Metal-organic frameworks derived hierarchical CoSx@Ni-Co-O nanosheet structures for supercapacitors with excellent charge storage properties

摘要

The composite of multiple metal materials is an effective means of improving the electrochemical performance of supercapacitors, however the synergistic effect of composites is currently facing challenges. In this work, the metal-organic framework was constructed by a simple solvent method to synthesize the Co-MOF and the CoSx material was derived by sulfidation. Subsequently, Ni-Co-O nanosheets were deposited on the above structures by electrodeposition. The Ni-Co-O nanosheets were grown on the CoSx surface to build cross-linked structures, while maintaining the structural stability, the conductivity and reaction site of the material are improved, and the ion transport is accelerated. The synergistic effect of both materials CoSx and Ni-Co-O effectively improves the specific capacity of the material (899 C g(-1) at 1 A g(-1)). In addition, the assembled asymmetric supercapacitors show a high energy density 42.43 kW kg(-1) at a power density of 0.725 kW h kg(-1) as well as an excellent cycle stability (83.73% capacity retention after 3000 cycles). (C) 2021 Published by Elsevier B.V.