Synthesis of hierarchical porous CoS2/MWCNTs nanohybrids as electrode for high-performance supercapacitors with enhanced rate capability and cycling stability

Here we report a facile one-step hydrothermal synthesis of cobalt sulfide-modified multi-walled carbon nanotubes (CoS2/MWCNTs) nanohybrids as electrode materials for application in supercapacitor. Benefiting from the stable network structure constructed by the synergistic effect of MWCNTs and cobalt sulfide materials, the volume change caused by ion intercalation/de-intercalation during the charging/discharging process is buffered, thus reducing the influence on the electrochemical performance, which greatly enhances the rate capability and cycling stability of the nanohybrids electrode. Through the synergistic enhancement effect of cobalt sulfide and MWCNT electrode materials, the electrochemical energy storage performance of the nanohybrids is greatly improved. The optimal CoS2/MWCNT-30 electrode exhibits a high specific capacitance of 632.5 F g−1, excellent rate capability of 81.5% (0.3–10 A g−1), and outstanding cycling stability with about 95.3% retention after 5000 cycles. These results indicate that the CoS2/MWCNT-30 nanohybrid electrode synthesized by a facile and cost-effective synthesis pathway has excellent electrochemical energy storage performance and has a great prospect as an electrode material for the application of high-performance supercapacitors.