23 results on '"Yang, Wu"'
Search Results
2. Synthesis of heteroatom and metallic compound self-co-doped porous carbon derived from swine manure for supercapacitor electrodes and lead ion adsorbents
- Author
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Yang Wu, Zhiwei Hou, Enchen Jiang, Liyuan Qin, and Zhang Shihui
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Supercapacitor ,Materials science ,General Chemical Engineering ,Heteroatom ,Electrochemistry ,Metal ,Adsorption ,Chemical engineering ,visual_art ,Pseudocapacitor ,medicine ,visual_art.visual_art_medium ,Pyrolysis ,Activated carbon ,medicine.drug - Abstract
Swine manure activated carbon (SMAC) with self-co-doped metallic compounds and heteroatoms was prepared by combining KOH activation with pyrolysis. The structure, electrochemical performance and adsorption of SMACs prepared with various activation temperatures, activation times, alkali-carbon ratios and pickling steps were investigated. A hierarchical pore structure existed in all the SMACs, which showed excellent and significantly different properties, including a specific capacitance of 278 F/g, and a high SSA of 2321 m2/g (SMACHF), which retained 100% of its capacitance after 10,000 cycles at 5 A/g and a Pb2+ adsorption capacity of 211.8 mg/g at room temperature (SMACNON). The SMACs contained heteroatom functional groups and Si, Ca and Mg compounds, which did not produce pseudocapacitors but did increase the Pb2+ adsorption capacity and electrochemical cycling stability. The Pb2+ adsorption capacities of SMACNON, SMACPHF and SMACHF corresponded to the effect of the functional group content rather than the effect of the SSA. These porous carbons were derived from inexpensive swine manure, combine suitable porosity with metallic elements and heteroatom doping, and have promising uses in multifunctional applications.
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- 2021
3. A stretchable, asymmetric, coaxial fiber-shaped supercapacitor for wearable electronics
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Guang Wang, Yuxing Zhao, Yuegang Zhang, Yang Liu, Yang Wu, and Hua Yuan
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Supercapacitor ,Materials science ,Fabrication ,business.industry ,02 engineering and technology ,Carbon nanotube ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Capacitance ,Atomic and Molecular Physics, and Optics ,Cathode ,Energy storage ,0104 chemical sciences ,law.invention ,Anode ,law ,Optoelectronics ,General Materials Science ,Electrical and Electronic Engineering ,Coaxial ,0210 nano-technology ,business - Abstract
Fiber-shaped supercapacitors (FSCs), owing to their high-power density and feasibility to be integrated into woven clothes, have drawn tremendous attentions as a key device for flexible energy storage. However, how to store more energy while withstanding various types of mechanical deformation is still a challenge for FSCs. Here, based on a magnetron sputtering method, different pseudocapacitive materials are conformally coated on self-supported carbon nanotube aligned films. This fabrication approach enables a stretchable, asymmetric, coaxial fiber-shaped supercapacitors with high performance. The asymmetric electrode configuration that consists of CNT@NiO@MnOx cathode and CNT@Fe2O3 anode successfully extends the FSC’s electrochemical window to 1.8 V in an aqueous electrolyte. As a result, a high specific capacitance of 10.4 F·cm−3 is achieved at a current density of 30 mA·cm−3 corresponding to a high energy density of 4.7 mWh·cm−3. The mechanical stability of the stretchable FSC is demonstrated with a sustainable performance under strains up to 75% and a capacitance retention of 95% after 2,000 cycles under 75% strain.
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- 2020
4. Direct Construction of Mesoporous Metal Sulfides via Reactive Spray Deposition Technology
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Yang Wang, Radenka Maric, Junkai He, Jared Fee, Steven L. Suib, Lei Jin, Peter Kerns, Alireza Shirazi-Amin, and Yang Wu
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Supercapacitor ,Materials science ,Energy Engineering and Power Technology ,chemistry.chemical_element ,One-Step ,Metal ,Nickel ,Transition metal ,chemistry ,Chemical engineering ,visual_art ,Specific surface area ,Materials Chemistry ,Electrochemistry ,visual_art.visual_art_medium ,Chemical Engineering (miscellaneous) ,Deposition (phase transition) ,Electrical and Electronic Engineering ,Mesoporous material - Abstract
A rapid one-step flame combustion deposition method was developed to fabricate the mesoporous metal sulfides directly on nickel foam without binder and template. The first-row transition metal sulfides, Co9S8, Ni3S4, NiCo2S4, and FeS, were successfully synthesized with three-dimensional architecture, large specific surface area (around 110 m2 g–1), and interconnected pore networks. The binary meso-NiCo2S4 exhibited a high specific capacitance (1350 F g–1 at 10 A g–1), excellent rate capability, and robust cycling stability in both three-electrode half-cells and asymmetric supercapacitor. This study demonstrated a new scalable strategy to obtain mesoporous metal sulfides with high electrochemical performance.
