Expanding the Range of Sodium Electrolytes: Bigger Anions, Supramolecular Size Control, and Ionic Liquids

The project involves the synthesis of new sodium electrolytes for sodium batteries, containing large, weakly coordinating anions to maximise ionic conductivity and to obtain ionic liquid electrolytes. The work will involve the examination of the electrochemistry of these electrolytes in batteries, with particular focus on the mechanism of formation of solid electrolyte interfaces (SEIs). The main aim is to explore how size and chemical makeup is related to electrolyte stability and battery performance. Techniques for study include full cell and pouch cell analysis, impedance measurements, cyclic voltammetry, solid-state and solution NMR spectroscopy and post-cycling exploration of the SEIs using SEM, AFM and XPS. The broader aim of the project is to introduce improved electrolytes and additives for sodium ion batteries.