Electrochemical Performance of Polypyrrole/Multi-Walled Carbon Nanotubes Composites for Supercapacitors Electrodes

2011 ◽  
Vol 399-401 ◽  
pp. 1415-1418
Author(s):  
Jing Li ◽  
Hua Qing Xie ◽  
Yang Li

Nanocomposites supercapacitors electrodes are synthesized by homogeneously coating the nano-structured polypyrrole (PPy) on multi-walled carbon nanotubes (MWCNTs) via a facile electrochemical method. The capacitance properties of the composites are evaluated by cyclic voltammetry (CV) and galvanostatic charge/discharge techniques. The results show that the porous composites structure exhibit a remarkable specific capacitance of 674 F g-1 at a current density of 2 A g-1. Electrochemical experiments indicate that the high specific capacitance is associated with uniform PPy coating. Moreover, the composites present a nearly ideal rectangular shape of cyclic voltammetry characteristics. The stability of the composites electrode is also examined and only 10% capacitance decrease after 800 cycles. This technique provides a feasible solution for developing high-performance electrical energy storage devices.

Author(s):  
Yaofeng Wang ◽  
Fan Wang ◽  
Yang Kong ◽  
Lei Wang ◽  
Qinchuan Li

Abstract High-performance bioartificial muscles with low-cost, large bending deformation, low actuation voltage, and fast response time have drawn extensive attention as the development of human-friendly electronics in recent years. Here, we report a high-performance ionic bioartificial muscle based on the bacterial cellulose (BC)/ionic liquid (IL)/multi-walled carbon nanotubes (MWCNT) nanocomposite membrane and PEDOT:PSS electrode. The developed ionic actuator exhibits excellent electro-chemo-mechanical properties, which are ascribed to its high ionic conductivity, large specific capacitance, and ionically crosslinked structure resulting from the strong ionic interaction and physical crosslinking among BC, IL, and MWCNT. In particular, the proposed BC-IL-MWCNT (0.10 wt%) nanocomposite exhibited significant increments of Young's modulus up to 75% and specific capacitance up to 77%, leading to 2.5 times larger bending deformation than that of the BC-IL actuator. More interestingly, bioinspired applications containing artificial soft robotic finger and grapple robot were successfully demonstrated based on high-performance BC-IL-MWCNT actuator with excellent sensitivity and controllability. Thus, the newly proposed BC-IL-MWCNT bioartificial muscle will offer a viable pathway for developing next-generation artificial muscles, soft robotics, wearable electronic products, flexible tactile devices, and biomedical instruments.


2009 ◽  
Vol 79-82 ◽  
pp. 47-50
Author(s):  
Tung Feng Hsieh ◽  
Chia Chih Chuang ◽  
Ming Yang Liu ◽  
Yu Chuan Chou ◽  
Chi Min Shu

A nanocomposite electrode of vertically aligned multi-walled carbon nanotubes (MWCNTs) on gold was fabricated to improve the specific capacitance and power density of the conventional supercapacitor. The novel supercapacitor built from MWCNTs and gold electrode showed a very high specific capacitance of 92.74 F/g using cyclic voltammetry (CV) at 10 mV/s, and 96.43 F/g was measured at 100 Hz. This nanocomposite electrode greatly enhanced the utilization efficiency of supercapacitor electrode material, low material cost and provided both high capacitance and power density. It was shown that the nanocomposite electrode based on vertically aligned carbon nanotube electrode had the characteristics of high specific capacitance.