- Published
- 2019
5. Unique holey graphene/carbon dots frameworks by microwave-initiated chain reduction for high-performance compressible supercapacitors and reusable oil/water separation
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Wenqiang Wang, Jie Jin, Xingwei Li, Wenyi Zhang, Yi-Yang Wu, Gengchao Wang, and Hao Jiang
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Supercapacitor ,Materials science ,Renewable Energy, Sustainability and the Environment ,Graphene ,Oxide ,Nanoparticle ,Nanotechnology ,02 engineering and technology ,General Chemistry ,021001 nanoscience & nanotechnology ,Energy storage ,law.invention ,chemistry.chemical_compound ,chemistry ,law ,Specific surface area ,General Materials Science ,0210 nano-technology ,Absorption (electromagnetic radiation) ,Reusability - Abstract
It is still a big challenge to integrate intrinsic modification and self-standing structure construction into graphene via a rapid and facile approach. Herein, we report a sampling and quick in situ chain reduction technology to prepare nitrogen-doped porous graphene frameworks. In this process, easily dispersible graphene serves as an effective receptor for microwave absorption and initiates the reduction of graphene oxide; the reduced part of GO becomes the microwave-absorbing receptor to cause a “chain reduction”, which allows the NPGFs to form in 3–5 s. The as-prepared graphene frameworks maintain the long-range layered structure of the precursor film, while the holey graphene sheets loaded with nanoparticles form a networked structure in the short range. Furthermore, the hierarchical framework with a high specific surface area shows interesting applications in supercapacitors and oil–water separation. The assembled compressible supercapacitor delivered a volumetric energy density of 12.3 mW h cm−3 at a power density of 0.42 W cm−3 and exhibits stable performance under compression. In addition, the graphene frameworks exhibited reusability with mechanical squeezing and extremely high volumetric absorption capacity of 100–243 g cm−3 for different oils and organic solvents, which is much higher than that in other reports (the performance index is ∼1 g cm−3). This study provides a new way to construct a multi-functional graphene self-standing structure, which presents potential application value in catalysis, energy storage, and environmental protection.
- Published
- 2019
6. Salt-assisted pyrolysis of covalent organic frameworks to porous heteroatom-doped carbons for supercapacitive energy storage
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Dongwan Yan, Ryo Kitaura, Kunio Awaga, and Yang Wu
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chemistry.chemical_classification ,Supercapacitor ,Materials science ,Renewable Energy, Sustainability and the Environment ,Heteroatom ,02 engineering and technology ,General Chemistry ,Polymer ,Microporous material ,021001 nanoscience & nanotechnology ,chemistry ,Chemical engineering ,Specific surface area ,General Materials Science ,0210 nano-technology ,Mesoporous material ,Porosity ,Pyrolysis - Abstract
Supercapacitors have attracted intensive research interest due to their advantages including longer cycling ability and higher power density. Porous heteroatom-doped carbons (PHCs) have been regarded as a class of promising electrode materials for supercapacitors because of their unique porous, electronic and chemical properties. However, synthesis of PHCs with hierarchical mesoporous/microporous structures and ultra-high porosity and electrochemical performance remains a great research challenge. In this research, two oxygen and nitrogen co-doped PHCs (denoted as ONC-T1s) are prepared via a salt-assisted pyrolysis method using covalent organic frameworks (COFs) as the precursor. ONC-T1s show a hierarchical porous structure with an ultra-high specific surface area (up to 3451 m2 g−1). The ONC-T1-850-based supercapacitor exhibits a high specific capacitance of 1711 F g−1 at 1 A g−1, an ultra-fast charge–discharge rate up to 500 A g−1 with a specific capacitance of 856 F g−1, and excellent stability. This work establishes a promising strategy for preparation of PHCs using COFs or other porous organic polymers as precursors and demonstrates the great potential of PHC-based supercapacitors.
- Published
- 2019
7. Ni(OH)2/NiSe Nanoparticles Supported on Carbon Microspheres for Long‐Life and High‐Performance Asymmetric Supercapacitors.
