Intercalation pseudocapacitance of expanded graphite in sodium‐ion capacitors. (1st May 2018)

• Record Type: Journal Article
• Authors: Zhang, Zhendong; Zhao, Jiachang; Guo, Chaofei; Xu, Jingli
• Is Part Of: Micro & nano letters. Volume 13:Number 5(2018)
• Page Start: 669
• Page End: 672
• Publication Date: 2018-05-01
• Subjects: graphite intercalation compounds -- supercapacitors -- oxidation -- reduction (chemical) -- X‐ray diffraction -- transmission electron microscopy -- voltammetry (chemical analysis) -- electrochemical impedance spectroscopy -- electrochemical electrodes -- capacitance -- current density; intercalation pseudocapacitance -- expanded graphite -- sodium‐ion capacitors -- oxidation -- partial reduction -- X‐ray diffraction -- XRD -- high‐resolution transmission electron microscopy -- HRTEM -- cyclic voltammetry -- galvanostatic charge‐discharge method -- electrochemical impedance spectroscopy -- interlayer distance -- electrode -- specific capacitance -- current density -- cycle stability -- supercapacitors -- C; Nanotechnology -- Periodicals; Nanostructures -- Periodicals; Microtechnology -- Periodicals; 620.5
• DOI: 10.1049/mnl.2017.0714
• Languages: English
• ISSNs: 1750-0443

Abstract

Abstract : The intercalation pseudocapacitance of expanded graphite (EG) which was prepared by a process of oxidation and partial reduction on pristine graphite was investigated in this work. The structure of EG was characterised by X‐ray diffraction (XRD) and high‐resolution transmission electron microscope (HRTEM), and the electrochemical performance of EG was measured by cyclic voltammetry, galvanostatic charge–discharge and electrochemical impedance spectroscopy. The interlayer distance of EG is enlarged from 0.34 to 0.40 nm, which is demonstrated by XRD and HRTEM. EG electrode exhibits a specific capacitance of 228 F/g at current density of 0.5 A/g. Moreover, the material shows excellent cycle stability after 2000 charge–discharge cycles at a current density of 1 A/g. EG could be a very promising material for the supercapacitors industry.