Construction of NiCo₂S₄@NiMoO₄ Core‐Shell Nanosheet Arrays with Superior Electrochemical Performance for Asymmetric Supercapacitors

Abstract

In this work, we develop hierarchical NiCo2S4@NiMoO4 nanosheet arrays directly anchored on nickel foam by a hydrothermal method. The self‐supported core‐shell architecture take advantage of high electroactive surface area, rapid channels for ion diffusion and electron transport, and the synergistic contributions from both the NiCo2S4 core and NiMoO4 shell. Remarkably, the NiCo2S4@NiMoO4 electrode showed high specific capacitance of 1487.6 F g−1 at a current density of 1 A g−1 and superior cycling stability (89.7 % capacitance retention after 8000 charge‐discharge cycles). An asymmetric supercapacitor (ASC) with an optimized cell voltage of 1.6 V was assembled by using activated carbon (AC) as the negative electrode and NiCo2S4@NiMoO4 electrode as the positive electrode, achieving an extraordinary energy density of 53.2 Wh kg−1 at a power density of 560 W kg−1, and remained 34.8 Wh kg−1 at a maximum power density of 11.2 kW kg−1. The outstanding electrochemical behavior indicate that the NiCo2S4@NiMoO4 nanosheet arrays hold great promise for high‐performance energy storage devices.

Unlocking the potential of a novel hierarchical hybrid (Ni–Co)Se2@NiMoO4@rGO–NF core–shell electrode for high-performance hybrid supercapacitors

“…The energy and power densities of the proposed HSC device were comparable and even higher than the values of previously reported transition metal chalcogenide-based supercapacitors. 42,68,[72][73][74][75] As a pivotal parameter in measuring its practical applicability, long-term cycling tests were performed on the NCSe@NMO@rGO-NF//OA_MOFs-PC-CNTs HSC device. Fig.…”

“…37,39 Moreover, the ample electroactive surface area due to the octahedral and tetrahedral localities of Ni and Mo atoms along with their prominent nanoscale features could amplify the reversible redox reaction (pseudocapacitive nature) kinetics of Ni-Mo-based electrode materials. [40][41][42] However, to the best of our knowledge, the design of a hybrid heterostructure coreshell nanoarchitecture using oxalic acid assisted hollow Ni-Co-Se nanotubes as a core and NiMoO 4 nanosheets as a protective shell material on a carbonaceous materials-garnished 3D current collector has not been reported elsewhere. Moreover, the scrupulous construction of a core-shell nanostructure on an rGO embellished 3D current collector could be highly benecial to produce a heterostructure core-shell electrode with intensi-ed electrochemical performance for SCs.…”

NiCo2S4‐Based Composite Materials for Supercapacitors

“…When the current density increased to 20 A g −1 , the capacitance is still up to 1729.7 F g −1 . Besides these, some other composites have also been synthesized, such ashybrid NiCo 2 S 4 @Fe 2 O 3 nanoneedle arrays, hierarchical NiCo 2 S 4 @MnMoO 4 core‐shell composites, NiCo 2 S 4 @MnO 2 heterostructure nanowires, Ni x Co 3‐x S 4 @NiCo 2 O 4 nanostructure, NiCo 2 S 4 @NiMoO 4 core‐shell nanotubes and NiCo 2 S 4 @NiMoO 4 core‐shell nanosheet arrays …”

High-performance asymmetric supercapacitor made of NiMoO4 nanorods@Co3O4 on a cellulose-based carbon aerogel

“…To date, Ni foam [27], copper grid [28] and titanium mesh [29] have been mostly selected as collectors, whereas the high cost of these materials limited their practical application. Carbon aerogel (CA) has been considered an ideal supporting material to hybridize with electroactive materials because of its low cost, easy fabrication, large surface area, interconnected porosity and high electrical conductivity [30,31].…”