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Zhang, Junye, Guo, Hao, Yang, Fan, Wang, Mingyue, Zhang, Tingting, Zhang, Hao, and Yang, Wu
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SUPERCAPACITOR electrodes ,SUPERCAPACITORS ,NANOSTRUCTURED materials ,MICROSPHERES ,ENERGY density ,NANOPARTICLES ,METAL nanoparticles - Abstract
The application of Ni‐MOF in supercapacitors has received widespread attention, but its poor conductivity and bad stability hinder its application. Therefore, Ni‐MOF derived CMs@Ni(OH)2/NiSe with a core‐shell structure was designed. Here, carbon microspheres (CMs) were explored as the conductive substrate to enhance the stability and in situ prepared Ni‐MOF was anchored on the surface of CMs. Then, alkali‐treatment and selenylation were carried out on CMs@Ni−MOF to improve stability and conductivity. The obtained core‐shell nanostructure material possesses a high contact area, excellent synergistic effect and can provide more reactive active sites. The prepared CMs@Ni(OH)2/NiSe shows a higher specific capacitance (2106 F g−1) and excellent cycling performance with a capacitance retention of 95 % after 30000 cycles. Furthermore, the assembled CMs@Ni(OH)2/NiSe//AC device delivers a high energy density of 70.84 Wh kg−1 at the power density of 756.8 W kg−1 and maintains 100 % of the initial capacitance after 40000 cycles. [ABSTRACT FROM AUTHOR]
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- 2022
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8. The Optimal Energy Storage Capacity Configuration of Photovoltaic Generation under Changing Meteorological Conditions
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Bei Zhao, Jian Liang Zhong, Hai Bao, and Ming Yang Wu
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Insolation ,Supercapacitor ,Engineering ,business.industry ,MOSFET ,Photovoltaic system ,General Engineering ,Electrical engineering ,Dc bus voltage ,business ,Signal ,Energy storage ,Power (physics) - Abstract
In the paper, energy storage system and charge and discharge control strategy for large-scale photovoltaic generation are designed. The optimal energy storage capacity is configurated for PV array. The energy storage system and control module for PV generation are built in MATLAB-Simulink platform. Supercapacitor (SC) is the energy storage element. Considering the insolation and temperature under the changing meteorological conditions, the output power would be fluctuant. By controlling MOSFET switches based on power signal, SC will charge when the lighting is adequate and discharge in the instance of lack of light to keep DC bus voltage in constant. Configuring the optimal energy storage capacity by simulation, the result proves that the control strategy is feasible and the configuration is optimal.
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- 2014
9. A long-life pseudocapacitive triazine-based porous organic framework and resulting N-doped microporous carbons for supercapacitance application.
- Author
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Wang, Mingyue, Xue, Rui, Guo, Hao, and Yang, Wu
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TRIAZINES ,OXYGEN reduction ,ELECTRIC double layer ,POROUS materials ,PORE size distribution - Published
- 2019
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10. Ni@NC@NiCo-LDH nanocomposites from a sacrificed template Ni@NC@ZIF-67 for high performance supercapacitor.
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Chen, Yuan, Guo, Hao, Yang, Fan, Wu, Ning, Zhang, Junye, Peng, Liping, Liu, Bingqing, Pan, Zhilan, and Yang, Wu
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SUPERCAPACITORS , *SUPERCAPACITOR performance , *POROUS metals , *POROUS materials , *ENERGY density , *FLORAL morphology - Abstract
A metal porous carbon (Ni@NC) supported nickel/cobalt layered double hydroxide (NiCo-LDH) (Ni@NC@NiCo-LDH) with a cauliflower morphology was synthesized by a successive double template method. At first a nickel metal-organic framework (Ni-MOF) was prepared and used as a sacrifice template to produce metal porous carbon (Ni@NC). Then the prepared conductive porous carbon material was exploited as a substrate for in-situ growing of ZIF-67 on its surface. Lastly the obtained Ni@NC@ZIF-67 was further used as a sacrifice template to prepare the final electrode material Ni@NC@NiCo-LDH by Ni2+ etching and co-precipitation. The cooperation of Ni@NC with excellent conductivity and NiCo-LDH with superior pseudocapacitive property yielded a synergistic effect, which effectively improved the electrochemical performance of the resulted electrode material. And the special flower morphology exposed more redox active sites and provided proper charge transport path for enhanced electrochemical performance. The prepared Ni@NC@NiCo-LDH exhibited a high specific capacitance of 1761.8 F·g−1 at the current density of 1 A·g−1. The assembled Ni@NC@NiCo-LDH//AC asymmetric supercapacitor also displayed an acceptable energy density (39.27 Wh·kg−1 at the power density of 757.21 W·kg−1) and ultrahigh cycling stability (94.74% capacitance retention after 25000 cycles at 10 A g−1). [Display omitted] • Ni@NC@NiCo-LDH was prepared by combination of Ni@NC and NiCo-LDH for the first time. • Ni@NC@NiCo-LDH had a big specific capacitance. • The assembled supercapacitor with Ni@NC@NiCo-LDH and AC had excellent cycle stability. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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11. A new Co-ZIF derived nanoporous cobalt-rich carbons with high-potential-window as high-performance electrodes for supercapacitors.
