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Design and synthesis of NiCo2O4/NiCoO2/graphene hybrid nanoarrays with enhanced capacitive performance
- Source :
- Ceramics International. 46:20191-20200
- Publication Year :
- 2020
- Publisher :
- Elsevier BV, 2020.
-
Abstract
- NiCo2O4/NiCoO2/graphene hybrid nanoarrays on Ni foam have been designed and synthesized through a hydrothermal method and post-annealing treatment. Highly conductive graphene sheets were embedded into or coated onto the NiCo2O4/NiCoO2 arrays, which strongly affect influence the morphology and electrochemical performance of hybrid nanoarrays. Under the effect of graphene, the architecture of the NiCo2O4/NiCoO2 consists of cluster-like arrays that are self-assembled from numerous nanoneedles and provides more electroactive sites for the redox reaction. However, without the assistance of graphene, the pure NiCo2O4/NiCoO2 exhibits the morphology of flake-like arrays on the Ni foam. The NiCo2O4/NiCoO2/graphene arrays show an ultrahigh capacity of 1439 C g-1 at a current density of 1 mA cm-2, which is far larger than that of the pure NiCo2O4/NiCoO2 flake-arrays (695 C g-1). Furthermore, even at a high current density of 60 mA cm-2, the NiCo2O4/NiCoO2/graphene arrays maintain a high gravimetric capacity of 1172 C g-1 (capacity retention: 81.4%), which indicates an excellent rate capability. Further, the hybrid capacitor shows a maximum energy density of 34.3 Wh kg-1. The present study suggests that the NiCo2O4/NiCoO2/graphene hybrid arrays have great application potential as a positive electrode for hybrid supercapacitors.
- Subjects :
- 010302 applied physics
Supercapacitor
Materials science
Graphene
Process Chemistry and Technology
Capacitive sensing
Nanotechnology
02 engineering and technology
021001 nanoscience & nanotechnology
Electrochemistry
01 natural sciences
Surfaces, Coatings and Films
Electronic, Optical and Magnetic Materials
law.invention
Capacitor
law
0103 physical sciences
Electrode
Materials Chemistry
Ceramics and Composites
0210 nano-technology
Current density
Electrical conductor
Subjects
Details
- ISSN :
- 02728842
- Volume :
- 46
- Database :
- OpenAIRE
- Journal :
- Ceramics International
- Accession number :
- edsair.doi...........1567aa86014a876b59bf42ebaae48211