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Articles 1 - 10 of 10
Full-Text Articles in Engineering
Enhanced Reversible Lithium Storage In A Nanosize Silicon/Graphene Composite, Shulei Chou, Jiazhao Wang, Mohammad Choucair, Hua Liu, John Stride, S Dou
Enhanced Reversible Lithium Storage In A Nanosize Silicon/Graphene Composite, Shulei Chou, Jiazhao Wang, Mohammad Choucair, Hua Liu, John Stride, S Dou
Shulei Chou
Si/graphene composite was prepared by simply mixing of commercially available nanosize Si and graphene. Electrochemical tests show that the Si/graphene composite maintains a capacity of 1168 mAh g-1 and an average coulombic efficiency of 93% up to 30 cycles. EIS indicates that the Si/graphene composite electrode has less than 50% of the charge-transfer resistance compared with nanosize Si electrode, evidencing the enhanced ionic conductivity of Si/graphene composite. The enhanced cycling stability is attributed to the fact that the Si/graphene composite can accommodate large volume charge of Si and maintain good electronic contact.
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
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 …
Electrochemical Performances Of Layered Polypyrrole/Chemically Reduced Graphene Oxide Nanocomposites As Supercapacitor Electrodes, Si-Zhe Xu, Xue-Jiao Zhou, Kun Wu, Yong-Qiang Yang, Hai-Xia Wu
Electrochemical Performances Of Layered Polypyrrole/Chemically Reduced Graphene Oxide Nanocomposites As Supercapacitor Electrodes, Si-Zhe Xu, Xue-Jiao Zhou, Kun Wu, Yong-Qiang Yang, Hai-Xia Wu
Journal of Electrochemistry
Nanocomposites of polypyrrole (Ppy) and chemically reduced graphene oxide (CRGO), Ppy/CRGO, have been fabricated through in-situ polymerization of pyrrole on graphene oxide (GO) sheets. The as-synthesized Ppy/CRGO composites were characterized complementarily using scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and Fourier transformed infrared spectroscopy (FT-IR). By controlling the initial ratio of the GO to pyrrole, the layered composites could be obtained and their thickness could be tuned properly. The Ppy/CRGO electrodes were prepared using a mechanical compressing technique and their electrical conductivity and electrochemical properties were characterized systematically. We demonstrated that as electrodes for supercapacitor, the Ppy/CRGO composites with Ppy …
Cross-Linked Pdms Expansion Due To Submersion In Liquid And Supercritical Co2, Teng Yang
Cross-Linked Pdms Expansion Due To Submersion In Liquid And Supercritical Co2, Teng Yang
Graduate Theses and Dissertations
Characterization of micro/nano-copper particles impregnated Polydimethylsiloxane (PDMS) submersed in supercritical carbon dioxide (scCO2) was studied. The purpose of this investigation was to advance micro-corrosion sensor technology utilizing PDMS and micro-metal particle composite as the sensing element currently under-development. One of the key challenges encountered was the removal of the native oxides inherently existing on the metal particles. Numerous techniques were experimented with to counter this problem at the UA Engineered Micro/Nano Systems Laboratory (EMNSL), with swell-based protocols being identified as the most promising solution. In terms of compatibility to Micro-electro-mechanical Systems (MEMS) fabrication, CO2 is often used in the release …
Synthesis And Electrochemical Performance Of Xlifepo4·Yli3v2(Po4)3 Composites, Ping-Ping Ma, Zhi-Jian Liu, Jian-Hua Xia, Yu Chen, Pu Hu, Zhi-Chao Lu, Ding-Guo Xia
Synthesis And Electrochemical Performance Of Xlifepo4·Yli3v2(Po4)3 Composites, Ping-Ping Ma, Zhi-Jian Liu, Jian-Hua Xia, Yu Chen, Pu Hu, Zhi-Chao Lu, Ding-Guo Xia
Journal of Electrochemistry
A series of xLiFePO4·yLi3V2(PO4)3 composites were systematically synthesized through solid state reactions by variations in the proportions of LiFePO4 and Li3V2(PO4)3. The properties of the prepared compounds were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM) and electrochemical measurements. The capacity of 162.7 mAh/g at 0.2 C rate was obtained with the relatively good cycle stability and good conductivity for 0.95LiFePO4·0.05Li3V2(PO4)3 due to more uniformed distributed and smaller particle sizes.
