scholarly journals A simple route to prepare a Cu2O–CuO–GN nanohybrid for high-performance electrode materials

RSC Advances ◽  
2017 ◽  
Vol 7 (20) ◽  
pp. 12027-12032 ◽  
Author(s):  
Yanyun Liu ◽  
Ling Ma ◽  
Dong Zhang ◽  
Gaoyi Han ◽  
Yunzhen Chang

The prepared Cu2O–CuO–GN nanohybrid shows a higher specific capacitance than that of pure GN.

RSC Advances ◽  
2017 ◽  
Vol 7 (24) ◽  
pp. 14516-14527 ◽  
Author(s):  
Bing Hu ◽  
Ling-Bin Kong ◽  
Long Kang ◽  
Kun Yan ◽  
Tong Zhang ◽  
...  

There is an excellent linear relationship between E-SSA and specific capacitance of HNC-IPNs as electrode materials for EDLCs.


2017 ◽  
Vol 20 (4) ◽  
pp. 197-204
Author(s):  
Weiliang Chen ◽  
Shuhua Pang ◽  
Zheng Liu ◽  
Zhewei Yang ◽  
Xin Fan ◽  
...  

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.


2020 ◽  
Vol 20 (8) ◽  
pp. 4854-4859 ◽  
Author(s):  
Lei Chen ◽  
Xu Chen ◽  
Yaqiong Wen ◽  
Bixia Wang ◽  
Yangchen Wu ◽  
...  

Nitrogen-enriched reduced graphene oxide electrode material can be successfully prepared through a simple hydrothermal method. The morphology and microstructure of ready to use electrode material is measured by field emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD). Physical characterizations revealed that nitrogen-enriched reduced graphene oxide electrode material possessed high specific surface area of 429.6 m2 · g−1, resulting in high utilization of electrode materials with electrolyte. Electrochemical performance of nitrogen-enriched reduced graphene oxide electrode was also investigated by cyclic voltammetry (CV), galvanostatic charge/discharge measurements and electrochemical impedance spectroscopy (EIS) in aqueous in 6 M KOH with a three-electrode system, which displayed a high specific capacitance about 223.5 F · g−1 at 1 mV · s−1. More importantly, nitrogenenriched reduced graphene oxide electrode exhibited outstanding stability with 100% coulombic efficiency and with no specific capacitance loss under 2 A · g−1 after 10000 cycles. The supercapacitive behaviors indicated that nitrogen-enriched reduced graphene oxide can be a used as a promising electrode for high-performance super-capacitors.


2021 ◽  
Author(s):  
Luomeng Zhang ◽  
Hui Xia ◽  
Shaobo Liu ◽  
Yishan Zhou ◽  
Yuefeng Zhao ◽  
...  

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.


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.


RSC Advances ◽  
2021 ◽  
Vol 11 (15) ◽  
pp. 8468-8474
Author(s):  
Yihan Lin ◽  
Jianyu Li ◽  
Peng Ren ◽  
Xiuchun Yang

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.


e-Polymers ◽  
2019 ◽  
Vol 19 (1) ◽  
pp. 313-322 ◽  
Author(s):  
Honghong Song ◽  
Jing Zhang ◽  
Pengfei Song ◽  
Yubing Xiong

AbstractIn this study, ionic liquids (IL) containing carboxyl and different alkyl chains were fabricated and used to dope polyaniline (PANI). The results revealed that IL@PANI composites could be facilely obtained via template-free polymerization of aniline using ammonium persulfate as the oxidant. The as-prepared IL@PANI composites were measured by FT-IR, XPS, and SEM. Electrochemical performances of IL@PANI nanocomposites were investigated by cyclic voltammetry and galvanostatic charge/discharge. The results indicate that the alkyl chains of ILs have an important influence on the morphology and capacitance performance of IL@PANI electrode materials. With the shorter alkyl group in ILs, IL@PANI materials presented higher specific capacitance. Especially, 1-vinyl-3-carboxymethyl-imidazolium chloride ([VCMIm]Cl)@PANI composite presented the highest specific capacitance. Cycling performance measurement demonstrated that 82% capacitance retention could be achieved after 1000 cycles in 0.5 M H2SO4 aqueous solution. Therefore, our strategy provides a new technique for PANI nanocomposites with tunable morphology and high performance.


