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Dong G.-H.,Shanghai Shanshan Technology Co. | Dong G.-H.,Shanghai JiaoTong University | Liu H.-J.,Shanghai Shanshan Technology Co. | Liu H.-J.,Shanghai Second Polytechnic University | And 6 more authors.
Journal of Alloys and Compounds | Year: 2014

Poor electronic conductivity is one of the biggest obstacles for practical application of lithium titanate as lithium-ion battery anode material. Utilizing the advantages of coating and doping techniques to optimize the conductive and rate performances of lithium titanate was reported in this work. Herein, the effects of various synthetic conditions including calcination temperatures and holding times, lithium overdoses, carbon contents, doping contents and doping elements on phase, primary particles' size and electrochemical performance were comprehensively investigated. The optimal Li3.98Al 0.06Ti4.96O12/C secondary microspheres were synthesized, which possessed high electronic conductivity, tap density, reversible capacity and first columbic efficiency, and excellent rate performances. Furthermore, the synthesized samples were characterized by various techniques. © 2014 Elsevier B.V. All rights reserved.


Liu P.,Shanghai Shanshan Technology Co. | Liu P.,Zhejinag University | Wang N.,Shanghai Ninth Peoples Hospital | Hao Y.,Shanghai Ninth Peoples Hospital | And 4 more authors.
Medical Principles and Practice | Year: 2014

Objective: To investigate the effect of entangled titanium fibre balls (ETFBs) combined with nano strontium hydroxyapatite (nano-Sr-HAP) on the repair of bone defects in vivo. Materials and Methods: Twenty-four 6-month-old, specific pathogen-free, male Sprague-Dawley rats were used. Drill defects were created in bilateral femoral condyles. ETFBs combined with nano-Sr-HAP were selected randomly from 72 samples and implanted into the femoral bone defects of left legs, which served as the experimental group, while ETFBs without nano-Sr-HAP were implanted into right legs for comparison. The bone defects on both sides were X-rayed. The anteroposterior positions and histological procedures and evaluations of each sample were performed at 1, 2, 4 and 8 weeks post-surgery. Results: Histological results showed that the ETBs allowed new bone to grow within their structure. Additionally, an increase in new bone was seen on the nano-Sr-HAP side compared to the control side. The results of histomorphometric analysis confirmed that the new bone formation on the left side gradually increased with time. There was a statistical increase in new bone at 2, 4 and 8 weeks, and the differences between the two sides were statistically significant at weeks 4 and 8 (p < 0.05 for all comparisons). Conclusion: The results showed that ETFBs possess a unique 3-dimensional interconnective porous structure and have excellent biocompatibility, cell affinity and osteoconductivity, which makes them useful as scaffold materials for repairing bone defects. On the other hand, nano-Sr-HAP improved the bone defect-repairing capacity of the ETFBs, which showed osteoinductive properties. © 2014 S. Karger AG, Basel.


Wan C.,Shanghai Institute of Technology | Wu M.,Shanghai Shanshan Technology Co. | Wu D.,Shanghai Institute of Technology
Powder Technology | Year: 2010

Spherical LiMn2O4 particles were successfully synthesized by dynamically sintering spherical precursor powders, which were prepared by a slurry spray-drying method. The effect of the sintering process on the morphology of LiMn2O4 was studied. It was found that a one-step static sintering process combined with a spray-drying method could not be adopted to prepare spherical products. A two-step sintering procedure consisting of completely decomposing sprayed precursors at low temperature and further sintering at elevated temperature facilitated spherical particle formation. The dynamic sintering program enhanced the effect of the two-step sintering process in the formation of spherical LiMn2O4 powders. The LiMn2O4 powders prepared by the dynamic sintering process, after initially decomposing the spherical spray-dried precursor at 180 °C for 5 h and then sintering it at 700 °C for 8 h, were spherical and pure spinel. The as-prepared spherical material had a high tap density (ca. 1.6 g/cm3). Its specific capacity was about 117 mAh/g between 3.0 and 4.2 V at a rate of 0.2 C. The retention of capacity for this product was about 95% over 50 cycles. The rate capability test indicated that the retention of the discharge capacity at 4C rate was still 95.5% of its 0.2 rate capacity. All the results showed that the spherical LiMn2O4 product made by the dynamic sintering process had a good performance for lithium ion batteries. This novel method combining a dynamic sintering system and a spray-drying process is an effective synthesis method for the spherical cathode material in lithium ion batteries. © 2010 Elsevier B.V. All rights reserved.


