Journal of Alloys and Compounds2022，Vol.8939.DOI:10.1016/j.jallcom.2021.162368

Coordination-induced activation of reversible Co(II)/Co(III) redox reaction in carbon nanodots/cobalt hexacyanoferrate composites with enhanced electrochemical performance

Song, Zhaoxia Liu, Wei Du, Jiaqi Chen, Junlin Wei, Xiaofei Hua, Ruinian Zhao, Zhongfu Zhou, Quan
Journal of Alloys and Compounds2022，Vol.8939.DOI:10.1016/j.jallcom.2021.162368
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  • NSTL
  • Elsevier

Coordination-induced activation of reversible Co(II)/Co(III) redox reaction in carbon nanodots/cobalt hexacyanoferrate composites with enhanced electrochemical performance

Song, Zhaoxia 1Liu, Wei 2Du, Jiaqi 2Chen, Junlin 2Wei, Xiaofei 1Hua, Ruinian 1Zhao, Zhongfu 2Zhou, Quan1
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作者信息

  • 1. Dalian Minzu Univ
  • 2. Dalian Univ Technol
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Abstract

Cobalt hexacyanoferrate (CoHCF) as a promising cathode material of asymmetrical supercapacitors gen-erally undergoes a single redox reaction of Fe(II)/Fe(III) couple to store energy in neutral aqueous elec-trolytes. Its framework Co ions are electrochemically inactivated, leading to a limited electrochemical capacity. Herein, we develop a strategy to activate the reversible Co(II)/Co(III) redox reaction through tuning the microenvironment of Co ions. A carbon nanodots/CoHCF (C-dots/CoHCF) hybrid nanostructure has been successfully fabricated via a simple co-precipitation reaction of Co2+ and [Fe(CN)(6)](3-) ions in the presence of carboxylate-rich C-dots. Impressively, electrochemical results and X-Ray photoelectron spectroscopy (XPS) reveal the charge storage of C-dots/CoHCFs due to two-specie (Fe and Co) redox reactions, which render an enhanced electrochemical capacity. It is considered that the activation of reversible Co(II)/Co(III) redox reaction is due to the strong coordination interaction between the terminated framework Co ions and carboxylate groups of C-dots. In addition, this nanostructure offers increased active sites and promotes electron conductivity, thereby achieving a remarkable high specific capacitance (394 F g(-1) at 1 A g(-1)) and excellent rate performance. The C-dots/CoHCF cathode is paired with an activated carbon anode to assemble an aqueous asymmetrical supercapacitor, which can deliver a high energy density of 48.6 Wh kg(-1) (488 W kg(-1)) and retain 88.3% of its initial capacitance over 5000 charge/discharge cycles. (C) 2021 Elsevier B.V. All rights reserved.

Key words

Carbon dots/Cobalt hexacyanoferrate/Asymmetrical supercapacitor/Cathode/NICKEL-COBALT HEXACYANOFERRATE/COATED STAINLESS-STEEL/PRUSSIAN BLUE/SUPERIOR PERFORMANCE/ELECTRODE MATERIALS/FACILE SYNTHESIS/SUPERCAPACITORS/DOTS/NANOCOMPOSITES/COPPER

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出版年

2022
Journal of Alloys and Compounds

Journal of Alloys and Compounds

EISCI
ISSN：0925-8388
被引量12
参考文献量74
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