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1.
To avoid an enormous energy crisis in the not-too-distant future, it be emergent to establish high-performance energy storage devices such as supercapacitors. For this purpose, a three-dimensional (3D) heterostructure of Co3O4 and Co3S4 on nickel foam (NF) that is covered by reduced graphene oxide (rGO) has been prepared by following a facile multistep method. At first, rGO nanosheets are deposited on NF under mild hydrothermal conditions to increase the surface area. Subsequently, nanowalls of cobalt oxide are electro-deposited on rGO/Ni foam by applying cyclic-voltammetry (CV) under optimized conditions. Finally, for the synthesis of Co3O4@Co3S4 nanocomposite, the nanostructure of Co3S4 was fabricated from Co3O4 nanowalls on rGO/NF by following an ordinary hydrothermal process through the sulfurization for the electrochemical application. The samples are characterized by using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The obtained sample delivers a high capacitance of 13.34 F cm−2 (5651.24 F g−1) at a current density of 6 mA cm−2 compared to the Co3O4/rGO/NF electrode with a capacitance of 3.06 F cm−2 (1230.77 F g−1) at the same current density. The proposed electrode illustrates the superior electrochemical performance such as excellent specific energy density of 85.68 W h Kg−1, specific power density of 6048.03 W kg−1 and a superior cycling performance (86% after 1000 charge/discharge cycles at a scan rate of 5 mV s−1). Finally, by using Co3O4 @Co3S4/rGO/NF and the activated carbon-based electrode as positive and negative electrodes, respectively, an asymmetric supercapacitor (ASC) device was assembled. The fabricated ASC provides an appropriate specific capacitance of 79.15 mF cm−2 at the applied current density of 1 mA cm−2, and delivered an energy density of 0.143 Wh kg−1 at the power density of 5.42 W kg−1.  相似文献   

2.
《Journal of Energy Chemistry》2017,26(6):1260-1266
Electrode material based on a novel core–shell structure consisting of NiCo_2S_4(NCS) solid fiber core and Mn S(MS) sheet shell(NCS@MS) in situ grown on carbon cloth(CC) has been successfully prepared by a simple sulfurization-assisted hydrothermal method for high performance supercapacitor. The synthesized NiCo_2S_4@Mn S/CC electrode shows high capacitance of 1908.3 F g~(-1) at a current density of 0.5 A g~(-1) which is higher than those of NiCo_2S_4 and Mn S at the same current density. A flexible all-solid-state asymmetric supercapacitor(ASC) is constructed by using NiCo_2S_4@Mn S/CC as positive electrode, active carbon/CC as negative electrode and KOH/poly(vinyl alcohol)(PVA) as electrolyte. The optimized ASC shows a maximum energy density of 23.3 Wh kg~(-1) at 1 A g~(-1), a maximum power density of about7.5 kw kg~(-1) at 10 A g~(-1) and remarkable cycling stability. After 9000 cycles, the ASC still exhibited67.8% retention rate and largely unchanged charge/discharge curves. The excellent electrochemical properties are resulted from the novel core–shell structure of the NiCo_2S_4@Mn S/CC electrode, which possesses both high surface area for Faraday redox reaction and superior kinetics of charge transport. The NiCo_2S_4@Mn S/CC electrode shows a promising potential for energy storage applications in the future.  相似文献   

3.
A 3D hierarchical carbon cloth/nitrogen-doped carbon nanowires/Ni@MnO2 (CC/N-CNWs/Ni@MnO2) nanocomposite electrode was rationally designed and prepared by electrodeposition. The N-CNWs derived from polypyrrole (PPy) nanowires on the carbon cloth have an open framework structure, which greatly increases the contact area between the electrode and electrolyte and provides short diffusion paths. The incorporation of the Ni layer between the N-CNWs and MnO2 is beneficial for significantly enhancing the electrical conductivity and boosting fast charge transfer as well as improving the charge-collection capacity. Thus, the as-prepared 3D hierarchical CC/N-CNWs/Ni@MnO2 electrode exhibits a higher specific capacitance of 571.4 F g−1 compared with those of CC/N-CNWs@MnO2 (311 F g−1), CC/Ni@MnO2 (196.6 F g−1), and CC@MnO2 (186.1 F g−1) at 1 A g−1 and remarkable rate capability (367.5 F g−1 at 10 A g−1). Moreover, asymmetric supercapacitors constructed with CC/N-CNWs/Ni@MnO2 as cathode material and activated carbon as anode material deliver an impressive energy density of 36.4 W h kg−1 at a power density of 900 W kg−1 and a good cycling life (72.8 % capacitance retention after 3500 cycles). This study paves a low-cost and simple way to design a hierarchical nanocomposite electrode with large surface area and superior electrical conductivity, which has wide application prospects in high-performance supercapacitors.  相似文献   

