One-Step Hydrothermal Synthesis of 3D Petal-like Co₉S₈/RGO/Ni₃S₂ Composite on Nickel Foam for High-Performance Supercapacitors

Abstract

Co9S8, Ni3S2, and reduced graphene oxide (RGO) were combined to construct a graphene composite with two mixed metal sulfide components. Co9S8/RGO/Ni3S2 composite films were hydrothermal-assisted synthesized on nickel foam (NF) by using a modified "active metal substrate" route in which nickel foam acted as both a substrate and Ni source for composite films. It is found that the Co9S8/RGO/Ni3S2/NF electrode exhibits superior capacitive performance with high capability (13.53 F cm(-2) at 20 mA cm(-2), i.e., 2611.9 F g(-1) at 3.9 A g(-1)), excellent rate capability, and enhanced electrochemical stability, with 91.7% retention after 1000 continuous charge-discharge cycles even at a high current density of 80 mA cm(-2).

Encapsulation of CoSx Nanocrystals into N/S Co‐Doped Honeycomb‐Like 3D Porous Carbon for High‐Performance Lithium Storage

“…All three samples' plots have similar shapes with a straight line in the low‐frequency region accompanied by a semicircle in the high frequency region. The equivalent circuit model (Figure 7a, inset) is used to better understand the impedance spectrum, which is composed of R s (the sum of electrolyte resistance and ohmic resistances of the cell components), R f (film resistance), R ct (charge‐transfer resistance), CPE‐1 (the constant phase element of the SEI film), CPE‐2 (the double‐layer capacitance), and Z w (Warburg impedance) 18, 64, 65. The primary fitting parameters of three samples are listed in Table S3 (Supporting Information).…”

“…However, TMC materials undergo serious volume changes during the cycling process, which results in poor cycle stability 8. Thus, many strategies have been adopted to improve the performances of electrode materials such as carbon modification,9, 10, 11, 12, 13 tuning particle morphology,14, 15, 16 electrolyte optimization,17 hybridization with other composites,18, 19 cut‐off voltage control,20 and nanonization 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20. Among numerous TMCs materials, cobalt sulfide materials with different stoichiometric compositions such as Co 9 S 8 , CoS, Co 3 S 4 , and CoS 2 are considered as ideal candidates for next‐generation LIB's high‐capacity anodes 21…”

NiCo2S4@NiMoO4 Core-Shell Heterostructure Nanotube Arrays Grown on Ni Foam as a Binder-Free Electrode Displayed High Electrochemical Performance with High Capacity

“…Over 2000 cycles, there is still 75.3% of its initial capacitance retained and it performs better than NiCo 2 S 4 (64.6% over 2000 cycles). For NiCo 2 S 4 @NiMoO 4 electrode, the specific capacitance increases at the initial 100 cycles, which is because the electrode activation increases the available active sites [41]. Besides, EIS measurement was carried out to further examine the excellent electrochemical performance of the NiCo 2 S 4 @NiMoO 4 electrode.…”

Self-supported phase-pure Ni3S2 sheet-on-rod nanoarrays with enhanced pseudocapacitive properties and high energy density

“…No peaks due to other phases can be identified, suggesting a high phase purity of the sample. The valence state of Ni element in the Ni 3 S 2 sample was investigated by X-ray photoelectron microscopy (XPS) and the two main peaks at 855.4 and 873.2 eV in Figure S2B can be assigned to Ni 2p 3/2 and Ni 2p 1/2 [20,21], respectively, with each accompanied by a single smaller satellite peak (marked as "sate" on the spectrum). Such satellite peaks are usually associated with a socalled "shake-up" process where electrons in the valence band are excited to higher energy states [22].…”