scholarly journals Ethylenediamine-Catalyzed Preparation of Nitrogen-Doped Hierarchically Porous Carbon Aerogel under Hypersaline Condition for High-Performance Supercapacitors and Organic Solvent Absorbents

Nanomaterials ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 771 ◽  
Author(s):  
Jing Gao ◽  
Xuan Zhang ◽  
Jiaxing Yang ◽  
Junxi Zhou ◽  
Mingxing Tong ◽  
...  

The simple and cost-efficient preparation of high-performance nitrogen-doped carbon aerogel (N-CA) for supercapacitors and other applications is still a big challenge. In this work, we have presented a facile strategy to synthesize hierarchically porous N-CA, which is based on solvothermal polymerization of phenol and formaldehyde under hypersaline condition with ethylenediamine (EDA) functioning as both a catalyst and a nitrogen precursor. Benefited from the catalytic effect of EDA on the polymerization, the obtained N-CA has a predominant amount of micropores (micropore ratio: 52%) with large specific surface area (1201.1 m2·g−1). In addition, nitrogen doping brings N-CA enhanced wettability and reduced electrochemical impedance. Therefore, the N-CA electrode shows high specific capacitance (426 F·g−1 at 1 A·g−1 in 0.5 M H2SO4) and excellent cycling stability (104% capacitance retention after 10,000 cycles) in three-electrode systems. Besides, a high energy density of 32.42 Wh·kg−1 at 800 W·kg−1 can be achieved by symmetric supercapacitor based on the N-CA electrodes, showing its promising application for energy storage. Furthermore, N-CA also exhibits good capacity and long recyclability in the absorption of organic solvents.

Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1143 ◽  
Author(s):  
Anil Yedluri ◽  
Tarugu Anitha ◽  
Hee-Je Kim

Hierarchical NiMoO4/NiMoO4 nanoflowers were fabricated on highly conductive flexible nickel foam (NF) substrates using a facile hydrothermal method to achieve rapid charge-discharge ability, high energy density, long cycling lifespan, and higher flexibility for high-performance supercapacitor electrode materials. The synthesized composite electrode material, NF/NiMoO4/NiMoO4 with a nanoball-like NF/NiMoO4 structure on a NiMoO4 surface over a NF substrate, formed a three-dimensional interconnected porous network for high-performance electrodes. The novel NF/NiMoO4/NiMoO4 nanoflowers not only enhanced the large surface area and increased the electrochemical activity, but also provided an enhanced rapid ion diffusion path and reduced the charge transfer resistance of the entire electrode effectively. The NF/NiMoO4/NiMoO4 composite exhibited significantly improved supercapacitor performance in terms of a sustained cycling life, high specific capacitance, rapid charge-discharge capability, high energy density, and good rate capability. Electrochemical analysis of the NF/NiMoO4/NiMoO4 nanoflowers fabricated on the NF substrate revealed ultra-high electrochemical performance with a high specific capacitance of 2121 F g−1 at 12 mA g−1 in a 3 M KOH electrolyte and 98.7% capacitance retention after 3000 cycles at 14 mA g−1. This performance was superior to the NF/NiMoO4 nanoball electrode (1672 F g−1 at 12 mA g−1 and capacitance retention 93.4% cycles). Most importantly, the SC (NF/NiMoO4/NiMoO4) device displayed a maximum energy density of 47.13 W h kg−1, which was significantly higher than that of NF/NiMoO4 (37.1 W h kg−1). Overall, the NF/NiMoO4/NiMoO4 composite is a suitable material for supercapacitor applications.


NANO ◽  
2019 ◽  
Vol 14 (04) ◽  
pp. 1950049 ◽  
Author(s):  
Jingjing Lin ◽  
Song Yan ◽  
Xiaojie Zhang ◽  
Yueran Liu ◽  
Jun Lian ◽  
...  

Holey Fe-Anderson-type polyoxometalate/polyaniline/graphene (PPG) hybrid materials were first prepared by anchoring Anderson-type polyoxometalates [FeMo6O[Formula: see text]H6][Formula: see text] (FeMo[Formula: see text] onto graphene modified with polyaniline via a facile hydrothermal treatment. The as-prepared materials exhibited an excellent electrochemical performance with a high specific capacitance of 1366 F g[Formula: see text] at 1 A g[Formula: see text] and outstanding cycling stability (97.6% capacitance retention after 5000 cycle times). The uptake of polyaniline/FeMo6 nanoparticles on graphene not only provided the pseudocapacitance but also weakened the aggregation between the graphene layers, resulting in a higher surface area compared with pure graphene. In addition, the AC//PPG-15 asymmetric supercapacitor device showed a high energy density of 24.65[Formula: see text]W h kg[Formula: see text] at a low power density of 326.25[Formula: see text]W kg[Formula: see text] and good cycling stability (94.82% capacitance retention after 5000 cycles). Hence, the as-prepared PPG hybrid materials in this work possess tremendous potential as electrodes for high-performance supercapacitors.