4.
Rational designing and constructing multiphase hybrid electrode materials is an effective method to compensate for the performance defects of the single component. Based on this strategy, Cu2Se hexagonal nanosheets@Co3Se4 nanospheres mixed structures have been fabricated by a facile two-step hydrothermal method. Under the synergistic effect of the high ionic conductivity of Cu2Se and the remarkable cycling stability of Co3Se4, Cu2Se@Co3Se4 can exhibit outstanding electrochemical performance as a novel electrode material. The as-prepared Cu2Se@Co3Se4 electrode displays high specific capacitance of 1005 F g−1 at 1 A g−1 with enhanced rate capability (56 % capacitance retention at 10 A g−1), and ultralong lifespan (94.2 % after 10 000 cycles at 20 A g−1). An asymmetric supercapacitor is assembled applying the Cu2Se@Co3Se4 as anode and graphene as cathode, which delivers a wide work potential window of 1.6 V, high energy density (30.9 Wh kg−1 at 0.74 kW kg−1), high power density (21.0 Wh kg−1 at 7.50 kW kg−1), and excellent cycling stability (85.8 % after 10 000 cycles at 10 A g−1).  相似文献   

5.
Carbon-based symmetric supercapacitors (SCs) are known for their high power density and long cyclability, making them an ideal candidate for power sources in new-generation electronic devices. To boost their electrochemical performances, deriving activated carbon doped with heteroatoms such as N, O, and S are highly desirable for increasing the specific capacitance. In this regard, activated carbon (AC) self-doped with heteroatoms is directly derived from bio-waste (lima-bean shell) using different KOH activation processes. The heteroatom-enriched AC synthesized using a pretreated carbon-to-KOH ratio of 1:2 (ONS@AC-2) shows excellent surface morphology with a large surface area of 1508 m2 g−1. As an SC electrode material, the presence of heteroatoms (N and S) reduces the interfacial charge-transfer resistance and increases the ion-accessible surface area, which inherently provides additional pseudocapacitance. The ONS@AC-2 electrode attains a maximum specific capacitance (Csp) of 342 F g−1 at a specific current of 1 Ag−1 in 1 m NaClO4 electrolyte at the wide potential window of 1.8 V. Moreover, as symmetric SCs the ONS@AC-2 electrode delivers a maximum specific capacitance (Csc) of 191 F g−1 with a maximum specific energy of 21.48 Wh kg−1 and high specific power of 14 000 W kg−1 and excellent retention of its initial capacitance (98 %) even after 10000 charge/discharge cycles. In addition, a flexible supercapacitor fabricated utilizing ONS@AC-2 electrodes and a LiCl/polyvinyl alcohol (PVA)-based polymer electrolyte shows a maximum Csc of 119 F g−1 with considerable specific energy and power.  相似文献   

6.
A simple and versatile method for general synthesis of uniform one‐dimensional (1D) MxCo3−xS4 (M=Ni, Mn, Zn) hollow tubular structures (HTSs), using soft polymeric nanofibers as a template, is described. Fibrous core–shell polymer@M‐Co acetate hydroxide precursors with a controllable molar ratio of M/Co are first prepared, followed by a sulfidation process to obtain core–shell polymer@MxCo3−xS4 composite nanofibers. The as‐made MxCo3−xS4 HTSs have a high surface area and exhibit exceptional electrochemical performance as electrode materials for hybrid supercapacitors. For example, the MnCo2S4 HTS electrode can deliver specific capacitance of 1094 F g−1 at 10 A g−1, and the cycling stability is remarkable, with only about 6 % loss over 20 000 cycles.  相似文献   

7.
In this work, we report the biosynthesis of CuCo2S4 nanoparticles (Bio-NPs) via hydrothermal method. The synthetized Bio-NPs-CuCo2S4 was studied as an active material of working electrode for electrochemical supercapacitor and non-enzymatic hydrazine sensor. The Bio.NPs-CuCo2S4/ITO electrode has a specific capacitance of 264 F/g at a current density of 1 A/g. Meanwhile, the electrode exhibits excellent electrochemical performances, such as an energy density of 33 Wh/Kg and a power density of 900 W/Kg. The Bio.NPs-CuCo2S4/ITO electrode for non-enzymatic hydrazine sensor exhibits a very high sensitivity of 2400 μA.mM−1.cm−2, a wide linear range from 0.001 to 1.400 mM and shows an excellent selectivity.  相似文献   

