Monolithic cathodes of optimized porosity prepared by sintering LiCoO2 powders provide high volume utilization and surprising stability under electrochemical cycling. Combined with a novel packaging approach, ultrahigh energy densities in small volumes are enabled. The microbatteries have volumes < 6 mm3 and provide sustained 2.5 h discharges with energy densities of 400-650 W h L-1.
A new class of bulk metamaterials is proposed, which are assembled of functional layers with differing layout properties, as shown in the figure. These enhanced degrees of freedom allow to design metamaterials, which perform optically in a predefined manner. We apply this approach to design isotropic metamaterials and metamaterials in which light propagates free of diffraction.
The properties of a molecular quantum dot system are investigated using a novel structure of vertical molecular transistor. This C60-based device can be operated in two new modes: voltage-controlled switching and gate-controlled hysteresis. A polaron-based model is used to explain the operation of the transistor and to introduce some general rules for the construction of polaronic molecular transistors.
Metal nanoparticles have been the subject of widespread research over the past two decades. In recent years, noble metals have been the focus of numerous studies involving synthesis, characterization, and applications. Synthesis of an impressive range of noble metal nanoparticles with varied morphologies has been reported. Researchers have made a great progress in learning how to engineer materials on a nanometer length scale that has led to the understanding of the fundamental size- and shape-dependent properties of matter and to devising of new applications. In this article, we review the recent progress in the colloid-chemical synthesis of nonspherical nanoparticles of a few important noble metals (mainly Ag, Au, Pd, and Pt), highlighting the factors that influence the particle morphology and discussing the mechanisms behind the nonspherical shape evolution. The article attempts to present a thorough discussion of the basic principles as well as state-of-the-art morphology control in noble metal nanoparticles.