Author(s):  
Shiying Lin ◽  
Lanlan Mo ◽  
Tao Lyu ◽  
Feijun Wang

Abstract Heteroatom doping is an effective modification to improve electrochemical performance of carbon materials as electrodes in storage devices and multi-doping works better because of synergistic effect. In this report, a N/O/S multi-doped carbon nanospheres (SLS/PANI-700) are prepared from crosslinking hydrogel beads of polyaniline and sodium lignosulfonate. The addition of sodium lignosulfonate significantly improve the electrochemical performance of PANI-based carbon by changing micromorphology, building interconnected network and offering diverse doping. SLS/PANI-700 has ultrahigh specific surface area of 2861 m2 g−1, well-developed hierarchically porous structure, interconnected conducting carbon network and high N and O concentration. Take these advantages, it delivers very high capacitance of 487.7 F g−1 at 1 A g−1, a superior rate retention with capacitance of 373.6 F g−1 at a high current density of 20 A g−1 as electrode material. The assembled symmetric supercapacitor device exhibits a very high energy density of 43.68 Wh kg−1 at 488.98 W kg−1 and keeps 21.18 Wh kg−1 under a high power density of 8664.54 W kg−1. Based on these properties, SLS/PANI-700 possesses a great promising potential as electrode material for advanced supercapacitor.


2020 ◽  
Vol 15 (1) ◽  
pp. 147-153
Author(s):  
Yucai Li ◽  
Yan Zhao ◽  
Dong Zhang ◽  
Shiwei Song ◽  
Jian Wang ◽  
...  

Electrochemical performance of the electrode materials is seriously dependent on the structure and morphology of the electrode material. In this work, the nanoflower-like Co3O4 samples are successfully prepared on Ni foam via a facile hydrothermal method. The as-fabricated Co3O4 samples exhibit superior electrochemical performance with a high specific capacitance of 382.6 C g-1 at 1 A g-1 and excellent capacitance retention. In addition, the as-fabricated device presents a high energy density of 23.6 Wh kg-1 at a power density of 508.6 W kg-1 and excellent cycle stability with a capacitance retention of 81.2% after 10000 cycles, indicating a promising application as electrodes for energy storage device.


2021 ◽  
Author(s):  
Chaofei Guo ◽  
Jiaojiao Xu ◽  
Li-Ping Lv ◽  
Shuangqiang Chen ◽  
Weiwei Sun ◽  
...  

Lithium-sulfur batteries are attracting more attention for high theoretical capacity and high energy density. And in order to overcome the problem of short cycling performance, low sulfur loading and shuttle...


2018 ◽  
Vol 47 (47) ◽  
pp. 17146-17152 ◽  
Author(s):  
Xiao Liang ◽  
Qiufan Wang ◽  
Yun Ma ◽  
Daohong Zhang

A two-ply CNT yarn asymmetric supercapacitor was fabricated by assembling a CuCo2O4 nanowire positive electrode and a PPy nanoparticle negative electrode. The full cell exhibits a high specific capacitance of 59.55 mF cm−2 and a high energy density of 0.02 mW h cm−2.


Materials ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1626 ◽  
Author(s):  
Muhammad Fahim ◽  
Anwar ul Haq Ali Shah ◽  
Salma Bilal

The use of electroactive polyaniline (PANI) as an electrode material for a symmetric supercapacitor has been reported. The material was synthesized via interfacial polymerization, using ammonium per sulfate, dodecylbenzene sulfonic acid (DBSA), and gasoline, respectively, in the oxidant, dopant, and novel organic phase, and was subsequently employed as an electrode material to design a binder-free symmetric capacitor. As properties of PANI rely on the method of synthesis as well as reaction parameters, the present combination of reactants, at pre-optimized conditions, in the interfacial polymerization, led to the formation of PANI exhibiting a high specific capacitance (712 Fg−1 at 0.5 Ag−1), a good rate capability (86% capacitance retention at 10 Ag−1), a very low solution resistance (Rs = 0.61 Ω), and a potential drop (IR = 0.01917 V). The device exhibited a high energy density of 28 Whkg−1, at a power density of 0.28 kWkg−1, and retained as high as 15.1 Whkg−1, at a high power density of 4.5 kWkg−1. Moreover, it showed an excellent cycling stability and retained 98.5% of coulombic efficiency after 5000 charge discharge cycles, without showing any signs of degradation of polymer.


Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 318
Author(s):  
Yudan Yuan ◽  
Yi Sun ◽  
Zhichen Feng ◽  
Xingjian Li ◽  
Ruowei Yi ◽  
...  

A facile and environmentally friendly fabrication is proposed to prepare nitrogen-doped hierarchical porous activated carbon via normal-pressure popping, one-pot activation and nitrogen-doping process. The method adopts paddy as carbon precursor, KHCO3 and dicyandiamide as the safe activating agent and nitrogen dopant. The as-prepared activated carbon presents a large specific surface area of 3025 m2·g−1 resulting from the synergistic effect of KHCO3 and dicyandiamide. As an electrode material, it shows a maximum specific capacitance of 417 F·g−1 at a current density of 1 A·g−1 and very good rate performance. Furthermore, the assembled symmetric supercapacitor presents a large specific capacitance of 314.6 F·g−1 and a high energy density of 15.7 Wh·Kg−1 at 1 A·g−1, maintaining 14.4 Wh·Kg−1 even at 20 A·g−1 with the energy density retention of 91.7%. This research demonstrates that nitrogen-doped hierarchical porous activated carbon derived from paddy has a significant potential for developing a high-performance renewable supercapacitor and provides a new route for economical and large-scale production in supercapacitor application.


Author(s):  
Karthikeyan Gunasekaran Govindarasu ◽  
Boopathi Ganesan ◽  
Ramani Venkatesan ◽  
Pandurangan Arumugam

AbstractDoping of heteroatom into well-structured mesoporous carbon architecture can significantly augment the capacitive performance. In this work, we report P-doped graphitic hollow carbon spheres (P-GHCS) grown over Fe-KIT-6 through the in situ approach using the catalytic CVD technique. The obtained P-GHCS possesses a relatively high surface area with uniform mesoporous structure, good graphitization with tunable P-doping contents. The highly favorable structure and desirable heteroatom doping were taken into account to evaluate the P-GHCS as a modified electrode material towards high-performance supercapacitor. The optimized P-GHCS-800 sample exhibits superior specific capacitance (Csp) 321 F g−1 at 0.2 A g−1 with outstanding cycling stability with 2.9% loss of its initial capacitance after 2000 cycles in 6 M KOH electrolyte background in the three-electrode computerized system. More importantly, the fabricated P-GHCS-800 symmetric supercapacitor device can withstand at a wide potential width of 2.0 V, together with remarkable cyclic stability (89.09%) after 2000 cycles at a current density of 1 A g−1 in aqueous 1 M Na2SO4 as electrolyte providing a relatively high energy density of 10.83 Wh kg−1 with a power density of 222.78 W kg−1. Additionally, we demonstrated the single symmetric supercapacitor cell which provided sufficient energy to turn on a red LED of 20 mW and emit light over a certain period of time opens up possible realistic applications.


Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2736
Author(s):  
Rui Liu ◽  
Rui Jiang ◽  
Yu-Han Chu ◽  
Wein-Duo Yang

A novel MnO2/graphene/Ni foam electrode was fabricated via the impregnation and electrochemical deposition technique with Ni foams serving as substrates and graphene serving as a buffer layer for the enhanced conductivity of MnO2. The samples were characterized using X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). Compared with other methods, our strategy avoids using surfactants and high-temperature treatments. The electrodes exhibited excellent electrochemical performance, high capabilities, and a long cycle life. Various electrochemical properties were systematically studied using cyclic voltammetry and electrochemical impedance spectroscopy. The results showed that the specific capacitance of the MnO2/graphene/Ni composite prepared at 1 mA cm−2 of electrodeposition could achieve a scan rate of 10 mV s−1 at 292.8 F g−1, which confirmed that the graphene layer could remarkably improve electron transfer at the electrolyte–electrode interface. The capacitance retention was about 90% after 5000 cycles. Additionally, a MnO2/graphene//graphene asymmetric supercapacitor was assembled and it exhibited a high-energy density of 91 Wh kg−1 as well as had an excellent power density of 400 W kg−1 at 1 A g−1. It is speculated that the strong adhesion between the graphene and MnO2 can provide a compact structure to enhance the mechanical stability, which can be applied as a new method for energy storage devices.


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