8.
Biocarbon-supported polymetallic composites (CAS@Ni3S4/CeO2) were fabricated by a facile hydrothermal process. The as-prepared CAS@Ni3S4/CeO2 materials integrated the advantages of transition metal sulfides (good conductivity), rare-earth metal oxides (excellent stability), as well as porous carbon with high surface area, thus exhibiting promising electrochemical performance in supercapacitor applications. Indeed, the optimal CAS@Ni3S4/CeO2-150 composite displayed a high specific capacitance of 1364 F g?1 and impressive cycle performance with capacitance retention of 93.81 % after 10,000 cycles. The calculation of capacitance contribution showed that the satisfying behavior of the electrode was a combination of the diffusion process and the surface capacitance characteristics. Furthermore, the assembled asymmetric supercapacitor (CAS@Ni3S4/CeO2-150//CAS) delivered an ultrahigh energy density of 102.76 Wh kg?1, which was better than that of the commercial activated carbon-based ASC device. This novel strategy might provide a new perspective for transition metal sulfide/rare earth metal oxide composite in the electrochemical energy storage field.  相似文献   

9.
Transition metal sulfides have emerged as promising materials in supercapacitor. In this work, we firstly developed an interface-induced superassembly approach to fabricate NiSx and CoSx nanoparticles, which based on ordered mesoporous carbon-graphene aerogel composites for supercapacitor electrodes. The obtained multi-component superassembled nanoparticles-carbon matrix composites have controllable 3D porous structure of multi-stage composite. The two-dimensional graphene interlaced to form a 3D framework with large sponge-like pores, and then the graphene surface was loaded with mesoporous carbon with mesoporous pore size and vertical orientation. The composites display high specific capacitance of 958.1 F g−1 at 0.1 A g−1. The capacitance retains about 97.3 % after 3000 charging-discharging cycles at 2 A g−1. These results indicate that the obtained OMC−GA−Ni3S2/Co4S3 is a promising material for electrochemical capacitors, which providing new technical methods and ideas for the research of new energy and analytical sensor materials in the fields of energy storage, photocatalysis, point-of-care testing devices and other fields.  相似文献   

10.
采用离子刻蚀和化学气相沉积法制备出具有沸石咪唑酯骨架(ZIFs)型双壳层纳米笼状的CoS/NiCo_2S_4并组装成超级电容器。该结构有较大的比表面积(98 m2·g-1),合适的孔道(孔径4 nm),且保留了ZIFs骨架构型。作为电极活性材料时,具有良好的结构稳定性和电化学活性,有利于增强所组装的超级电容器的循环稳定性和比容量。在三电极体系中,在1 A·g-1的电流密度下,容量为1 230 F·g-1;在3 A·g-1电流密度下循环9 000圈后,初始电容保持率为76.6%。在以该电极、活性炭电极与KOH/聚乙烯醇(PVA)凝胶态电解质组装的器件中,当功率密度为702 W·kg-1时,能量密度达31.6 Wh·kg-1;在7 056 W·kg-1的高功率密度下,仍保持16.5 Wh·kg-1的能量密度。  相似文献   

11.
Porous core–shell CuCo2S4 nanospheres that exhibit a large specific surface area, sufficient inner space, and a nanoporous shell were synthesized through a facile solvothermal method. The diameter of the core–shell CuCo2S4 nanospheres is approximately 800 nm„ the radius of the core is about 265 nm and the thickness of the shell are approximately 45 nm, respectively. On the basis of the experimental results, the formation mechanism of the core–shell structure is also discussed. These CuCo2S4 nanospheres show excellent Li storage performance when used as anode material for lithium-ion batteries. This material delivers high reversible capacity of 773.7 mA h g−1 after 1000 cycles at a current density of 1 A g−1 and displays a stable capacity of 358.4 mA h g−1 after 1000 cycles even at a higher current density of 10 A g−1. The excellent Li storage performance, in terms of high reversible capacity, cycling performance, and rate capability, can be attributed to the synergistic effects of both the core and shell during Li+ ion insertion/extraction processes.  相似文献   

