scholarly journals Research on the High-Performance Electrochemical Energy Storage of a NiO@ZnO (NZO) Hybrid Based on Growth Time

Crystals ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 47 ◽  
Author(s):  
Jiahong Zheng ◽  
Runmei Zhang ◽  
Kangkang Cheng ◽  
Ziqi Xu ◽  
Pengfei Yu ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Specific Capacitance ◽  
High Performance ◽  
Reaction Times ◽  
Electrochemical Energy Storage ◽  
Growth Time ◽  
Hydrothermal Time ◽  
Supercapacitor Electrode ◽  
Negative Electrodes ◽  
Promising Electrode Material

A NiO@ZnO (NZO) hybrid with different reaction times was successfully synthesized by a green hydrothermal method. After comparison, it was found that hydrothermal time had a great impact on specific capacitance. As a supercapacitor electrode of NZO-12h, it exhibited the maximum reversible specific capacitance of 985.0 F/g (3.94 F/cm2) at 5 mA/cm2 and 587.5 F/g (2.35 F/cm2) at 50 mA/cm2, as well as a high retention of 74.9% capacitance after 1500 cycles at 20 mA/cm2. Furthermore, the asymmetric electrode device with ZnO-12h and activated carbon (AC) as the positive and negative electrodes was successfully assembled. In addition, the device exhibited a specific capacitance of 85.7 F/g at 0.4 A/g. Moreover, the highest energy density of 27.13 Wh kg−1 was obtained at a power density of 321.42 W kg−1. These desirable electrochemical properties demonstrate that the NZO hybrid is a promising electrode material for a supercapacitor.

scholarly journals Tuning the hierarchical pore structure of graphene oxide through dual thermal activation for high-performance supercapacitor

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jeongpil Kim ◽  
Jeong-Hyun Eum ◽  
Junhyeok Kang ◽  
Ohchan Kwon ◽  
Hansung Kim ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Pore Structure ◽  
Specific Capacitance ◽  
Surface Area ◽  
Thermal Annealing ◽  
High Performance ◽  
Annealing Process ◽  
Supercapacitor Electrode ◽  
Simple Method ◽  
Surface Areas

AbstractHerein, we introduce a simple method to prepare hierarchical graphene with a tunable pore structure by activating graphene oxide (GO) with a two-step thermal annealing process. First, GO was treated at 600 °C by rapid thermal annealing in air, followed by subsequent thermal annealing in N2. The prepared graphene powder comprised abundant slit nanopores and micropores, showing a large specific surface area of 653.2 m2/g with a microporous surface area of 367.2 m2/g under optimized conditions. The pore structure was easily tunable by controlling the oxidation degree of GO and by the second annealing process. When the graphene powder was used as the supercapacitor electrode, a specific capacitance of 372.1 F/g was achieved at 0.5 A/g in 1 M H2SO4 electrolyte, which is a significantly enhanced value compared to that obtained using activated carbon and commercial reduced GO. The performance of the supercapacitor was highly stable, showing 103.8% retention of specific capacitance after 10,000 cycles at 10 A/g. The influence of pore structure on the supercapacitor performance was systematically investigated by varying the ratio of micro- and external surface areas of graphene.

Hierarchical Dendritic Polypyrrole with High Specific Capacitance for High-performance Supercapacitor Electrode Materials

2017 ◽  
Vol 20 (4) ◽  
pp. 197-204
Author(s):  
Weiliang Chen ◽  
Shuhua Pang ◽  
Zheng Liu ◽  
Zhewei Yang ◽  
Xin Fan ◽  
...  
Keyword(s):  
Specific Capacitance ◽  
Current Density ◽  
High Performance ◽  
Electrode Materials ◽  
High Specific Capacitance ◽  
Chemical Oxidation ◽  
Channel Structure ◽  
Supercapacitor Electrode ◽  
Infrared Spectrometer ◽  
A Current