Li H.,Shanghai Shanshan Technology Co. | Li H.,Shanxi Institute of Coal CAS Chemistry | Zhang B.,Shanxi Institute of Coal CAS Chemistry | Lu C.,Shanxi Institute of Coal CAS Chemistry
Materials Letters | Year: 2014

The graphene hydrogels (GHGs) could be prepared via hydrothermal process using graphene oxide (GO) hydrosol. However, the formation of GHGs is unavailable when the GO concentration is low. In this work, we successfully address this problem with the aid of some organic solvents such as tetrahydrofuran, acetone and ethanol. The as-obtained GHGs have different mesopore structure and interior microstructure depending on the organic solvents used. Ethanol-enabled GHGs (eGHGs) show a cross-linked three-dimensional (3D) network structure composed of random dispersed graphene, and greatly enhance the cycling stability of Si nanoparticles as an anode material for lithium ion batteries. This work extends the possibility of synthesizing network graphene macroform. © 2014 Elsevier B.V.


Zhao P.,CAS Xinjiang Technical Institute of Physics and Chemistry | Zhao P.,University of Chinese Academy of Sciences | Bian L.,CAS Xinjiang Technical Institute of Physics and Chemistry | Wang L.,CAS Xinjiang Technical Institute of Physics and Chemistry | And 4 more authors.
Applied Physics Letters | Year: 2014

Inorganic-organolead halide perovskite CH3NH3PbI3 modified BiFeO3 polycrystalline film has been established. The composite photoelectrode presents much larger open voltage and several magnitudes superior photoelectric conversion performance in comparison to the ordinary BiFeO3 polycrystalline film. The I-V curve shows that the short-circuit current (Jsc) is 1.74 mA·cm-2 and open-circuit voltage (Voc) is 1.62 V, the device's photon to current efficiency is over 1%. The large open voltage and high photovoltaic efficiency is believed to attributed to the spontaneous polarization of composite perovskite induced by BiFeO3 lattice and modified reduced work function of the modified BiFeO3 surface. Our results clearly show that the present BiFeO3-CH3NH3PbI3 planar device is capable to generate a large voltage in macro scale under visible light, leading an approach to further applications on photodetectors and optoelectronic switch. © 2014 AIP Publishing LLC.


Yang X.,China Three Gorges University | Zhang P.,China Three Gorges University | Zhang P.,Shanghai Shanshan Technology Co. | Shi C.,China Three Gorges University | Wen Z.,CAS Shanghai Institute of Ceramics
ECS Solid State Letters | Year: 2012

Porous graphite/silicon micro-sphere is prepared by carbothermal reduction and spray drying method. X-ray diffraction (XRD), scanning electron microscope (SEM), and transmission electron microscope (TEM) are used to evaluate the phases, morphology and microstructure of the composite. Compared with the commercial graphite anode, the as-prepared composites with different silicon contents can exhibit reversible capacity between 426.5 and 755.5 mAh/g without dramatic capacity fading. The superior electrochemical performance is attributed to integrity of electrode material, improved adhesive strength between silicon and graphite, and porous structure composed of graphite flakes with different orientations. © 2012 The Electrochemical Society. All rights reserved.


Liu P.,Shanghai Shanshan Technology Co. | Zheng J.,Shanghai Shanshan Technology Co. | Qiao Y.,Shanghai Shanshan Technology Co. | Li H.,Shanghai Shanshan Technology Co. | And 2 more authors.
Journal of Solid State Electrochemistry | Year: 2014

Porous Si-Al films were fabricated by magnetron sputtering (co-sputtering) using three different copper substrates as current collectors, respectively. The morphology, compositions, structure, and crystallinity of the porous Si-Al films anodes were examined by using SEM, EDX, TEM, XRD, and Raman spectroscopy. The electrochemical properties of the porous Si-Al films anodes were evaluated by galvanostatic cycling. The Si-Al film deposited on copper foam showed higher insertion/extraction capacity, capacity retention, and longer cycle life in comparison to the Si-Al films deposited on expanded copper mesh and even copper mesh grid, which could be attributed to its unique three-dimensional macroporous structure. The three-dimensional macroporous structure could offer larger materials/electrolyte contact area, a much better adhesion, lower electrical resistance (i.e., well conductive), and stress-alleviated environment to partly accommodate volume expansion that leads to exfoliation during cycling. © 2014 Springer-Verlag Berlin Heidelberg.


