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    Current Advances in TiO2-Based Nanostructure Electrodes for High Performance Lithium Ion Batteries
    (Basel : MDPI, 2018-2-6) Madian, Mahmoud; Eychmüller, Alexander; Giebeler, Lars
    The lithium ion battery (LIB) has proven to be a very reliably used system to store electrical energy, for either mobile or stationary applications. Among others, TiO2-based anodes are the most attractive candidates for building safe and durable lithium ion batteries with high energy density. A variety of TiO2 nanostructures has been thoroughly investigated as anodes in LIBs, e.g., nanoparticles, nanorods, nanoneedles, nanowires, and nanotubes discussed either in their pure form or in composites. In this review, we present the recent developments and breakthroughs demonstrated to synthesize safe, high power, and low cost nanostructured titania-based anodes. The reader is provided with an in-depth review of well-oriented TiO2-based nanotubes fabricated by anodic oxidation. Other strategies for modification of TiO2-based anodes with other elements or materials are also highlighted in this report.
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    Deformation behavior of metallic glass composites reinforced with shape memory nanowires studied via molecular dynamics simulations
    (Melville, NY : American Inst. of Physics, 2015) Şopu, D.; Stoica, M.; Eckert, J.
    Molecular dynamics simulations indicate that the deformation behavior and mechanism of Cu64Zr36 composite structures reinforced with B2 CuZr nanowires are strongly influenced by the martensitic phase transformation and distribution of these crystalline precipitates. When nanowires are distributed in the glassy matrix along the deformation direction, a two-steps stress-induced martensitic phase transformation is observed. Since the martensitic transformation is driven by the elastic energy release, the strain localization behavior in the glassy matrix is strongly affected. Therefore, the composite materials reinforced with a crystalline phase, which shows stress-induced martensitic transformation, represent a route for controlling the properties of glassy materials. The authors acknowledge the financial support of the European Research Council under the ERC Advanced Grant INTELHYB (Grant No. ERC-2013-ADG-340025) and the German Science Foundation (DFG) under the Leibniz Program (Grant No. EC 111/26-1). A DAAD-PPP travel grant is also acknowledged. Computing time was made available at ZIH TU Dresden and IFW Dresden as well as by CSC Julich. The authors acknowledge Dr. Simon Pauly and Sergio Scudino for fruitful discussions.
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    Thermal conductivity of hybrid filled HDPE nanocomposites
    (Melville, NY : AIP, 2017) Müller, M. T.; Krause, Beate; Kretzschmar, B.; Jahn, I.; Pötschke, Petra
    In this study composite materials based on high-density polyethylene (HDPE) with fillers containing nanostructures were prepared using melt mixing. Vapour Grown Carbon Fibers (VGCF), multiwalled carbon nanotubes (MWCNT) of the types Baytubes® C150P and Nanocyl™ NC7000, anthracite powder, microsilica, organoclay and expanded graphite (EG) as well as mixtures of these fillers were used. The amount and mixing ratios of the hybrid filled systems have been varied to determine their effects on the achievable level of thermal conductivity as measured on compression molded plates. The filler dispersion and phase adhesion were studied using scanning electron microscopy. When limiting the maximum filler content to 10 wt%, the highest enhancement in thermal conductivity by 166% was found for VGCF followed by a 1:1 filler combination of VGCF with EG (148%).
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    Electrical and thermal conductivity of polypropylene filled with combinations of carbon fillers
    (Melville, NY : AIP, 2016) Krause, Beate; Pötschke, Petra
    The thermal and electrical conductivity of polymer composites filled with a low content up to 7.5 vol% of different carbon fillers (carbon nanotubes, carbon fibers, graphite nanoplates) were investigated. It was found that the combination of two or three carbon fillers leads to an increase of thermal conductivity up to 193% which is higher than the sum of the effects of both fillers.