Síntese de análogos do azul da prússia de manganês e sua aplicação como material ativo em eletrodos de supercapacitores

• Ano de defesa: 2024
• Autor(a) principal: Victor Delfim dos Santos Fortunato
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; Brasil; ICX - DEPARTAMENTO DE QUÍMICA; Programa de Pós-Graduação em Química; UFMG
• Palavras-chave em Português: MnHCF; Aditivo de MnCl2; Substituição parcial de Mn; Compósito; Supercapacitor híbrido; Físico-Química; Energia – Armazenamento; Eletrodos; Capacitores; Eletroquímica; Baterias de lítio; Polímeros condutores; Compostos de carbono
• Link de acesso: http://hdl.handle.net/1843/73761

This study presents the development of a hybrid supercapacitor using a positive electrode composed of PbMnHCF@CNT, a Prussian Blue analogue, in combination with activated carbon as the negative electrode. Manganese hexacyanoferrate (MnHCF) was synthesized via the co-precipitation method. A sodium perchlorate electrolyte with a manganese chloride additive was used to increase the capacity retention and specific capacity of MnHCF. Subsequent partial substitutions of Mn with Zn and, for the first time as a battery electrode, Pb, were conducted to enhance the stability and conductivity of MnHCF, with the 50% Pb substitution proving most effective. Composites were developed with functionalized carbon nanotubes, with PbMnHCF@CNT exhibiting higher specific capacity and capacity retention after 1000 cycles. The most promising material, PbMnHCF050, was then studied as a positive electrode in a hybrid supercapacitor with an activated carbon negative electrode. The device showed an energy density of 7.3 Wh/kg at a power density of 57.4 W/kg, along with excellent cycling performance, demonstrating a 168% increase in cell capacitance after 1000 charge-discharge cycles. These results underscore the potential of these materials for applications in high-performance electrochemical supercapacitors.