Pseudocapacitive behaviour of iron oxides supported on carbon nanofibers as a composite electrode material for aqueous-based supercapacitors

Autor: Cesar B. Brocchi, Bruno Freitas, Murilo Alexandreli, Davi Marcelo Soares, F.E.R. Oliveira, Leonardo M. Da Silva, Willian G. Nunes, Luiz Eduardo Camargo Aranha Schiavo, Alfredo C. Peterlevitz, Hudson Zanin
Rok vydání: 2021
Předmět:
Zdroj: Journal of Energy Storage. 42:103052
ISSN: 2352-152X
DOI: 10.1016/j.est.2021.103052
Popis: Due to the pseudocapacitive charge storage, transition metal oxides occupy a prominent position as high-energy-density electrode materials for supercapacitors. Environmentally friendly, facile synthesis and earth-abundant precursor materials are highly desirable in the investigation of novel electrodes. We report the synthesis of a binder-free electrode composed of iron oxide (FeOx) nanoparticles supported on radially oriented multi-walled carbon nanofibers (CNF). Characterization studies revealed a homogeneous distribution of nanoparticles composed of α-Fe2O3 (hematite), γ-Fe2O3 (maghemite), and Fe3O4 (magnetite) phases on the CNF scaffold. A high specific pseudocapacitance of 239.2 F g−1 was verified for the iron oxides due to contributions of the reversible solid-state redox reactions involving the Fe(II)/Fe(III) redox couple. Likewise, this work also discusses in detail the charge storage mechanism involving the FeOx species. It is reported a facile synthesis of an electrode material with a pseudocapacitive behaviour, good cyclability, and low equivalent series resistance (e.g., 3.79 mΩ g). As seen, the composite electrode material is promising for the energy storage process in aqueous-based supercapacitors.
Databáze: OpenAIRE