My work so far has focused on the following specific areas of research:
- Solid oxide fuel cells (SOFCs) :
These high temperature fuel cells offer the highest energy conversion efficiencies and are fuel flexible. We are developing first principles models at the smallest scales (Å to μm) to improve the fundamental understanding of the highly coupled physical and chemical processes in these devices.
Current projects:- Detailed reaction models for SOFC electrochemistry : We are working on continuum-scale models which couple surface transport in the active region of SOFC electrodes with a detailed microkinetic description of the electrochemistry.
- Control relevant modeling of SOFCs : We are developing coarser-scale cell, stack and system models that can be used to simulate the dynamics of these devices in order to facilitate the design of model predictive controllers for solid oxide fuel cell systems.
- Sulfur poisoning of SOFCs : We are modeling the sulfur poisoning of fuel-side (electro)chemistry in an SOFC anode and the direct simulation of the impact of this poisoning on anode performance.
- Redox flow batteries (RFBs) :
These are batteries which work by flowing 'positive' and 'negative' solutions through porous electrodes. We are developing first principles models at the μm to cm scales to improve the fundamental understanding of the highly coupled physical and chemical processes in these devices.
Current projects:- Design and optimization of VRFB cells and stacks : We are working on continuum-scale models which couple transport in the electrodes and flow channels with the electrochemistry. One of the design issues we hope to answer is the need and importance of including flow fields in the bipolar plates.
- Ion crossover in RFBs : We are developing models for ion crossover from one electrode to the other across the membrane during battery operation. This is a key degradation mechanism that leads to electrolyte imbalance in an RFB cell.
- First principles catalysis and ab–initio thermodynamics :
Most chemical transformations in nature as well as industry would not be possible without the various catalysts that allow these reactions to proceed at ‘reasonable’ rates. Density functional theory (DFT) is a standard computational chemistry tool that is used to compute reaction energetics for surface reactions on heterogeneous catalysts. However, the reaction energetics obtained directly from DFT are the ‘zero Kelvin electronic energetics’ which need to be corrected for real world reaction conditions (temperature and pressure). The combination of DFT calculations with methods from statistical mechanics to obtain corrected reaction energetics is a relatively young research area commonly known as ab-initio thermodynamics.
Current projects:- Ab–initio thermodynamics of H2S–H2–Ni : We are examining the sulfur poisoning of Ni using ab–initio thermodynamics, and through our work are extending the technique to incorporate competitive adsorption as well as the effect of surface coverage effects on the energetics.