12.
《化学:亚洲杂志》2017,12(16):2127-2133
In this work, β‐Co(OH)2 nanosheets are explored as efficient pseudocapacitive materials for the fabrication of 1.6 V class high‐energy supercapacitors in asymmetric fashion. The as‐synthesized β‐Co(OH)2 nanosheets displayed an excellent electrochemical performance owing to their unique structure, morphology, and reversible reaction kinetics (fast faradic reaction) in both the three‐electrode and asymmetric configuration (with activated carbon, AC). For example, in the three‐electrode set‐up, β‐Co(OH)2 exhibits a high specific capacitance of ∼675 F g−1 at a scan rate of 1 mV s−1. In the asymmetric supercapacitor, the β‐Co(OH)2∥AC cell delivers a maximum energy density of 37.3 Wh kg−1 at a power density of 800 W kg−1. Even at harsh conditions (8 kW kg−1), an energy density of 15.64 Wh kg−1 is registered for the β‐Co(OH)2∥AC assembly. Such an impressive performance of β‐Co(OH)2 nanosheets in the asymmetric configuration reveals the emergence of pseudocapacitive electrodes towards the fabrication of high‐energy electrochemical charge storage systems.  相似文献   

13.
The design of hierarchical electrodes comprising multiple components with a high electrical conductivity and a large specific surface area has been recognized as a feasible strategy to remarkably boost pseudocapacitors. Herein, we delineate hexagonal sheets-in-cage shaped nickel–manganese sulfides (Ni-Mn-S) with nanosized open spaces for supercapacitor applications to realize faster redox reactions and a lower charge-transfer resistance with a markedly enhanced specific capacitance. The hybrid was facilely prepared through a two-step hydrothermal method. Benefiting from the synergistic effect between Ni and Mn active sites with the improvement of both ionic and electric conductivity, the resulting Ni-Mn-S hybrid displays a high specific capacitance of 1664 F g−1 at a current density of 1 A g−1 and a capacitance of 785 F g−1 is maintained at a current density of 50 A g−1, revealing an outstanding capacity and rate performance. The asymmetric supercapacitor device assembled with the Ni-Mn-S hexagonal sheets-in-cage as the positive electrode delivers a maximum energy density of 40.4 Wh kg−1 at a power density of 750 W kg−1. Impressively, the cycling retention of the as-fabricated device after 10 000 cycles at a current density of 10 A g−1 reaches 85.5 %. Thus, this hybrid with superior capacitive performance holds great potential as an effective charge-storage material.  相似文献   

14.
Porous organic polymers (POPs) with high physiochemical stability and pseudocapacitive activity are crucial for supercapacitors with high specific capacitance and long cycle life. We report herein a hexaazatrinaphthylene-based POP (HPOP-1) for high-performance supercapacitor by introducing redox-active hexaazatrinaphthylene (HATN) moiety through Sonogashira–Hagihara coupling reaction. HATN moiety can undergo a proton-induced electron transfer redox reaction, which endows HPOP-1 with high pseudocapacitive activity. As electrode materials for supercapacitor application, HPOP-1 exhibits high specific capacitance (667 F g−1 at 0.5 A g−1) and long-term cyclic stability (90% capacitance retention after 10,000 cycles at 5 A g−1) in a three-electrode system with 1 M H2SO4 as the electrolyte. In addition, HPOP-1 also exhibits a specific capacitance of 376 F g−1 at 0.5 A g−1 in 1 M KOH electrolyte. An asymmetric supercapacitor was further fabricated with HPOP-1 as negative electrode and rGO as positive electrode, respectively. The device delivers a specific capacitance of 63 F g−1 at 0.5 A g−1 and a rate performance of 37 F g−1 at 5 A g−1. Our work provides a facile approach for the design and preparation of pseudocapacitive POPs with high specific capacitance and long cycle life.  相似文献   

15.
A simple and versatile method for general synthesis of uniform one‐dimensional (1D) MxCo3?xS4 (M=Ni, Mn, Zn) hollow tubular structures (HTSs), using soft polymeric nanofibers as a template, is described. Fibrous core–shell polymer@M‐Co acetate hydroxide precursors with a controllable molar ratio of M/Co are first prepared, followed by a sulfidation process to obtain core–shell polymer@MxCo3?xS4 composite nanofibers. The as‐made MxCo3?xS4 HTSs have a high surface area and exhibit exceptional electrochemical performance as electrode materials for hybrid supercapacitors. For example, the MnCo2S4 HTS electrode can deliver specific capacitance of 1094 F g?1 at 10 A g?1, and the cycling stability is remarkable, with only about 6 % loss over 20 000 cycles.  相似文献   

