Expanding Interlayer Spacing in MoS₂ for Realizing an Advanced Supercapacitor

Abstract

Charge-storage mechanism of free-standing MoS 2 /r-GO (r-GO = reduced graphene oxide) hybrid nanoflakes on molybdenum (Mo) foil in Na 2 SO 4 solution is elucidated for realizing a high-performance asymmetric supercapacitor (ASC). Thiourea that acts primarily as sulfur source also helps intercalating ammonium ions, which along with r-GO facilitate in situ exfoliation of MoS 2 , producing hierarchical MoS 2 with expanded interlayer spacing. This interlayer expansion in MoS 2 facilitates Na + -ions intercalation/deintercalation and ensures enhanced capacitance, rate capability, and cycling stability of the capacitor . Besides exhibiting attractive energy-cum-power traits, the 2 V MoS 2 /r-GO//Fe 2 O 3 /MnO 2 ASC shows compelling cycling performance for over 20 000 cycles in an aqueous electrolyte.

Two‐Dimensional Layered Metallic VSe2/SWCNTs/rGO Based Ternary Hybrid Materials for High Performance Energy Storage Applications

“…in which a and b are variable parameters. Generally, if b =1, then the charge storage is dominated by the non‐faradaic process, and if b =0.5, then the charge storage is dominated by the faradaic process by satisfying Cortell's equation i = aυ 1/2 . It is evident that the charge storage in an intercalation‐based supercapacitor electrode includes three parts: 1) the electric double layer formation, 2) fast redox reaction at the electrode–electrolyte interface and 3) solid‐state diffusion.…”

Molybdenum Disulphide Heterointerfaces as Potential Materials for Solar Cells, Energy Storage, and Hydrogen Evolution

“…There are many reports of suitable wrapping/interfacing of MoS 2 in different forms of carbon such as bulk, graphene/r‐GO, single‐/multiwalled CNTs (SWCNs/MWCNTs), micro/nanospheres, etc. ; these were successfully investigated to constitute electrochemical supercapacitors and other electrochemical energy‐storages devices . Nanocomposites with graphene are prepared by solution phase exfoliation using aqueous electrolyte (Na 2 SO 4 ).…”

“…The exfoliation of MoS 2 layers can be enhanced in the composite of MoS 2 –r–GO using thiourea as a source of sulfur; it is noticed that the latter also encourages intercalation/deintercalation of ammonium ions. Here asymmetric supercapacitors were formed on molybdenum foil using Na 2 SO 4 electrolytic solution . A unique technique of the laser writing of polyimide foils has been explored for in situ formation of MoS 2 ‐decorated graphene composites.…”

Vanadium‐Incorporated Metallic (1‐T) Molybdenum Sulfide Nanoroses for High‐Energy‐Density Asymmetric Supercapacitors

“…However, when this strategy was adopted, maximum utilization for charge storage was not possible. Moreover, besides being metastable (1T phase), MS is formed with low 1T (25 %) content, thereby restricting the charge storage …”

“…Moreover,b esides being metastable (1T phase), MS is formed with low 1T (25 %) content,t hereby restricting the charge storage. [14] Particularly,b imetallic sulfides have tremendous potential to compensate the electrochemical limitations posed by single-metal sulfides. [15,16] Sahoo et al aimed to investigate the electrochemical properties of Cu 2 MoS 4 on Ni foam to achieve a high-energy-density supercapacitor.…”