While metal sulfides have extensively investigated as electrode materials for supercapacitors, the further optimization of their material system is still necessary to achieve satisfied performance. In this work, we reported the synthesis of ternary metal sulfide SnNiCoS and its application as electrode material of asymmetric supercapacitors, in which active carbon is used as the other electrode. For control experiments, asymmetric supercapacitors based on single metal sulfide CoS and binary metal sulfide NiCoS are also fabricated and investigated. The results show that the nanospherical SnNiCoS achieves the best performance. Ternary sulphide materials offer more redox than corresponding single-metal sulphides due to the synergy among various transition metal elements. The specific capacitance is 18.6 F cm-2 at current density of 5 mA·cm-2. An energy density of 937.2 μWh cm-2 is achieved at a power density of 4000 μW·cm-2. After 8000 cycles, the capacity retention rate is 82.9%. Present work indicates that SnNiCoS ternary metal sulfide could be a promising composite for high performance supercapacitors.

While supercapacitors have been widely studied as the next generation of energy storage devices, to develop active electrode materials for enhancing device performance is still challenging. Herein, we fabricated asymmetric supercapacitors based on NiZn-Layered double hydroxide (LDH) @NiCoSe2 hierarchical nanostructures as electrode materials. The NiZn-LDH@NiCoSe2 composites are deposited on Ni foam by a two-step strategy, in which NiZn-LDH nanosheets were firstly grown on Ni foam by hydrothermal method, and then NiCoSe2 particles were prepared by electrodeposition. Due to the synergistic effect between NiZn-LDH and NiCoSe2, excellent device performance was achieved. In a three-electrode system, the NiZn-LDH@NiCoSe2 exhibits a specific capacitance of 2980 F g-1 at 1 A g-1. Furthermore, the asymmetric supercapacitor of NiZn-LDH@NiCoSe2//activated carbon (AC) device was assembled, which exhibits the energy density of 49.2 Wh kg−1 at the power density of 160 W kg−1, with the capacity retention rate is 91% after 8000 cycles. The results indicates that NiZn-LDH@NiCoSe2 is a promising candidate as electrode materials for efficient energy storage devices.

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Metal-based sulfides are favored by researchers because of their high theoretical capacity, but their inherent volume expansion problems limit their further applications. To address the above issues, we prepared ZnS-Sb@C@rGO core–shell nanosphere anode materials for high-performance sodium-ion batteries (SIBs). The ZnS-Sb heteromeric core with synergistic effects was designed to facilitate rapid electrolyte penetration and accelerate Na+ transformation kinetics. Meanwhile, the double coating of the outer carbon shell and rGO layer provides rich sodium embedding sites and improves the conductivity and charge transfer capability of the composite. Its unique layered heterogeneous structure design provides a lot of buffer space and effectively prevents the shedding of active substances. The composite has excellent electrochemical properties in sodium-ion batteries, with a high initial discharge specific capacity of 1117.1 mAh g–1 at 0.1 A g–1. The battery achieves a long cycle life, and the discharge specific capacity is 210.3 mAh g–1 after 300 cycles at 1 A g–1. This novel structural design may be one of the feasible solutions to achieve the excellent properties of SIB anode materials.