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Facile Synthesis of Hematite Quantum-Dot/Functionalized Graphene-Sheet Composites as Advanced Anode Materials for Asymmetric Supercapacitors.
- Source :
- Advanced Functional Materials; Jan2015, Vol. 25 Issue 4, p627-635, 9p
- Publication Year :
- 2015
-
Abstract
- For building high-energy density asymmetric supercapacitors, developing anode materials with large specific capacitance remains a great challenge. Although Fe<subscript>2</subscript>O<subscript>3</subscript> has been considered as a promising anode material for asymmetric supercapacitors, the specific capacitance of the Fe<subscript>2</subscript>O<subscript>3</subscript>-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<subscript>2</subscript>O<subscript>3</subscript> quantum dots (QDs, ≈2 nm) decorated on functionalized graphene-sheets (FGS) is prepared by a facile and scalable method. The Fe<subscript>2</subscript>O<subscript>3</subscript> QDs/FGS composites exhibit a large specific capacitance up to 347 F g<superscript>−1</superscript> in 1 m Na<subscript>2</subscript>SO<subscript>4</subscript> between -1 and 0 V versus Ag/AgCl. An asymmetric supercapacitor operating at 2 V is fabricated using Fe<subscript>2</subscript>O<subscript>3</subscript>/FGS as anode and MnO<subscript>2</subscript>/FGS as cathode in 1 m Na<subscript>2</subscript>SO<subscript>4</subscript> aqueous electrolyte. The Fe<subscript>2</subscript>O<subscript>3</subscript>/FGS//MnO<subscript>2</subscript>/FGS asymmetric supercapacitor shows a high energy density of 50.7 Wh kg<superscript>−1</superscript> at a power density of 100 W kg<superscript>−1</superscript> as well as excellent cycling stability and power capability. The facile synthesis method and superior supercapacitive performance of the Fe<subscript>2</subscript>O<subscript>3</subscript> QDs/FGS composites make them promising as anode materials for high-performance asymmetric supercapacitors. [ABSTRACT FROM AUTHOR]
- Subjects :
- HEMATITE
QUANTUM dot synthesis
GRAPHENE
ANODES
SUPERCAPACITORS
FERRIC oxide
Subjects
Details
- Language :
- English
- ISSN :
- 1616301X
- Volume :
- 25
- Issue :
- 4
- Database :
- Complementary Index
- Journal :
- Advanced Functional Materials
- Publication Type :
- Academic Journal
- Accession number :
- 100550838
- Full Text :
- https://doi.org/10.1002/adfm.201403554