Nanostructured cobalt hydroxide thin films as high performance pseudocapacitor electrodes by graphene oxide wrapping

2015 ◽  
Vol 44 (36) ◽  
pp. 16119-16126 ◽  
Author(s):  
Sangmi Bae ◽  
Ji-Hyun Cha ◽  
Jong Hyeon Lee ◽  
Duk-Young Jung

Thin cobalt hydroxide nanoplates on nickel electrode exhibit a high specific capacitance and good cyclic stability due to fast electrolyte diffusion in their nanostructures and GO wrapping.

RSC Advances ◽  
2017 ◽  
Vol 7 (76) ◽  
pp. 48341-48353 ◽  
Author(s):  
Xia Yang ◽  
Yuying Yang ◽  
Quancai Zhang ◽  
Xiaotong Wang ◽  
Yufeng An ◽  
...  

1-Hydroxyanthraquinone (HAQ) is selected to functionalize the dissected carbon nanotubes (rDCNTs) with reduced graphene oxide layers through non-covalent modification. The composite achieves high specific capacitance and ultrahigh rate capability.


2018 ◽  
Vol 21 (2) ◽  
pp. 097-102
Author(s):  
Shuhua Pang ◽  
Weiliang Chen ◽  
Zhewei Yang ◽  
Zheng Liu ◽  
Xin Fan ◽  
...  

Composite materials based on the combination of graphene oxide and PANI are expected not only to improve the PANI conductivity, but also relieve graphene oxide aggregation via a synergistic effect. We report an easy synthesis of a polyaniline/graphene oxide (PGO) composite with a relatively high specific capacitance by chemical oxidation polymerization. As the employ of phytic acid and increasing aniline monomer concentration, more and more PANI nanoparticles deposited into the interval between GO layers. PGO3 composite exhibits the largest specific capacitance (349 F·g-1) and PGO4 composite follows (314 F·g-1), whereas PGO has a minimal specific capacitance (206 F·g-1). The enhanced capacitance originates from the high capacitance of more PANI nanoparticles and better configuration as well as higher surface area of PGO3 and PGO4 composites for fast ion transport. The as-prepared PGO3 sheets composite with improved electrochemical performance is a promising electrode material for supercapacitor.


2014 ◽  
Vol 2 (39) ◽  
pp. 16723-16730 ◽  
Author(s):  
Arvinder Singh ◽  
Alexander J. Roberts ◽  
Robert C. T. Slade ◽  
Amreesh Chandra

A high-performance asymmetric supercapacitor was fabricated using MWCNTs/NiS composite and GNPs as electrodes, exhibiting high specific capacitance of ∼181 F g−1 at 1 A g−1 current density and excellent cyclic stability with 92% retention after 1000 cycles at 2 A g−1 current density.


RSC Advances ◽  
2017 ◽  
Vol 7 (1) ◽  
pp. 327-335 ◽  
Author(s):  
Gourav Bhattacharya ◽  
Ganeshlenin Kandasamy ◽  
Navneet Soin ◽  
Ravi Kant Upadhyay ◽  
Sujit Deshmukh ◽  
...  

Nanocomposite of π-conjugated 2-aminoterephthalic acid (ATA) coated iron oxide (Fe3O4) nanoparticles and reduced graphene oxide (RGO) provides an enhanced capacitive performance with higher specific capacitance and long term cyclic stability.


2014 ◽  
Vol 1644 ◽  
Author(s):  
Pingping Yu ◽  
Xin Zhao ◽  
Yingzhi Li ◽  
Qinghua Zhang

ABSTRACTA novel type of nitrogen-doped hierarchically 3D macroporous CMG films electrode (NCMG) was prepared through a facile ultrafiltration method using graphene oxide (GO) and polystyrene (PS) as precursors, then annealed in N2 atmosphere at 1000°. This NCMG electrode exhibits high specific capacitance (150 F g-1), excellent rate capacity and good cycle life (98% of initial capacitance), which can be a good candidate for supercapacitor application.


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.


2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Xiaona Wang ◽  
Zhenyu Zhou ◽  
Zhijian Sun ◽  
Jinho Hah ◽  
Yagang Yao ◽  
...  

Abstract Coaxial fiber-shaped supercapacitors are a promising class of energy storage devices requiring high performance for flexible and miniature electronic devices. Yet, they are still struggling from inferior energy density, which comes from the limited choices in materials and structure used. Here, Zn-doped CuO nanowires were designed as 3D framework for aligned distributing high mass loading of MnO2 nanosheets. Zn could be introduced into the CuO crystal lattice to tune the covalency character and thus improve charge transport. The Zn–CuO@MnO2 as positive electrode obtained superior performance without sacrificing its areal and gravimetric capacitances with the increasing of mass loading of MnO2 due to 3D Zn–CuO framework enabling efficient electron transport. A novel category of free-standing asymmetric coaxial fiber-shaped supercapacitor based on Zn0.11CuO@MnO2 core electrode possesses superior specific capacitance and enhanced cell potential window. This asymmetric coaxial structure provides superior performance including higher capacity and better stability under deformation because of sufficient contact between the electrodes and electrolyte. Based on these advantages, the as-prepared asymmetric coaxial fiber-shaped supercapacitor exhibits a high specific capacitance of 296.6 mF cm−2 and energy density of 133.47 μWh cm−2. In addition, its capacitance retention reaches 76.57% after bending 10,000 times, which demonstrates as-prepared device’s excellent flexibility and long-term cycling stability.


2018 ◽  
Vol 6 (1) ◽  
pp. 160-166 ◽  
Author(s):  
Yuxi Liu ◽  
Zechuan Xiao ◽  
Yongchang Liu ◽  
Li-Zhen Fan

N and S-co-doped activated corncob sponge of honeycomb-like porous carbon with the interconnected micro-meso-macropores and the large specific surface area was evaluated as an electrode material for flexible solid-state supercapacitors, exhibiting high specific capacitance, high energy–power density, and great cyclic stability.


RSC Advances ◽  
2014 ◽  
Vol 4 (59) ◽  
pp. 31219-31225 ◽  
Author(s):  
Palanisamy Vinothbabu ◽  
Perumal Elumalai

The influence of the basal length of Co(OH)2 on supercapacitor performance was examined in detail by adding simple urea molecules during deposition. It was observed that the specific capacitance of Co(OH)2 could be tuned from 700 to 1200 F g−1. This high specific capacitance was attributed to the better access of electrolyte.


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