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Wang, Xiao, Yue, Liguo, Ai, Jiebing, Shi, Zheru, Lei, Xi, Sun, Taotao, Guo, Hao, and Yang, Wu
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NANOPOROUS materials , *ACTIVATED carbon , *SUPERCAPACITOR electrodes - Abstract
Abstract In this work, a Co-ZIF material and the derived nanoporous cobalt-rich carbons by direct carbonization of this Co-ZIF material were synthesized and used as electrode materials for supercapacitors. This ZIF material exhibited a high specific capacitance of 160.3 F g−1 at 0.5 A g−1, an excellent rate capability (73.72 F g−1 at 10 A g−1), and a good cycling stability with 100% of its initials specific capacitance after 8000 cycles. In addition, the obtained derived nanoporous carbons displayed ideal capacitor behaviors and were promising electroactive materials for supercapacitors at low current density. The nanoporous carbon obtained at 650 °C possessed a highest specific capacitance of 393 F g−1 at 0.5 A g−1 and a wide potential application range of −1.0–0.33 V. In addition, a symmetric supercapacitor device consisting of Z-C-650 and activated carbon exhibited a maximum energy density of 61.23 Wh Kg−1 at a power density of 700 W kg−1 and predicted that Z-C-650 could be used as a potential energy storage material. Graphical abstract Image 1 Highlights • Cobalt zeolite imidazolate framework and derived nanoporous carbons were prepared. • The framework and the derived carbons showed good electrochemical properties. • The assembled symmetric supercapacitor showed good performances. • The capacitor had energy density of 61.23 Wh kg−1 at 700 W kg−1 power density. [ABSTRACT FROM AUTHOR]
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- 2019
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12. Non-metallic element modified metal-organic frameworks as high-performance electrodes for all-solid-state asymmetric supercapacitors.
- Author
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Yue, Liguo, Guo, Hao, Wang, Xiao, Sun, Taotao, Liu, Hui, Li, Qi, Xu, Mengni, Yang, Yuying, and Yang, Wu
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METAL-organic frameworks , *SUPERCAPACITOR electrodes , *ELECTROCHEMISTRY , *CURRENT density (Electromagnetism) , *CRYSTAL defects - Abstract
Graphical abstract Abstract This paper is the first study of the application of non-metallic element modified metal-organic frameworks in supercapacitors. Three-dimensional metal-organic frameworks modified by non-metallic element have a novel flower cluster structure, which effectively improve the structural stability and the electrochemical performance of the supercapacitors. The electrochemical performances of the materials modified by the vulcanizing agent are particularly significant with a high specific capacitance of 1453.5F g−1 at a current density of 1 A g−1 and excellent cycle stability (retention rate of 89.23% after 5000 cycles). In addition, the assembled asymmetric supercapacitor S@Ni-MOF//AC also shows a high energy density of 56.85 Wh kg−1 at power density of 480 W kg−1 and good cycle stability with a capacitance retention of 86.67% after 20,000 cycles at current density 5 A g−1. As a result, metal-organic frameworks materials modified by the non-metallic element make up for the crystal defects, which can be used as promising electrode materials for practical applications. [ABSTRACT FROM AUTHOR]
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- 2019
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13. Solvothermal synthesis of pompon-like nickel-cobalt hydroxide/graphene oxide composite for high-performance supercapacitor application.
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Lei, Xi, Shi, Zheru, Wang, Xiao, Wang, Ting, Ai, Jiebing, Shi, Peiling, Xue, Rui, Guo, Hao, and Yang, Wu
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FLUORINE compounds , *FASCIOLA hepatica , *THERMAL analysis , *GRAPHENE oxide , *DIGITAL image processing - Abstract
Novel pompon-like nickel-cobalt double hydroxide/graphene oxide (Ni(OH) 2 /Co(OH) 2 /GO) composites were successfully synthesized via a simple one-step solvothermal process. Their structure, morphology, surface and electrochemical properties were characterized by scanning electron microscopy(SEM), transmission electron microscopy(TEM), X-ray diffraction(XRD), electrochemical impedance spectroscopy (EIS) and galvanostatic charge/discharge(GCD) curves. The composite electrodes showed typical pseudocapacitance performances. When addition amount of graphene oxide was 10mg, resulted composite exhibited a high specific capacitance (2050.6 F g −1 at 1 A g −1 ) and good cycling stability with a capacitance retention of 84% after 1000 cycles. Appropriate amount of graphene oxide not only served as a structural director but also enhanced the conductivity and stability of the resulted composite. The attractive performances and facile fabrication made the prepared Ni(OH) 2 /Co(OH) 2 /GO composite become a promising candidate for low-cost high-performance energy storage device. [ABSTRACT FROM AUTHOR]
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- 2018
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14. Metal-organic frameworks (MOFs) derived hollow microspheres with rich sulfur vacancies for hybrid supercapacitors.
