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Shulei Chou

Carbon

Articles 1 - 9 of 9

Full-Text Articles in Engineering

Free-Standing Single-Walled Carbon Nanotube/Sno2 Anode Paper For Flexible Lithium-Ion Batteries, Lukman Noerochim, Jia-Zhao Wang, Shulei Chou, David Wexler Feb 2013

Free-Standing Single-Walled Carbon Nanotube/Sno2 Anode Paper For Flexible Lithium-Ion Batteries, Lukman Noerochim, Jia-Zhao Wang, Shulei Chou, David Wexler

Shulei Chou

Free-standingsingle-walledcarbonnanotube/SnO2 (SWCNT/SnO2) anodepaper was prepared by vacuum filtration of SWCNT/SnO2 hybrid material which was synthesized by the polyol method. From field emission scanning electron microscopy and transmission electron microscopy, the CNTs form a three-dimensional nanoporous network, in which ultra-fine SnO2 nanoparticles, which had crystallite sizes of less than 5 nm, were distributed, predominately as groups of nanoparticles on the surfaces of singlewalled CNT bundles. Electrochemical measurements demonstrated that the anodepaper with 34 wt.% SnO2 had excellent cyclic retention, with the high specific capacity of 454 mAh g−1 beyond 100 cycles at a current …


Irradiation Si On Carbon Nanotube Paper As A Flexible Anode Material For Lithium-Ion Batteries, Shulei Chou, Mihail Ionescu, Jia-Zhao Wang, Brad Winton, Hua Liu Feb 2013

Irradiation Si On Carbon Nanotube Paper As A Flexible Anode Material For Lithium-Ion Batteries, Shulei Chou, Mihail Ionescu, Jia-Zhao Wang, Brad Winton, Hua Liu

Shulei Chou

Silicon single walled carbon nanotube composite paper was modified by low energy ion implantation using 5i to obtain a flexible composite paper. Raman and FE-SEM results show that structure of SWCNT could be destroyed by the implantation. Electrochemical measurements display that the implanted SI can improve the specific capacity and the reversible capacity of CNT paper. After 50 cycles, the specific capacity of 5Hmplanted CNT paper is 30 per cent higher than the pristine CNT.


Silicon/Single-Walled Carbon Nanotube Composite Paper As A Flexible Anode Material For Lithium Ion Batteries, Shulei Chou, Yue Zhao, Jiazhao Wang, Zhixin Chen, Hua-Kun Liu, S. X. Dou Nov 2012

Silicon/Single-Walled Carbon Nanotube Composite Paper As A Flexible Anode Material For Lithium Ion Batteries, Shulei Chou, Yue Zhao, Jiazhao Wang, Zhixin Chen, Hua-Kun Liu, S. X. Dou

Shulei Chou

Flexible silicon/single-walled carbon nanotube (Si/SWCNT) composite paper was prepared using the pulsed laser deposition (PLD) method to deposit Si onto SWCNT paper. In the composite, Si mainly shows nanoworm-like morphology. Increasing deposition time results in an increased amount of Si microspheres. Electrochemical measurements show that the capacity of the composite paper is improved by the presence of Si. The Si/SWCNT composite with only 2.2% Si shows a capacity of 163 mA h g−1 at a current density of 25 mA g−1 up to 50 cycles, which is more than 60% improvement of the capacity of pristine CNT paper. The Si …


High-Surface-Area -Fe2o3/Carbon Nanocomposite: One-Step Synthesis And Its Highly Reversible And Enhanced High-Rate Lithium Storage Properties, S X. Dou, David Wexler, Jiazhao Wang, Hua-Kun Liu, Konstantin K. Konstantinov, Chao Zhong, Shulei Chou Nov 2012

High-Surface-Area -Fe2o3/Carbon Nanocomposite: One-Step Synthesis And Its Highly Reversible And Enhanced High-Rate Lithium Storage Properties, S X. Dou, David Wexler, Jiazhao Wang, Hua-Kun Liu, Konstantin K. Konstantinov, Chao Zhong, Shulei Chou

Shulei Chou

Hollow-structured α-Fe2O3/carbon (HIOC) nanocomposite with a high surface area of around 260 m2 g−1 was synthesized by a one-step, in situ, and industrially-oriented spray pyrolysis method using iron lactate and sucrose solution as the precursors. The small α-Fe2O3 nanocrystals were highly dispersed inside amorphous carbon to form a carbon nanocomposite. Electrochemical measurements showed that the carbon played an important role in affecting both the cycle life and the rate capability of the electrode. The HIOC composites showed the best electrochemical performance in terms of high capacity (1210 mAh g−1 at a current density of 0.1 C), enhanced rate capability and …


Electrodeposition Of Mno2 Nanowires On Carbon Nanotube Paper As Free-Standing, Flexible Electrode For Supercapacitors, Shulei Chou, Jia-Zhao Wang, Sau-Yen Chew, Hua Liu, S Dou Nov 2012

Electrodeposition Of Mno2 Nanowires On Carbon Nanotube Paper As Free-Standing, Flexible Electrode For Supercapacitors, Shulei Chou, Jia-Zhao Wang, Sau-Yen Chew, Hua Liu, S Dou

