One-Step Hydrothermal Synthesis of MoO₂/MoS₂ Nanocomposites as High-Performance Electrode Material for Supercapacitors

Abstract

By only changing the ratio of Mo to S source, a distinctive single phase MoO 2 or MoS 2 and MoO 2 /MoS 2 nanocomposites (NCs) are obtained through a simple one-step hydrothermal method based on CH 4 N 2 S as a sulfur source and (NH 4 ) 6 Mo 7 O 24 •4H 2 O as a source of Mo in oxalic acid. The effect of ratio of Mo to S source on the composition, structure, and electrochemical performance are systematically researched. Due to its unique design, abundant macropores active sites in MoO 2 / MoS 2 NCs induce superior rate property (55.30% capacitance retention to 20 from 1 A g −1 ) and larger specific capacitance (1667.3 F g −1 at 1 A g −1 ) and longer cycle life (94.75% after 5000 cycles) as used directly as an electrode. Furthermore, at a power density of 225 W kg −1 , a maximal energy density of 21.85 Wh kg −1 is provided by the asymmetric supercapacitor (MoO 2 /MoS 2 //AC). The capacitance of asymmetric supercapacitor (ASC) is remarkably enhanced by 129.02% under 5000 cycles at a current density of 1.5 A g −1 , demonstrating outstanding cycle property. These results imply the prepared MoO 2 /MoS 2 NCs have promising applications in advanced energy storages. It is important and should be noted that NCs of oxide and sulfide are prepared with only a simple one-step process.

Etching-induced ion exchange engineering of two-dimensional layered NiFeCo-based hydroxides for high energy charge storage

“…4 In the high-frequency region, the charge transfer resistance ( R ct ) can be expressed by the diameter of the semicircle, primarily reflecting the ion transfer between the electrolyte and the material. 51 The intersection with the real axis corresponds to the equivalent series resistance ( R s ), which arises from the intrinsic resistance of both the electrolyte and the electrode. 19 The R s and R ct values for pure NF, NiFe 0.5 /NF, Ni 1 (Fe/Co = 2/1) 0.5 /NF, Ni 1 (Fe/Co = 1/1) 0.5 /NF, Ni 1 (Fe/Co = 1/1) 0.5 /NF and NiCo 0.5 /NF calculated using ZsimpWin software are 0.882 Ω, 1.051 Ω, 1.002 Ω, 0.857 Ω, 0.978 Ω, and 0.915 Ω and 4.89 Ω, 4.44 Ω, 3.07 Ω, 1.69 Ω, 3.52 Ω, and 2.91 Ω, respectively.…”

“…Paper the charge transfer resistance (R ct ) can be expressed by the diameter of the semicircle, primarily reflecting the ion transfer between the electrolyte and the material. 51 The intersection with the real axis corresponds to the equivalent series resistance (R s ), which arises from the intrinsic resistance of both the electrolyte and the electrode. 19 The R S11, † the electrodes maintained 68.5% (Ni/NF), 56.2% (NiFe 0.5 /NF), and 74.9% (Ni 1 (Fe/ Co = 1/1) 0.5 /NF) of the initial capacitance after 5000 cycles at a current density of 10 mA cm −2 , respectively.…”

Microwave‐Induced Rapid Synthesis of MoS2@Cellulose Composites as an Efficient Electrode Material for Quasi‐Solid‐State Supercapacitor Application

“…Impressively, the E D archived in our asymmetric supercapacitor device is higher than in the earlier literature on MoS 2 ‐based electrode materials. [ 36,52–60 ]…”

“…Impressively, the E D archived in our asymmetric supercapacitor device is higher than in the earlier literature on MoS 2 -based electrode materials. [36,[52][53][54][55][56][57][58][59][60] Notability, the superior electrochemical performance such as C sp , E D , and cyclic stability of fabricated MoS 2 @Cellulose//MZ carbon asymmetric device can be ascribed to the layered structure of MoS 2, and CFs contribute a sufficient amount of electrochemically active sites and shortened diffusion path for electrolyte ions and electrons, benefiting efficient Faradaic reactions.…”

Designed fabrication of MoS2 hollow structures with different geometries and the comparative investigation toward capacitive properties

“…It can be found that the template method is an effective method for controlling the structure of molybdenum disulfide, and the template method is simple to operate and easy to implement, and it is easy to control the synthesis process. 21 The hard template method has the following advantages over the soft template method: (1) the hard template method has considerable flexibility in the synthesis of nanomaterials. 22 (2) The experimental device is simple and the operating conditions are mild.…”