A redox-mediated 3D graphene based nanoscoop design for ultracapacitor applications

2017 ◽  
Vol 41 (16) ◽  
pp. 8390-8398
Author(s):  
Pallavi Rani ◽  
Suman Kumari Jhajharia ◽  
Kaliaperumal Selvaraj
Keyword(s):  
Specific Capacitance ◽  
High Specific Capacitance ◽  
Cycle Stability ◽  
Redox Species ◽  
3D Graphene

The judicious design of 3D graphene with a unique nanostructure blended with an active redox species demonstrates the ability to boost capacitance as high as 8-fold. This design not only exhibits high specific capacitance but also sustains it with a good cycle stability of even beyond 5000 cycles.

Ultralight and flexible supercapacitor electrodes made from Ni(OH)2 nanosheets doped with Ag nanoparticle/3D graphene composite

RSC Advances ◽  
2015 ◽  
Vol 5 (27) ◽  
pp. 20878-20883 ◽  
Author(s):  
Wei Lan ◽  
Yaru Sun ◽  
Youxin Chen ◽  
Junya Wang ◽  
Guomei Tang ◽  
...  
Keyword(s):  
Specific Capacitance ◽  
Hydrothermal Method ◽  
Rate Capability ◽  
High Specific Capacitance ◽  
Ag Nanoparticle ◽  
Cycle Stability ◽  
Facile Hydrothermal Method ◽  
3D Graphene ◽  
Flexible Supercapacitor ◽  
Graphene Composite

Ag nanoparticle doped Ni(OH)2 nanosheets are deposited on flexible 3D graphene by a facile hydrothermal method. The electrode shows high specific capacitance with an increase of ~23% and excellent rate capability. The electrode also has good cycle stability.

Poly(aniline-co-pyrrole)-coated Ni-doped manganese dioxide as electrode materials for supercapacitors

2020 ◽  
Vol 13 (02) ◽  
pp. 2051007
Author(s):  
Jie Dong ◽  
Qinghao Yang ◽  
Qiuli Zhao ◽  
Zhenzhong Hou ◽  
Yue Zhou ◽  
...  
Keyword(s):  
Electrochemical Performance ◽  
Manganese Dioxide ◽  
Specific Capacitance ◽  
Electrode Materials ◽  
High Specific Capacitance ◽  
Cycle Stability ◽  
Mass Ratio ◽  
Scan Rate ◽  
Poly Aniline ◽  
Inorganic And Organic

Electrode materials with a high specific capacitance, outstanding reversibility and excellent cycle stability are constantly pursued for supercapacitors. In this paper, we present an approach to improve the electrochemical performance by combining the advantages of both inorganic and organic. Ni-MnO2/PANi-co-PPy composites are synthesized, with the copolymer of aniline/pyrrole being coated on the surface of Ni-doped manganese dioxide nanospheres. The inorganic–organic composite enables a substantial increase in its specific capacitance and cycle stability. When the mass ratio of Ni-MnO2 to aniline and pyrrole mixed monomer is 1:5, the composite delivers high specific capacitance of 445.49[Formula: see text]F/g at a scan rate of 2[Formula: see text]mV/s and excellent cycle stability of 61.65% retention after 5000 cycles. The results indicate that the Ni-MnO2/PANi-co-PPy composites are promising electrode materials for future supercapacitors application.

Three-Dimensional Graphene/MnO2 Nanowalls Hybrid for High-Efficiency Electrochemical Supercapacitors

NANO ◽  
2018 ◽  
Vol 13 (01) ◽  
pp. 1850013 ◽  
Author(s):  
Chuanyin Xiong ◽  
Tiehu Li ◽  
Tingkai Zhao ◽  
Alei Dang ◽  
Xianglin Ji ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Specific Capacitance ◽  
High Efficiency ◽  
Hydrogen Reduction ◽  
Three Dimensional ◽  
High Specific Capacitance ◽  
High Energy ◽  
High Energy Density ◽  
Energy Storage Devices ◽  
3D Graphene

