Back to Search
Start Over
Heterostructural Graphene Quantum Dot/MnO 2 Nanosheets toward High-Potential Window Electrodes for High-Performance Supercapacitors.
- Source :
-
Advanced science (Weinheim, Baden-Wurttemberg, Germany) [Adv Sci (Weinh)] 2018 Mar 06; Vol. 5 (5), pp. 1700887. Date of Electronic Publication: 2018 Mar 06 (Print Publication: 2018). - Publication Year :
- 2018
-
Abstract
- The potential window of aqueous supercapacitors is limited by the theoretical value (≈1.23 V) and is usually lower than ≈1 V, which hinders further improvements for energy density. Here, a simple and scalable method is developed to fabricate unique graphene quantum dot (GQD)/MnO <subscript>2</subscript> heterostructural electrodes to extend the potential window to 0-1.3 V for high-performance aqueous supercapacitor. The GQD/MnO <subscript>2</subscript> heterostructural electrode is fabricated by GQDs in situ formed on the surface of MnO <subscript>2</subscript> nanosheet arrays with good interface bonding by the formation of Mn-O-C bonds. Further, it is interesting to find that the potential window can be extended to 1.3 V by a potential drop in the built-in electric field of the GQD/MnO <subscript>2</subscript> heterostructural region. Additionally, the specific capacitance up to 1170 F g <superscript>-1</superscript> at a scan rate of 5 mV s <superscript>-1</superscript> (1094 F g <superscript>-1</superscript> at 0-1 V) and cycle performance (92.7%@10 000 cycles) between 0 and 1.3 V are observed. A 2.3 V aqueous GQD/MnO <subscript>2</subscript> -3//nitrogen-doped graphene ASC is assembled, which exhibits the high energy density of 118 Wh kg <superscript>-1</superscript> at the power density of 923 W kg <superscript>-1</superscript> . This work opens new opportunities for developing high-voltage aqueous supercapacitors using in situ formed heterostructures to further increase energy density.
Details
- Language :
- English
- ISSN :
- 2198-3844
- Volume :
- 5
- Issue :
- 5
- Database :
- MEDLINE
- Journal :
- Advanced science (Weinheim, Baden-Wurttemberg, Germany)
- Publication Type :
- Academic Journal
- Accession number :
- 29876214
- Full Text :
- https://doi.org/10.1002/advs.201700887