Developing new technological solutions that can guarantee a steady supply of clean, renewable energy is one the greatest challenges of our time. Interestingly, current technologies (such as solar, wind, fuel cells, nuclear etc.) are always limited by the materials they use. Indeed, we need to find new material solutions that are cheaper, environmentally friendly, abundant and that have higher performance. This poses a tremendous challenge that can only be addressed with a paradigm-shift approach to materials science, in which previous trial-and-error approaches are substituted by the rational design of materials. To this end, computer modeling is one of the most promising tools at our disposal.
In this presentation I will report on some recent work on understanding the properties of certain energy materials and predicting new ones with higher performance. This was done by combining Density Functional Theory and Molecular Dynamics calculations, with state-of-the-art experimental work. The bulk of my presentation will focus on CeO2 and ZrO2 based materials used as the electrolyte in solid oxide fuel cells (SOFC). I will first talk about their chemical expansion (which can cause an SOFC to breakdown), show how we obtained a detailed understanding of the factors responsible for this phenomenon and how we successfully predicted new materials compositions that minimize this effect. Then I will focus on the ionic conductivity of doped CeO2 and explore, computationally, two possible routes to optimize their conductivity: 1) strain and 2) co-doping strategies. I will discuss the limitations and promises of both approaches. Finally, other examples of my work on Li-ion battery materials and oxygen storage capacity materials will also be briefly discussed.