Outcome

1. Understanding Fuel Cell Microstructure EvolutionKatsuyoS. Thornton, University of Michigan Ann Arbor, DMR 0907030 S.A. Barnett, P.W. Voorhees & V.P. Dravid (Northwestern) DMR-0907639 & S.B. Adler (Washington) DMR 0907662 Outcome A simulation tool has been developed to enable more precise interpretation of electrochemical impedance spectroscopy measurements. Impact The ability to identify processes that occur within electrochemical cells is important since it informs researchers and engineers what aspects of device performance must be enhanced and possibly how to approach the optimization. While electrochemical impedance spectroscopy has been key to this identification, its interpretation is difficult because the measured quantity is not only dependent on the processes themselves, but also on the microstructure. The simulation tool that uses experimental microstructure as input will significantly reduce misinterpretation of the data, and will have impact not only on fuel cells, but also on other electrochemical systems such as batteries and supercapacitors. Explanation The simulation tool is based on continuum equations describing coupled diffusion-reaction processes solved using the smoothed boundary method developed by the Thornton group. It is capable of utilizing high performance computing resources such has NSF’s XSEDE. Above: A solution obtained to generate electrochemical impedance spectrum. Below: A simulated spectrum.

2. Undergraduate Research ExperienceKatsuyoThornton, University of Michigan Ann Arbor, DMR 0907030 S.A. Barnett, P.W. Voorhees & V.P. Dravid (Northwestern) DMR-0907639 & S.B. Adler (Washington) DMR-0907662 Outcome Mr. Alex Wang, an undergraduate researcher at the University of Michigan, is contributing to improved characterization of three-dimensional microstructures of solid oxide fuel cell electrode. Impact Mr. Wang is gaining knowledge and skills in performing research in computational materials science and fuel cell materials. Explanation Mr. Wang is examining the reduced characterization of complex three-dimensional solid oxide microstructures such that they could be described by simpler equivalent microstructures. The work is also fostering collaboration with Prof. Adler’s group. Above: Alex Wang, an undergraduate student, is analyzing complex three-dimensional microstructures of fuel cell cathodes.