Facile Synthesis of Hematite Quantum‐Dot/Functionalized Graphene‐Sheet Composites as Advanced Anode Materials for Asymmetric Supercapacitors. (12th December 2014)

• Record Type: Journal Article
• Authors: Xia, Hui; Hong, Caiyun; Li, Bo; Zhao, Bin; Lin, Zixia; Zheng, Mingbo; Savilov, Serguei V.; Aldoshin, Serguei M.
• Is Part Of: Advanced functional materials. Volume 25:Number 4(2014)
• Page Start: 627
• Page End: 635
• Publication Date: 2014-12-12
• Subjects: Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.201403554
• Languages: English
• ISSNs: 1616-301X

Abstract

<abstract abstract-type="main" xml:lang="en"> <title> <x xml:space="preserve">Abstract</x> </title> <p>For building high‐energy density asymmetric supercapacitors, developing anode materials with large specific capacitance remains a great challenge. Although Fe<sub>2</sub>O<sub>3</sub> has been considered as a promising anode material for asymmetric supercapacitors, the specific capacitance of the Fe<sub>2</sub>O<sub>3</sub>‐based anodes is still low and cannot match that of cathodes in the full cells. In this work, a composite material with well dispersed Fe<sub>2</sub>O<sub>3</sub> quantum dots (QDs, ≈2 nm) decorated on functionalized graphene‐sheets (FGS) is prepared by a facile and scalable method. The Fe<sub>2</sub>O<sub>3</sub> QDs/FGS composites exhibit a large specific capacitance up to 347 F g<sup>−1</sup> in 1 <sc>m</sc> Na<sub>2</sub>SO<sub>4</sub> between –1 and 0 V versus Ag/AgCl. An asymmetric supercapacitor operating at 2 V is fabricated using Fe<sub>2</sub>O<sub>3</sub>/FGS as anode and MnO<sub>2</sub>/FGS as cathode in 1 <sc>m</sc> Na<sub>2</sub>SO<sub>4</sub> aqueous electrolyte. The Fe<sub>2</sub>O<sub>3</sub>/FGS//MnO<sub>2</sub>/FGS asymmetric supercapacitor shows a high energy density of 50.7 Wh kg<sup>−1</sup> at a power density of 100 W kg<sup>−1</sup> as well as excellent cycling stability and power capability. The facile synthesis method and superior supercapacitive performance of the Fe<sub>2</sub>O<sub>3</sub> QDs/FGS composites make them promising as anode materials for high‐performance asymmetric supercapacitors.</p> </abstract>