scholarly journals Widening of the electroactivity potential range by composite formation – capacitive properties of TiO2/BiVO4/PEDOT:PSS electrodes in contact with an aqueous electrolyte

2019 ◽  
Vol 10 ◽  
pp. 483-493 ◽  
Author(s):  
Konrad Trzciński ◽  
Mariusz Szkoda ◽  
Andrzej P Nowak ◽  
Marcin Łapiński ◽  
Anna Lisowska-Oleksiak

Composites based on the titania nanotubes were tested in aqueous electrolyte as a potential electrode material for energy storage devices. The nanotubular morphology of TiO2 was obtained by Ti anodization. TiO2 nanotubes were covered by a thin layer of bismuth vanadate using pulsed laser deposition. The formation of the TiO2/BiVO4 junction leads to enhancement of pseudocapacitance in the cathodic potential range. The third component, the conjugated polymer PEDOT:PSS, was electrodeposited from an electrolyte containing the monomer EDOT and NaPSS as a source of counter ions. Each stage of modification and deposition affected the overall capacitance and allowed for an expansion of the potential range of electroactivity. Multiple charge/discharge cycles were performed to characterize the electrochemical stability of the inorganic–organic hybrid electrode. Capacitance values higher than 10 mF·cm−2 were maintained even after 10000 galvanostatic cycles (i c = i a = 0.5 mA·cm−2).

In this study, graphene-molybdenum oxide composite materials were prepared via green hydrothermal synthesis method and evaluated as supercapacitor electrodes. The morphology and structure of the composite were examined by using Scanning Electron Microscopy (SEM), Raman spectroscopy. The electrochemical performances of the composite were evaluated by cyclic voltammetry (CV), galvanostatic chargedischarge (CD) method, and electrochemical impedance spectroscopy (EIS). The electrochemical results show that the composite electrodes possess improved specific capacitance of 122 F/g at a scan rate of 5 mV/s, which is about 22% higher that of pure graphene. Additionally, the composite electrodes exhibit good capacitive properties and a high specific energy with superior capacitive retention after 1000 cycles. In contrast to the previously reported systems that are usually complicated and costly, the present work potentially provides a readily scalable technological platform for economic mass production of energy storage devices.


Membranes ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 642
Author(s):  
Vladislav V. Shunaev ◽  
Olga E. Glukhova

The outstanding mechanical and conductive properties of graphene and high theoretical capacity of magnetite make a composite based on these two structures a prospective material for application in flexible energy storage devices. In this study using quantum chemical methods, the influence of magnetite concentration on energetic and electronic parameters of graphene/Fe3O4 composites is estimated. It is found that the addition of magnetite to pure graphene significantly changes its zone structure and capacitive properties. By varying the concentration of Fe3O4 particles, it is possible to tune the capacity of the composite for application in hybrid and symmetric supercapacitors.


Nanomaterials ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3235
Author(s):  
Jasmin Smajic ◽  
Amira Alazmi ◽  
Nimer Wehbe ◽  
Pedro M. F. J. Costa

Being environmentally friendly, safe and easy to handle, aqueous electrolytes are of particular interest for next-generation electrochemical energy storage devices. When coupled with an abundant, recyclable and low-cost electrode material such as aluminum, the promise of a green and economically sustainable battery system has extraordinary appeal. In this work, we study the interaction of an aqueous electrolyte with an aluminum plate anode and various graphitic cathodes. Upon establishing the boundary conditions for optimal electrolyte performance, we find that a mesoporous reduced graphene oxide powder constitutes a better cathode material option than graphite flakes.


2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Bo Liu ◽  
Yan Wang ◽  
Hong-Wu Jiang ◽  
Ben-Xue Zou

WO3nanowires directly grown on graphene sheets have been fabricated by using a seed-mediated hydrothermal method. The morphologies and electrochemical performance of WO3films prepared by different process were studied. The results show that the precoated nanoseeds and graphene sheets on graphite electrode provide more reactive centers for the nucleation and formation of uniform WO3nanowires. The WO3nanowires electrode exhibits a high area specific capacitance of 800 mF cm−2over negative potential range from −1.0 V to 0 V versus SCE in 1 M Li2SO4solution. A high performance electrochemical supercapacitor assembled with WO3nanowires as negative electrode and PANI/MnO2as positive electrodes over voltage range of 1.6 V displays a high volumetric capacitance of 2.5 F cm−3, which indicate great potential applications of WO3nanowires on graphene sheets as negative electrode for energy storage devices.