Shulei Chou

MnO2 nanowires were electrodeposited onto carbon nanotube (CNT) paper by a cyclic voltametric technique. The as-prepared MnO2 nanowire/CNT composite paper (MNCCP) can be used as a flexible electrode for electrochemical supercapacitors. Electrochemical measurements showed that the MNCCP electrode displayed specific capacitances as high as 167.5 F g-1 at a current density of 77 mA g-1. After 3000 cycles, the composite paper can retain more than 88% of initial capacitance, showing good cyclability. The CNT paper in the composite acted as a good conductive and active substrate for flexible electrodes in supercapacitors, and the nanowire structure of the MnO2 could facilitate …


The Compatibility Of Transition Metal Oxide/Carbon Composite Anode And Ionic Liquid Electrolyte For The Lithium-Ion Battery, Shulei Chou, Lin Lu, Jiazhao Wang, Md Mokhlesur Rahman, Chao Zhong, Hua Liu Nov 2012

The Compatibility Of Transition Metal Oxide/Carbon Composite Anode And Ionic Liquid Electrolyte For The Lithium-Ion Battery, Shulei Chou, Lin Lu, Jiazhao Wang, Md Mokhlesur Rahman, Chao Zhong, Hua Liu

Shulei Chou

Three types of transition metal oxide/carbon composites including Fe2O3/C, NiO/C and CuO/Cu2O/C synthesized via spray pyrolysis were used as anode for lithium ion battery application in conjunction with two types of ionic liquid: 1 M LiN(SO2CF3)2 (LiTFSI) in 1-ethyl-3-methyl-imidazolium bis(fluorosulfonlyl)imide (EMI-FSI) or 1-methyl-1-propylpyrrolidinium bis(fluorosulfonyl)imide (Py13-FSI). From the electrochemical measurements, the composite electrodes using Py13-FSI as electrolyte show much better electrochemical performance than those using EMI-FSI as electrolyte in terms of reversibility. The Fe2O3/C composite shows the highest specific capacity and the best capacity retention (425 mAh g−1) under a current density of 50 mA g−1 for up to 50 cycles, …


Sno2-Coated Multiwall Carbon Nanotube Composite Anode Materials For Rechargeable Lithium-Ion Batteries, Lukman Noerochim, Jiazhao Wang, Shulei Chou, Huijun Li, Hua Liu Nov 2012

Sno2-Coated Multiwall Carbon Nanotube Composite Anode Materials For Rechargeable Lithium-Ion Batteries, Lukman Noerochim, Jiazhao Wang, Shulei Chou, Huijun Li, Hua Liu

Shulei Chou

SnO2-coated multiwall carbon nanotube (MWCNT) nanocomposites were synthesized by a facile hydrothermal method. The as-prepared nanocomposites were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), and thermogravimetric analysis (TGA). The SnO2/MWCNT composites, when combined with carboxymethyl cellulose (CMC) as a binder, show excellent cyclic retention, with the high specific capacity of 473 mAh g−1 beyond 100 cycles, much greater than that of the bare SnO2 which was also prepared by the hydrothermal method in the absence of MWCNTs. The enhanced capacity retention could be mainly attributed to …


One-Step Spray Pyrolysis Synthesized Cuo-Carbon Composite Combined With Carboxymethyl Cellulose Binder As Anode For Lithium-Ion Batteries, Chao Zhong, Jia-Zhao Wang, Xuan-Wen Gao, Shulei Chou, Konstantin Konstantinov, Hua Liu Nov 2012

One-Step Spray Pyrolysis Synthesized Cuo-Carbon Composite Combined With Carboxymethyl Cellulose Binder As Anode For Lithium-Ion Batteries, Chao Zhong, Jia-Zhao Wang, Xuan-Wen Gao, Shulei Chou, Konstantin Konstantinov, Hua Liu

Shulei Chou

Copper oxide-carbon composite with hollow sphere structure has been synthesized by a one-step spray pyrolysis method and tested as anode material for lithium-ion batteries. Different analytical methods, including X-ray powder diffraction, scanning electron microscopy, energy-dispersive X-ray spectrometry, thermogravimetric analysis, and systematic electrochemical tests were performed. The results demonstrate that the CuO-carbon composite in conjunction with carboxymethyl cellulose (CMC) binder has an excellent electrochemical performance, with a capacity of 577 mAh g-1 up to 100 cycles. The usage of the water soluble binder, CMC, not only obviously improves the electrochemical performance, but also makes the electrode fabrication process much easier and …


Hollow Hematite Nanosphere/Carbon Nanotube Composite: Mass Production And Its High-Rate Lithium Storage Properties, Shulei Chou, Jiazhao Wang, Zhixin Chen, Hua Liu, S. Dou May 2012

Hollow Hematite Nanosphere/Carbon Nanotube Composite: Mass Production And Its High-Rate Lithium Storage Properties, Shulei Chou, Jiazhao Wang, Zhixin Chen, Hua Liu, S. Dou

Shulei Chou

Spray pyrolysis was used to produce hollow hematite (α-Fe(2)O(3)) nanosphere (HHNS)/carbon nanotube (CNT) composite on a large scale. The method offers simplicity, high productivity, versatility, low cost, and suitability for industry. The structure is composed of hollow nanospheres in a network of CNTs. The possible formation mechanism of hollow α-Fe(2)O(3) nanospheres is due to the rapid evaporation of water and the super-hydrophobicity of the CNT surface. The electrochemical tests show that the HHNS/CNT composite is a promising lithium storage material in terms of high capacity (∼700 mAh g(-1)), good high-rate capability, and good cycle life (up to 150 cycles). The …