Electrospray-assisted synthesis methods of nanostructured materials for Li-ion batteries

Abstract

This PhD thesis focuses on the synthesis of nanostructured materials via an aerosol-assisted route based on electrospraying of liquid precursors. Electrospraying is a powerful technique for the production of nearly-monodispersed, highly-charged droplets. The possibility of tailoring the droplet size, as well as coupling the process to different chemical reactions makes this technique attractive for the production of a wide variety of nanostructured functional materials in a simple, direct and cost-effective way. The materials investigated in this work are directly related to applications in advanced Li-ion battery negative electrodes. The electrospray process has been implemented in two novel approaches for the production of different materials. The first one consists in the production of nanoparticles via an alternative method that combines charged aerosols with red-ox reactions in liquids, while the second one develops a single-step process for complete synthesis and assembly of nanocomposite coated electrodes by pyrolysis and/or deposition of precursor solutions and suspensions. In this way advanced negative electrodes containing active nanoparticles dispersed in polymer binders have been directly fabricated in one step at relatively low temperature without any further processing. The resulting materials show enhanced electrochemical performances and could replace graphite in commercial electrodes, due to their high capacities. It should be stressed that this approach is extremely general and it has the potential to be implemented in a roll-to-roll process for the continuous production of nanocomposite coatings for various purposes, not necessarily restricted to Li-ion batteries.