scholarly journals V2O5/Carbon Nanotube/Polypyrrole Based Freestanding Negative Electrodes for High-Performance Supercapacitors

Catalysts ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 980
Author(s):  
Jincy Parayangattil Jyothibasu ◽  
Ming-Zhu Chen ◽  
You-Ching Tien ◽  
Chi-Ching Kuo ◽  
Erh-Chiang Chen ◽  
...  

In this study, the vanadium pentoxide (V2O5), functionalized carbon nanotubes (f-CNT), and polypyrrole (PPy) based composites films have been prepared through a facile synthesis method and their electrochemical performance were evaluated as freestanding negative electrodes of supercapacitor. A hydrous V2O5 gel prepared by treating V2O5 powder with H2O2 was mixed with f-CNT to obtain V2O5/f-CNT composite film. V2O5/f-CNT composite was then coated with PPy through vapor phase polymerization method. The PPy deposited on the V2O5/f-CNT prevented the dissolution of V2O5 and thus resulted in an improved the capacitance and cycle life stability for V2O5/f-CNT/PPy composite electrode. V2O5/f-CNT/PPy freestanding negative electrode exhibited a high areal capacitance value (1266 mF cm−2 at a current density of 1 mA cm−2) and good cycling stability (83.0% capacitance retention after 10,000 charge-discharge cycles). The superior performance of the V2O5/f-CNT/PPy composite electrode can be attributed to the synergy between f-CNT with high conductivity and V2O5 and PPy with high-energy densities. Thus, V2O5/f-CNT/PPy composite based electrode can effectively mitigate the drawbacks of the low specific capacitance of CNTs and the poor cycling life of V2O5.

Author(s):  
Irshad Mohammad ◽  
Lucie Blondeau ◽  
Eddy Foy ◽  
Jocelyne Leroy ◽  
Eric Leroy ◽  
...  

Following the trends of alloys as negative electrodes for Na-ion batteries, the sodiation of the InSb intermetallic compound was investigated for the first time. The benefit of coupling Sb with...


2021 ◽  
Author(s):  
yajun JI ◽  
Fei Chen ◽  
Shufen Tan ◽  
Fuyong Ren

Abstract Transition metal oxides are generally designed as hybrid nanostructures with high performance for supercapacitors by enjoying the advantages of various electroactive materials. In this paper, a convenient and efficient route had been proposed to prepare hierarchical coral-like MnCo2O4.5@Co-Ni LDH composites on Ni foam, in which MnCo2O4.5 nanowires were enlaced with ultrathin Co-Ni layered double hydroxides nanosheets to achieve high capacity electrodes for supercapacitors. Due to the synergistic effect of shell Co-Ni LDH and core MnCo2O4.5, the outstanding electrochemical performance in three-electrode configuration was triggered (high area capacitance of 5.08 F/cm2 at 3 mA/cm2 and excellent rate capability of maintaining 61.69 % at 20 mA/cm2), which is superior to those of MnCo2O4.5, Co-Ni LDH and other metal oxides based composites reported. Meanwhile, the as-prepared hierarchical MnCo2O4.5@Co-Ni LDH electrode delivered improved electrical conductivity than that of pristine MnCo2O4.5. Furthermore, the as-constructed asymmetric supercapacitor using MnCo2O4.5@Co-Ni LDH as positive and activated carbon as negative electrode presented a rather high energy density of 220 μWh/cm2 at 2400 μW/cm2 and extraordinary cycling durability with the 100.0 % capacitance retention over 8000 cycles at 20 mA/cm2, demonstrating the best electrochemical performance compared to other asymmetric supercapacitors using metal oxides based composites as positive electrode material. It can be expected that the obtained MnCo2O4.5@Co-Ni LDH could be used as the high performance and cost-effective electrode in supercapacitors.


2020 ◽  
Vol 8 (45) ◽  
pp. 24040-24052
Author(s):  
Bobby Singh Soram ◽  
Jiu Yi Dai ◽  
Ibomcha Singh Thangjam ◽  
Nam Hoon Kim ◽  
Joong Hee Lee

One-step electrodeposited MoS2@Ni-mesh as a high-performance negative electrode; a high energy density flexible and transparent asymmetric solid-state supercapacitor is fabricated.


2020 ◽  
Vol 8 (6) ◽  
pp. 3333-3343 ◽  
Author(s):  
Changjian Deng ◽  
Miu Lun Lau ◽  
Chunrong Ma ◽  
Paige Skinner ◽  
Yuzi Liu ◽  
...  

Nanoscale oxide-based negative electrodes are of great interest for lithium ion batteries due to their high energy/power density, and enhanced safety. The crystallinity effect of mesoporous TiO2 nanoparticle electrode was investigated in this work.


Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2303
Author(s):  
Wei Meng ◽  
Yanlin Xia ◽  
Chuanguo Ma ◽  
Xusheng Du

Transition molybdenum oxides (MoO3) and conductive polymer (polyaniline, PANI) nanomaterials were fabricated and asymmetric supercapacitor (ASC) was assembled with MoO3 nanobelts as negative electrode and PANI nanofibers as a positive electrode. Branched PANI nanofibers with a diameter of 100 nm were electrodeposited on Ti mesh substrate and MoO3 nanobelts with width of 30–700 nm were obtained by the hydrothermal reaction method in an autoclave. Redox active electrolyte containing 0.1 M Fe2+/3+ redox couple was adopted in order to enhance the electrochemical performance of the electrode nano-materials. As a result, the PANI electrode shows a great capacitance of 3330 F g−1 at 1 A g−1 in 0.1 M Fe2+/3+/0.5 M H2SO4 electrolyte. The as-assembled ASC achieved a great energy density of 54 Wh kg−1 at power density of 900 W kg−1. In addition, it displayed significant cycle stability and its capacitance even increased to 109% of the original value after 1000 charge–discharge cycles. The superior performance of the capacitors indicates their promising application as energy storage devices.


