One-step synthesis of hollow C-NiCoS nanostructures for high-performance supercapacitor electrodes

• Published in: Nanoscale 2018-04, Vol.1 (14), p.662-6628
• Main Authors: Mohamed, Saad Gomaa, Hussain, Iftikhar, Shim, Jae-Jin
• Format: Article
• ISSN: 2040-3364; 2040-3372
• DOI: 10.1039/c7nr07338k

Carbon-containing NiCo 2 S 4 hollow-nanoflake structures were fabricated by a one-step solvothermal method using CS 2 as a single source for sulfidation and carbonization. The reaction mechanism for the hollow structure with carbon residues was explored based on the formation of a bis(dithiocarbamate)-metal complex and the Kirkendall effect during solvothermal synthesis. The NiCo 2 S 4 nanoflake electrode exhibited a high specific capacitance of 1722 F g −1 (specific capacity 688.8 C g −1 ) at a current density of 1 A g −1 and an excellent cycling stability (capacity retention of 98.8% after 10 000 cycles). The as-fabricated asymmetric supercapacitor based on NiCo 2 S 4 nanoflakes and activated carbon electrodes revealed a high energy density of 38.3 W h kg −1 and a high power density of 8.0 kW kg −1 with a capacitance retention of 91.5% and a coulombic efficiency of 95.6% after 5000 cycles, highlighting its great potential for practical supercapacitor applications. A highly conductive mesoporous hollow-nanostructured C-NiCo 2 S 4 synthesized by a one-step procedure exhibited a remarkable electrochemical activity and stability for supercapacitor applications.