Electrochemical properties of colloidal nanocrystal assemblies of manganese ferrite as the electrode materials for supercapacitors

• Published in: Journal of materials science Vol. 52; no. 9; pp. 5359 - 5365
• Main Authors: Guo, Peizhi, Li, Zhen, Liu, Shuibo, Xue, Jing, Wu, Guanglei, Li, Hongliang, Zhao, X. S.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.05.2017; Springer; Springer Nature B.V
• Subjects: Assemblies; Capacitance; Capacitors; Characterization and Evaluation of Materials; Chemical properties; Chemistry and Materials Science; Classical Mechanics; Crystallography and Scattering Methods; Current density; Electrochemical analysis; Electrochemical impedance spectroscopy; Electrochemistry; Electrode materials; Iron compounds; Manganese; Materials Science; Nanocrystals; Nanoparticles; Original Paper; Polymer Sciences; Self-assembly; Solid Mechanics; Supercapacitors; MnFe2O4; Ferrite; Equivalent Series Resistance; Electrochemical Performance; Ferrite Nanoparticles
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/s10853-017-0778-2

The electrocapacitive behavior of MnFe 2 O 4 -based supercapacitors has been studied by a series of electrochemical techniques, including circle voltammetry, galvanostatic charge–discharge and electrochemical impedance spectroscopy. The size of the used MnFe 2 O 4 colloidal nanocrystal assemblies (CNAs) was in the range of 230–950 nm, formed by the in situ self-assembly of primary MnFe 2 O 4 nanoparticles with different sizes. Electrochemical measurements showed that the electrochemical performances of MnFe 2 O 4 -based supercapacitors were related to the structure of MnFe 2 O 4 CNAs. MnFe 2 O 4 CNAs with the size of 420 nm, composed of 16 nm nanoparticles, displayed the highest capacitance of about 88.4 F/g at the current density of 0.01 A/g, which, respectively, decreased to 55.8 and 20.2 F/g for CNAs with size of 230 and 950 nm, assembled by 21 and 43 nm nanoparticles. Electrochemical stability data showed that 420 nm MnFe 2 O 4 CNAs had the best capacitance retention of 59.4% with the current density increased from 0.01 to 2 A/g and the best capacitance retention of 69.2% after 2000 cycles among all the samples under the current density of 0.2 A/g. The structure–property relationship of MnFe 2 O 4 CNAs was analyzed and discussed based on the experimental data.