Characterization of porous cobalt hexacyanoferrate and activated carbon electrodes under dynamic polarization conditions in a sodium-ion pseudocapacitor

Cyclic voltammetry of activated carbon/cobalt hexacyanoferrate composite as electrode materials for symmetric coin cells in sodium sulfate aqueous electrolyte. Electronic micrographs shows composite morphology and porous structure of cobalt hexacyanoferrate. [Display omitted] •Porous cobalt hexacyan...

Full description

Saved in:

Bibliographic Details
Published in:	Journal of energy chemistry Vol. 54; pp. 53 - 62
Main Authors:	Pires, Bruno Morandi, Nunes, Willian Gonçalves, Freitas, Bruno Guilherme, Oliveira, Francisca Elenice Rodrigues, Katic, Vera, Rodella, Cristiane Barbieri, Da Silva, Leonardo Morais, Zanin, Hudson
Format:	Journal Article
Language:	English
Published:	Elsevier B.V 01-03-2021
Subjects:	Activated carbon Cobalt hexacyanoferrate High specific capacitance Operando studies Raman XRD synchrotron light XRD synchrotron light Cobalt hexacyanoferrate Raman Operando studies High specific capacitance Activated carbon
Online Access:	Get full text
Tags:	Add Tag No Tags, Be the first to tag this record!

Description
Summary:	Cyclic voltammetry of activated carbon/cobalt hexacyanoferrate composite as electrode materials for symmetric coin cells in sodium sulfate aqueous electrolyte. Electronic micrographs shows composite morphology and porous structure of cobalt hexacyanoferrate. [Display omitted] •Porous cobalt hexacyanoferrate onto high surface area AC electrodes.•CoHCF incorporation in AC has improved more than 300% of the specific energy.•High specific capacitance and very stable electrodes operating at 2 V in aqueous electrolytes.•Operando analysis elucidated the high stability and reversibility of the charge-storage process. We report here the activated carbon and cobalt hexacyanoferrate composite, which is applied as the electrode materials in symmetric supercapacitors containing a 1.0 M Na2SO4 aqueous electrolyte. This novel material combines high specific surface area and electrochemical stability of activated carbon with the redox properties of cobalt hexacyanoferrate, resulting in maximum specific capacitance of 329 F g−1 with large voltage working window of 2.0 V. Electrochemical studies indicated that cobalt hexacyanoferrate introduces important pseudocapacitive properties accounting for the overall charge-storage process, especially when I < 0.5 A g−1. At lower gravimetric currents (e.g., 0.05 A g−1) and up to 1.0 V, the presence of cobalt hexacyanoferrate improves the specific energy for more than 300%. In addition, to better understanding the energy storage process we also provided a careful investigation of the electrode materials under dynamic polarization conditions using the in situ Raman spectroscopy and synchrotron light X-ray diffraction techniques. Interesting complementary findings were obtained in these studies. We believe that this novel electrode material is promising for applications regarding the energy-storage process in pseudocapacitors with long lifespan properties.
ISSN:	2095-4956
DOI:	10.1016/j.jechem.2020.05.045