scholarly journals The Performance of Fibrous CDC Electrodes in Aqueous and Non-Aqueous Electrolytes

2021 ◽  
Vol 7 (2) ◽  
pp. 46
Author(s):  
Siret Malmberg ◽  
Mati Arulepp ◽  
Krista Laanemets ◽  
Maike Käärik ◽  
Ann Laheäär ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Specific Capacitance ◽  
Salt Concentration ◽  
Electrochemical Behaviour ◽  
High Specific Capacitance ◽  
Production Costs ◽  
Constant Current ◽  
Aqueous Electrolytes ◽  
Concentration Effects ◽  
Cv Measurements

The aim of this study was to investigate the electrochemical behaviour of aqueous electrolytes on thin-layer (20 µm) nanoporous carbide-derived carbon (CDC) composite fibrous directly electrospun electrodes without further carbonisation. There have been previously investigated fibrous electrodes, which are produced by applying different post-treatment processes, however this makes the production of fibrous electrodes more expensive, complex and time consuming. Furthermore, in the present study high specific capacitance was achieved with directly electrospun nanoporous CDC-based fibrous electrodes in different neutral aqueous electrolytes. The benefit of fibrous electrodes is the advanced mechanical properties compared to the existing commercial electrode technologies based on pressure-rolled or slurry-cast powder mix electrodes. Such improved mechanical properties are preferred in more demanding applications, such as in the space industry. Electrospinning technology also allows for larger electrode production capacities without increased production costs. In addition to the influence of aqueous electrolyte chemical composition, the salt concentration effects and cycle stability with respect to organic electrolytes are investigated. Cyclic voltammetry (CV) measurements on electrospun electrodes showed the highest capacitance for asymmetrical cells with an aqueous 1 M NaNO3-H2O electrolyte. High CV capacitance was correlated with constant current charge–discharge (CC) data, for which a specific capacitance of 191 F g−1 for the positively charged electrode and 311 F g−1 for the negatively charged electrode was achieved. The investigation of electrolyte salt concentration on fibrous electrodes revealed the typical capacitance dependence on ionic conductivity with a peak capacitance at medium concentration levels. The cycle-life measurements of selected two-electrode test cells with aqueous and non-aqueous electrolytes revealed good stability of the electrospun electrodes.

A Facile Synthesis of NiFe2O4 with High Specific Capacitance as Supercapacitor Electrode Material

2018 ◽  
Vol 281 ◽  
pp. 854-858
Author(s):  
Xi Cheng Gao ◽  
Jian Qiang Bi ◽  
Wei Li Wang ◽  
Guo Xun Sun ◽  
Xu Xia Hao ◽  
...  
Keyword(s):  
Particle Size ◽  
Specific Capacitance ◽  
Electrochemical Property ◽  
Electrode Materials ◽  
High Specific Capacitance ◽  
Constant Current ◽  
X Ray Diffraction ◽  
Supercapacitor Electrode ◽  
Constant Current Charge ◽  
Supercapacitor Electrode Materials

NiFe2O4 powders were synthesized by a facile hydrothermal method at 180°C followed by a thermal treatment at 300°C. The phase composition and morphology were analyzed by X-ray diffraction (XRD) and scanning electron microscope (SEM). The results showed that the NiFe2O4 powders were well-crystallized, and they possessed a particle size in the range of 50-100 nm. The electrochemical property was characterized via cyclic voltammetry (CV) and constant current charge-discharge method. Encouragingly, the NiFe2O4 powders had an excellent electrochemical property, whose specific capacitance reached 266.84 F/g at the electric current density of 1 A/g due to the small particle size. Compared with other Fe-based metal compound oxides, NiFe2O4 has a better electrochemical performance, which can be widely used in the supercapacitor electrode materials.

scholarly journals Highly Effective Self-Propagating Synthesis of Lamellar ZnO-Decorated MnO2 Nanocrystals with Improved Supercapacitive Performance

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1680
Author(s):  
Luming Li ◽  
Jing Li ◽  
Hongmei Li ◽  
Li Lan ◽  
Jie Deng
Keyword(s):  
Electrical Conductivity ◽  
Specific Capacitance ◽  
Doping Level ◽  
High Performance ◽  
Electrode Materials ◽  
High Specific Capacitance ◽  
Electrode System ◽  
Constant Current ◽  
Supercapacitive Performance ◽  
Zno Doping

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.

scholarly journals Ultralight, High Capacitance, Mechanically Strong Graphene-Cellulose Aerogels

Molecules ◽  
2021 ◽  
Vol 26 (16) ◽  
pp. 4891
Author(s):  
Xiuya Wang ◽  
Ke Wan ◽  
Pengbo Xie ◽  
Yuanyuan Miao ◽  
Zhenbo Liu
Keyword(s):  
Mechanical Properties ◽  
Specific Capacitance ◽  
Energy Demand ◽  
High Surface ◽  
High Surface Area ◽  
High Specific Capacitance ◽  
High Capacitance ◽  
Electrochemical Tests ◽  
Composite Aerogels ◽  
One Step