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Chen, Yuan, Guo, Hao, Yang, Fan, Wu, Ning, Pan, Zhilan, Liu, Bingqing, Wang, Mingyue, Xu, Jiaxi, and Yang, Wu
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METAL-organic frameworks , *NEGATIVE electrode , *SULFUR , *MICROSPHERES , *SUPERCAPACITORS , *LITHIUM sulfur batteries - Abstract
• A hollow structure PZ-20 was prepared by controlling the ligand exchange time. • Hollow structure r-NiCo 2 S 4 with sulfur vacancies for more active sites and redox reactions was synthesized. • The fabricated structure exhibited an ultra-high specific capacitance. • The assembled device presented an high energy density of 43.80 Wh·kg−1 under 800 W·kg−1. Defect and hollow structure on transition metal sulfides can produce abundant active sites and shorten electron/ion diffusion paths, improving the conductivity of electrochemically active materials. In this study, an effective strategy was proposed for preparing r-NiCo 2 S 4 electrode materials with sulfur vacancies and hollow structures and resulted excellent electrochemical performance through ligand exchange followed chemical reduction. Due to the unique structure, the prepared r-NiCo 2 S 4 electrode exhibited excellent specific capacitance (1406.4 F g−1 at 1 A g−1) and rate capacity (90.03%). Additionally, a hybrid supercapacitor r-NiCo 2 S 4 //AC HSC was assembled using r-NiCo 2 S 4 as the positive electrode and AC as the negative electrode. It presented an excellent energy density of 43.8 Wh kg−1 under 800 W kg−1 and cycling performance with 93.93% capacity retention after 10,000 cycles at 5 A g−1. This study provided a simple strategy for design and optimization of electrode materials with a unique hollow structure and sulfur vacancies. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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15. A novel CDs coated polyoxometalate/metal-organic framework composite for supercapacitors.
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Guo, Hao, Chen, Yuan, Wu, Ning, Peng, Liping, Yang, Fan, Pan, Zhilan, Liu, Bingqing, Zhang, Hao, Li, Cuiliu, and Yang, Wu
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SUPERCAPACITORS , *SUPERCAPACITOR electrodes , *ENERGY density , *CARBON electrodes , *ELECTRIC conductivity , *NEGATIVE electrode , *COMPOSITE materials - Abstract
Considering the high electrical conductivity of carbon dots (CDs) and good oxidation-reduction property of polyoxometalates (POMs), a novel CDs coated POMs /metal organic frameworks (POMOFs) composition structure, CDs@PMo 12 /Ni-MOF, was prepared by hydrothermal reaction in this work. PMo 12 was encapsulated in the Ni-MOF framework to form the POMOF composite material, which realized the fixation of water-soluble [PMo 12 O 40 ]3- (PMo 12). A comparison study on the cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD) of the resulting CDs@PMo 12 /Ni-MOF with different compositions revealed that 6CDs@PMo 12 /Ni-MOF was better formulation in terms of specific capacity (748.8 C·g−1 at 1 A·g−1) and rate performance (75.93 % at 10 A·g−1). Furthermore, a hybrid supercapacitor device was assembled using 6CDs@PMo 12 /Ni-MOF as positive electrode and activated carbon (AC) as negative electrode, which showed an high energy density of 39.22 Wh·kg−1 under 749.9 W·kg−1 and excellent cyclic stability (98.4 % for 20000 cycles at 5 A·g−1). [Display omitted] • Fixation of water-soluble PMo 12 was realized to form POMOF composite material. • CDs@PMo 12 /Ni-MOF has excellent rate performance and cycle stability. • 6CDs@PMo 12 /Ni-MOF exhibits high specific capacitance and energy density. [ABSTRACT FROM AUTHOR]
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- 2022
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16. Zeolite-imidazole framework derived nickel-cobalt hydroxide on ultrathin MXene nanosheets for long life and high performance supercapacitance.
- Author
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Guo, Hao, Zhang, Junye, Xu, Mengni, Wang, Mingyue, Yang, Fan, Wu, Ning, Zhang, Tingting, Sun, Lei, and Yang, Wu
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LONGEVITY , *NANOSTRUCTURED materials , *HYDROXIDES , *ENERGY density , *POWER density , *CHARGE transfer , *POLYANILINES , *ALKALIES - Abstract
• Design and fabrication of self-assembled Ni-doped ZIF-67 (NiCo-ZIF-67). • Sandwich MXene/NiCoZDHis used for supercapacitor for the first time. • The specific capacitance of MXene/NiCoZDH is greater than that of MXene and ZIF-67. • Excellent cyclic stability of MXene/NiCoZDH (90.9%@30,000). Zeolite-imidazole frameworks (ZIFs) are the promising materials for supercapacitors (SC), however, the shortcomings of easy agglomeration, low conductivity and low stability limit the further improvement of their electrochemical properties. Hence, in order to produce high-performance SC, ZIFs are usually grown directly on some conductive substrates or post-treated. In this paper, MXene was explored as the substrate and Ni-doped ZIF-67 (denoted as NiCo-ZIF-67) was in situ anchored on negatively charged MXene surface via chemical bonds to supply more available active sites for the enhancement of capacitance. At the same time, the surface functional groups in MXene can also enhance the chemical connection between NiCo-ZIF-67 and MXene to attain higher ion diffusion and charge transfer rates. The size of the NiCoZDH (ZIFs-derived double hydroxide denoted as ZDH) obtained by the alkali treatment of NiCo-ZIF-67 is smaller, which is good for increasing specific surface area. The prepared composite MXene/NiCoZDH electrode shows a larger specific capacitance (877 F g-1) than MXene/NiCo-ZIF-67 (460 F·g-1), NiCoZDH (354 F g-1), NiCo-ZIF-67 (130 F g-1) and MXene (15 F g-1), and superior cycling stability with a capacitance retention of 90.9% after 30000 cycles. Additionally, the assembled asymmetric supercapacitor delivers an energy density of 34 Wh kg-1 at the power density of 748 W kg-1 and maintains 93.3% of the initial capacitance after 30,000 cycles. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
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17. Walnut shell-derived porous carbon integrated with Ni-MOF/SPANI composites for high-performance supercapacitor.
