Enhancement of the Ni-Co hydroxide response as energy storage material by electrochemically reduced graphene oxide

• Autor(a) principal: Adán-Más, Alberto
• Data de Publicação: 2017
• Outros Autores: Duarte, Raquel G., Morais Silva, Teresa, Guerlou-Demourgues, Liliane, MONTEMOR, MARIA
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10400.21/6952
• topic: Electrochemically Reduced Graphene Oxide; Nickel-Cobalt Hydroxide; Energy Storage Electrode; Electrochemistry; Electrochemical Impedance Spectroscopy

Nickel-Cobalt double hydroxide materials are combined with Electrochemically Reduced Graphene Oxide (Er-GO) on top of Stainless Steel collectors by means of a one-step pulsed electrodeposition technique. Results show that, when Er-GO is integrated into the Nickel-Cobalt hydroxide matrix, there is an improvement of the electrochemical performance of the material, which shows increased capacity, stability and rate capability. As seen by Scanning Electron Microscopy (SEM), X-Ray Photoelectron Spectroscopy (XPS), Grazing-Incidence X-Ray Diffraction (GIXD) and Raman Spectroscopy, there is an excellent integration between the materials that leads to the enhanced electrochemical response. Capacity values up to 96 mA h/g and a 62% capacity retention after 5000 cycles were achieved. Moreover, scan rates up to 2000 mV/s without loss in electrochemical response were possible proving its good rate capabilities. A detailed study of the cycling degradation phenomena was also done by means of electrochemical impedance spectroscopy (EIS). Thus, this novel electrodeposited material serves as an excellent material for energy storage applications.