Deposition of silicon on substrates of interest for lithium-ion battery anodes

Tese de mestrado integrado, Engenharia da Energia e do Ambiente , 2022, Universidade de Lisboa, Faculdade de CiênciasThe development of lithium-ion batteries in recent years has focused on the anode, with progresses made in order to increase its capacity by using environmentally friendly and available materials such as silicon. This work aims at setting up a previously developed chemical vapour deposition system while using it for the deposition of silicon on carbon-based substrates for lithium-ion battery anodes. After deposition, the samples are analysed through different techniques: cyclic voltammetry to evaluate the lithiation and delithiation, scanning electron microscopy and energy dispersive spectroscopy to observe the morphology and chemical composition while X-ray diffraction was used to obtain insights on the crystallinity of the deposited materials. The results confirm that we were successful in depositing silicon on different substrates with silicon mass loading up to 3% of the total sample weight, having a shell type structure on carbon coated metal substrates and clusters of particles in rigid graphite substrates. Cyclic voltammetry exhibits lithiation and delithiation behaviours achieving coulombic efficiencies in the range of 60 to 70% after 3 cycles