Development of Graphene Based Supercapacitors

• Autor(a) principal: Almeida, António Carranca de
• Data de Publicação: 2016
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10362/21759
• topic: Graphene; Graphene Oxide; Supercapacitors; Laser reduction; Electrochemical; Domínio/Área Científica::Engenharia e Tecnologia::Engenharia dos Materiais

The modern world is gasping for electrical energy, from our homes to our daily used devices such as phones, computers and even to our cars. Everything needs to be connected to a battery and the solution existent is becoming obsolete. The market is with a huge gap and supercapacitors are the answer for that space. Graphene assumes a role play in this field for its amazing surface area and its conductivity, making it a perfect candidate for the electrodes of this devices. In this work, two synthesis of graphene were produce: laser reduction of graphene oxide and electrochemical exfoliation of graphite. The first one allows to develop patterns and build the devices in graphene oxide film, producing 2D supercapacitors. The geometry and the influence of the electrolyte were studied to maximize the capacitance. The graphene produced were analysed for its conductivity, quality and uniformity by CV curves, SEM and Raman Spectroscopy. The electrochemical exfoliation allows to start from graphite and use a salt solution with application of voltage, which is an economic and safer alternative for producing graphene. Several concentrations of Na2SO4 were tested and all the material produced by this technique was characterized with Raman Spectroscopy, SEM and TEM images to evaluate the procedure.