Jump to main content
Jump to site search

Issue 33, 2019
Previous Article Next Article

Partially delocalized charge in Fe-doped NiCo2S4 nanosheet–mesoporous carbon-composites for high-voltage supercapacitors

Author affiliations

Abstract

Unraveling the effect of transition-metal doping on the energy storage properties of bimetallic sulfides remains a grand challenge. Herein, we construct bimetallic sulfide nanosheets and hence deliberately introduce transition-metal doping domains on their surface. The resulting materials show not only an enhanced density of states near the Fermi level but also partially delocalized charge as shown by density functional theory (DFT) calculations. Fe-doped NiCo2S4 nanosheets wrapped on N,S-doped ordered mesoporous carbon (Fe-NiCo2S4@N,S-CMK-3) are prepared, which show an enhanced specific capacitance of 197.8 F g−1 in ionic liquid-based supercapacitors at a scan rate of 2 mV s−1. This is significantly higher as compared to the capacitance of 155.2 and 135.9 F g−1 of non-iron-doped NiCo2S4@N,S-CMK and Fe-NiCo2S4@CMK-3 electrodes, respectively. This result arises from the enhanced ionic liquid polarization effect and transportation ability from the Fe-NiCo2S4 surface and N,S-CMK-3 structure. Furthermore, the importance of matching multi-dimensional structures and ionic liquid ion sizes in the fabrication of asymmetric supercapacitors (ASCs) is demonstrated. As a result, the ASC device exhibits a high energy density of 107.5 W h kg−1 at a power density of 100 W kg−1 in a working-voltage window of 4 V when using Fe-NiCo2S4@N,S-CMK-3 and N,S-CMK-3 as positive and negative electrodes, respectively. This work puts forward a new direction to design supercapacitor composite electrodes for efficient ionic liquid coupling.

Graphical abstract: Partially delocalized charge in Fe-doped NiCo2S4 nanosheet–mesoporous carbon-composites for high-voltage supercapacitors

Back to tab navigation

Supplementary files

Publication details

The article was received on 11 Jun 2019, accepted on 24 Jul 2019 and first published on 29 Jul 2019


Article type: Paper
DOI: 10.1039/C9TA06250E
J. Mater. Chem. A, 2019,7, 19342-19347
  • Open access: Creative Commons BY license
  •   Request permissions

    Partially delocalized charge in Fe-doped NiCo2S4 nanosheet–mesoporous carbon-composites for high-voltage supercapacitors

    F. Lai, J. Feng, T. Heil, Z. Tian, J. Schmidt, G. Wang and M. Oschatz, J. Mater. Chem. A, 2019, 7, 19342
    DOI: 10.1039/C9TA06250E

    This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. Material from this article can be used in other publications provided that the correct acknowledgement is given with the reproduced material.

    Reproduced material should be attributed as follows:

    • For reproduction of material from NJC:
      [Original citation] - Published by The Royal Society of Chemistry (RSC) on behalf of the Centre National de la Recherche Scientifique (CNRS) and the RSC.
    • For reproduction of material from PCCP:
      [Original citation] - Published by the PCCP Owner Societies.
    • For reproduction of material from PPS:
      [Original citation] - Published by The Royal Society of Chemistry (RSC) on behalf of the European Society for Photobiology, the European Photochemistry Association, and RSC.
    • For reproduction of material from all other RSC journals:
      [Original citation] - Published by The Royal Society of Chemistry.

    Information about reproducing material from RSC articles with different licences is available on our Permission Requests page.

Search articles by author

Spotlight

Advertisements