Dottorato in SCIENZE CHIMICHE

Titolo della tesi: Novel Electrolyte Formulations for Next-Generation Lithium-Based Energy Storage Devices

This thesis investigates innovative electrolyte formulations designed for next generation lithium based energy storage systems, addressing the shortcomings of traditional carbonate based electrolytes. Odd attention was paid to sulphur based solvents, with SO and SO2 functional groups, due to their high dielectric constants, thermal stability, compatibility with high-voltage cathodes and relatively low toxicity. This research shows that the new formulations proposed and studied, made of 1 mol/kg LiTFSI solutions in sulphoxide and sulphone solvent mixtures, can increase ionic conductivity, overcome viscosity challenges, and extend the range of electrochemical stability, making them strong contenders to replace current commercial electrolytes. These properties make them suitable for high-performance applications in lithium-ion, lithium-sulphur and lithium-air batteries. Combining advanced spectroscopic techniques, electrochemical characterisation, and polarizable molecular dynamics simulations, the project offers a detailed look at the physicochemical and structural properties, solvation processes, and ion transport mechanisms of lithium electrolytes. Computational models supported the experimental results, offering valuable insights into how ions interact with different solvents and the diffusion mechanism through the bulk. These findings highlight the critical role of solvent selection and combination in optimizing electrolyte performance. This work not only suggests practical approaches to develop less toxic and safer electrolytes but also provides a solid foundation for future research aimed at integrating these solutions into cutting-edge battery technologies, with the potential to significantly enhance energy efficiency.