Molecules ◽  
2019 ◽  
Vol 24 (19) ◽  
pp. 3588 ◽  
Author(s):  
Xiao-Ming Yue ◽  
Zhao-Yang An ◽  
Mei Ye ◽  
Zi-Jing Liu ◽  
Cui-Cui Xiao ◽  
...  

Coal-based porous materials for supercapacitors were successfully prepared using Taixi anthracite (TXA) by multi-stage activation. The characterization and electrochemical tests of activated carbons (ACs) prepared in different stages demonstrated that the AC from the third-stage activation (ACIII) shows good porous structures and excellent electrochemical performances. ACIII exhibited a fine specific capacitance of 199 F g−1 at a current density of 1 A g−1 in the three-electrode system, with 6 mol L−1 KOH as the electrolyte. The specific capacitance of ACIII remained 190 F g−1 even despite increasing the current density to 5 A g−1, indicating a good rate of electrochemical performance. Moreover, its specific capacitance remained at 98.1% of the initial value after 5000 galvanostatic charge-discharge (GCD) cycle tests at a current density of 1 A g−1, suggesting that the ACIII has excellent cycle performance as electrode materials for supercapacitors. This study provides a promising approach for fabricating high performance electrode materials from high-rank coals, which could facilitate efficient and clean utilization of high-rank coals.


2020 ◽  
Vol 10 (1) ◽  
pp. 422
Author(s):  
Haihan Zhang ◽  
Li Xu ◽  
Guoji Liu

In this work, nitrogen-doped carbon materials (NCMs) were prepared using aniline-phenol benzoxazine (BOZ) or aniline-cardanol benzoxazine as the carbon precursor and SBA-15 as the hard template. The effects of the carbonization temperature (700, 800, and 900 °C) and different nitrogen contents on the electrochemical properties of carbon materials were investigated. The samples synthesized using aniline-phenol benzoxazine as precursors and treated at 900 °C (NCM-900) exhibited an excellent electrochemical performance. The specific capacitance was 460 F/g at a current density of 0.25 A/g and the cycle stability was excellent (96.1% retention rate of the initial capacitance after 2000 cycles) in a 0.5 M H2SO4 electrolyte with a three-electrode system. Furthermore, NCM-900 also exhibited a high specific capacitance, comparable energy/power densities, and excellent cycling stability using a symmetrical electrode system. The characterization of the morphology and structure of the materials suggests it possessed an ordered mesoporous structure and a large specific surface area. NCM-900 could thus be considered a promising electrode material for supercapacitors.


Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1680
Author(s):  
Luming Li ◽  
Jing Li ◽  
Hongmei Li ◽  
Li Lan ◽  
Jie Deng

A series of MOx (M = Co, Ni, Zn, Ce)-modified lamellar MnO2 electrode materials were controllably synthesized with a superfast self-propagating technology and their electrochemical practicability was evaluated using a three-electrode system. The results demonstrated that the specific capacitance varied with the heteroatom type as well as the doping level. The low ZnO doping level was more beneficial for improving electrical conductivity and structural stability, and Mn10Zn hybrid nanocrystals exhibited a high specific capacitance of 175.3 F·g−1 and capacitance retention of 96.9% after 2000 cycles at constant current of 0.2 A·g−1. Moreover, XRD, SEM, and XPS characterizations confirmed that a small part of the heteroatoms entered the framework to cause lattice distortion of MnO2, while the rest dispersed uniformly on the surface of the carrier to form an interfacial collaborative effect. All of them induced enhanced electrical conductivity and electrochemical properties. Thus, the current work provides an ultrafast route for development of high-performance pseudocapacitive energy storage nanomaterials.


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