CONTACT INFORMATION

Department of Materials,
University of Oxford,
Parks Road,
Oxford
OX1 3PH
United Kingdom

 

Department:

Tel +44 (0)1865 273777

Fax +44(0)1865 273789

enquiries@materials.ox.ac.uk

 

http://www.materials.ox.ac.uk

Lab:

Tel +44 (0)1865 212799

alex.robertson@materials.ox.ac.uk

 

 

If you are a student looking for a PhD project, please see below for a description of my available positions. If you are interested and would like more details please contact me and I'd be happy to discuss.

For Post-Docs, I'm afraid I don't have funding available at present, however if you are competitive to apply for some of the individual post-doctoral fellowships available (for instance see here, here, and here) and are looking for a host, please contact me with a CV plus small statement of your interests and we can discuss what would make a good proposal to develop and submit.

PHD PROJECTS AVAILABLE

Direct Real-Time Imaging of the Dynamic Structural Changes of Li- and Na-ion Electrode Materials

 

The lithium-ion battery is the indispensable technology behind the portable electronics boom, and will once again be pivotal for the upcoming revolutions in electric vehicles and renewable-friendly ‘smart grids’. Sustained advances in capacity and reliability mandate the continued development of new electrode materials. The informed design of these materials requires rigorous characterisation across a range of techniques in order to illuminate the limitations and mechanisms that inhibit their performance; however, application-relevant characterisation of the dynamic degradation processes as they occur is a significant technical challenge.

This project will develop new micro-fabrication techniques for the integration of desired electrode materials into a ‘micro-battery’ that can operate within the vacuum of a transmission electron microscope (TEM), allowing for the simultaneous imaging of the structural changes of the electrodes as they undergo charging and discharging. By complementing these TEM investigations with a range of other techniques available at Oxford the project will yield fundamental insights into the materials degradation dynamics that limit these electrode materials.

If you are interested, please contact me at alex.robertson@materials.ox.ac.uk, and visit the PhD projects page of the Materials Department at 

http://www.materials.ox.ac.uk/admissions/postgraduate/newprojects.html

Exploring the Mechanisms Inhibiting Reversible Cycling of Multivalent Electrolytes

 

Rechargeable batteries based on multivalent cations, such as Mg 2+ or Ca 2+, are promising candidates for next-generation energy storage. However, it has proven exceptionally challenging to construct electrolytes that facilitate reversible charging and discharging, with the repeatable deposition and dissolution of Mg or Ca on to the anode often inhibited by a passivating interfacial layer that forms across the electrode. Fortunately there have been several recent breakthrough candidate electrolytes that appear to address this; however, understanding exactly how these new electrolyte compositions facilitate reversible cycling, and the nature of the interfacial layer that forms, are still uncertain.

 

This project will utilise in-situ liquid-cell transmission electron microscopy (TEM) to visualise the deposition and dissolution dynamics of these new multivalent electrolytes in order to illuminate the mechanisms that allow them to operate reversibly. By combining the insights gleaned from direct imaging with a variety of other techniques that are available at Oxford, including online mass spectrometry and cryo-TEM, it will be possible to correlate the observed deposition morphologies with the chemical constitution of the interfacial layer.

If you are interested, please contact me at alex.robertson@materials.ox.ac.uk, and visit the PhD projects page of the Materials Department at 

http://www.materials.ox.ac.uk/admissions/postgraduate/newprojects.html

A time-series of images taken from a real-time in-situ TEM movie, showing the deposition of Ca clusters from a novel Ca-ion electrolyte. On the right is a ‘post-mortem’ scanning electron micrograph (SEM) image of the electrode after the experiment.

Diagnosing and Combating Efficiency Loss in Lithium Metal Batteries

 

The next-generation of “beyond Li-ion” battery architectures, such as Li-air and Li-S, typically require a lithium metal anode. Unfortunately these anodes present significant challenges compared to the graphite electrodes used presently, as the reactive Li metal surface rapidly degrades over repeated charge-discharge cycles due to Li dendrite growth. These dendrites ultimately lead to Li loss due to becoming disconnected from the electrode and by causing electrolyte depletion, and thus permanently reduce the cell capacity.

A number of strategies have been proposed to combat this loss, including using high concentration lithium electrolytes or engineering the electrode surface. A fundamental problem many of these strategies have is that they rely on us merely inferring their effect on the dynamics at the electrode surface, hindering their informed further development. With recent advances in transmission electron microscopy (TEM), it is now possible to directly image Li deposition in-situ and at the nanoscale under conditions that are representative of an active battery. The project will exploit this in-situ TEM technique to directly image the effectiveness of strategies in suppressing Li dendrite growth.  In particular, the project will explore how different approaches lead to improvements in Li electrode stability, and whether the many disparate approaches toward dendrite suppression have any unifying underlying concepts that can be recognised through direct imaging of Li electroplating dynamics.

If you are interested, please contact me at alex.robertson@materials.ox.ac.uk, and visit the PhD projects page of the Materials Department at 

http://www.materials.ox.ac.uk/admissions/postgraduate/newprojects.html

A frame extracted from a real-time TEM movie of Li depositing from a commercial Li-ion battery electrolyte, showing the formation of a disperse network of micron-sized Li grains that are poorly connected to the current collector electrode.

Please also see the Department's own webpage for the latest advertised projects, as well as for details for how to apply, funding routes and so on.

Contact

Department of Materials

Parks Road

Oxford OX1 3PH

+44 (0)1865 212799