Prof. Peter G. Bruce FRS, Wolfson Chair in Materials, Departments of Materials and Chemistry
Prof. Bruce has recently relocated his research to new state-of-the-art labs at the University of Oxford.
Three PhD positions on the materials chemistry and electrochemistry of lithium-air, lithium-ion & sodium-ion batteries, and Li-ion solid electrolytes, are available.
1. The materials chemistry and electrochemistry of the lithium-air battery
Energy storage represents one of the major scientific challenges of our time. Pioneering work in Oxford in the 1980s led to the introduction of the lithium-ion battery and the subsequent portable electronics revolution (ipad, mobile phone). Storing electrons is key to a step change in electric vehicles and the storage of electricity from renewable sources.
Theoretically the Li-air battery can store more energy than any other device, as such it could revolutionise energy storage. The challenge is to understand the materials chemistry and electrochemistry of the Li-air battery and by advancing the science unlock the door leading to a practical device. The Li-air battery consists of a lithium metal negative electrode and a porous positive electrode, separated by an organic electrolyte. On discharge, at the positive electrode, O2 is reduced to O22- forming solid Li2O2, which is oxidised on subsequent charging. The project will involve understanding the electrochemistry of O2 reduction in Li+ containing organic electrolytes to form Li2O2 and its reversal on charging. While O2 reduction in aqueous media has been studied exhaustively for many decades, much less is known about the process in aprotic solvents.
2. Polymer and ceramic Li-ion conducting electrolytes - the challenges
Replacing the flammable liquid electrolytes, used in current Li-ion batteries, with solid polymers or ceramics would transform safety and make the all-solid-state Li-ion battery a reality. There is worldwide interest in this topic. The project can focus on either polymer or ceramic Li-ion conducting solid electrolytes depending on the interests of the student. The work will involve the discovery, synthesis and understanding of solid polymer or ceramic electrolytes, but will also include the investigation of the interfaces between these electrolytes and typical solid anodes and cathodes used in Li-ion batteries. The interfaces are as significant a problem as is finding new electrolytes with high conductivity. A range of techniques to synthesise and characterise the solid electrolytes, including X-ray and neutron diffraction, electron microscopy, NMR, Raman and IR spectroscopy, X-ray tomography, as well as several electrochemical techniques will be employed.
3. The materials chemistry and electrochemistry of lithium and sodium-ion batteries
Lithium-ion batteries have revolutiosnised portable electronics and are now used in electric vehicles. However new generations are required for future applications in transport and storing electricity from renewable sources (wind, wave, solar). Such advances are vital to mitigating climate change. Sodium is more abundant than lithium and so attractive especially for applications on the electricity grid.
Lithium and sodium ion batteries both consist of intercalation compounds as the negative and positive electrodes. The charge and discharge involves shuttling Li+ or Na+ ions between the two intercalation hosts (electrodes) across the electrolyte. In the case of Li-ion batteries currently the most common technology is still graphite (anode) and LiCoO2 (cathode). However, the development of increased energy storage in Li ion systems drives research to discover new materials. In the case of Na-ion batteries whilst the principles are analogous to that of the Li-ion battery, as yet there are no preferred candidates as electrodes, which provides excellent motivation for further work.
Please use this link for further information for all available positions http://www.materials.ox.ac.uk/vacancies.html?d=1#ResearchStudentships