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Multi-porous Co3O4 nanoflakes @ sponge-like few-layer partially reduced graphene oxide hybrids: towards highly stable asymmetric supercapacitors
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Multi-porous Co3O4 nanoflakes @ sponge-like few-layer partially reduced graphene oxide hybrids: towards highly stable asymmetric supercapacitors

Qorbani, M

Multi-porous Co3O4 nanoflakes @ sponge-like few-layer partially reduced graphene oxide hybrids: towards highly stable asymmetric supercapacitors

Qorbani, M ; Sharif University of Technology

399 Viewed
  1. Type of Document: Article
  2. DOI: 10.1039/c7ta00694b
  3. Abstract:
  4. The controlled growth of metal oxide nanostructures within hierarchically porous conductive carbon-based frameworks is critically important to achieving high volumetric performance and appropriate channel size for energy storage applications. Herein, we grow cobalt oxide (Co3O4) nanoflakes, using a sequential-electrodeposition process, into spherically porous sponge-like few-layer partially reduced graphene oxide (SrGO) synthesized by template-directed ordered assembly. Maximum specific/volumetric capacitances of 1112 F gCo3O4-1 (at 3.3 A gCo3O4-1), 178 F cm-3 (at 2.6 A cm-2), and 406 F gtotal-1 (at 1 A gtotal-1) and sensible rate capability (80% retention by increasing the charge/discharge current from 1 A g-1 to 16 A g-1) are obtained for the Co3O4 nanoflakes@SrGO hybrid electrodes. Besides, an asymmetric supercapacitor is made with the Co3O4[63%]@SrGO[37%] hybrid and activated carbon as a positive and a negative electrode, respectively. Electrochemical results indicate an energy density of 23.3 W h kg-1 at a high power density of 2300 W kg-1 (discharge time of about 42 s) and 62% retention even at a remarkable power density of 36 600 W kg-1 (discharge time of 1.6 s). Moreover, it shows excellent cycling stability with no decay after 20 000 charge/discharge cycles. This performance is attributed to the unique pore-sizes for an ion to channel into the porous structures, conductivity, and mechanical stability of the SrGO framework, which makes it promising for next-generation supercapacitors. © 2017 The Royal Society of Chemistry
  5. Keywords:
  6. Activated carbon ; Electric discharges ; Electrodes ; Mechanical stability ; Metals ; Supercapacitor ; Asymmetric supercapacitor ; Charge/discharge cycle ; Electrodeposition process ; Energy storage applications ; Hierarchically porous ; High power density ; Negative electrode ; Reduced graphene oxides ; Graphene
  7. Source: Journal of Materials Chemistry A ; Volume 5, Issue 24 , 2017 , Pages 12569-12577 ; 20507488 (ISSN)
  8. URL: https://pubs.rsc.org/en/content/articlelanding/2017/ta/c7ta00694b#!divAbstract