In this paper, a facile method is designed to fabricate three-dimensional (3D) graphene (GR)/manganese dioxide (MnO2) nanowall electrode material. The 3D GR/MnO2 hybrid is prepared by a combination of electrochemical deposition (ELD) and electrophoresis deposition (EPD), followed by thermal reduction (TR). Firstly, the 3D graphene oxide (GO)/MnO2 hybrid is obtained by the ELD–EPD method. Secondly, the 3D GR/MnO2 hybrid is obtained through hydrogen reduction at a certain temperature. The as-fabricated hybrid has been characterized by scanning electron microscope (SEM), transmission electron microscope (TEM) and Raman spectroscopy. The electrochemical properties have been also measured by cyclic voltammetry. The results showed that the 3D GR/MnO2 nanowalls hybrid has a high specific capacitance of 266.75[Formula: see text]Fg[Formula: see text] and a high energy density of 25.36[Formula: see text]Whkg[Formula: see text]. Moreover, a high specific capacitance (240.15[Formula: see text]Fg[Formula: see text]) at a high scan rate of 200[Formula: see text]mVs[Formula: see text] (90% capacity retention) has been also obtained. Additionally, the hybrid can serve directly as the electrodes of supercapacitor without adding binder. This work provides a novel road to fabricate a binder-free 3D GR-based hybrid for high-performance energy storage devices.

Facile synthesis of exfoliated Co–Al LDH–carbon nanotube composites with high performance as supercapacitor electrodes

2014 ◽  
Vol 16 (33) ◽  
pp. 17936-17942 ◽  
Author(s):  
Lei Yu ◽  
Nannan Shi ◽  
Qi Liu ◽  
Jun Wang ◽  
Bin Yang ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Specific Capacitance ◽  
High Performance ◽  
High Specific Capacitance ◽  
Cycle Stability ◽  
Facile Synthesis ◽  
Nanotube Composites ◽  
Carbon Nanotube Composites

A novel sandwich-like structured Co–Al LDH–CNT composite has been successfully synthesized. The as-prepared Co–Al LDHs–CNTs composite exhibites a high specific capacitance and a good cycle stability over 2000 cycles

Bead chain structure RFC/ACF by electrospinning for supercapacitors

2019 ◽  
Vol 48 (5) ◽  
pp. 439-448
Author(s):  
Lei Guo ◽  
Lien Zhu ◽  
Lei Ma ◽  
Jian Zhang ◽  
QiuYu Meng ◽  
...  
Keyword(s):  
Composite Material ◽  
Specific Surface ◽  
Specific Capacitance ◽  
Surface Area ◽  
Specific Surface Area ◽  
Carbon Fibers ◽  
High Specific Capacitance ◽  
Chain Structure ◽  
Cycle Stability ◽  
Content Type

Purpose The purpose of this paper is to prepare a spherical modifier-modified activated carbon fiber of high specific capacitance intended for electrode materials of supercapacitor. Design/methodology/approach In this study, phenolic-based microspheres are taken as modifiers to prepare PAN-based fiber composites by electrospinning, pre-oxidation and carbonization. Pearl-chain structures appear in RFC/ACF composites, and pure polyacrylonitrile fibers show a dense network. The shape and cross-linking degree are large. After the addition of the phenolic-based microspheres, the composite material exhibits a layered pearlite chain structure with a large porosity, and the RFC/ACF composite material is derived because of the existence of a large number of bead chain structures in the composite material. The density increases, the volume declines and the mass after being assembled into a supercapacitor as a positive electrode material decreases. The specific surface area of RFC/ACF composites is increased as compared to pure fibers. The increase in specific surface area could facilitate the diffusion of electrolyte ions in the material. Owing to the large number of bead chains, plenty of pore channels are provided for the diffusion of electrolyte ions, which is conducive to enhancing the electrochemical performance of the composite and improving the RFC/ACF composite and the specific capacitance of the material. The methods of electrochemical testing on symmetric supercapacitors (as positive electrodes) are three-electrode cyclic voltammetry, alternating current impedance and cycle stability. Findings The specific capacitance value of the composite material was found to be 389.2 F/g, and the specific capacitance of the electrode operating at a higher current density of 20 mA/cm2 was 11.87 F/g (the amount of the microsphere modifier added was 0.3 g). Using this material as a positive electrode to assemble into asymmetrical supercapacitor, after 2,000 cycles, the specific capacitance retention rate was 87.46 per cent, indicating excellent cycle stability performance. This result can be attributed to the fact that the modifier embedded in the fiber changes the porosity between the fibers, while improving the utilization of the carbon fibers and making it easier for electrolyte ions to enter the interior of the composites, thereby increasing the capacitance of the composites. Originality/value The modified PAN-based activated carbon fibers in the study had high specific surface area and significantly high specific capacitance, which makes it applicable as an efficient and environment-friendly absorbent, as well as an advanced electrode material for supercapacitor.

