Urea-treatment of CoO_(x)carbon nanofibers to improve the electrochemical performance of supercapacitor using aqueous electrolytes  

作　　者：Bhavana Joshi Seongdong Kim Edmund Samuel Jungwoo Huh Mohammed S.Almoiqli Khalid N.Alharbi Sam S.Yoon 

机构地区：[1]School of Mechanical Engineering,Korea University,Seoul 02841,Republic of Korea [2]Energy Environment Policy and Technology,Graduate School of Energy and Environment(KU-KIST Green School),Korea University,Seoul 02841,Republic of Korea [3]Desalination Technologies Institute,King Abdulaziz City for Science and Technology(KACST),Riyadh 11442,Kingdom of Saudi Arabia [4]Nuclear Technologies Institute(NTI),King Abdulaziz City for Science and Technology(KACST),Riyadh 11442,Kingdom of Saudi Arabia

出　　处：《Journal of Materials Science & Technology》2024年第33期83-92,共10页材料科学技术(英文版)

基　　金：supported by the National Research Foundation of Korea(NRF)Grant funded by the Korea govern-ment(Nos.NRF-2020R1A5A1018153 and 2022M3J1A106422611);supported by King Abdulaziz City for Science and Technology(KACST).

摘　　要：Supercapacitors(SCs)play a crucial role in flexible electronics,necessitating innovative approaches to enhance surface faradaic reactions and minimize faradaic diffusion while using aqueous electrolytes.Thus,the urea treatment of cobalt oxide(CoO_(x))-decorated carbon nanofibers(CNFs)is proposed in this study to decrease the contribution of faradaic diffusion-limited current.Flexible CoO_(x)/CNF electrodes were obtained by annealing ZIF-67-grafted polyacrylonitrile(PAN)fibers via a wet chemical method.The urea treatment of CoO_(x)/CNFs increased the content of sp2-hybridized carbon and pyridinic nitrogen,as confirmed by X-ray photoelectron spectroscopy,effectively enhancing conductivity and pseudocapacitive charge storage capability via nitrogen doping.Notably,urea-treated CoO_(x)/CNF electrode samples exhibited a capacitance of 750 mF cm^(−2)at a scan rate of 10 mV s^(−1),while retaining more than 81%capacitance at a higher scan rate of 100 mV s-1.The cyclic voltammetry curves during variable bending angle testing(0°,45°,and 90°)exhibited negligible changes,indicating the excellent flexibility of the SCs.The CoO_(x)/CNFs and urea-treated CoO_(x)/CNFs exhibited 80%and 91%capacitance retentions,respectively,after 10,000 galvanostatic charge and discharge cycles.Furthermore,the attained energy densities of 76 and 61μWh cm^(−2)at the respective power densities of 2 and 20 mW cm^(−2)indicated the excellent electrochemical performance of the optimal urea-treated CoO_(x)/CNF electrode.

关 键 词：ELECTROSPINNING ZIF-67 Carbon nanofiber Freestanding electrode Flexible supercapacitor UREA 

分 类 号：TB3[一般工业技术—材料科学与工程]