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A Novel Lithium Ion Battery Combining a Sustainable CuO-Carbon Conversion Anode with a High Voltage Li0.85Ni0.46Cu0.1Mn1.49O4 cathode
No full textThe development of novel cell configurations represents a key step towards a lithium ion batteries technology able to meet the increasing global energy demand.The search for sustainable and low cost electrode materials exhibiting high specific capacity, efficiency and stability is a longstanding goal of electrochemistry(1).
In this respect, the replacement of conventional intercalation anodes with transition metal oxides reacting by conversion mechanisms is a promising, cheap approach to increase the cell specific capacity(2). Furthermore, the exploitation of cobalt-free, manganese spinel-structure materials at the cathode side is expected to overcome the problems deriving from the high cost and relatively low operating voltage of the presently most used LiCoO2 electrodes.
Here we propose an alternative lithium ion battery combining an easily prepared, eco-compatible CuO-MCMB (Meso Carbon Micro Beads) conversion anode(3) (Theoretical capacity: 520 mAh g-1) with a high voltage, Li0.85Ni0.46Cu0.1Mn1.49O4 spinel-structure cathode(4) (Theoretical capacity: 146 mAh g-1), using propylene carbonate (PC), LiPF6 electrolyte solution.
Both the anode, prepared by high energy ball milling, and the cathode, obtained by co-precipitation and solid state reaction, exhibit optimized morphologies that lead to good electrochemical responses in terms of stability, efficiency and rate-capability. The electrodes structures and morphologies are analyzed by X-ray diffraction and scanning electron microscopy, respectively, while their electrochemical behaviors in cell are investigated by means of potentiodinamic cycling with galvanostatic acceleration (PCGA) and galvanostatic cycling tests at different C-rates.
The novel electrode combination here disclosed results in a full lithium ion battery characterized by an operating voltage of 3.4 V, a stable capacity of 90 mA h g-1 and a coulombic efficiency higher than 95% (see Figure below), with estimated gravimetric and volumetric energy densities of about 100 Wh/kg and 220 Wh/l, respectively.
The rationale of this cell configuration lies in the employment of sustainable, low-cost and easily prepared electrode materials that make the battery particularly suitable for practical exploitation
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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
A lithium ion battery exploiting a composite Fe2O3 anode and a high voltage Li1.35Ni0.48Fe0.1Mn1.72O4 cathode
No full textIn this paper we report a new lithium ion battery (LIB) consisting of a conversion-type, high capacity
Fe2O3–Meso Carbon Micro Beads (MCMB) composite anode and a high voltage, Li1.35Ni0.48Fe0.1Mn1.72O4
cathode, prepared by using facile, low cost synthetic pathways. These electrodes have been
characterized by a series of techniques including scanning and transmission electron microscopy, X-ray
diffraction analysis, potentiodynamic cycling with galvanostatic acceleration (PCGA) and galvanostatic
cycling tests in lithium cells at different C-rates. The results show that the Fe2O3–MCMB anode benefits
by a composite, sub micrometric morphology and by a stable specific capacity ranging from 800 to
600 mA h g1, evolving around 0.9 V, while the Li1.35Ni0.48Fe0.1Mn1.72O4 cathode is formed by an
agglomeration of micrometric crystals delivering a reversible capacity of about 115 mA h g1 at a 4.7 V high
voltage. The combination of the Fe2O3–MCMB anode with the Li1.35Ni0.48Fe0.1Mn1.72O4 cathode leads to a
complete lithium ion battery having an operating voltage of about 3 V, a high coulombic efficiency and a
stable capacity of about 100 mA h g1,which translates into in a theoretical energy density of about 300Wh kg1
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