22 research outputs found

    Insights into Electrolytic Pre Lithiation A Thorough Analysis Using Silicon Thin Film Anodes

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    Pre lithiation via electrolysis, herein defined as electrolytic pre lithiation, using cost efficient electrolytes based on lithium chloride LiCl , is successfully demonstrated as a proof of concept for enabling lithium ion battery full cells with high silicon content negative electrodes. An electrolyte for pre lithiation based on amp; 947; butyrolactone and LiCl is optimized using boron containing additives lithium bis oxalato borate, lithium difluoro oxalate borate and CO2 with respect to the formation of a protective solid electrolyte interphase SEI on silicon thin films as model electrodes. Reversible lithiation in Si Li metal cells is demonstrated with Coulombic efficiencies CEff of 95 96 for optimized electrolytes comparable to 1 m LiPF6 EC EMC 3 7. Formation of an effective SEI is shown by cyclic voltammetry and X ray photoelectron spectroscopy XPS . electrolytic pre lithiation experiments show that notable amounts of the gaseous product Cl2 dissolve in the electrolyte leading to a self discharge Cl2 Cl amp; 8722; shuttle mechanism between the electrodes lowering pre lithiation efficiency and causing current collector corrosion. However, no significant degradation of the Si active material and the SEI due to contact with elemental chlorine is found by SEM, impedance, and XPS. In NCM111 Si full cells, the capacity retention in the 100th cycle can be significantly increased from 54 to 78 by electrolytic pre lithiation, compared to reference cells without pre lithiation of S

    A new Late Agenian (MN2a, Early Miocene) fossil assemblage from Wallenried (Molasse Basin, Canton Fribourg, Switzerland)

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    Excavations of two fossiliferous layers in the Wallenried sand- and marl pit produced a very diversified vertebrate fauna. New material allows the reassessment of the taxonomic position of the ruminant taxa Andegameryx andegaviensis and endemic Friburgomeryx wallenriedensis. An emended diagnosis for the second species is provided and additional material of large and small mammals, as well as ectothermic vertebrates, is described. The recorded Lagomorpha show interesting morphological deviations from other Central European material, and probably represent a unique transitional assemblage with a co-occurrence of Titanomys, Lagopsis and Prolagus. Rodentia and Eulipotyphla belong to typical and well-known species of the Agenian of the Swiss Molasse Basin. Abundant small mammal teeth have allowed us to pinpoint the biostratigraphic age of Wallenried to late MN2a. The biostratigraphic age conforms to data derived from the charophyte assemblages and confirms the oldest occurrence of venomous snake fangs. The palaeoenvironmental context is quite complex. Sedimentary structures and fauna (fishes, frogs, salamanders, ostracods) are characteristic for a humid, lacustrine environment within a flood plain system

    Photography-based taxonomy is inadequate, unnecessary, and potentially harmful for biological sciences

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    The question whether taxonomic descriptions naming new animal species without type specimen(s) deposited in collections should be accepted for publication by scientific journals and allowed by the Code has already been discussed in Zootaxa (Dubois & NemĂ©sio 2007; Donegan 2008, 2009; NemĂ©sio 2009a–b; Dubois 2009; Gentile & Snell 2009; Minelli 2009; Cianferoni & Bartolozzi 2016; Amorim et al. 2016). This question was again raised in a letter supported by 35 signatories published in the journal Nature (Pape et al. 2016) on 15 September 2016. On 25 September 2016, the following rebuttal (strictly limited to 300 words as per the editorial rules of Nature) was submitted to Nature, which on 18 October 2016 refused to publish it. As we think this problem is a very important one for zoological taxonomy, this text is published here exactly as submitted to Nature, followed by the list of the 493 taxonomists and collection-based researchers who signed it in the short time span from 20 September to 6 October 2016

    The early Turolian (late Miocene) Cervidae (Artiodactyla, Mammalia) from the fossil site of Dorn-DĂŒrkheim 1 (Germany) and implications on the origin of crown cervids

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    Dental and cranial appendage remains of Cervidae from the fossil site of Dorn-DĂŒrkheim are studied in detail. The material mainly includes isolated teeth, isolated pedicles and antler pieces. Neither tooth rows nor complete appendages are recorded. Comparative morphology and statistics of morphometrics (principal component analysis and discriminant analysis) allow for the classification of small and large dentitions, small cranial appendages, two morphotypes of large pedicles and two morphotypes of large antlers. Possible combinations of the classified units document the sympatric occurrence of three species, namely, Procapreolus sp., Muntiacinae gen. and sp. indet., cf. Cervavitulus mimus, but the fragmentary condition of the material leads to ambiguity regarding their composition and, consequently, to a certain extent regarding the taxonomic identification. However, these remains indicate the contemporaneous occurrence of early Turolian members of the crown cervids Muntiacinae and Capreolinae and close a previous spatiotemporal gap in the European cervid record. In addition, their presence proves the progressive turnover from dichotomous-antlered muntiacines to early monopodial-antlered crown cervids from NE to SW Europe in the late Miocene. The taxonomical assignment challenges the recent hypothesis on the origin of crown Cervidae around the middle/late Miocene border since Dorn-DĂŒrkheim cervids provide further evidence for the successive achievement of derived characters in cranial appendages of crown cervids (mediopostorbital position and backwards orientation of pedicles, coronet development, shaft development/elongation, beam development and increase in number of antler tines) in the lineage of crown cervids, which originated during the middle Miocene.Fil: Azanza, Beatriz. Universidad de Zaragoza. Facultad de Ciencias; EspañaFil: Rössner, Gertrud E.. Bayerische Staatssammlung Fur Palaontologie Und Geologie; AlemaniaFil: Ortiz Jaureguizar, Edgardo. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas; Argentin
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