Abstract:The integrated hybrid architectures composed of edge site-enriched nickel–cobalt sulfide (Ni–Co–S) nanoparticles and graphene as advanced materials for asymmetric supercapacitors are configured, delivering a superb rate capability.
“…Finally, Fig. 4f reveals the C 2p spectrum; clearly, it shows one distinct peak at binding energy of 284.7 eV illustrating the existence of Sp 2 hybridized carbon atoms forming honeycomb, implying existence of graphene in the composite 33, 34 .Figure 4CV and GCD plots using three electrodes test results ( a ) CV plots of GNF/NCS/CNS core/shell at different scan rates, ( b ) comparison of CV plots of GNF/NCS/CNS core/shell, NF/NCS/CNS core/shell and NF/NCS at scan rate of 3 mV/S, ( c ) GCD plots of GNF/NCS/CNS core/shell at different current densities and ( d ) comparative GCD plots of GNF/NCS/CNS core/shell, NF/NCS/CNS core/shell and NF/NCS at current density of 10 mA/cm 2 .
…”
Three-dimensional (3D) core/shell structure of nickel cobalt sulfide is nano-engineered by using series of hydrothermal steps on a CVD grown graphene for supercapacitor application. This core/shell is composited of NiCo2S4 nanotube (NCS) as core and CoxNi(3−x)S2 (CNS) nanosheets as a shell. The as-synthesized composite exhibits excellent electrochemical properties by using the advantage of NCS nanontube core as superhighway for electron and ion transport, and CNS nanosheets shell as high active area pseudocapacitive material. The 3D graphene layer serves as excellent surface area to support 3D NCS/CNS; moreover, it provides excellent electrical conductivity between nickel foam current collector and the 3D NCS/NCS composite. Using these hybrid advantages the as-synthesized graphene/NCS/CNS composite electrode exhibits high areal capacitance of 15.6 F/cm2 at current density of 10 mA/cm2; excellent cycling stability of 93% after 5000 of cycles and excellent rate capability of 74.36% as current increase from 10 to 100 mA/cm2. Moreover, a prototype of asymmetric device fabricated using graphene/NCS/CNS as positive electrode and RGO as negative electrode exhibits high energy density of 23.9 Wh/kg and power density of 2460.6 W/kg at high operating current of 100 mA. Such high performance electrode material may get great application in future energy storage device.
“…Finally, Fig. 4f reveals the C 2p spectrum; clearly, it shows one distinct peak at binding energy of 284.7 eV illustrating the existence of Sp 2 hybridized carbon atoms forming honeycomb, implying existence of graphene in the composite 33, 34 .Figure 4CV and GCD plots using three electrodes test results ( a ) CV plots of GNF/NCS/CNS core/shell at different scan rates, ( b ) comparison of CV plots of GNF/NCS/CNS core/shell, NF/NCS/CNS core/shell and NF/NCS at scan rate of 3 mV/S, ( c ) GCD plots of GNF/NCS/CNS core/shell at different current densities and ( d ) comparative GCD plots of GNF/NCS/CNS core/shell, NF/NCS/CNS core/shell and NF/NCS at current density of 10 mA/cm 2 .
…”
Three-dimensional (3D) core/shell structure of nickel cobalt sulfide is nano-engineered by using series of hydrothermal steps on a CVD grown graphene for supercapacitor application. This core/shell is composited of NiCo2S4 nanotube (NCS) as core and CoxNi(3−x)S2 (CNS) nanosheets as a shell. The as-synthesized composite exhibits excellent electrochemical properties by using the advantage of NCS nanontube core as superhighway for electron and ion transport, and CNS nanosheets shell as high active area pseudocapacitive material. The 3D graphene layer serves as excellent surface area to support 3D NCS/CNS; moreover, it provides excellent electrical conductivity between nickel foam current collector and the 3D NCS/NCS composite. Using these hybrid advantages the as-synthesized graphene/NCS/CNS composite electrode exhibits high areal capacitance of 15.6 F/cm2 at current density of 10 mA/cm2; excellent cycling stability of 93% after 5000 of cycles and excellent rate capability of 74.36% as current increase from 10 to 100 mA/cm2. Moreover, a prototype of asymmetric device fabricated using graphene/NCS/CNS as positive electrode and RGO as negative electrode exhibits high energy density of 23.9 Wh/kg and power density of 2460.6 W/kg at high operating current of 100 mA. Such high performance electrode material may get great application in future energy storage device.