2020 ◽  
Vol 9 (1) ◽  
pp. 93-104
Author(s):  
Mingrui Du ◽  
Yuan Gao ◽  
Guansheng Han ◽  
Luan Li ◽  
Hongwen Jing

AbstractMulti-walled carbon nanotubes (MWCNTs) have been added in the plain cementitious materials to manufacture composites with the higher mechanical properties and smart behavior. The uniform distributions of MWCNTs is critical to obtain the desired enhancing effect, which, however, is challenged by the high ionic strength of the cement pore solution. Here, the effects of methylcellulose (MC) on stabilizing the dispersion of MWCNTs in the simulated cement pore solution and the viscosity of MWCNT suspensions werestudied. Further observations on the distributions of MWCNTs in the ternary cementitious composites were conducted. The results showed that MC forms a membranous envelope surrounding MWCNTs, which inhibits the adsorption of cations and maintains the steric repulsion between MWCNTs; thus, the stability of MWCNT dispersion in cement-based composites is improved. MC can also work as a viscosity adjuster that retards the Brownian mobility of MWCNTs, reducing their re-agglomerate within a period. MC with an addition ratio of 0.018 wt.% is suggested to achieve the optimum dispersion stabilizing effect. The findings here provide a way for stabilizing the other dispersed nano-additives in the cementitious composites.


2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Xiaona Wang ◽  
Zhenyu Zhou ◽  
Zhijian Sun ◽  
Jinho Hah ◽  
Yagang Yao ◽  
...  

Abstract Coaxial fiber-shaped supercapacitors are a promising class of energy storage devices requiring high performance for flexible and miniature electronic devices. Yet, they are still struggling from inferior energy density, which comes from the limited choices in materials and structure used. Here, Zn-doped CuO nanowires were designed as 3D framework for aligned distributing high mass loading of MnO2 nanosheets. Zn could be introduced into the CuO crystal lattice to tune the covalency character and thus improve charge transport. The Zn–CuO@MnO2 as positive electrode obtained superior performance without sacrificing its areal and gravimetric capacitances with the increasing of mass loading of MnO2 due to 3D Zn–CuO framework enabling efficient electron transport. A novel category of free-standing asymmetric coaxial fiber-shaped supercapacitor based on Zn0.11CuO@MnO2 core electrode possesses superior specific capacitance and enhanced cell potential window. This asymmetric coaxial structure provides superior performance including higher capacity and better stability under deformation because of sufficient contact between the electrodes and electrolyte. Based on these advantages, the as-prepared asymmetric coaxial fiber-shaped supercapacitor exhibits a high specific capacitance of 296.6 mF cm−2 and energy density of 133.47 μWh cm−2. In addition, its capacitance retention reaches 76.57% after bending 10,000 times, which demonstrates as-prepared device’s excellent flexibility and long-term cycling stability.


RSC Advances ◽  
2017 ◽  
Vol 7 (76) ◽  
pp. 48341-48353 ◽  
Author(s):  
Xia Yang ◽  
Yuying Yang ◽  
Quancai Zhang ◽  
Xiaotong Wang ◽  
Yufeng An ◽  
...  

1-Hydroxyanthraquinone (HAQ) is selected to functionalize the dissected carbon nanotubes (rDCNTs) with reduced graphene oxide layers through non-covalent modification. The composite achieves high specific capacitance and ultrahigh rate capability.


2009 ◽  
Vol 60-61 ◽  
pp. 394-398 ◽  
Author(s):  
Gen Sheng Wu ◽  
Jue Kuan Yang ◽  
Shu Lin Ge ◽  
Yu Juan Wang ◽  
Min Hua Chen ◽  
...  

The stable and homogeneneous aqueous suspension of carbon nanotubes was prepared in this study. The stability of the nanofluids was improved greatly due to the use of a new dispersant, humic acid. The thermal conductivity of the aqueous suspension was measured with the 3ω method. The experimental results showed that the thermal conductivity of the suspensions increases with the temperature and also is nearly proportional to the loading of the nanoparticles. The thermal conductivity enhancement of single-walled carbon nanotubes (SWNTs) suspensions is better than that of the multi-walled carbon nanotubes (MWNTs) suspensions. Especially for a volume fraction of 0.3846% SWNTs, the thermal conductivity is enhanced by 40.5%. Furthermore, the results at 30°C match well with Jang and Choi’s model.


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