1,720,957 research outputs found
High loading CuS-based cathodes for all-solid-state lithium sulfur batteries with enhanced volumetric capacity
Full text linkTransition metal sulfides have shown to improve the performance of lithium-sulfur batteries both with liquid and solid electrolytes. In this work, the beneficial effect of copper sulfide for enabling high areal capacity lithiumsulfur all-solid-state batteries is shown. Copper sulfide-carbon (CuSC) and three different copper sulfide-sulfurcarbon (CuSS) composites are investigated as positive electrodes in all-solid-state lithium-sulfur batteries. The composites are prepared via facile and low-cost mechanochemical ball-milling. It is found that the CuS/C ratio greatly influences the redox properties of the CuSC cathode. Scanning electron microscopy, ex-situ X-ray diffraction, and galvanostatic cycling were also conducted to evaluate the CuSS composite electrodes in Li|LiI-LiPS|CuS–S–C solid-state cells. High mass loading cells made using these composite electrodes deliver capacities as high as 1600 mAh g and 7 mAh cm at 20 °C. The higher density of CuS also leads to larger volumetric capacities, up to 3900 mAh cm, thus enabling a potential energy density gain up to 15% with respect to a conventional Carbon–Sulfur cathode
All solid-state battery using layered oxide cathode, lithium-carbon composite anode and thio-LISICON electrolyte
No full textThe investigation of a lithium-carbon composite (Li-C) anode for application in all-solid-state battery, based on (Li2S)(0.75)-(P2S5)(0.25) glassy thio-LISICON electrolyte (Li2S-P2S5) is herein reported. The Li-C anode material is prepared by a mechanochemical, single step synthesis procedure. The Li-C/electrolyte interface is characterized in terms of cyclic voltammetry, electrochemical impedance spectroscopy and galvanostatic cycling in comparison with lithium metal, in order to evaluate the improvements in terms of resistance and lithium stripping deposition ability. Li-C anode powder is pressed into a pellet together with the Li2S-P2S5 electrolyte and Li2ZrO3-coated, Li[Ni0.8Co0.15Al0.05]O-2 cathode powder (NCA-LZO), to form a new type of solid-state battery operating at room temperature. The Li-C/Li2S-P2S5/NCA-LZO battery shows remarkable cycling performance under galvanostatic conditions, particularly if compared to a more conventional configuration employing lithium metal as the anode. In addition, the all solid-state battery is characterized at various current densities, showing satisfactory rate capability. Under long term-cycling condition, performed at low current and prolonged to more than 250 days, the cell shows a stability over 100 cycles without fading. This is considered a remarkable result suggesting the solid-state cell here studied as suitable candidate-for efficient and safe energy storage
All solid-state lithium-sulfur battery using a glass-type P2S5-Li2S electrolyte: Benefits on anode kinetics
No full textLithium-sulfur (Li-S) batteries are promising candidates for next generation electrical energy storage devices due to their high specific energy. Despite intense research, there are still a number of technical challenges in developing a high performance Li-S battery. To elucidate the issues, an all solid-state Li-S battery was fabricated using Li3PS4 solid electrolyte. Most of the theoretical capacity of sulfur, 1600 mAhg−1 was attained in the initial discharge-charge cycles with a high coulombic efficiency approaching 99%. To verify the benefit of the solid state electrolyte, galvanostatic stripping-deposition tests were also carried out on a symmetrical Li/Li cell and compared with those of a liquid electrolyte (1M- lithium bis(trifluoromethane sulfonyl) imide (LiTFSI) in a mixture of 1,3-dioxolane (DOL)-diethoxyethane (DEE)). The kinetics and thermodynamics of the solid-state cell are discussed from the viewpoint of the charge transfer processes. This study demonstrates both the merits and drawbacks of using the solid sulfide electrolyte in a Li-S battery and facilitates the further improvement of this important high energy storage device
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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