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Zhang, Junye, Guo, Hao, Yang, Fan, Wang, Mingyue, Zhang, Hao, Zhang, Tingting, Sun, Lei, Yang, Meng, and Yang, Wu
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SUPERCAPACITORS , *SANDWICH construction (Materials) , *WALNUT , *ENERGY density , *SUPERCAPACITOR electrodes , *ENERGY storage , *CARBON composites - Abstract
In this paper, novel hybrid nanomaterials constituting carbonized biomass materials derived from walnut shells and metal-organic framework (MOF) have been researched as a new class of renewable supercapacitor materials for electrochemical energy storage. One synthetic route is employed to grow Ni-MOF in the peripheries and channels of walnut shells derived carbon (WS), which had been carbonized previously by heat treatment in air at 850 °C to produce a highly porous network, and vulcanized polyaniline (SPANI) is used as a dummy plate preventing the agglomeration of MOFs and a wire connecting WS and MOFs, which easily improves the electron transfer and enhances the conductivity of the electrode material. The specific capacitance of the obtained WS@Ni-MOF composite is up to 4 times that of the biochar at the current density of 1 A g-1. The connection of SPANI also obviously accelerates the transfer of electrolyte ions. The resulting specific capacitance could reach 14 times of the biochar and exhibit high cycle stability (retention rate of 90.4% after 20000 cycles). In addition, the assembled asymmetrical supercapacitor (ASC) shows a high energy density of 34.79 Wh kg-1 at the power density of 824 W kg-1. This work provides a brilliant renewable candidate for the excellent energy storage device and a promising route design strategy for preparation of high performance and long life electrode materials. [Display omitted] • Design and fabrication of self-assembled Walnut shell-derived carbon and MOF composites. • WS@Ni-MOF/SPANI, as a new electrode material with sandwich structure, applied for supercapacitors for the first time. • The specific capacitance of WS@Ni-MOF/SPANI is greater than that of WS, Ni-MOF and SPANI. • Excellent cyclic stability of WS@Ni-MOF/SPANI (90.4%@20000). [ABSTRACT FROM AUTHOR]
- Published
- 2021
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18. Nitrogen-doped carbon-enriched MOF and derived hierarchical carbons as electrode for excellent asymmetric aqueous supercapacitor.
- Author
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Huang, Dongdong, Chen, Li, Yue, Liguo, Yang, Fan, Guo, Hao, and Yang, Wu
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CARBON electrodes , *ENERGY density , *ENERGY storage , *POWER density , *NITROGEN , *SUPERCAPACITOR electrodes , *CHEMICAL stability , *METAL-organic frameworks , *DOPING agents (Chemistry) , *CHEMICAL synthesis - Abstract
• A simple ultrasound-assisted method was used to synthesize nitrogen-containing p - π conjugated-organic ligands. • Nitrogen-containing conjugated organic ligands have good conductivity. • Carbon-enriched MOFs and derived porous carbon have excellent electrochemical performance. • The change law of electrochemical performance was explored with gradient temperature. • The MOF-B-600//AC ASC device exhibits a high energy density of 63.62 Wh·kg−1 at power density of 400 W·kg−1. [Display omitted] This article aims to use nitrogen-doped metal p - π conjugated-organic frameworks and derived carbon-rich electrode materials for high-performance electrode materials. Nitrogen-doped contributes to the energy storage performance, and the p-π conjugated-organic ligands of the conjugated system can not only improve the stability of the structure, but increase the conductivity of the material. Gradient carbonization can explore the maximum electrochemical potential of MOF-B, from which the previous 1271.0 increased to 2727.5 F·g−1 at a current density of 1.0 A·g−1. The excellent capacitance retention rate is 86.67% of the initial value at a high current density after 20,000 cycles. Besides, the MOF-B-600//AC also shows a high energy density of 63.62 Wh·kg−1 at a power density of 400 W·kg−1 and good coulomb efficiency of 90.7%. As a result, the excellent electrochemical performance of the nitrogen-doped and carbon-enriched MOF-B-600 has potential application prospects in energy storage devices. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
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19. Sandwich-like GO@Co(OH)2/PANI derived from MOFs as high-performance electrode for supercapacitors.
