Chemical Vapour Deposition for Advanced Lithium-Ion Battery Materials and Supercapacitors

点击翻译按钮获取中文摘要

The ever-growing global presence of the electric vehicle is seen as a positive solution to decarbonise the transport industry. As a result, chemists and material scientists are aiming to develop materials that can be used as a backbone for improved electrodes and electrolytes for next-generation batteries and supercapacitors.The research will focus on the generation of materials that are considered to be part of the next generation of batteries through the use of non-line-of-sight deposition techniques, including chemical vapour deposition (CVD) and atomic layer deposition (ALD). This will provide opportunities to produce current collectors and thin films that are well-defined. Through the methods chosen, the microstructure, morphology and chemistry of the composites can be finely-tuned to overcome potential challenges that battery materials face, such as volume changes during charging and the mechanical, chemical or electrochemical degradation of the electrodes. Focus will be drawn to potential lithium- or sodium-chalcogenide intercalation or conversion type electrode, or electrolyte materials, such as Lithium sulfides, lithium phosphates and lithium anti-perovskites, and their sodium counterparts. The initial stages will involve the synthesis of molecules that can be used as precursor material for CVD and ALD, which will then be characterised via a host of methods, including X-ray diffraction, NMR and elemental analysis. The thermal decomposition will be assessed, as will the ability of the precursor to create a thin film. The thin films will be characterised using scanning electron microscopy and will be assessed on its ability as a charge carrier. The advantages of the chosen techniques (CVD and ALD) will be exploited to improve upon cell performance. These include the ability to deposit uniform layers on a surface which can be used as a protection against chemical degradation, the ability to deposit conformally active materials onto structured backbones, such as nano-tubes, -flakes or -rods. There is also the advantage of high levels of control over stoichiometry of new materials that will be tailored to suit the cell performance by appropriately choosing the precursor materials, changing the deposition parameters and through chemical doping.The output of this work will seek to provide new materials that are suitable for use as a deposition precursor. These precursors will then generate a thin film which can be used as a charge carrier. The impact of this work will result in an optimisation of conditions for CVD or ALD, so that the thin film can be tuned to offer an improved performance as an electrode or electrolyte material.The intended outcomes would be the generation of suitable thin films that can be used as electrode or electrolyte materials. Further outcomes could include the realisation of novel ways to produce chemical structures that could be later used in the deposition applications. This research is carried out in conjunction with the Advanced Automotive Propulsion Systems (AAPS) CDT and holds relevance to their "Propulsion Electrification" research theme.