Understanding the cycling and degradation of atomically thin 2D/1D anodes for Li & Na-ion batteries with in-situ & operando scanning probe microscopy

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The unique properties of 2D, 1D and 0D materials, isolated from their bulk layered materials, has sparked a materials revolution. They have distinctive properties, high surface areas, electrical conductivity and mechanical stability, and can be assembled into functional films and electrodes. It is therefore anticipated that these materials will play an enormous role in future energy generation and storage. Recent work has presented a new method for forming 2D nanosheets in liquids, [1] and 1D phosperene nano-ribbons (PNRs) with unique characteristics [2].By utilising atmospherically controlled electrochemical atomic force microscopy (EC-AFM)[3] and the related technique 'SECM-AFM' (methods few labs in the UK are set up to exploit) the successful candidate will image and electrochemically characterise nanoscale changes at the surface of 2D and 1D nanomaterial electrodes during their charge-discharge cycle. This will show the effects of material micro/nano-structure change (swelling, cracking, surface layer formation, metal plating) on cell performance. When combined with x-ray photoelectron spectroscopy (XPS), possible in this project without air exposure, we will quantitatively characterise the chemical composition of the same particles at various states of charge (ex-situ). This will enable a truly representative understanding of the materials' chemical and mechanical properties. These core techniques will be complemented by a wide array of other characterisation tools at both institutions including electron microscopy (SEM, TEM), x-ray diffraction, micro-Raman spectroscopy, EIS and a broad range of electrochemical techniques.In this project, the student will develop multidisciplinary skills in synthesis, battery fabrication, electrochemistry and advanced characterisation for energy storage, whilst developing strong links with industry and academia.[1] Cullen PL et al...Howard CA, "Ionic solutions of two-dimensional materials." Nature Chemistry 9.3 (2017)[2] Watts MC et al...Howard CA "Production of phospherene nanoribbons" Nature 568, 216-220 (2019).[3] Zhang et al.... Miller TS "Operando Electrochemical Atomic Force Microscopy of Solid-Electrolyte Interphase Formation on Graphite Anodes: The Evolution of SEI Morphology and Mechanical Properties" ACS App Mat. 1944-8244 (2021)