The synthesis of shape-controlled α-MoO3/graphene nanocomposites for high performance supercapacitors

2015 ◽  
Vol 39 (11) ◽  
pp. 8780-8786 ◽  
Author(s):  
Jinhua Zhou ◽  
Juan Song ◽  
Huihua Li ◽  
Xiaomiao Feng ◽  
Zhendong Huang ◽  
...  
Keyword(s):  
Specific Capacitance ◽  
High Performance ◽  
High Specific Capacitance ◽  
Cycle Stability ◽  
Graphene Nanocomposites ◽  
Shape Controlled

Novel nanoflake-like α-MoO3/graphene nanocomposites were synthesized and exhibited a high specific capacitance of up to 360 F g−1 and excellent long term cycle stability.

Facile and low-cost fabrication of nanostructured NiCo2O4 spinel with high specific capacitance and excellent cycle stability

2012 ◽  
Vol 63 ◽  
pp. 220-227 ◽  
Author(s):  
Changhui Wang ◽  
Xiong Zhang ◽  
Dacheng Zhang ◽  
Chao Yao ◽  
Yanwei Ma
Keyword(s):  
Specific Capacitance ◽  
Low Cost ◽  
High Specific Capacitance ◽  
Cycle Stability

Flexible symmetrical planar supercapacitors based on multi-layered MnO2/Ni/graphite/paper electrodes with high-efficient electrochemical energy storage

2014 ◽  
Vol 2 (9) ◽  
pp. 2985-2992 ◽  
Author(s):  
Jin-Xian Feng ◽  
Qi Li ◽  
Xue-Feng Lu ◽  
Ye-Xiang Tong ◽  
Gao-Ren Li
Keyword(s):  
Energy Storage ◽  
Specific Capacitance ◽  
High Specific Capacitance ◽  
Electrochemical Energy Storage ◽  
Storage Device ◽  
Energy Storage Device ◽  
Cycle Stability ◽  
Electrodeposition Method ◽  
High Efficient ◽  
Electrochemical Energy

We develop a cheap and simple drawing-electrodeposition method to fabricate highly flexible MnO2/Ni/graphite/paper electrodes and assemble a paper-based energy storage device with high specific capacitance and excellent cycle stability.

Ni(OH)2 nanosheets grown on a 3D graphene framework as an excellent cathode for flexible supercapacitors

RSC Advances ◽  
2014 ◽  
Vol 4 (88) ◽  
pp. 47609-47614 ◽  
Author(s):  
Yufang Ma ◽  
Wanjun Chen ◽  
Peng Zhang ◽  
Feng Teng ◽  
Jinyuan Zhou ◽  
...  
Keyword(s):  
Specific Capacitance ◽  
Hydrothermal Method ◽  
Rate Capability ◽  
High Specific Capacitance ◽  
3D Graphene ◽  
Graphene Composite ◽  
Flexible Supercapacitors ◽  
Good Rate Capability

A simple and scalable hydrothermal method is used to fabricate the Ni(OH)2 nanosheets/3D graphene composite, which presents high specific capacitance and good rate capability.

A cost effective, highly porous, manganese oxide/carbon supercapacitor material with high rate capability

2016 ◽  
Vol 4 (15) ◽  
pp. 5390-5394 ◽  
Author(s):  
Rongfang Wang ◽  
Yuanyuan Ma ◽  
Hui Wang ◽  
Julian Key ◽  
Dan Brett ◽  
...  
Keyword(s):  
Specific Capacitance ◽  
Carbon Material ◽  
Rate Capability ◽  
High Specific Capacitance ◽  
Cost Effective ◽  
High Rate ◽  
Cycle Stability ◽  
High Rate Capability ◽  
Highly Porous

A porous, cube-shaped, Mn2O3/carbon material has been prepared and it shows a high specific capacitance of 349.6 F g−1 at 50 mA g−1 and excellent long-term cycle stability after 2000 cycles.

Sign in / Sign up

Export Citation Format

Share Document