Probing Metal–Ligand Covalency in High-Valent 3d Transition Metal Battery Cathodes

High-valent redox processes of common, earth-abundant transition metals (e.g. Fe4+/5+) offer a route to achieve high voltage cathode materials for next generation batteries. Electrochemical de-intercalation of Li-ions is a ‘soft’ chemical approach which enables access to the study of these metastable oxidation states. This project will involve the synthesis of novel, high valent cathode materials and their study using advanced operando characterisation (i.e. during battery operation). With state-of-the-art X-ray spectroscopy tools, underpinned by spectral modelling, we aim to understand the nature and dynamics of metal-ligand covalency in cathodes where transition metals can access these rare, high valence states. This understanding will ultimately enable the design of new cathode materials for high-performance batteries.