Nanosheet-assembled 3D flower-like MoS2/NiCo(OH)2CO3 composite for enhanced supercapacitor performance

Abstract 3D flower-like MoS2/NiCo(OH)2CO3 (MoS2/NiCoHC) composites are synthesized by a hydrothermal method using MoS2 nanospheres as precursors. The microstructure of the composite is characterized by X-ray diffraction, Raman spectroscopy, scanning electron microscopy, transmission electron microscopy and X-ray photoelectron spectroscopy. The MoS2 nanospheres are served as nucleating agent to trigger the formation of NiCoHC nanosheets, which self-assemble into 3D flower-like MoS2/NiCoHC particles. The MoS2/NiCoHC composites exhibit a high supercapacitive performance with a specific capacity of 583 C g-1 (1296 F g-1) at 1 A g -1 and a long-term cycling stability by retaining 94.3% after 2000 cycles in 2 M KOH. Moreover, the asymmetric supercapacitor of MoS2/NiCoHC as the positive electrode and commercial active carbon as the negative electrode achieves a high power density of 375 W·kg-1 at 16.4 Wh·kg-1. The enhanced performance of the MoS2/NiCoHC composite can be attributed to the larger surface area provided by 3D flower-like structure and the synergy of the two hybrids.