- Author
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Xu, Mengni, Guo, Hao, Xue, Rui, Wang, Mingyue, Wu, Ning, Wang, Xiaoqiong, Zhang, Junye, Zhang, Tingting, and Yang, Wu
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SANDWICH construction (Materials) , *COMPOSITE materials , *ENERGY storage , *CHARGE exchange , *GRAPHENE oxide , *SUPERCAPACITOR electrodes , *PROTON conductivity - Abstract
Sandwich-like layered composite materials possess a high contact area and can expose many reactive active sites, which exhibit great potential in the application of supercapacitors. In this paper, a sandwich-like composite material was synthesized based on polyaniline (PANI), graphene oxide (GO) and ZIF-67 (denoted as GO@ZIF-67/PANI). Among them, GO is designed as a deposition substrate of ZIF-67 and transfer scaffold of electrons and PANI works as a wire to connect graphene layers and nanoparticles, which increases the conductivity of the material and makes the electron transfer easier. At the current density of 1 A g−1, the specific capacitance of the ZIF-67 composite is up to 5 times that of the ZIF-67. After alkali treatment, ZIF-67 is converted into Co(OH) 2 nanosheet (denoted as GO@Co(OH) 2 /PANI), which remarkably promotes the transfer of electrolyte ions and electrons. At the current density of 1 A g−1, the resulting specific capacitance is 15 times more than ZIF-67. The excellent energy storage performance indicates that the prepared novel composite material has important development prospects in energy storage. Image 1 • Simple & cheap. • GO@Co(OH) 2 /PANI, a new electrode material with special sandwich structure, applied for supercapacitors for the first time. • The specific capacitance of GO@Co(OH) 2 /PANI is up to 15 times that of the ZIF-67. • Excellent cyclic stability of GO@Co(OH) 2 /PANI (80%@20,000).. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
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20. MoS2/Ni(OH)2 composites derived from in situ grown Ni-MOF coating MoS2 as electrode materials for supercapacitor and electrochemical sensor.
- Author
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Yang, Wenhu, Guo, Hao, Fan, Tian, Zhao, Xin, Zhang, Longwen, Guan, Qixia, Wu, Ning, Cao, Yujuan, and Yang, Wu
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SUPERCAPACITOR electrodes , *SUPERCAPACITORS , *ELECTROCHEMICAL sensors , *CARBON electrodes , *NEGATIVE electrode , *ENERGY density , *ENERGY storage - Abstract
[Display omitted] • MoS 2 @Ni-MOF was prepared and alkalized to obtain MoS 2 /Ni(OH) 2. • MoS 2 /Ni(OH) 2 has high specific capacitance and long cycling life for supercapacitor. • MoS 2 /Ni(OH) 2 was used to construct electrochemical sensor for HQ and CC. A nickel-based metal-organic framework (Ni-MOF) layer was in situ grown on the surface of the sheet MoS 2 to synthesize MoS 2 @Ni-MOF as a precursor. In order to improve the properties of the precursor material, the final MoS 2 /Ni(OH) 2 material was obtained by alkalizing the precursor material. Supercapacitors and electrochemical sensors were prepared by MoS 2 /Ni(OH) 2 composite material. The test indicates that alkaline treatment of Ni-MOF materials is helpful to improve electrochemical performance. MoS 2 /Ni(OH) 2 material used as supercapacitor electrode has a high specific capacitance of 2192 F g−1 and excellent cyclic stability (the capacitance retention rate remains 85.19% after 10,000 charge/discharge cycles). The hybrid supercapacitor (HSC) was assembled with MoS 2 /Ni(OH) 2 as the positive electrode and activated carbon as the negative electrode. The MoS 2 /Ni(OH) 2 //AC HSC device shows an excellent energy density of 50.58 Wh kg−1 at the power density of 800 W·Kg−1. In addition, the MoS 2 /Ni(OH) 2 modified GCE electrode is an excellent electrochemical sensor for the simultaneous determination of hydroquinone (HQ) and catechol (CC). The modified electrode provides wide linear ranges of 1 ∼ 500 and 2 ∼ 400 μM and low detection limits of 0.43 and 0.48 μM for HQ and CC, respectively (S/N=3). The MoS 2 /Ni(OH) 2 material can be applied to supercapacitors and electrochemical sensors, indicating that the material has great potential application value in energy storage and biosensing. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
21. A new two-dimensional covalent organic framework with intralayer hydrogen bonding as supercapacitor electrode material.
