Reciclagem do eletrodo positivo de baterias de íon-Li exauridas utilizando ácido cítrico como lixiviador e precursor na formação de eletroquímica de Co(OH)2/Co3O4/LiCoO2 e química de Co3O4/LiCoO2

• Ano de defesa: 2016
• Autor(a) principal: Santana, Ívina Langsdorff
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal do Espírito Santo; BR; Mestrado em Química; Centro de Ciências Exatas; UFES; Programa de Pós-Graduação em Química
• Palavras-chave em Português: Recycling; Lithium ion batteries; Citric acid; Cobalt oxide; Cobalt hydroxide; Cobalt lithium oxide; Reciclagem - Indústria; Baterias de lítio; Ácido cítrico; Óxido de cobalto; Óxido litiado de cobalto; Hidróxido de cobalto; Química; 54
• Link de acesso: http://repositorio.ufes.br/handle/10/4749

In this present work, cobalt and lithium from spent lithium ion batteries Samsumg® and HP® was recovered in hydrometallurgical process. Citric acid was leachant and H2O2was reductant agent. Two recycling routes was developed using leaching solution of cobalt and lithium: an electrochemical route; and a synthetic route. On electrochemical route, cobalt oxides (LiCoO2and Co3O4) and hydroxides electrodeposited on nickel substrate using galvanostatic technique. High current density of -0,45 Acm-2used for electrodeposition due to great stability of cobalt and lithium complex. Electrodeposition carried out using charge densities of -250, -300 and -350Ccm-2. Electrochemical recycling route presented low efficiency of electrodeposition (~1,5%) and recycled material, tested as pseudocapacitors, presented irrelevant capacitances (lower than 1 Fg-1). Synthetic recycling route was carried out using a sol-gel method for LiCoO2and Co3O4preparation. To form sol-gel precursor, leaching solution of cobalt and lithium citrate was used. Sol-gel precursor calcined at 250°C, 350 °C, 450 °C and 650 °C formed a mixed cobalt oxides compounds (LiCoO2and Co3O4). Mixed cobalt and lithium oxides tested as catalyst for methylene blue photodegradation presented good catalytic activity. Mixed cobalt oxides calcined at 450 °C degraded 90% of methylene blue after 10 hours and 100% after 24 hours of photocatalysis. Sol-gel precursor calcined at 850 °C formed only LiCoO2. Electrochemical properties of recycled cobalt and lithium oxide were studied using cyclic voltammetry. Recycled LiCoO2is a promising material for lithium ion batteries cathodes. The contribution of this work is that it presents a means to produce valuable materials having electrochemical and catalytic properties from recycled batteries trough a spent lithium ion batteries without polluting the environment