Polypyrrole with hierarchical dendritic structures assembled with cauliflower-like structure of nanospheres, was synthesized by chemical oxidation polymerization. The structure of polyryrrole was characterized by Fourier transform infrared spectrometer and scanning electron microscopy. The electrochemical performance was performed on CHI660 electrochemical workstation. The results show that oxalic acid has a significant effect on morphology of PPy products. The hierarchical dendritic PPyOA(3) electrodes possess a large specific capacitance as high as 744 F/g at a current density of 0.2 A/g and could achieve a higher specific capacitance of 362 F/g even at a current density of 5.0 A/g. Moreover, the dendritic PPy products produce a large surface area on the electrode through the formation of the channel structure with their assembled cauliflower-like morphology, which facilitates the charge/electron transfer relative to the spherical PPy electrode. The spherical dendritic PPyOA(3) electrode has 58% retention of initial specific capacitance after 260 cycles. The as-prepared dendritic polypyrrole with high performance is a promsing electrode material for supercapacitor.

scholarly journals Nickel Cobalt Hydroxides With Tunable Thin-layer Nanosheets for High-performance Supercapacitor Electrode

2021 ◽  
Author(s):  
Luomeng Zhang ◽  
Hui Xia ◽  
Shaobo Liu ◽  
Yishan Zhou ◽  
Yuefeng Zhao ◽  
...  
Keyword(s):  
Thin Layer ◽  
Specific Capacitance ◽  
Current Density ◽  
Layered Double Hydroxides ◽  
High Performance ◽  
Electrode Materials ◽  
Supercapacitor Electrode ◽  
Nickel Cobalt ◽  
Capacitance Performance ◽  
Double Hydroxides

Abstract Layered double hydroxides as typical supercapacitor electrode materials can perform superior energy storage if the structures are well regulated. In this work, a simple one-step hydrothermal method is used to prepare diverse nickel cobalt layered double hydroxides (NiCo-LDHs), in which the different contents of urea are used to synthesize the different nanostructures of NiCo-LDHs. The results show that the decrease in urea content can effectively improve the dispersibility of NiCo-LDHs, adjust the thickness of materials and optimize the internal pore structures, thereby enhancing the capacitance performance of NiCo-LDHs. When the content of urea is reduced from 0.03 g to 0.0075 g under a fixed precursor materials mass ratio of nickel (0.06 g) to cobalt (0.02 g) of 3:1, the prepared sample NiCo-LDH-1 exhibits the thickness of 1.62 nm, and the clear thin-layer nanosheets structures and a large number of surface pores are formed, which is beneficial to the transmission of ions into the electrode material. After being prepared as a supercapacitor electrode, the NiCo-LDH-1 displays an ultra-high specific capacitance of 3982.5 F g-1 under the current density of 1 A g-1, and high capacitance retention above 93.6% after 1000 cycles of charging and discharging at a high current density of 10 A g-1. The excellent electrochemical performance of NiCo-LDH-1 is proved by assembling two-electrode asymmetric supercapacitor with carbon spheres, displaying the specific capacitance of 95 F g-1 at 1 A g-1 and the capacitance retention with 78% over 1000 cycles. As a result, it offers a facile way to control the nanostructure of NiCo-LDHs, confirms the important affection of urea on enhancing capacitive performance for supercapacitor electrode and provides the high possibility for the development of high-performance supercapacitors.

scholarly journals N, S-Codoped Activated Carbon Material with Ultra-High Surface Area for High-Performance Supercapacitors

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1982
Author(s):  
Qinghua Yuan ◽  
Zhuwen Ma ◽  
Junbiao Chen ◽  
Zhenrui Huang ◽  
Zeming Fang ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Specific Surface ◽  
Specific Capacitance ◽  
Surface Area ◽  
Specific Surface Area ◽  
Carbon Material ◽  
High Surface ◽  
Koh Activation ◽  
Supercapacitor Electrode ◽  
Tobacco Stalk

