Cubic-Like Nickel Oxide Nanostructures as Large Specific Capacitance and Long-Life Supercapacitors

2012 ◽  
Vol 516-517 ◽  
pp. 1688-1691 ◽  
Author(s):  
Jia Wei Deng ◽  
Huan Pang ◽  
Shao Mei Wang ◽  
Jiang Shan Zhang

Monodispersed anamorphic cubic NiO materials have been synthesized by a simple method. SEM, TEM and XRD have been employed for the morphology and structure characterization. The calcination conditions have been carefully studied about their effects on supercapacitor properties. Electrochemical data prove that the monodispersed nano anamorphic cubic NiO materials contain a good specific capacitance and excellent specific capacitance retention after 2000 continuous charge-discharge cycles. These results suggest that both the morphology and structure have important effects on the high performance supercapacitors.

2012 ◽  
Vol 557-559 ◽  
pp. 628-631
Author(s):  
Shao Mei Wang ◽  
Huan Pang ◽  
Hang Zhang ◽  
Ya Hui Ma ◽  
Xue Xue Li ◽  
...  

Monodispersed porous cubic nickel oxide nanostructures have been synthesized by a simple method. TEM have been employed for the morphology and structure characterization. Electrochemical data prove that the monodispersed porous cubic nickel oxide nanostructures contain a good specific capacitance.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jeongpil Kim ◽  
Jeong-Hyun Eum ◽  
Junhyeok Kang ◽  
Ohchan Kwon ◽  
Hansung Kim ◽  
...  

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.


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.


Author(s):  
Aqib Muzaffar ◽  
Keerthana Muthusamy ◽  
M. Basheer Ahamed

Ferrous nitrate/nickel oxide {Fe(NO3)2–NiO} nanocomposite was synthesized via two-step facile hydrothermal route. The nanocomposite exhibits crystalline structure as unveiled by X-ray diffraction (XRD) pattern, while as the scanning electron microscope (SEM) images divulge spherical morphologies for both Fe(NO3)2 as well as NiO nanoparticles differentiating from each other in size. Cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), and electrochemical impedance spectroscopy (EIS) techniques were used to investigate supercapacitive behavior of the symmetrically fabricated nanocomposite electrode configuration using aqueous KOH as the electrolyte. The CV analyses demonstrate dominant electrical double layer capacitance (EDLC) behavior in the potential range of 0–1 V. From charge–discharge curves, the maximum specific capacitance calculated was 460 F g−1 corresponding to the energy density of 16 W h kg−1 at a high power density of 250 W kg−1. EIS data affiliate well with the CV and GCD results justifying the maximum contribution of specific capacitance due to double layer capacitance. The nanocomposite retained 84% of its original capacitance after 1000 cycles and yielded maximum efficiency of 78%.


2020 ◽  
pp. 115-127
Author(s):  
Yu Wang ◽  
Ying Zhu ◽  
Hailiang Chu ◽  
Shujun Qiu ◽  
Yongjin Zou ◽  
...  

As a renewable biomass and a low-cost crude carbon source, the ginkgo shell is explored for preparing high-value porous carbon via carbonization and the following KOH activation. Structure characterization shows that GSPC has microporous and mesoporous structure with specific surface area (SSA) of up to 1941 m2 g-1 , which exhibits superior capacitive properties. In a three-electrode system by using 6 M KOH as electrolyte, GSPC-700-1:2 could deliver a high specific capacitance of 345 F g-1 at 0.5 A g-1 . Even at a high current density of 20 A g-1 , the specific capacitance of as high as 280 F g-1 can be still maintained. Furthermore, a symmetric supercapacitor device (SCD) is fabricated by GSPC-700-1:2, which exhibits a capacitance retention rate of 83% at 5 A g-1 after 10000 charging/discharging cycles. A power density of 301 W kg-1 is achieved at an energy density of 13 W h kg-1 . The superior electrochemical performance demonstrates that ginkgo shell can function as a new biomass material for the production of porous carbon materials that are used in high-performance supercapacitors and other energy storage devices.


