. Satjaritanun, S. Shimpalee, B. A. Devivo, J. W. Weidner, S. Greenway, M. Henson; C. Turick, “In-situ Electrochemical Analysis of Microbial Activity,” AMB Express, 8, 162, 1-10, 2018.

Develop a working model to quantitatively understand particle mixing with Lattice Boltzmann Method (LBM). The main goals of this study are to characterize and compare contra-rotating single shaft impellers to single shaft co-rotating dual impellers.



1. P. Satjaritanun, E. Bringley, J.R. Regalbuto, J.A. Regalbuto, J. Register, J.W. Weidner, Y. Khunatorn, and S. Shimpalee, “Experimental and Computational Investigation of Mixing with Contra-Rotating, Baffle-Free Impellers,” J. of Chemical Engineering Research and Design, 130, 63-77, 2018.