Co9S8 quasi-hexagonal nanoparticles coupled with WS2 nanoring anchored on 3D sulfur, nitrogen Co-doped carbon nanotubes@graphene oxide cross-linking architecture for high performance asymmetric supercapacitor

Designing advanced hybrid supercapacitors (SCs) electrode materials with 3D cross-linking hierarchical porous architecture has desirable structural advantages, which can facilitate ion transport and provide excellent reaction site. Herein, a unique nanostructure consisting of Co9S8 quasi-hexagonal nanoparticles coupled with WS2 nanoring anchored on 3D sulfur, nitrogen Co-doped carbon nanotubes@graphene oxide (Co9S8@WS2-NS-15mlGO@CNTs) was obtained using a facile solvothermal strategy. This crosslinking and hierarchical porous nanostructure can maximize the electrical conductivity of entirety, which provides a favorable transport and permeability for the ions and electrons of the electrolyte environment. Benefiting from the structural compositional advantages and full play of the synergetic coupling effect, the as-prepared Co9S8@WS2-NS-15mlGO@CNTs electrode material exhibits absolutely the topmost specific capacitance of 1820.8 F g(-1) at a current density of 1 A g(-1) and outstanding cycle stability with a capacitance retention of 90.2% after 10000 cycles at 30 A g(-1). Moreover, an asymmetric supercapacitor (ASC) fabricated by Co9S8@WS2-NS-15mlGO@CNTs (positive electrode) and NS-15mlGO@CNTs (negative electrode) presents an ultra-high energy density of 95.3 Wh kg(-1) at a power density of 600 W kg(-1), and long cycle life with 86.7% specific capacity retention at a current density of 20 A g(-1) after 10000 cycles. It is believed that the presented work may open a new perspective to fabricate future competitive high-performance energy storage devices. (C) 2021 Elsevier Ltd. All rights reserved.