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Wang L.,Shanxi Institute of Coal CAS Chemistry | Wang L.,Hebei Normal University | Liu Z.,Shanxi Institute of Coal CAS Chemistry | Guo Q.,Shanxi Institute of Coal CAS Chemistry | And 5 more authors.
Electrochimica Acta | Year: 2016

Carbon nanocoils (CNCs) have been used as anode materials for preparation of lithium ion batteries. As pure carbon material without any chemical modification, the graphitized CNCs anode exhibited larger capacities with good Coulombic efficiency, a higher rate capability, and better reversibility than the hollow graphite fibers (HGFs) anode. The excellent performance of the CNCs was possibly ascribed to the special structure and the high degree of graphitization. As a result, the CNCs anode exhibited high reversible capacity of 385.5 mA h g-1 at 50 mA g-1, 104.7% reversible capacity retention after 105 cycles, and superior reversible capability of 177.4 mA h g-1 at 1 A g-1 after 100 cycles. This result indicated that CNCs could be an attractive choice as anode material for high-energy density and high-power lithium-ion batteries. © 2016 Elsevier Ltd. All rights reserved.

Wu X.,Nanjing University of Technology | Shao G.,Nanjing University of Technology | Shen X.,Nanjing University of Technology | Cui S.,Nanjing University of Technology | Wang L.,AVIC Composite Corporation. Ltd
RSC Advances | Year: 2016

We have developed a new sol-gel route to synthesise Al2O3-SiO2 composite aerogels with different alumina/silica (Al/Si) molar ratios using an inexpensive inorganic salt. The approach is straightforward, inexpensive, and it produces monolithic mesoporous material with high specific surface area heat-treated at elevated temperatures. The effects of different Al/Si molar ratios and calcination temperatures on the microstructures and properties of Al2O3-SiO2 composite aerogels are investigated in this study. Results show that SiO2 is essentially amorphous, while Al2O3 predominately exists as polycrystalline boehmite for the as-dried composite aerogels. With the increase of Al/Si molar ratios, the morphologies change from connected spheroidal particles to nanometer-sized fibrous particles and web-like microstructures with varying diameters. As the heat treatment temperature increases to 600 °C, structural transition from boehmite to γ-Al2O3 occurs within all the composite aerogels, and mullitization firstly occurs with the Al/Si molar ratio of 1 at around 1000 °C. The specific surface area undergoes an increase-decrease-increase process at 600 °C and 1200 °C for the composite aerogels with different Al/Si molar ratios. The specific surface area is as high as 166 m2 g-1 at 1200 °C for the sample with an Al/Si molar ratio of 8, which is higher than ever reported. The thermal conductivities of mullite fiber mat reinforced aerogel composites at room temperatures are 0.023 W m-1 K-1, 0.029 W m-1 K-1 and 0.025 W m-1 K-1 with the Al/Si molar ratios of 2, 3 and 8, respectively, suitable for efficient thermal insulations uses. © 2016 The Royal Society of Chemistry.

Avic Composite Corporation Ltd. and Avic Beijing Institute Of Aeranutical Materials | Date: 2013-03-01

The present disclosure provides a plant fiber textile, a laminate with the plant fiber textile and a fabricating method of the laminate. The plant fiber textile has a matrix resin and continuous plant fibers distributed within the matrix resin. The plant fibers are subjected to a surface modification pretreatment including a coupling treatment with a coupling agent and/or a fire retardation treatment with a fire retardant. The laminate has a stack structure including a layer of the plant fiber textile and at least one layer selected from a group consisting of following layers: glass fiber, aramid fiber or carbon fiber non-woven cloth or textile, preferably distributed within the matrix resin; polymer fiber non-woven cloth or textile, preferably distributed within the matrix resin; or polymer foam or rubber material.

Shao G.,Nanjing University of Technology | Wu X.,Nanjing University of Technology | Kong Y.,Nanjing University of Technology | Shen X.,Nanjing University of Technology | And 4 more authors.
Journal of Alloys and Compounds | Year: 2016

The objective of this research was to develop a high emissivity coating on the low thermal conductivity ZrO2 ceramic insulation, which can be used in a reusable thermal protective system for short-term applications. The effects of SiB6 and heat-treatment time on the microstructures and radiative properties of the TaSi2-SiO2-borosilicate glass composite coatings prepared on fibrous ZrO2 ceramic with slurry dipping and subsequent sintering method were investigated. The coating prepared in the presence of SiB6 with a heat-treatment time of 15 min maintains a dense structure and infiltrates into the ZrO2 substrate, possessing a gradient structure and good compatibility. The emissivity of the coating is up to 0.9 in the range of 0.3-2.5 μm and 0.8 in the range of 3-30 μm at room temperature. The emissivity mechanism regarding electron transition absorption, lattice vibration absorption and the effect of surface roughness on the emissivity is discussed. The increased roughness leads to the increased emissivity, which can be explained by "circular grooves" and "pyramidal grooves" models. After thermal cycling between 1573 K and room temperature 10 times, the weight gain of the coating prepared with SiB6 is only 0.29%. The high emissivity TaSi2-SiO2-borosilicate glass coatings with high temperature resistance show a promising potential for application in thermal insulation materials. © 2015 Elsevier B.V. All rights reserved.

Shao G.,Nanjing University of Technology | Wu X.,Nanjing University of Technology | Kong Y.,Nanjing University of Technology | Cui S.,Nanjing University of Technology | And 3 more authors.
Surface and Coatings Technology | Year: 2015

An integrative insulation consisting of a MoSi2/borosilicate glass coating and a fibrous ZrO2 ceramic substrate was explored for applications up to 1673K. The MoSi2/borosilicate glass coating was prepared using the slurry dipping and subsequent firing method. The thermal shock behavior of the integrative insulation and the evolution of the surface morphology of the coatings for various thermal shock times were evaluated using confocal laser scanning microscopy (CLSM). The results revealed that the as-prepared coatings could maintain the dense structure and infiltrate into the substrate, forming a gradient structure and exhibiting good compatibility and adherence. After thermal cycling between 1673K and room temperature 15 times, the integrative insulation is also without micro cracks and spalling, and the weight loss is only 2.84%, revealing outstanding thermal shock performance. Additionally, the emissivity of the coatings reached 0.8 at room temperature, which was attributed to the synergistic effect of inter band absorption, crystal lattice vibration and the roughness of the coating. The gradual increase in the roughness resulted in the increase of the emissivity in 200-2500nm at room temperature, which was explained with a "circular grooves" model. These results imply that the integrative insulation can be a promising candidate material in high temperature application. © 2015 Elsevier B.V.

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