Speaker
Description
The development of efficient and cost-effective solid oxide fuel cells (SOFCs) will allow hydrogen or other low-carbon fuels to replace hydrocarbon fuels in commercial energy-generation applications. A wide variety of oxide structure classes are being explored in an effort to discover SOFC electrolyte and electrode materials with competitive ionic conductivity in the “intermediate” temperature range (450-600 °C). In order to rationally design and tune these materials for better performance, a clear understanding of the causes and mechanisms of ionic conductivity in the most promising materials is essential.
Our work utilises a combination of experimental and theoretical methods to investigate the structural and dynamic origins of oxide ion mobility in diverse solid oxide materials. We have used the optical floating-zone furnace facility recently installed at Durham University to grow single crystals of conductive scheelites ($\mathrm{CeNb}_{1-x}M_{x}\mathrm{O}_{4+\delta}$ and $\mathrm{LaNb}_{1-x}M_{x}\mathrm{O}_{4+\delta}$, M = V, Mo, W), apatites ($\mathrm{(La,Bi)}_{9.33+x}\mathrm{Si}_{6}\mathrm{O}_{26\pm\delta}$) and “hybrid” hexagonal perovskites ($\mathrm{Ba}_{3}\mathrm{Nb}M\mathrm{O}_{8.5}$, M = Mo, W), in many cases for the first time. These crystals have enabled a variety of experiments to be performed, including single-crystal x-ray and neutron diffraction, directional quasielastic neutron scattering, and oriented $^{18}$O tracer diffusion measurements. Our poster will present new insights obtained from these studies concerning the roles of ionic order and disorder, interstitial site behaviour, low-energy diffusion pathways, and cation coordination environments on efficient ionic conductivity in some of the mentioned materials.
| Travel Funding | No |
|---|---|
| Do yo wish to take part in the poster slam | No |
| Level of Expertise | Early Career <5 Years since PdD |
| Speakers Gender | Female |