16.
Rechargeable magnesium batteries (RMBs) have been considered a promising energy-storage device due to their high energy density and high safety, but they still suffer from a lack of high-rate performance and cycle performance of the cathode. Nanosized CuCo2S4/Cu7.2S4 composites have been synthesized for the first time by a facile solvothermal method. Herein, the magnesium ion storage behavior when applied in the cathode for RMBs is discussed. Electrochemical results demonstrated that the CuCo2S4/Cu7.2S4 composites exhibit a high initial discharge capacity of 256 mAh g−1 at 10 mA g−1 and 123 mAh g−1 at 300 mA g−1 at room temperature and an outstanding long-term cyclic stability over 300 cycles at 300 mA g−1. Furthermore, the electrochemical storage mechanism demonstrated that the storage process of magnesium ion in the CuCo2S4/Cu7.2S4 cathode is mainly driven by strong pseudocapacitive effects.  相似文献   

17.
In this work, hybrid porous Co3O4–CeO2 hollow polyhedrons have been successfully obtained via a simple cation‐exchange route followed by heat treatment. In the synthesis process, ZIF‐67 polyhedron frameworks are firstly prepared, which not only serve as a host for the exchanged Ce3+ ions but also act as the template for the synthesis of hybrid porous Co3O4–CeO2 hollow polyhedrons. When utilized as electrode materials for supercapacitors, the hybrid porous Co3O4–CeO2 hollow polyhedrons delivered a large specific capacitance of 1288.3 F g?1 at 2.5 A g?1 and a remarkable long lifespan cycling stability (<3.3 % loss after 6000 cycles). Furthermore, an asymmetric supercapacitor (ASC) device based on hybrid porous Co3O4–CeO2 hollow polyhedrons was assembled. The ASC device possesses an energy density of 54.9 W h kg?1, which can be retained to 44.2 W h kg?1 even at a power density of 5100 W kg?1, indicating its promising application in electrochemical energy storage. More importantly, we believe that the present route is a simple and versatile strategy for the preparation of other hybrid metal oxides with desired structures, chemical compositions and applications.  相似文献   

18.
A hierarchical hollow hybrid composite, namely, MnO2 nanosheets grown on nitrogen‐doped hollow carbon shells (NHCSs@MnO2), was synthesized by a facile in situ growth process followed by calcination. The composite has a high surface area (251 m2g?1) and mesopores (4.5 nm in diameter), which can efficiently facilitate transport during electrochemical cycling. Owing to the synergistic effect of NHCSs and MnO2, the composite shows a high specific capacitance of 306 F g?1, good rate capability, and an excellent cycling stability of 95.2 % after 5000 cycles at a high current density of 8 A g?1. More importantly, an asymmetric supercapacitor (ASC) assembled by using NHCSs@MnO2 and activated carbon as the positive and negative electrodes exhibits high specific capacitance (105.5 F g?1 at 0.5 A g?1 and 78.5 F g?1 at 10 A g?1) with excellent rate capability, achieves a maximum energy density of 43.9 Wh kg?1 at a power density of 408 W kg?1, and has high stability, whereby the ASC retains 81.4 % of its initial capacitance at a current density of 5 A g?1 after 4000 cycles. Therefore, the NHCSs@MnO2 electrode material is a promising candidate for future energy‐storage systems.  相似文献   

19.
以泡沫镍作为基底,采用水热法原位生长出具有片状结构的NiMoO4活性材料,然后通过水热硫化制备出NiMoO4/NiMoS4复合材料,研究了水热时间和硫脲添加量对样品形貌和电化学性能的影响。电化学结果表明,NiMoO4/NiMoS4电极在电流密度为1A·g-1时,比电容为1560.7F·g-1,在电流密度为40A·g-1时循环2000次后,比电容仍为初始比电容的76.7%。将NiMoO4/NiMoS4电极材料与活性炭(AC)分别作为正、负极组装的非对称超级电容器(ASC)在400W·kg-1的功率密度下可提供29.0Wh·kg-1的能量密度。  相似文献   

20.
以泡沫镍作为基底,采用水热法原位生长出具有片状结构的NiMoO4活性材料,然后通过水热硫化制备出NiMoO4/NiMoS4复合材料,研究了水热时间和硫脲添加量对样品形貌和电化学性能的影响。电化学结果表明,NiMoO4/NiMoS4电极在电流密度为 1 A·g-1时,比电容为 1 560.7 F·g-1,在电流密度为 40 A·g-1时循环 2 000次后,比电容仍为初始比电容的 76.7%。将 NiMoO4/NiMoS4电极材料与活性炭(AC)分别作为正、负极组装的非对称超级电容器(ASC)在 400 W·kg-1的功率密度下可提供 29.0 Wh·kg-1的能量密度。  相似文献   

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