Modelling disorder in magnesium battery cathode materials (RENU21/EE/MPEE/WHALLEY)

The EPSRC Centre for Doctoral Training (CDT) in Renewable Energy Northeast Universities (ReNU)is a collaborative doctoral training programme run by the Universities of Northumbria, Newcastle and Durham. In addition to undertaking an individual scientific research project at one of the three partner Universities, doctoral candidates will engage with added value training opportunities, for example in business, innovation and internationalisation through a 4-year training programme that has been designed to maximise the benefits of a cohort approach to doctoral training. The start date is 1st October 2021.

Modelling disorder in Mg-ion battery cathode materials

A problem with developing new materials for battery cathodes is that while the fully charged material may fill the requirements for an ideal cathode (e.g. thermodynamic stability, ion conduction), the actual performance during use may be lower than expected. For example, in the high voltage spinel cathode LiNi0.5Mn1.5O4 (LNMO) the disordering of Ni/Mn results in the formation of Mn2+ ions that dissolve into the electrolyte. Knowledge of atomic disorder in these materials, and how this relates to charge transport and chemical stability, is crucial for optimising their performance during operation.

We will combine quantum chemistry, statistical techniques and high-performance computing to predict the materials performance of chalcogenide spinel battery cathode materials. The chalcogenide spinels show good Mg-ion mobility, with a diffusion activation energy <650 meV; initial studies have identified candidate cathode materials (MgB2S4 with B = Cr, Ti, Mn). Mixed S/Se spinels provide the possibility of tuning optical and electronic properties via anion stoichiometry and disorder, a currently unexplored research area.

In year one we will use density functional theory to predict the compounds that will optimise cathode performance. In years two/three we will develop a cluster expansion model to consider i) the impact of anion disorder on performance (charge/discharge rates, cell voltage and chemical stability) and ii) whether disorder can be utilised for further optimisation. In the final year, to enable comparison with experiment, we will predict the vibrational spectra of the disordered materials. We will use best practice in research software engineering to ensure that the methods and codes developed can be used by the wider research community (see, for example, our package: dx.doi.org/10.21105/joss.00797). This project builds on our expertise modelling defects and vibrations in complex energy materials and complements a growing programme of electrochemical research at Northumbria .

This project is supervised by Dr Lucy Whalley. For informal queries, please contact [Email Address Removed]

The application closing date is 7 February 2021 and we will aim to have the interviews take place in early March. Please note that interviews, should they be arranged, will be online rather than in person due to COVID-19.

Eligibility and How to Apply

Please note eligibility requirement:

• Academic excellence of the proposed student i.e. 2:1 (or equivalent GPA from non-UK universities [preference for 1st class honours]); or a Masters (preference for Merit or above); or APEL evidence of substantial practitioner achievement.

• Appropriate IELTS score, if required.

• Applicants cannot apply for this funding if currently engaged in Doctoral study at Northumbria or elsewhere.

For further details of how to apply, entry requirements and the application form, see:

https://www.northumbria.ac.uk/research/postgraduate-research-degrees/how-to-apply/

Please note that applications must include all of the following to be considered:

1. A research proposal of approximately 1,000 words (not a copy of the advert), and include the advert reference (e.g. ReNU21/…).
2. You must upload with your application at least 2 reference letters

Deadline for applications: 7 February 2021

Start Date: 1 October 2021

Northumbria University takes pride in, and values, the quality and diversity of our staff. We welcome applications from all members of the community.

* please note: to be classed as a Home student, candidates must meet the following criteria:

• Be a UK National (meeting residency requirements), or

• have settled status, or

• have pre-settled status (meeting residency requirements), or

• have indefinite leave to remain or enter.

If a candidate does not meet the criteria above, they would be classed as an International student.