Electrodeposition of actives species on carbonaceous materials for energy applications

The thesis work focuses on the electrosynthesis of active species on carbonaceous materials, their characterization and energy applications. Two protocols of electrochemical synthesis that lead to two forms of hexacyanoferrate copper (CuHCF) with different composition and structure, were applied. The procedure used is a “two–step” method that involves the deposition of metallic copper and the subsequent anodization in the presence of ferricyanide ion, using as support graphite sheet, carbon cloth and carbon toray paper. Another protocol was that of electrosynthesis of double layer hydroxide (LDH) containing cobalt as bivalent cation and aluminium or iron as trivalent metal, using as support graphite sheet, carbon cloth, carbon toray paper and nickel foam. After studying the correlation between the electrodeposition time and the masses obtained, the specific capacities of the deposited materials were calculated.The last used protocol was the electrochemical synthesis of nickel hexacyanoferrate on nickel foam. All the film obtained were electrochemically characterized by cyclic voltammetry. SEM – EDX and XRD analyses were performed on some samples in order to obtain morphological and chemical informations. Some tests were conducted using the supports or some of the electrodeposited samples as cathodes in lithium–air batteries, to understand their potential as sources of energy. After performing oxygen and argon cyclic voltammetries, controlling in what way the potential change at different current density and carrying out full discharge at constant current density, it was found that the carbon tissue was the one that produced the best results. It was decided to study in deep the behaviour of this support when active species are electrodeposited above it. As a parallel work, attempts were made to obtain porous carbon from hair, with the intention of using it as a support, in a slurry for example, for testing electrodepositions of active species mentioned above.