2016 ◽  
Vol 4 (46) ◽  
pp. 18164-18173 ◽  
Author(s):  
Xiaoyu Lu ◽  
Yang Bai ◽  
Ranran Wang ◽  
Jing Sun

A carbon fiber-based positive electrode enhanced by CNT modification with NiCo(OH)x and a negative electrode functionalized with activated carbon were prepared. The supercapacitor showed high energy and power densities.


2015 ◽  
Vol 3 (31) ◽  
pp. 16150-16161 ◽  
Author(s):  
Dezhi Kong ◽  
Chuanwei Cheng ◽  
Ye Wang ◽  
Jen It Wong ◽  
Yaping Yang ◽  
...  

A novel asymmetric supercapacitor composed of Co3O4@C@Ni3S2 NNAs as the positive electrode and activated carbon (AC) as the negative electrode can deliver a high energy density and excellent long cycle stability.


2021 ◽  
Author(s):  
Jincy Parayangattil Jyothibasu ◽  
Ruei-Hong Wang ◽  
Kenneth Ong ◽  
Juping Hillary Lin Ong ◽  
Rong-Ho Lee

Abstract This paper reports a simple, cost-effective, and environmentally friendly procedure for the synthesis of cellulose/functionalized carbon nanotube (f-CNT)/Fe2O3 (CCF) composite films and their performance as freestanding negative electrodes in supercapacitors. A facile chemical precipitation process was performed at room temperature within a short reaction time without requiring any of the special processing conditions used in the conventional hydrothermal synthesis, making it the most cost-efficient method for the bulk-scale production of sustainable supercapacitors. The binder-free negative electrode with ultra-high active material loading exhibited outstanding areal (9107.1 mF cm–2) and volumetric (314 F cm–3) capacitances, which were much greater than the values reported previously in the literature for negative electrodes. Moreover, an asymmetric supercapacitor cell featuring cellulose/f-CNT/MnO2 (CCM) and CCF as its positive and negative electrodes, respectively, achieved superior electrochemical performances. Therefore, on account of the economic and environmental superiority of this method and its bulk scalability, this paper provides a simple, eco-friendly, and cost-effective approach for the development of sustainable supercapacitors for practical use.


Micromachines ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1195
Author(s):  
Jianhao Lin ◽  
Xusheng Du

Urchin-like tungsten oxide (WO3) microspheres self-assembled with nanobelts are deposited on the surface of the hydrophilic carbon cloth (CC) current collector via hydrothermal reaction. The WO3 nanobelts in the urchin-like microspheres are in the hexagonal crystalline phase, and their widths are around 30–50 nm. The resulted hierarchical WO3 / CC electrode exhibits a capacitance of 3400 mF / cm2 in H2SO4 electrolyte in the voltage window of −0.5 ~ 0.2 V, which makes it an excellent negative electrode for asymmetric supercapacitors. To improve the capacitive performance of the positive electrode and make it comparable with that of the WO3 / CC electrode, both the electrode material and the electrolyte have been carefully designed and prepared. Therefore, the hydrophilic CC is further coated with carbon nanotubes (CNTs) to create a hierarchical CNT / CC electrode via a convenient flame synthesis method, and a redox-active electrolyte containing an Fe2+ / Fe 3+ couple is introduced into the half-cell system as well. As a result, the high performance of the asymmetric supercapacitor assembled with both the asymmetric electrodes and electrolytes has been realized. It exhibits remarkable energy density as large as 403 μW h / cm2 at 15 mW / cm2 and excellent cyclic stability after 10,000 cycles.


2020 ◽  
Author(s):  
Xiao-Xue Wang ◽  
De-Hui Guan ◽  
Fei Li ◽  
Ma-Lin Li ◽  
Li-Jun Zheng ◽  
...  

Abstract The photo-assisted lithium-oxygen (Li-O2) system emerged as an important direction for future development by effectively reducing the large overpotential in Li-O2 batteries. However, the advancement is greatly hindered by the rapidly recombined photoexcited electrons and holes upon the discharging and charging processes. Herein, we make a breakthrough in overcoming these challenges by developing a new magnetic and optical field multi-assisted Li-O2 battery with 3D porous NiO nanosheets on the Ni foam (NiO/FNi) as a photoelectrode. Under illumination, the photogenerated electrons and holes of the NiO/FNi photoelectrode play a key role in reducing the overpotential during discharging and charging, respectively. By introducing the external magnetic field, the Lorentz force acts oppositely on the photogenerated electrons and holes, suppressing the recombination of charge carriers. The magnetic and optical field multi-assisted Li-O2 battery achieves an ultra-low charge potential of 2.73 V, a high energy efficiency of 96.7%, as well as a good cycling stability of 200 h. This external magnetic and optical field multi-assisted technology paves a new way of developing high-performance Li-O2 batteries and other energy storage systems.


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