Li and Na wetting of cathode ceramics

Lead Research Organisation: University of Oxford
Department Name: Materials

Abstract

A deeper scientific understanding of the wetting relationship between solid Li/Na and the cathode ceramic material will lead to more informed ways of optimising the cathode for best performance. The doctoral student will aim to carry out tasks and answer the following questions, whilst always doing these in the context of the main challenges of the SOLBAT project.

Whilst satisfying the usual requirements for a 1st year DPhil student, the student will be trained to be proficient in the use of advanced surface analysis equipment available to the SOLBAT project such as scanning electron microscopy (SEM), X-ray photoemission spectroscopy (XPS), and scanning tunneling microscopy (STM). Li and Na will be deposited in UHV and in other inert environments on doped single crystals of SrTiO3. This is a model conducting ceramic oxide where the surface structure is well known. Experiments will be carried out to establish the wetting behaviour of Li/Na on the atomic (STM) and microstructural (SEM) length scales, and also to investigate the reactivity of Li/Na with the substrate. Towards the end of the year the student will use the hard X-ray XPS (HAXPES) facility in Manchester (SHR Institute) that has a penetration depth up 50 nm and will be able to provide information on the chemical environment of the buried Li/Na metal - oxide ceramic interfaces.

Having performed some model experiments on a conducting SrTiO3 substrate the student will now face the challenge of working on insulating ceramic oxides used in Li / Na ion batteries such as LMO, LCO, NCA, and most relevant to the SOLBOT aims LLZO garnet. To be able to study these insulators with electron-based probes it will be necessary to prepare them in ultra-thin film form as epitaxial overlayers on a conducting substrate. This can be achieved either through UHV evaporation and oxidation of the elemental materials or via pulsed laser deposition of the target oxide.

Having grown suitable thin films it will be possible to revert to the Li / Na wetting studies of year 1, but on technologically pertinent oxides.

EPSRC research area Theme: Energy

Publications

10 25 50

Studentship Projects

Project Reference Relationship Related To Start End Student Name
EP/S514901/1 01/07/2018 31/03/2022
2285666 Studentship EP/S514901/1 01/10/2019 30/09/2023 Axel Forssberg