The recycling of macromolecular biowastes has been a problem for the agriculture industry. In this study, a novel N, S-codoped activated carbon material with an ultrahigh specific area was produced for the application of a supercapacitor electrode, using tobacco stalk biowastes as the carbon source, KOH as the activating agents and thiourea as the doping agent. Tobacco stalk is mainly composed of cellulose, but also contains many small molecules and inorganic salts. KOH activation resulted in many mesopores, giving the tobacco stem-activated carbon a large specific surface area and double-layer capacitance. The specific surface area of the samples reached up to 3733 m2·g−1, while the maximum specific capacitance of the samples obtained was up to 281.3 F·g−1 in the 3-electrode tests (1 A·g−1). The doping of N and S elements raised the specific capacitance significantly, which could be increased to a value as high as 422.5 F·g−1 at a current density of 1 A·g−1 in the 3-electrode tests, but N, S-codoping also led to instability. The results of this article prove that tobacco stalks could be efficiently reused in the field of supercapacitors.

Hierarchical nickel/phosphorus/nitrogen/carbon composites templated by one metal–organic framework as highly efficient supercapacitor electrode materials

2019 ◽  
Vol 7 (6) ◽  
pp. 2875-2883 ◽  
Author(s):  
Fan Yu ◽  
Xin Xiong ◽  
Liu-Yin Zhou ◽  
Jia-Luo Li ◽  
Ji-Yuan Liang ◽  
...  
Keyword(s):  
Energy Storage ◽  
High Performance ◽  
Electrode Materials ◽  
Carbon Materials ◽  
Metal Organic Framework ◽  
Electrochemical Energy Storage ◽  
Carbon Composites ◽  
Supercapacitor Electrode ◽  
Metal Organic ◽  
Supercapacitor Electrode Materials

Novel carbon materials containing Ni, P, N and O were fabricated from the sacrificial MOF template, which exhibits high performance in electrochemical energy storage.

scholarly journals Phosphorus-doped activated carbon as a promising additive for high performance lead carbon batteries

RSC Advances ◽  
2017 ◽  
Vol 7 (7) ◽  
pp. 4174-4178 ◽  
Author(s):  
Feng Wang ◽  
Chen Hu ◽  
Jiali Lian ◽  
Min Zhou ◽  
Kangli Wang ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
High Performance ◽  
Electrochemical Applications ◽  
Negative Electrodes ◽  
Phosphorus Doped

Remarkable inhibition of the hydrogen evolution reaction (HER) is demonstrated on phosphorus-doped activated carbon, which shows great potential as an additive to the negative electrodes of lead-carbon batteries and other electrochemical applications.

scholarly journals NH4V4O10 nanobelts vertically grown on 3D TiN nanotube arrays as high-performance electrode materials of supercapacitors

RSC Advances ◽  
2021 ◽  
Vol 11 (15) ◽  
pp. 8468-8474
Author(s):  
Yihan Lin ◽  
Jianyu Li ◽  
Peng Ren ◽  
Xiuchun Yang
Keyword(s):  
Specific Capacitance ◽  
High Performance ◽  
Electrode Materials ◽  
Nanotube Arrays ◽  
Supercapacitor Electrode ◽  
Capacity Retention

NH4V4O10 nanobelts were synthesized and decorated into TiN nanotube arrays as supercapacitor electrode with a specific capacitance of 749.0 F g−1 at 5 mV s−1 and a capacity retention of 85.7% after 200 cycles.

scholarly journals Nitrogen-Doped Hierarchical Porous Activated Carbon Derived from Paddy for High-Performance Supercapacitors

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 318
Author(s):  
Yudan Yuan ◽  
Yi Sun ◽  
Zhichen Feng ◽  
Xingjian Li ◽  
Ruowei Yi ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Energy Density ◽  
Specific Capacitance ◽  
High Performance ◽  
High Energy ◽  
High Energy Density ◽  
Scale Production ◽  
Nitrogen Doped ◽  
Hierarchical Porous ◽  
Porous Activated Carbon

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.

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