With increasing energy demand driving the need for eco-friendly and efficient energy storage technology, supercapacitors are becoming increasingly prevalent in wearable devices because of their portability and stability. The performance of these supercapacitors is highly dependent on the choice of electrode material. The high capacitance and mechanical properties needed for these materials can be achieved by combining graphene’s stable electrical properties with renewable cellulose’s excellent mechanical properties into porous aerogels. In this study, graphene-cellulose hydrogels were prepared by a one-step hydrothermal method, with porous, ultra-light, and mechanically strong graphene-cellulose aerogels then prepared by freeze-drying. These composite aerogels possess excellent mechanical strength and high specific capacitance, capable of bearing about 1095 times the pressure of their own weight. Electrochemical tests show the specific capacitance of these composite aerogels can reach 202 F/g at a scanning rate of 5 mA/cm2. In view of their high surface area and fast charge transport provided by their 3D porous structure, graphene-cellulose aerogels have great potential as sustainable supercapacitor electrodes.

Highly flexible and mechanically strong polyaniline nanostructure @ aramid nanofiber films for free-standing supercapacitor electrodes

Nanoscale ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 5507-5520 ◽  
Author(s):  
Qing Yin ◽  
Hongbing Jia ◽  
Amel Mohamed ◽  
Qingmin Ji ◽  
Liu Hong
Keyword(s):  
Mechanical Properties ◽  
Specific Capacitance ◽  
High Specific Capacitance ◽  
Free Standing ◽  
Flexible Electrode ◽  
Superior Mechanical Properties

The excellent integration of high specific capacitance and superior mechanical properties for flexible electrode can be achieved by the combination of aramid nanofiber and polyaniline.

scholarly journals A Promising Polymer Blend Electrolytes Based on Chitosan: Methyl Cellulose for EDLC Application with High Specific Capacitance and Energy Density

Molecules ◽  
2019 ◽  
Vol 24 (13) ◽  
pp. 2503 ◽  
Author(s):  
Shujahadeen B. Aziz ◽  
M. H. Hamsan ◽  
Ranjdar M. Abdullah ◽  
M. F. Z. Kadir
Keyword(s):  
Energy Density ◽  
Specific Capacitance ◽  
Double Layer ◽  
Polymer Blend ◽  
Electrochemical Techniques ◽  
High Specific Capacitance ◽  
Transference Number ◽  
Constant Current ◽  
Equivalent Series Resistance ◽  
Charge Discharge

In the present work, promising proton conducting solid polymer blend electrolytes (SPBEs) composed of chitosan (CS) and methylcellulose (MC) were prepared for electrochemical double-layer capacitor (EDLC) application with a high specific capacitance and energy density. The change in intensity and the broad nature of the XRD pattern of doped samples compared to pure CS:MC system evidencedthe amorphous character of the electrolyte samples. The morphology of the samples in FESEM images supported the amorphous behavior of the solid electrolyte films. The results of impedance and Bode plotindicate that the bulk resistance decreasedwith increasing salt concentration. The highest DC conductivity was found to be 2.81 × 10−3 S/cm. The electrical equivalent circuit (EEC) model was conducted for selected samples to explain the complete picture of the electrical properties.The performance of EDLC cells was examined at room temperature by electrochemical techniques, such as impedance spectroscopy, cyclic voltammetry (CV) and constant current charge–discharge techniques. It was found that the studied samples exhibit a very good performance as electrolyte for EDLC applications. Ions were found to be the dominant charge carriers in the polymer electrolyte. The ion transference number (tion) was found to be 0.84 while 0.16 for electron transference number (tel). Through investigation of linear sweep voltammetry (LSV), the CS:MC:NH4SCN system was found to be electrochemically stable up to 1.8 V. The CV plot revealed no redox peak, indicating the occurrence of charge double-layer at the surface of activated carbon electrodes. Specific capacitance (Cspe) for the fabricated EDLC was calculated using CV plot and charge–discharge analyses. It was found to be 66.3 F g−1 and 69.9 F g−1 (at thefirst cycle), respectively. Equivalent series resistance (Resr) of the EDLC was also identified, ranging from 50.0 to 150.0 Ω. Finally, energy density (Ed) was stabilized to anaverage of 8.63 Wh kg−1 from the 10th cycle to the 100th cycle. The first cycle obtained power density (Pd) of 1666.6 W kg−1 and then itdropped to 747.0 W kg−1 at the 50th cycle and continued to drop to 555.5 W kg−1 as the EDLC completed 100 cycles.

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.

Sign in / Sign up

Export Citation Format

Share Document