Role of Defects on the Particle Size-Capacitance Relationship of Zn-Co Mixed Metal Oxide Supported on Heteroatom-Doped Graphenes as Supercapacitors.
Adv Sci (Weinh)
; 9(34): e2204316, 2022 Dec.
Article
em En
| MEDLINE
| ID: mdl-36257897
ABSTRACT
Supercapacitors are considered among the most promising electrical energy storage devices, there being a need to achieve the highest possible energy storage density. Herein small mixed Zn-Co metal oxide nanoparticles are grown on doped graphene (O-, N- and, B-doped graphenes). The electrochemical properties of the resulting mixed Zn-Co metal oxide nanoparticles (4 nm) grown on B-doped graphene exhibit an outstanding specific capacitance of 2568 F g-1 at 2 A g-1 , ranking this B-doped graphene composite among the best performing electrodes. The energy storage capacity is also remarkable even at large current densities (i.e., 640 F g-1 at 40 A g-1 ). In contrast, larger nanoparticles are obtained using N- and O-doped graphenes as support, the resulting materials exhibiting lower performance. Besides energy storage, the Zn-Co oxide on B-doped graphene shows notable electrochemical performance and stability obtaining a maximum energy density of 77.6 W h Kg-1 at 850 W Kg-1 , a power density of 8500 W Kg-1 at 28.3 W h Kg-1 , and a capacitance retention higher than 85% after 5000 cycles. The smaller nanoparticle size and improved electrochemical performance on B-doped graphene-based devices are attributed to the higher defect density and nature of the dopant element on graphene.
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1
Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
Adv Sci (Weinh)
Ano de publicação:
2022
Tipo de documento:
Article
País de afiliação:
Espanha