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

Author(s)

Pires, Bruno Morandi ^[1] ; Nunes, Willian Goncalves ^[1] ; Freitas, Bruno Guilherme ^[1] ; Oliveira, Francisca Elenice Rodrigues ^[1] ; Katic, Vera ^[1] ; Rodella, Cristiane Barbieri ^[2] ; Da Silva, Leonardo Morais ^[3] ; Zanin, Hudson ^[1]

Affiliation

^[1] Univ Estadual Campinas, Ctr Innovat New Energies, Adv Energy Storage Div, Carbon Sci Tech Labs, Mfg Grp, BR-13083852 Campinas, SP - Brazil

^[2] Brazilian Ctr Energy & Mat CNPEM, Brazilian Synchrotron Light Lab LNLS, BR-13083970 Campinas, SP - Brazil

^[3] Fed Univ Jequitinhonha & Mucuris Valley, Lab Fundamental & Appl Electrochem, Dept Chem, BR-39100000 Diamantina, MG - Brazil

• Document type: Journal article
• Source: JOURNAL OF ENERGY CHEMISTRY; v. 54, p. 53-62, MAR 2021.
• Web of Science Citations: 0

Abstract

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. (C) 2020 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press. All rights reserved. (AU)

• FAPESP's process: 17/11958-1 - CINE - Advanced Energy Storage Division
• Grantee: Rubens Maciel Filho
• Support Opportunities: Research Grants - Research Centers in Engineering Program
• FAPESP's process: 14/02163-7 - Development of supercapacitors devices from graphene, carbon nanotubes and diamonds
• Grantee: Hudson Giovani Zanin
• Support Opportunities: Research Grants - Young Investigators Grants
• FAPESP's process: 18/20756-6 - Pseudocapacitors from metal oxides and activated carbon composites
• Grantee: Willian Gonçalves Nunes
• Support Opportunities: Scholarships in Brazil - Doctorate