Characterization and electrochemical performance of CeO2 and Eu-doped CeO2 films as a manganese redox flow battery component

• Autor(a) principal: Rodrigues, Monica A.
• Data de Publicação: 2018
• Outros Autores: Catto, Ariadne C. [UNESP], Longo, Elson, Nossol, Edson, Lima, Renata C.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://dx.doi.org/10.1016/j.jre.2018.05.004; http://hdl.handle.net/11449/184000
• topic: Cerium oxide; Europium; Nanoparticles; Electrochemical properties; Batteries; Rare earths

Hexagonal CeO2 and Eu-doped CeO2 nanoparticles were obtained using a facile microwave-hydrothermal method under mild conditions and their application towards manganese redox flow battery component were studied. The structural properties were studied by X-ray diffraction and indicate that samples present a fluorite structure. Raman spectroscopy shows Eu3+ ions substitute Ce4+ and generate oxygen vacancies. Electrochemical properties of pure and Eu-doped CeO2 films deposited at graphite substrates investigated by cyclic voltammetry and galvanostatic charge-discharge indicate that dopant concentration affects the electrochemical properties of CeO2. The increase in the reversibility redox of electrochemical systems observed is attributed to coexistence of Ce4+/Ce3+ redox couple confirmed by XPS. Charge-discharge tests display coulombic and voltage efficiency values of above 80% and 90%, respectively. The obtained specific capacity for Ce0.99Eu0.01O2 (372.49 mAh/g) and pure oxide (334.84 mAh/g) indicates that both samples are promising for application in Mn-batteries. (C) 2018 Published by Elsevier B.V. on behalf of Chinese Society of Rare Earths.