Materials Chemistry and Electrochemistry of O-Redox Cathode Materials

Lithium-ion batteries have revolutionised portable electronics and as transport is electrified, the demand for high energy density batteries will grow. The cathode represents one of the greatest barriers to increasing the energy density of Li-ion batteries.

In current cathode materials such as Li[Ni0.8Mn0.1Co0.1]O2, Li removal during charging is charge compensated by transition metal oxidation which limits energy density. We are investigating a new class of high voltage cathode materials in which charge is stored on both the transition metals and the oxide anions (O-redox). These new materials, such as Li2MnO2F, have the potential to offer a 50% increase in energy density over current state-of-the-art cathodes. However, several problems have prevented their practical application, including oxygen loss, slow kinetics and structural instability.

This project will investigate the fundamental processes underlying O-redox to tackle these problems and direct future materials discovery. You will gain experience in a broad range of experimental techniques. The project will involve synthesising, characterising and testing a number of Li-containing transition metal oxides. A range of synthetic approaches will be utilised, including solid state, sol-gel, hydrothermal, co-precipitation and mechanochemical. Characterisation will involve X-ray powder diffraction, solid-state NMR, XPS, FTIR, TEM and SEM. Synchrotron and neutron experiments, such as diffraction and spectroscopy, will be employed to understand the processes taking place during cycling. Furthermore, the interface between the cathode and the organic electrolyte will be investigated using FTIR, Raman, in-situ gas evolution analysis and XPS.

Candidates will be considered in the November 2020 admissions field which has an application deadline of 13 November 2020 and, if the studentship is unfilled, in the January 2021 admissions field which has an application deadline of 22 January 2021.

Any questions concerning the project can be addressed to Professor Peter Bruce ([Email Address Removed]). General enquiries on how to apply can be made by e mail to [Email Address Removed]. You must complete the standard Oxford University Application for Graduate Studies. Further information and an electronic copy of the application form can be found at https://www.ox.ac.uk/admissions/graduate/applying-to-oxford.