Madhual, Sudeshna2024-04-042024-04-042024ROLL NO.186121028https://gyan.iitg.ac.in/handle/123456789/2595Supervisor: Padmanabhan, Padma KumarSolid oxide fuel cells (SOFCs) are a class of portable primary energy devices, that stand the potential as a green and sustainable alternative to fossil fuels. However, widespread commercial adoption of these electrochemical devices demands significant advancements in their design and efficiency as well as the development of infrastructural ecosystem. The electrolyte, that is sandwiched between the electrodes, is a crucial component of an SOFC device, having a critical impact on its performance. For the efficiency, operational safety, and lifespan of SOFC devices, the electrolyte material has to meet several criteria, such as high ionic conductivity, high chemical and mechanical stability, compatibility with potential electrodes, etc. As argued in the Introduction of this thesis, zirconia (ZrO2) and ceria (CeO2) based ceramic solids are among the most promising choices for practical applications, though their commercial viability demands further improvements. A thorough understanding of the microscopic nature of ion transport and the factors governing it is crucial to the necessary advancement of SOFC devices.enThesis