Formation of a Flower‐Like Co−Mo−S on Reduced Graphene Oxide Composite on Nickel Foam with Enhanced Electrochemical Capacitive Properties

Abstract

Transition metal sulfides have attracted considerable attention due to their excellent electrochemical performance for supercapacitors. Herein, we prepared a Co3S4/CoMo2S4 (Co−Mo−S) composite on reduced graphene oxide/Ni foam (RGO/NF) with unique flower‐like morphology through a carefully time‐controlled sulfurization process. It was found that the vulcanization time has a great influence on the morphology and electrochemical properties of the composites. After 3 hours of vulcanization, the as‐prepared Co3S4/CoMo2S4@RGO/NF electrode exhibited a superior specific capacitance of 2530.4 F g−1 at a current density of 1 A g−1, as well as excellent cycling stability with 78.8 % retention of the initial capacitance even after 6,000 cycles at a current density of 10 A g−1. An asymmetric device was assembled employing the Co3S4/CoMo2S4@RGO/NF composite as a positive electrode and activated carbon (AC) as a negative electrode. The device delivered a maximum energy density of 59.0 Wh kg−1 at a power density of 640 W kg−1 and a high cycling performance (90.7 % capacitance retention after 6,000 cycles). These results demonstrate the promising potential of Co−Mo−S@RGO/NF as binder‐free, high‐performance electrode in renewable energy storage systems.

Construction of CoMo2S4 Nanorods/Nanosheets Electrodes with Enhanced Electrochemical Properties for Asymmetric Pseudocapacitors

“…Figure 3c shows the high‐resolution spectra of Mo 3d. The two main peaks were located at 228.6 and 232.0 eV (229.6 and 232.7 eV in Figure S2c for CMO), which corresponded to Mo 3d 5/2 and Mo 3d 3/2 electron orbitals, respectively, and the peak at 235.3 eV can be ascribed to the existence of Mo 6+ [32,33] . In addition, the small peak near 226.2 eV in CMS/NF‐120 was due to the influence of S 2s photoelectrons.…”

“…The two main peaks were located at 228.6 and 232.0 eV (229.6 and 232.7 eV in Figure S2c for CMO), which corresponded to Mo 3d 5/2 and Mo 3d 3/2 electron orbitals, respectively, and the peak at 235.3 eV can be ascribed to the existence of Mo 6 + . [32,33] In addition, the small peak near 226.2 eV in CMS/NF-120 was due to the influence of S 2s photoelectrons. Figure 3d was the S 2p spectrum of CMS/NF-120 phase, the two peaks at 163.0 and 161.4 eV could be attributed to the S 2p 1/2 and S 2p 3/2 electron orbitals of the Mo-S bond, respectively.…”

Design of Metals Sulfides with Carbon Materials for Supercapacitor Applications: A Review

“…Mo did not participate. [134,135] Xie et al also synthesized the carbon-based disulfide of vanadium for ion storage. [136] A literature survey revealed that the postmetal sulfides and transition metal sulfides both predicted the same trends, as the enhancement of the electrochemical characteristics of hybrid electrode structures; so, the carbonbased electrode materials may be suitable to solve the drawbacks and problems associated with individual metal sulfides.…”