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

作　　者：Bruno Morandi Pires Willian Goncalves Nunes Bruno Guilherme Freitas Francisca Elenice Rodrigues Oliveira Vera Katic Cristiane Barbieri Rodella Leonardo Morais Da Silva Hudson Zanin 

机构地区：[1]Advanced Energy Storage Division,Manufacturing Croup,Carbon Sci-Tech Labs,Center for Innovation on New Energies,University of Campinas,Campinas 13083-852,SP,Brazil [2]Brazilian Synchrotron Light Laboratory(LNLS/Brazilian Center of Energy and Materiab(CNPEM)),Campinas 13083-970,SP,Brazil [3]Department of Chemistry,Laboratory of Fundamental and Applied Electrochemistry,Federal University of Jequitinhonha and Mucuri's Vatley,Alto dajacuba 39100-000,Diamantina-MG,Brazil

出　　处：《Journal of Energy Chemistry》2021年第3期53-62,共10页能源化学（英文版）

基　　金：the financial support from the Brazilian funding agencies CNPq(301486/2016-6);FAPESP(2014/02163-7,2017/11958-1,2018/20756-6);FAPEMIG(Financial support for the LMMA/UFVJM Laboratory);CNPq(PQ-2 grant:Process 301095/2018-3);the support from Shell and the strategic importance of the support given by ANP(Brazil’s National Oil,Natural Gas and Biofuels Agency)through the R&D levy regulation。

摘　　要：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 Na_(2)SO_(4) 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 Xray 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.

关 键 词：Operando studies RAMAN XRD synchrotron light Cobalt hexacyanoferrate Activated carbon High specific capacitance 

分 类 号：TM53[电气工程—电器] TB332[一般工业技术—材料科学与工程]