Dedicated to Professor Herbert Griinewald on the occasion of his 60th birthdayThe aryldihydropyridines first prepared by Hanlzsch almost 100 years ago have recently been found to be highly effective calcium antagonists with suitable pharmacological profiles. An illustrative example is dimethyl-1,4-dihydro-2,6-dimethyl-4-(o-nitrophenyl)pyridine-3,5-dicarboxylate (Nifedipine) which is already employed therapeutically. This substance lowers the frequency of attack of angina pectoris and reduces blood pressure. The discovery of the therapeutic activity of this class of substances initiated renewed investigation of the Hantzsch condensation and the synthesis of numerous 4-aryldihydropyridines and related compounds. Qualitative and quantitative structure/activity relationships of these substances can be deduced from their biological data.

Designing usable geovisualization tools is an emerging problem in GIScience software development. We are often satisfied that a new method provides an innovative window on our data, but functionality alone is insufficient assurance that a tool is applicable to a problem in situ. As extensions of the static methods they evolved from, geovisualization tools are bound to enable new knowledge creation. We have yet to learn how to adapt techniques from interaction designers and usability experts toward our tools in order to maximize this ability. This is especially challenging because there is limited existing guidance for the design of usable geovisualization tools. Their design requires knowledge about the context of work within which they will be used, and should involve user input at all stages, as is the practice in any human-centered design effort. Toward that goal, we have employed a wide range of techniques in the design of ESTAT, an exploratory geovisualization toolkit for epidemiology. These techniques include; verbal protocol analysis, card-sorting, focus groups, and an in-depth case study. This paper reports the design process and evaluation results from our experience with the ESTAT toolkit.

In this contribution, we report on a novel composite solid electrolyte material, SiO2/[BMIM]BF4/LiTf ([BMIM]BF4 = 1-butyl-3-methylimidazolium tetrafluoroborate, LiTf = lithium trifluoromethanesulfonate), prepared via a one-pot sol−gel synthesis route, in which the amorphous SiO2 glass network provides the mechanical stability and the ionic liquid/Li salt part the high ionic conductivity (0.5 × 10−2 S cm−1 at 298 K). The mobility of the ionic liquid and Li salt confined within the pores of the fully condensed SiO2 network is found to increase with the [BMIM]BF4/LiTf ratio, exhibiting an almost liquidlike mobility, as evidenced by multinuclear solid-state NMR, pulsed-field-gradient solid-state NMR, and impedance spectroscopy.

Different types of carbonaceous materials, such as graphite and carbon black, are typically used as conductive additives in composite electrodes for lithium-ion cells. Since the next generation cathode materials, the so-called 5 V materials like LiCoPO4, operate at potentials above 4.5 V vs. Li/Li+, the issue of anion intercalation into the conductive carbon additive needs to be seriously considered. The anion intercalation from organic-solvent based electrolytes into more graphitic carbons can be accompanied by a solvent co-intercalation reaction, which may lead to the destruction of the graphite structure (graphite exfoliation) and to accelerated electrolyte degradation. These detrimental side reactions may result in a degradation of the overall cathode electrode performance and therefore need to be understood. In this contribution, the electrochemical intercalation of different anions, namely hexafluorophosphate, bis(trifluoromethanesulfonyl) imide and bis(pentafluoroethanesulfonyl) imide, from an organic solvent-based electrolyte into a graphite-based cathode is evaluated with respect to the reversible capacity and coulombic efficiency.

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Dual-ion cells based on the anion intercalation into a graphite positive electrode have been proposed as electrochemical energy storage devices. In this set-up, the electrolyte, in this case a mixture of N-butyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl) imide (Pyr14TFSI) and lithium bis(trifluoromethanesulfonyl) imide (LiTFSI) acts not only as charge carrier, but also as active material. Since the compatibility of this ionic liquid-based electrolyte mixture with graphitic anodes is relatively poor and not sufficient, the selection of the anode materials for the dual-ion system was limited to metallic lithium or Li4Ti5O12 so far. In this work, we present promising results concerning the use of graphite as both the anode and cathode material in a so-called “dual-graphite cell”. The Pyr14TFSI-LiTFSI ionic liquid electrolyte is used in combination with the SEI-forming additive ethylene sulfite (ES) and allows a stable and highly reversible lithium ion and TFSI- anion intercalation/de-intercalation into the graphite anode and cathode, respectively.

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