Activated Nitrogen-Enriched Carbon/Reduced Expanded Graphite Composites for Supercapacitors

2011 ◽  
Vol 211-212 ◽  
pp. 440-444 ◽  
Author(s):  
Shu Hui Tong ◽  
Chuan Li Qin ◽  
Zheng Jin ◽  
Xue Song Wang ◽  
Xu Duo Bai

Activated nitrogen-enriched carbon/reduced expanded graphite composites (ANC/REG-c) with different composite ratio were prepared by in-situ polymerization, carbonization, activation and reduction of aniline and expanded graphite. These were characterized by XPS, SEM and electrochemical measurements. XPS shows that N atoms exist in the ANC and ANC/REG-c. Compared to mechanical mixture of ANC and REG(ANC/REG-m), ANC/REG-c shows lower resistance and higherCp1(185.4 F/g) vs 124.3 F/g of ANC/REG-m measured by CV due to the introduction of the composite sturcture. When the composite ratio of ANC/REG-c is 6:1, the ANC/REG-c shows the highestCp1(264.0 F/g) and its symmetric supercapacitor also shows the best synthetical electrochemical performances. The optimal supercapacitor presents good cycle stability. ANC/REG-c is a suitable electrode material for supercapacitors.

2008 ◽  
Vol 111 (2-3) ◽  
pp. 368-374 ◽  
Author(s):  
Xiali Zhang ◽  
Liang Shen ◽  
Xue Xia ◽  
Haitao Wang ◽  
Qiangguo Du

2011 ◽  
Vol 239-242 ◽  
pp. 513-516
Author(s):  
Feng Ge Gao ◽  
Yan Hong Tian ◽  
Xue Jun Zhang

Polythionphene (PTH)/polyaniline (PANI)/activated carbon (AC) composites as electrode materials for supercapacitors were synthesized by in-situ polymerization of thionphene on PANI/AC. The surface morphology and the molecular structure of the composites were examined by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The electrochemical performances were tested by cyclic voltammetry, Galvanostatic charge-discharge and electrochemical impedance spectrometry. Results show that the PTH/PANI/AC composites exhibit better large current charge-discharge performance and higher capacitance than those of PANI/AC. The capacitance value of the composites would reach 597.4 F/g. The PTH/PANI/AC composites also have better cycle stability than that of PANI/AC.


2014 ◽  
Vol 16 (4) ◽  
pp. 45-50 ◽  
Author(s):  
Sandra Paszkiewicz ◽  
Małgorzata Nachman ◽  
Anna Szymczyk ◽  
Zdeno Špitalský ◽  
Jaroslav Mosnáček ◽  
...  

Abstract This work is the continuation and refinement of already published communications based on PET/EG nanocomposites prepared by in situ polymerization1, 2. In this study, nanocomposites based on poly(ethylene terephthalate) with expanded graphite were compared to those with functionalized graphite sheets (GO). The results suggest that the degree of dispersion of nanoparticles in the PET matrix has important effect on the structure and physical properties of the nanocomposites. The existence of graphene sheets nanoparticles enhances the crystallization rate of PET. It has been confirmed that in situ polymerization is the effective method for preparation nanocomposites which can avoid the agglomeration of nanoparticles in polymer matrices and improve the interfacial interaction between nanofiller and polymer matrix. The obtained results have shown also that due to the presence of functional groups on GO surface the interactions with PET matrix can be stronger than in the case of exfoliated graphene (EG) and matrix.


2010 ◽  
Vol 163-167 ◽  
pp. 1951-1954
Author(s):  
Gui Xiang Hou ◽  
Hai Ning Na ◽  
Xiao Ming Sang

Graphite nanosheets prepared through high-temperature oxidation via powdering the expanded graphite. After soaking the expanded graphite with styrene(S) and maleic anhydride(MA) monomers, the polymer (Poly(S-co-MA))/expanded graphite(EG) (PSMA/EG) composite granules were obtained by in situ polymerization. Light microscope,scanning electron microscope and X-ray diffraction characterization were performed. SEM analysis indicate that the expanded graphite was mostly tore to sheets with thickness of 50–80 nm and with diameter of 1μm. Optical micrographs showed that the distribution of graphite platelets is found to be nearly uniform.


2012 ◽  
Vol 479-481 ◽  
pp. 395-398
Author(s):  
Dan Qing Chen

This document explains and demonstrates how to prepare Polyurethane(PU)/Expanded Graphite powder(EGp) composite antistatic sponge by in situ polymerization. The morphology、mechanical、electrical and thermal properties of the PU/EGp composite antistatic sponge have been investigated. PU/ EGp composite sponge have better mechanical properties than that of CB composite. The resistivity of PU/EGp composite antistatic sponge can reach at about 108Ω•cm at the content around 5wt% of the EGp. EGp can stably exist in PU sponge and has little influence to the polymeric matrix while being heated.


2013 ◽  
Vol 448-453 ◽  
pp. 2938-2941
Author(s):  
Ping Ping Qi ◽  
Yan Li Ruan ◽  
Kun Wang ◽  
Zhe Wang

Graphene oxide (GO)/polyaniline (PANI) composite are synthesized via in situ polymerization in the presence of grapheme oxide under acid conditions. The GO/PANI was characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Scanning electron microscope (SEM) and electrochemical testing. The cathodes prepared using PANI and GO/PANI delivered initial discharge capacities of 78mAh/g and 104.4mAh/g ,respectively stable reversible capacities of 58.5mAh/g and 103.7mAh/g after 50 chargedischarge cycles. The GO enhances the discharge capacity of the PANI electrode material. GO/PANI is a good candidate as electrode material in lithium ion batteries


2016 ◽  
Vol 30 (12) ◽  
pp. 1603-1614 ◽  
Author(s):  
BTS Ramanujam ◽  
S Radhakrishnan ◽  
SD Deshpande

Polyphenylene sulfide (PPS)-expanded graphite (ExGr) conducting nanocomposites have been prepared by powder mixing and in situ polymerization routes after sonicating ExGr particles in acetone. Synthesized PPS has been used to make powder mixed composites. The powder mixed composites exhibit a percolation threshold of 3 wt% due to the formation of graphite nanosheets. When PPS-ExGr composites are prepared by in situ polymerization route, very low electrical percolation threshold less than 0.5 wt% ExGr is obtained. The low percolation threshold obtained is attributed to better dispersion of ExGr nanosheets in the polymer matrix when compared to powder mixed composites. The synthesized PPS has been characterized by X-ray diffraction, differential scanning calorimetry, and infrared spectroscopy. The formation of graphite nanosheets has been confirmed by transmission and scanning electron microcopy analysis.


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