• 文献标题:   Electroactive edge site-enriched nickel-cobalt sulfide into graphene frameworks for high-performance asymmetric supercapacitors
  • 文献类型:   Article
  • 作  者:   YANG J, YU C, FAN XM, LIANG SX, LI SF, HUANG HW, LING Z, HAO C, QIU JS
  • 作者关键词:  
  • 出版物名称:   ENERGY ENVIRONMENTAL SCIENCE
  • ISSN:   1754-5692 EI 1754-5706
  • 通讯作者地址:   Dalian Univ Technol
  • 被引频次:   317
  • DOI:   10.1039/c5ee03633j
  • 出版年:   2016

▎ 摘  要

Tailor-made edge site-enriched inorganics coupled graphene hybrids hold a promising platform material for high-performance supercapacitors. Herein, we report a simple strategy for fabricating edge site-enriched nickel-cobalt sulfide (Ni-Co-S) nanoparticles decorated on graphene frameworks to form integrated hybrid architectures (Ni-Co-S/G) via an in situ chemically converted method. The Kirkendall effect-involved anion exchange reaction, e.g. the etching-like effort of the S-2 ions, plays a crucial role for the formation of the edge site-enriched nanostructure. Density functional theory (DFT) calculations reveal that the Ni-Co-S edge sites have a high electrochemical activity and strong affinity for OH- in the electrolyte, which are responsible for the enhanced electrochemical performance. Benefiting from the integrated structures of Ni-Co-S nanoparticles and conductive graphene substrates, the resultant Ni-Co-S/G hybrid electrodes exhibit a high specific capacitance of 1492 F g(-1) at the current density of 1 A g(-1), a superior rate capability of 96% when the current density is increased to 50 A g(-1), and excellent electrochemical stabilities. An asymmetric supercapacitor fabricated using the edge site-enriched Ni-Co-S/G hybrids as the positive electrode and porous carbon nanosheets (PCNS) as negative electrodes shows a high energy density of 43.3 W h kg(-1) at a power density of 0.8 kW kg(-1), and an energy density of 28.4 W h kg(-1) can be retained even at a high power density of 22.1 kW kg(-1).