Transmission electron microscopy (TEM) is now capable of imaging individual atoms in materials, and electron spectroscopy data can provide atomic-scale information about the elements present and the nature of the bonding. Oxford Materials is one of the leading departments in high-precision quantitative measurements of materials using these methods. These methods have great potential for measuring structure and local chemistry to explain the performance of Li battery materials and to guide their development.
There are several outstanding questions regarding the nature of redox and challenges associated with structural stability and oxygen loss in high-capacity cathode materials including anion-redox and Ni-rich cathodes. Electron energy-loss spectroscopy in the transmission electron microscope can reveal information about oxidation states at very high spatial resolutions, and can be used alongside atomic-resolution imaging to relate chemical and structural changes and gain understanding of the fundamental processes in these materials. The project will involve experimental work, including microscope operation, and some computational modelling to enable interpretation of the spectroscopy data.