Organic Materials As Templates For The Formation Of Mesoporous Inorganic Materials And Ordered Inorganic Nanocomposites, Christopher Ryan Ziegler
Organic Materials As Templates For The Formation Of Mesoporous Inorganic Materials And Ordered Inorganic Nanocomposites, Christopher Ryan Ziegler
Open Access Dissertations
Hierarchically structured inorganic materials are everywhere in nature. From unicellular aquatic algae such as diatoms to the bones and/or cartilage that comprise the skeletal systems of vertebrates. Complex mechanisms involving site-specific chemistries and precision kinetics are responsible for the formation of such structures. In the synthetic realm, reproduction of even the most basic hierarchical structure effortlessly produced in nature is difficult. However, through the utilization of self-assembling structures or "templates", such as polymers or amphiphilic surfactants, combined with some favorable interaction between a chosen inorganic, the potential exists to imprint an inorganic material with a morphology dictated via synthetic molecular …
Synthesis And Electrochemical Characterization Of Lifepo4/C-Polypyrrole Composite Prepared By A Simple Chemical Vapor Deposition Method, Qiang Gong, Yu-Shi He, Yang Yang, Xiao Zhen Liao, Zi-Feng Ma
Synthesis And Electrochemical Characterization Of Lifepo4/C-Polypyrrole Composite Prepared By A Simple Chemical Vapor Deposition Method, Qiang Gong, Yu-Shi He, Yang Yang, Xiao Zhen Liao, Zi-Feng Ma
Australian Institute for Innovative Materials - Papers
A LiFePO4/C-polypyrrole (LiFePO4/C-PPy) composite as a high-performance cathode material is successfully prepared through a simple chemical vapor deposition (CVD) method. According to the transmission electron microscope (TEM) analysis, the surface of the LiFePO4/C is surrounded with PPy in the LiFePO4/C-PPy composite. The as-prepared LiFePO4/C-PPy material shows outstanding rate capability at 20°C and good cycle performance at 55°C in comparison with those of the bare LiFePO4/C material against Li anode. After 700 cycles, the discharge capacity of LiFePO4/C-PPy could still remain 110 mA h g−1 with …
Magnetic Properties And Microstructures Of Iron Oxide@Mesoporous Silica Core-Shell Composite For Applications In Magnetic Dye Separation, Weichang Hao, Yang Xi, Jingwei Hu, Tianmin Wang, Yi Du, X L. Wang
Magnetic Properties And Microstructures Of Iron Oxide@Mesoporous Silica Core-Shell Composite For Applications In Magnetic Dye Separation, Weichang Hao, Yang Xi, Jingwei Hu, Tianmin Wang, Yi Du, X L. Wang
Australian Institute for Innovative Materials - Papers
"In this report, hollow mesoporous silica (HMS) and iron oxide-hollow mesoporous silica (FexOy@HMS) core-shell composite were prepared by a one-step facile fabrication method. Transmission electron microscopy, X-ray diffraction, N-2 adsorption-desorption isotherms, and vibrating sample magnetometer were used to characterize the morphology, microstructure, and magnetic properties of the HMS and core-shell composite. The magnetic separability of FexOy@HMS core-shell composite was tested in Rhodamine B (Rh. B) dye solution. The results indicate that the core-shell composite can absorb Rh. B dyes molecules effectively up to 90.1%. (C) 2012 American Institute of Physics. [doi:10.1063/1.3670049]"
Exploiting High Quality Pedot:Pss-Swnt Composite Formulations For Wet-Spinning Multifunctional Fibers, Rouhollah Jalili, Joselito M. Razal, Gordon G. Wallace
Exploiting High Quality Pedot:Pss-Swnt Composite Formulations For Wet-Spinning Multifunctional Fibers, Rouhollah Jalili, Joselito M. Razal, Gordon G. Wallace
Australian Institute for Innovative Materials - Papers
In order to exploit the inherent properties of carbon nanotubes (CNT) in any polymer composite, systematic control of carbon nanotube loading and protocols that mitigate against CNT bundling are required. If such composites are to be rendered in fiber form via wet-spinning, then CNT bundling during the coagulation process must also be avoided. Here we have achieved this by utilizing highly exfoliated single walled carbon nanotubes (SWNT) and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonicacid) (PEDOT:PSS) to obtain wet-spinnable composite formulations at various nanotube volume fractions (Vf). The addition of only 0.02 Vf of aggregate-free and individually dispersed SWNT resulted in a …
Lifepo4-Fe2p-C Composite Cathode: An Environmentally Friendly Promising Electrode Material For Lithium-Ion Battery, M. Mahfuzur Rahman, Jiazhao Wang, Rong Zeng, David Wexler, Hua-Kun Liu
Lifepo4-Fe2p-C Composite Cathode: An Environmentally Friendly Promising Electrode Material For Lithium-Ion Battery, M. Mahfuzur Rahman, Jiazhao Wang, Rong Zeng, David Wexler, Hua-Kun Liu
Australian Institute for Innovative Materials - Papers
In this investigation, the synthesis strategy is involved the creation of LiFePO4-Fe2P-C composites with a porous conductive architecture, which includes distinct regions or clusters containing antiferromagnetic LiFePO4 in close proximity to ferromagnetic Fe2P. The microstructure is achieved by using a simple ultra-fast solvent assisted manual grinding method, combined with solid state reaction, which can replace the time-consuming high energy ball milling method. The crystalline structure, morphology, and electrochemical characterization of the synthesised product are investigated systematically. The electrochemical performance is outstanding, especially the high C rate. The composite cathode is found to display specific capacity of 167 mAh g-1 at …