“…Configuration of asymmetric supercapacitors (ASCs) has emerged as a desirable strategy because of the expanded V arised from the absolutely opposite potential window of the two dissimilar electrode materials. [10][11][12] Accordingly, considerable research interest has been invested in constructing highly capacitive negative and positive electrode materials.Until now, transition metal oxides, hydroxides, or phosphides, especially Ni-Co compounds with low cost, natural abundance, and environmentally benign, are mostly employed as positive electrode materials in ASCs because they can present variable oxidation states, favorable electrochemical activity, and large theoretical-specific capacitance based on redox reactions, so they have received extensive attentions as perfect candidates in ASCs. [13][14][15][16][17][18] However, in comparison of the extraordinary advancement obtained by positive electrode materials, the lack of desired negative electrodes restricts the progress of high-performance ASCs.…”
mentioning
confidence: 99%
“…Configuration of asymmetric supercapacitors (ASCs) has emerged as a desirable strategy because of the expanded V arised from the absolutely opposite potential window of the two dissimilar electrode materials. [10][11][12] Accordingly, considerable research interest has been invested in constructing highly capacitive negative and positive electrode materials.…”
environmentally friendly energy storage devices. As an emerging energy powering sources, supercapacitors (SCs) hold a vital and individual position owing to their high power density, excellent cycling stability, fast charge/discharge process as well as noticeable reliability, tremendously bridging the gap between rechargeable batteries and traditional capacitors in terms of energy density and power density. [1][2][3][4] Nevertheless, their commercial applications are still seriously impeded since energy densities of SCs are far lagging behind rechargeable batteries. [5,6] In the light of the critical parameters that decide the energy density (E = 1/2CV 2 ) of supercapacitor devices, [7][8][9] substantial efforts have been dedicated to maximizing the energy density via elevating the overall cell voltage (V) and total specific capacitance (C) governed by negative and positive electrodes. Configuration of asymmetric supercapacitors (ASCs) has emerged as a desirable strategy because of the expanded V arised from the absolutely opposite potential window of the two dissimilar electrode materials. [10][11][12] Accordingly, considerable research interest has been invested in constructing highly capacitive negative and positive electrode materials.Until now, transition metal oxides, hydroxides, or phosphides, especially Ni-Co compounds with low cost, natural abundance, and environmentally benign, are mostly employed as positive electrode materials in ASCs because they can present variable oxidation states, favorable electrochemical activity, and large theoretical-specific capacitance based on redox reactions, so they have received extensive attentions as perfect candidates in ASCs. [13][14][15][16][17][18] However, in comparison of the extraordinary advancement obtained by positive electrode materials, the lack of desired negative electrodes restricts the progress of high-performance ASCs. Previously, carbonaceous materials are still the most widely used as negative electrode, giving rise to low-specific capacitance of 100-250 F g −1 . [19][20][21][22][23] In this regard, pseudocapacitive negative electrode materials are proposed to be hopeful alternatives, whereas the restricted studies and poor , even when charging the device within 6.5 s, the energy density can still maintain as high as 45 W h kg −1 at 26.1 kW kg −1 , and the ASC manifests long cycling lifespan with 86.6% capacitance retention even after 5000 cycles. This pioneering work not only offers an attractive strategy for rational construction of high-performance SiC NW-based nanostructured electrodes materials, but also provides a fresh route for manufacturing next-generation high-energy storage and conversion systems.
“…In another work, Yang et al found that tailoring the edge site of nickel cobalt sulfide nanoparticles on the surface of rGO can further improve the capacitive performance. [137] They employed two strategies to synthesize Ni 1.5 Co 1.5 S 4 and rGO nano composites. In the first strategy, nanowire-shaped nickel cobalt carbonate hydroxide precursors are first grown on the surface of rGO through a hydrothermal process, and the as-obtained nanocomposites are then in situ converted to edge site-enriched Ni 1.5 Co 1.5 S 4 nanoparticles on rGO (Ni 1.5 Co 1.5 S 4 -rGO) in the presence of TAA.…”
Section: Ni-co-smentioning
confidence: 99%
“…Panels (f-h): Reproduced with permission. [137] Copyright 2016, Royal Society of Chemistry. Panels (i-k): Reproduced with permission.…”
Mixed metal sulfides (MMSs) have attracted increased attention as promising electrode materials for electrochemical energy storage and conversion systems including lithium‐ion batteries (LIBs), sodium‐ion batteries (SIBs), hybrid supercapacitors (HSCs), metal–air batteries (MABs), and water splitting. Compared with monometal sulfides, MMSs exhibit greatly enhanced electrochemical performance, which is largely originated from their higher electronic conductivity and richer redox reactions. In this review, recent progresses in the rational design and synthesis of diverse MMS‐based micro/nanostructures with controlled morphologies, sizes, and compositions for LIBs, SIBs, HSCs, MABs, and water splitting are summarized. In particular, nanostructuring, synthesis of nanocomposites with carbonaceous materials and fabrication of 3D MMS‐based electrodes are demonstrated to be three effective approaches for improving the electrochemical performance of MMS‐based electrode materials. Furthermore, some potential challenges as well as prospects are discussed to further advance the development of MMS‐based electrode materials for next‐generation electrochemical energy storage and conversion systems.
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