Hierarchical NiS@CoS with Controllable Core‐Shell Structure by Two‐Step Strategy for Supercapacitor Electrodes

Abstract

Constructing hierarchical core‐shell configuration from well‐known metal sulfides is one way to further tune and utilize unique species. Herein, a novel core‐shell structure is developed based on CoS deposited on NiS nanosheets, which involves hydrothermal and electrodeposition method. The micromorphology of the composite electrode can be optimized by adjusting the cycles of electrodeposition. Taking advantages of the highly conductive, open framework of the core‐shell nanolayer, the 5‐NiS@CoS electrode shows a specific capacitance of 1210 F g−1 at a current density of 1 A g−1 (retaining 82% from 1 to 10 A g−1, while NiS substrate is only 39%). The specific capacitance retention rate is 80.94% at 10 A g−1 after 2000 cycles (NiS substrate is 59.6%). Moreover, NiS@CoS//AC asymmetric supercapacitor device delivers an energy density of 24.1 Wh kg−1 at a power density of 752.15 W kg−1 and remarkable stability (over 80% retention after 5000 cycles). This work may prompt the exploration of the synthesis of inexpensive compounds incorporating highly reactive components for supercapacitors.

Nickel hydroxide/sulfide hybrids: halide ion controlled synthesis, structural characteristics, and electrochemical performance

“…2a), also confirmed by TEM technology. 34–37 As observed in Fig. S(2 and 3),† the crystal planes representing Ni 3 S 4 , NiS 2 , α-NiS and β-NiS are found in HRTEM images of S1, S2 and S3.…”

Interface Engineering of CoS/CoO@N-Doped Graphene Nanocomposite for High-Performance Rechargeable Zn–Air Batteries

“…3 b comprises two prominent peaks located at 781.1 and 797.1 eV, corresponding to the 2p 3/2 and 2p 1/2 , respectively [ 35 ]. Two satellite peaks of Co are located at 786.5 and 803.2 eV [ 45 ]. In comparison with CoS@NGNs, the Co 2P spectrum of CoS/CoO@NGNs exhibits a positive shift in binding energy, suggesting the electronic coupling and charge transfer between CoS and CoO, in accordance with the DFT prediction.…”

Interconnected network‐like single crystalline bimetallic carbonate hydroxide nanowires for high performance hybrid supercapacitors

“…The obtained results are higher or even comparable than those of the previous reports (Table S1). 23,25,29,35,[39][40][41][42][43][44][45][46][47][48][49]…”