Gaspar, Guilherme Manuel Morais, 1988-Correia, Jorge Palma, 1962-Capellari, Felix Karl2023-09-0720232022http://hdl.handle.net/10451/59165Tese de mestrado, Engenharia da Energia e Ambiente, 2022, Universidade de Lisboa, Faculdade de CiênciasA wide range of applications, such as powering electric vehicles, being used in consumer electronics and providing ancillary services to the power grid, make lithium-ion batteries one of the most promising storage technologies currently available. Due to the rapidly growing demand, major research efforts to constantly improve the performance of battery storage systems are being made. The use of silicon as an anode material for battery systems offers great potential due to its low cost, high abundance, and excellent specific capacity. The main objective of this work was to fabricate silicon-based anodes with suitable properties to be used in sodium and lithium-ion batteries. For this purpose, silicon films with suitable morphologies and chemistries deposited on substrates should be developed, resulting in working electrodes with good cyclability. In an experimental procedure with a cold-wall reactor and silane gas as the silicon source, rigid graphite substrates were used and deposited with silicon, by means of chemical vapour deposition. To validate the results, the fabricated electrodes were subjected to a standard electrochemical, structural and morphological characterisation procedures. The present chemical vapour deposition system enabled the production of samples with very different silicon contents by varying the experimental parameters. The achieved silicon loads were in the range of 0.1-5.1 mg cm-2 , with different morphological properties and silicon particles measuring 0.1-2 µm diameter. The results of the electrochemical characterisation revealed that the use of NaClO4 as electrolyte compromised the process reversibility. In contrast, when an electrolytic solution of LiClO4 was used, promising results were achieved with coulombic efficiencies of up to 80%.engdeposição química de vaporbaterias de iões de lítiobaterias de iões de sódiosilíciografiteTeses de mestrado - 2023master thesis203493630