- Author
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Li, Li, Lu, Feng, Guo, Hao, and Yang, Wu
- Subjects
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HYDROGEN bonding , *SUPERCAPACITORS , *SUPERCAPACITOR electrodes , *POWER density , *ENERGY density , *LONGEVITY , *MELAMINE , *THIOPHENES - Abstract
A new two-dimensional covalent organic framework (DBT-MA-COF) is designed and synthesized via Carbon–Nitrogen coupling reaction by using 2,5-dibromothiophene (DBT) and melamine (MA) as the monomers. The C−Hˑ N intralayer hydrogen bonding exists in the structure of DBT-MA-COF so that a plane rigid structure can be maintained. The material exhibits a quasi-reversible redox process caused by triazine units and the transformation of the quinone and aromatic structures to make the DBT-MA-COF possess pseudocapacitive characteristics. DBT-MA-COF has high heteroatom content for the existence of triazine and thiophene units, which can accelerate the transfer of electrolyte ions on the surface of DBT-MA-COF electrode and improve the solution conductivity of the material. The assembled asymmetric supercapacitor DBT-MA-COF//C-CTS ASC has a high energy density of 32.1 W h kg−1 with the power density of 800 W kg−1. The cycle life of the device is excellent which can reach 83% even after 30,000 continuous galvanostatic charge-discharge cycles. The strategy in this work provides a line of thinking to design and prepare new COFs used as long life and pseudocapacitive supercapacitor materials. Image 1 • A novel covalent organic framework(DBT-MA-COF) is synthesized via Carbon-Nitrogen coupling reaction. • C-H...N intralayer hydrogen bonding existed in DBT-MA-COF leads to a plane rigid structure. • The COF has pseudocapacitive characteristics for a transformation of quinone and aromatic structures in triazine unit. • The existence of triazine and thiophene units improves the conductivity of the resulting material. • Assembled asymmetric supercapacitor shows a high energy density of 32.1Wh kg-1 and the long life of 83% after 30000 cycles. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
22. Metal-organic frameworks derived N, S co-doped bimetal nanocomposites as high-performance electrodes materials for supercapacitor.
- Author
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Li, Qi, Yue, Liguo, Li, Li, Liu, Hui, Yao, Wenqin, Wu, Ning, Zhang, Longwen, Guo, Hao, and Yang, Wu
- Subjects
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SUPERCAPACITOR electrodes , *METAL-organic frameworks , *NANOCOMPOSITE materials , *ENERGY density , *NITROGEN , *ELECTRODE performance , *POWER density - Abstract
Nitrogen sulfur co-doped bimetal nanocomposites (NS-BNs) are prepared through vulcanization and annealing using bimetallic Ni/Co-MOF as a precursor. The nitrogen sulfur co-doped bimetal nanocomposites have abundant electroactive sites and redox reaction centres, which exhibit remarkable electrochemical performance as electrode materials for supercapacitor. The specific capacitance could reach 1529 F g−1 at a current density of 1 A g−1 and excellent cycle stability (retention rate of 89.29% after 10000 cycles). After the current density is expanded ten times, the specific capacitance can still reach 1069 F g−1, indicating superior rate performance. Furthermore, the assembled asymmetric supercapacitor displayed a high energy density of 41.04 Wh kg−1 at power density of 750 W kg−1. As a result, non-metal doped nanocomposites material has promised applications for electrochemical supercapacitors. Image 1 • Advanced asymmetric supercapacitor device assembled by nitrogen sulfur co-doped bimetal nanocomposites. • Outstanding electrochemical behaviour and ultrahigh specific capacitance of 1529 F g−1 at 1 A g−1. • High energy density of 41.04 Wh kg−1 at power density of 750 W kg−1. • Remarkable long term cycle stability with 90% after 10000 charge-discharge cycles. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
23. Ni-MOF coating MoS2 structures by hydrothermal intercalation as high-performance electrodes for asymmetric supercapacitors.
- Author
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Yue, Liguo, Wang, Xiao, Sun, Taotao, Liu, Hui, Li, Qi, Wu, Ning, Guo, Hao, and Yang, Wu
- Subjects
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SUPERCAPACITOR electrodes , *SUPERCAPACITORS , *COMPOSITE structures , *ENERGY density , *COMPOSITE materials , *ENERGY storage , *POTENTIAL energy - Abstract
• The method of synthesizing the composite has been novel and has not been reported so far. • MoS 2 @Ni-MOF shows the remarkable specific capacitance. • The introduction of sulfur has established a bridge for the charge transfer. • The MoS 2 @Ni-MOF//AC ASC device exhibits a high energy density of 72.93 Wh kg−1 at power density of 375 W·kg−1. • The assembled all-solid-state MoS 2 @Ni-MOF//AC can illuminate commercial red LED lamps for up to 30 s. Two-dimensional metal-organic frameworks and nanoflowers of the MoS 2 form a composite structure as an electrode material for high-performance supercapacitor application. MoS 2 expands in the accordion-type Ni-MOF layers, and -S- joins the two materials to form a Ni-MOF coating MoS 2 composite structure. The composite material MoS 2 @Ni-MOF combines the structural characteristics of the Ni-MOF and MoS 2 , and effectively improves the electrochemical performance. The basic skeleton structure of the MoS 2 @Ni-MOF material remains unchanged, showing a remarkable specific capacitance of 1590.24 F·g−1 at a current density of 1.0 A·g−1 and an excellent cycle stability (retention rate of 87.97% after 20,000 cycles at current of 5.0 A·g−1). Due to the special composite structure of MoS 2 @Ni-MOF, the as-assembled MoS 2 @Ni-MOF//AC assymmetric supercapacitor (ASC) device exhibits a maximum energy density of 72.93 Wh·kg−1 at a power density of 375 W·Kg−1. These excellent electrochemical properties indicate that the MoS 2 @Ni-MOF has potential applications in energy storage devices. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
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