Carbon Nanotubes@Nickel Cobalt Sulfide Nanosheets for High‐Performance Supercapacitors

Abstract

As new and alternative energy storage devices to batteries and traditional capacitors, supercapacitors exhibit both high power and high energy density as well as good cycle life. NiCo2S4, a spinel‐structured transition metal sulfide with a high specific capacity, is considered to be a promising electrode material for supercapacitors with great application potential. However, the poor electrical conductivity of NiCo2S4 results in poor rate and cycle performance of the material, which limits its practical application. In this work, we design a composite by loading NiCo2S4 on the surface of carbon nanotubes (CNTs) to enhance the conductivity. The best‐performing CNTs@NiCo2S4 electrode materials were obtained after the optimized heat‐treatment of CNTs@SiO2 precursors. At a current density of 1 A g−1, the CNTs@NiCo2S4 composite exhibits a specific capacity of 216.4 mAh g−1 and a capacity retention of 75 % after 2000 cycles. Even at a high current density of 5 A g−1, the capacity can still retain 87 % of that under 1 A g−1. It is demonstrated that the electrochemical performance of NiCo2S4 can be effectively boosted by combining with conductive CNTs.

Anion and Cation Co-Modified Vanadium Oxide for Cathode Material of Aqueous Zinc-Ion Battery

“…Because of the insertion of metal cations and H 2 O molecules, the distance between V 2 O 5 layers has been increased, which is more conducive to the intercalation and deintercalation of Zn 2+ . After this, a variety of cations were found to have similar effects, such as monovalent ions Li + [16], Na + [17], K + [18], NH 4 + [19][20][21], divalent ions Ca 2+ [22] and Mg 2+ [23], and transition metal ions Ni 2+ [24] and Co 2+ [25,26]. The electrochemical properties from previous studies have been compared and shown in Table S1.…”

Engineering NiCo2S4 nanoparticles anchored on carbon nanotubes as superior energy-storage materials for supercapacitors

“…[21][22][23] Researches indicate that, compared single-component suldes, binary metal suldes have higher specic capacity owing to their more redox reactions. 24,25 Nickel-cobalt sulde possess the fast Faraday reaction from the synergistic reaction of nickel and cobalt and it is reckoned as a promising candidate with enhanced electrocapacitive property toward energy-storage devices. [26][27][28][29] To date, nickel-cobalt suldes with various nanostructures, including nanowires, nanosheets and nanoparticles, have been extensively studied.…”

Tailoring the Hollow Structure within CoSn(OH)6 Nanocubes for Advanced Supercapacitors

“…This could be ascribed to the limited exposure of the active sites within the structure of the active component that otherwise would be fully utilized. Thus, the increased exposure of more active areas of transition metal compounds has been addressed by various strategies such as changing the morphology, enhancing the dispersion such as by loading NiCo 2 S 4 on the surface of carbon nanotubes [13], creating pores, and so on [14][15][16][17].…”