NANO ◽  
2020 ◽  
Vol 15 (08) ◽  
pp. 2050102
Author(s):  
Xiaoqi Tan ◽  
Xiaolei Yue ◽  
Meng Yuan ◽  
Shuxia Liu ◽  
Yaodong Zhang ◽  
...  

CuO/CNT composites were synthesized via simple and rapid microwave approach. The nanocomposites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). Further, the electrochemical performances of CuO/CNT composites were evaluated. The prepared samples displayed high specific capacitances of 164.5[Formula: see text]F[Formula: see text]g[Formula: see text] at 1[Formula: see text]A[Formula: see text]g[Formula: see text], during the cycle process, the capacitance value aggrandized to 274.7[Formula: see text]F[Formula: see text]g[Formula: see text], and the capacitance remained at 166% of the primary value after 10 000 turns. Moreover, the CuO/CNT//AC asymmetric supercapacitor (ASC) exhibited an energy density of 17.08[Formula: see text]Wh[Formula: see text]kg[Formula: see text] at 775[Formula: see text]W[Formula: see text]kg[Formula: see text] and excellent electrochemical stability in 6M KOH aqueous electrolyte, showing its enormous potential in energy-storage devices.


2018 ◽  
Vol 8 (10) ◽  
pp. 1732 ◽  
Author(s):  
Huankai Zhou ◽  
Hongsheng Luo ◽  
Xingdong Zhou ◽  
Huaquan Wang ◽  
Yangrong Yao ◽  
...  

Supercapacitors as novel and efficient energy storage devices could provide a higher power density and energy density compared to other electronics and devices. However, traditional supercapacitors are readily damaged, which leads to degraded performance or even failure. To make them more durable and efficient, healable flexible shape memory-based supercapacitors were unprecedentedly explored by a transfer process, in which the conductive nano-carbon networks were decorated with pseudocapacitance materials, followed by embedding them into a shape memory polymer matrix containing healing reagents. The composite exhibited flexibility, supercapacitance and self-healing capability originating from the shape memory effect and healing reagent. The morphologies, thermal, mechanical and capacitive properties, and the self-healability of the composite were investigated. In particular, the influence of the compositions on the healing efficiency was considered. The optimized composite exhibited good capacitance (27.33 mF cm−1), stability (only 4.08% capacitance loss after 1500 cycles) and healable property (up to 93% of the healing efficiency). The findings demonstrated how to endow the flexible polymeric electronics with healable bio-mimetic properties and may greatly benefit the application of intelligent polymers in the field of multi-functional electrical materials.


2020 ◽  
Vol 13 (10) ◽  
pp. 3527-3535 ◽  
Author(s):  
Nana Chang ◽  
Tianyu Li ◽  
Rui Li ◽  
Shengnan Wang ◽  
Yanbin Yin ◽  
...  

A frigostable aqueous hybrid electrolyte enabled by the solvation interaction of Zn2+–EG is proposed for low-temperature zinc-based energy storage devices.


2003 ◽  
Vol 772 ◽  
Author(s):  
M. Schmid ◽  
C. Goze-Bac ◽  
M. Mehring ◽  
S. Roth ◽  
P. Bernier

AbstractLithium intercalted carbon nanotubes have attracted considerable interest as perspective components for energy storage devices. We performed 13C Nuclear Magnetic Resonance spin lattice relaxation measurements in a temperature range from 4 K up to 300 on alkali intercalated Single Walled Carbon Nanotubes in order to investigate the modifications of the electronic properties. The density of states at the Fermi level were determined for pristine, lithium and cesium intercalated carbon nanotubes and are discussed in terms of intercalation and charge transfer effects.


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