2012 ◽  
Vol 20 ◽  
pp. 53-60 ◽  
Author(s):  
Zan Wang ◽  
Xin Wang ◽  
Yun Xiao Zhao ◽  
Cui Mei Zhao ◽  
Wei Tao Zheng

Nanostructured MnOx/Ni (OH)2 composites have been electrodeposited on Ni foam for synthesis of a binder-free electrode for electrochemical capacitors with high specific capacitance and stable electrochemical properties. The microstructure, morphology and chemical composition were characterized by X-ray diffraction, scanning electron microscopy and X-ray photoelectron spectroscopy. Cyclic voltammetry and galvanostatic charge/discharge measurements were applied to investigate the electrochemical capacitance of the electrode active materials. The results indicated that MnOx acted as a template for growth of Ni (OH)2 with an inter-connected 3D porous network nanostructure. A maximum capacitance value of 2334 F/g at current density of 5 A/g in 1 M KOH electrolyte was achieved, much higher than that of pure Ni (OH)2 and MnOx (992 and 179 F/g, respectively). Moreover, in the charge/discharge process at even larger current density of 20 A/g, the electrode could maintain 82.8 % of the initial specific capacitance after 500 cycles, higher than that of pure Ni (OH)2 (only 46.6% remains). The enhanced capacitance performance was attributed to the synergic effect between the respective single oxides.


2019 ◽  
Vol 32 (3) ◽  
pp. 258-267 ◽  
Author(s):  
Jia Chu ◽  
Xue Li ◽  
Qiaoqin Li ◽  
Jing Ma ◽  
Bohua Wu ◽  
...  

Polyaniline nanowires (PANI NWs) were synthesized under different temperatures through a facile hydrothermal method and used as electrodes for high-performance pseudocapacitor. The resulting samples were analyzed by X-ray diffraction, Fourier transform infrared spectroscopy, Raman spectroscopy, scanning electron micrographs, thermogravimetric analysis, and X-ray photoelectron spectroscopy. Electrochemical properties of these PANI electrodes are studied by cyclic voltammetry, galvanostatic charge–discharge test, and electrochemical impedance spectroscopy in 0.5M H2SO4 aqueous solution. The highest specific capacitance is obtained on the PANI NWs synthesized under 80°C (PANI-80) with 540.0 F g−1 at current density of 0.5 A g−1 accompanied with 82% specific capacitance retention after 1000 charge discharge cycles at 5 A g−1 current density.


RSC Advances ◽  
2015 ◽  
Vol 5 (3) ◽  
pp. 1680-1683 ◽  
Author(s):  
Li Zhang ◽  
Lei Chen ◽  
Bin Qi ◽  
Guocheng Yang ◽  
Jian Gong

Ordered TiO2@polyaniline nanorods exhibiting high specific capacitance were prepared by a simple method. The specific capacitance retention of the product is over 85% after 1000 charge and discharge cycles at a current density of 10 A g−1.


2011 ◽  
Vol 56 (16) ◽  
pp. 5815-5822 ◽  
Author(s):  
Iresha R.M. Kottegoda ◽  
Nurul Hayati Idris ◽  
Lin Lu ◽  
Jia-Zhao Wang ◽  
Hua-Kun Liu

2019 ◽  
Vol 12 (05) ◽  
pp. 1950065
Author(s):  
Mingyue Wang ◽  
Rui Xue ◽  
Hao Guo ◽  
Wu Yang

A porous organic framework as electrode material for supercapacitor was prepared successfully. It exhibited the remarkable specific capacitance of [Formula: see text] at current density of [Formula: see text], and 100% of capacitance retention after successive charge–discharge 10,000 cycles in an alkaline aqueous electrolyte solution. At the same time, we explored the electrochemical performance of porous N-doped carbon derived from the template of porous organic framework as supercapacitor electrode material. Impressively, it possessed the higher specific capacitance and better cycling stability, which showed specific capacitance of [Formula: see text] at the current density of [Formula: see text] and retained 100% of initial capacitance after 30,000 cycles.


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