Wang L.-L.,Shanghai Second Polytechnic University | Shen L.,Shanghai Shanshan Technology Co. | Jin H.-Y.,Shanghai Second Polytechnic University | Zhu L.-P.,Shanghai Second Polytechnic University | Wang L.-J.,Shanghai Second Polytechnic University
Chinese Journal of Chemical Physics | Year: 2014

A facile impregnation method under mild condition is designed for synthesis of highly dispersed Pt nanoparticles with a narrow size of 4-7 nm on nitrogen-doped carbon nanotubes (CNx). CNx do not need any pre-surface modification due to the inherent chemical activity. The structure and nature of Pt/CNx were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and energy dispersive spectroscopy spectrum. All the experimental results revealed that the large amount of doped nitrogen atoms in CNx was virtually effective for capturing the Pt(IV) ions. The improved surface nitrogen functionalities and hydrophilicity contributed to the good dispersion and immobilization of Pt nanoparticles on the CNx surface. The Pt/CNx served as active and reusable catalysts in the hydrogenation of allyl alcohol. This could be attributed to high dispersion of Pt nanoparticles and stronger interaction between Pt and the supports, which prevented the Pt nanoparticles from aggregating into less active Pt black and from leaching as well. © 2014 Chinese Physical Society.


Wang L.,Shanghai Second Polytechnic University | Shen L.,Shanghai Shanshan Technology Co. | Zhu L.,Shanghai Second Polytechnic University | Jin H.,Shanghai Second Polytechnic University | Bing N.,Shanghai Second Polytechnic University
Journal of Nanomaterials | Year: 2012

SnO2 nanoparticles coated on nitrogen-doped carbon nanotubes were prepared successfully via a simple wet-chemical route. The as-obtained SnO2/CNx composites were characterized using X-ray powder diffraction, scanning electron microscopy, and transmission electron microscopy. The photocatalytic activity of as-prepared SnO2/CNx for degradation Rhodamine B under UV light irradiation was investigated. The results show that SnO2/CNx nanocomposites have a higher photocatalytic activity than pure SnO2 and SnO2/CNTs nanocomposites. This enhanced photoresponse indicates that the photoinduced electrons in the SnO2 prefer separately transferring to the CNx, which has a high degree of defects. As a consequence, the radiative recombination of the electron-hole pairs is hampered and the photocatalytic activity is significantly enhanced for the SnO2/CNx photocatalysts. © 2012 Lingling Wang et al.


Wang L.,Shanghai Second Polytechnic University | Shen L.,Shanghai Shanshan Technology Co. | Li Y.,Shanghai Second Polytechnic University | Zhu L.,Shanghai Second Polytechnic University | Shen J.,Shanghai Second Polytechnic University
International Journal of Photoenergy | Year: 2013

TiO2-nitrogen-doped carbon nanotubes (TiO2-CNx) nanocomposites are successfully synthesized via a facile hydrothermal method. The prepared photocatalysts were systematically characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and thermogravimetric and differential scanning calorimetry analyses (TGA-DSC). The results show that the TiO2 nanoparticles with a narrow size of 7 nm are uniformly deposited on CNx. The photocatalytic activity of the nanocomposite was studied using methyl orange (MO) as a model organic pollutant. The experimental results revealed that the strong linkage between the CNx and TiO2 played a significant role in improving photocatalytic activity. However, the mechanical process for CNx and TiO 2 mixtures showed lower activity than neat TiO2. Moreover, TiO2-CNx nanocomposites exhibit much higher photocatalytic activity than that of neat TiO2 and TiO2-CNTs nanocomposites. The improved photodegradation performances are attributed to the suppressed recombination of electrons and holes caused by the effective transfer of photogenerated electrons from TiO2 to CNx. © 2013 Lingling Wang et al.

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