121,767 research outputs found
MgAl2SiO6-incorporated poly(ethylene oxide)-based electrolytes for all-solid-state lithium batteries
No full textPoly(ethylene oxide) (PEO)-based composite polymer electrolytes (CPEs), comprising various concentrations of lithium hexafluorophosphate and magnesium aluminium silicate, were prepared by hot-press technique. The membranes were characterised by scanning electron microscopy, tensile and thermal analyses. It has been demonstrated that the incorporation of the ceramic filler in the polymeric matrix has significantly enhanced the ionic conductivity, thermal stability and mechanical integrity of the membrane. It also improved the interfacial properties with lithiumelectrode. Finally, an all solid-state lithium cell composed of Li/CPE/LiFePO4 has been assembled and its cycling performance was analysed at 70 °C. The cell delivered a discharge capacity of 115 mAh g−1 at 1 °C rate and is found to be higher than previous reports
Viologen as an electrolyte additive for extreme fast charging of lithium-ion batteries
No full textAlthough lithium-ion batteries (LIBs) have found an unprecedented place among portable electronic devices owing to their attractive properties such as high energy density, single cell voltage, long shelf-life, etc., their application in electric vehicles still requires further improvements in terms of power density, better safety, and fast-charging ability (i.e., 15 min charging) for long driving range. The challenges of fast charging of LIBs have limitations such as low lithium-ion transport in the bulk and solid electrode/electrolyte interfaces, which are mainly influenced by the ionic conductivity of the electrolyte. Therefore, electrolyte engineering plays a key role in enhancing the fast-charging capability of LIBs. Here, we synthesize a novel propionic acid-based viologen that contains a 4,4′-bipyridinium unit and a terminal carboxylic acid group with positive charges that confine PF6‒ anions and accelerate the migration of lithium ions due to electrostatic repulsion, thus increasing the overall rate capability. The LiFePO4/Li cells with 0.25% of viologen added to the electrolyte show a discharge capacity of 110 mAh g‒1 at 6C with 95% of capacity retention even after 500 cycles. The added viologen not only enhances the electrochemical properties, but also significantly reduces the self-extinguishing time
Nanocellulose-laden composite polymer electrolytes for high performing lithium-sulphur batteries
No full textIn the endless search for superior and green power sources, lithium sulphur (Li-S) batteries held the promise of opening up a new era of long lasting and high energy storage systems for variety of applications. They might envisage remarkable benefits in utilising polymer electrolytes instead of liquids in terms of safety, low-cost and gravimetric/volumetric energy densities. In this work, for the first time, nanoscale microfibrillated cellulose-laden polymer systems are prepared using a thermally induced polymerisation process and tested as electrolyte separator in a Li-S rechargeable battery that contains sulphur-carbon composite based cathode. The polymer electrolyte demonstrates excellent ionic conductivity, thermal stability and most importantly stable interface towards lithium metal. While comparing our earlier report with non-aqueous liquid electrolyte, the present cell based on the abundant truly-natural cellulose-based polymer electrolyte as separator exhibits better cycling stability, higher specific capacity, superior Coulombic efficiency and rate capability at ambient conditions
Cycling profile of MgAl2O4-incorporated composite electrolytes composed of PEO and LiPF6 for lithium polymer batteries
No full textMagnesium aluminate (MgAl2O4)-incorporated poly(ethylene oxide) (PEO)-lithium hexafluorophosphate (LiPF6) based composite polymer electrolyte (CPE) membranes were prepared by a hot press for the first time. The membranes were subjected to X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric (TG), differential scanning calorimetry (DSC), tensile, impedance spectroscopy, compatibility and transport number studies. The incorporation of MgAl2O4 greatly enhanced the ionic conductivity, compatibility and mechanical integrity of the polymeric membrane. Finally, an all solid state lithium cell composed of Li/CPE/LiFePO4 was assembled and its cycling profile was analyzed at 70 ◦C. The cells delivered a discharge capacity of 127 mAh g−1 at 1 C-rate with very good capacity retention up to 100 cycles which is found to be better than those reported earlier
A Multi-Language Comparison of Influences on Author Verification using Character N-Grams
No full textWe create a new multi-language corpus for author verification based on Wikipedia talkpages, and evaluate the influence that differences in topic and time have on character n-gram author profiles. Topic alignment between two texts is found to increase author verification precision, and an authors writing style is found to change over time, but not more significantly after 3 years than after 1 year.Information ArchitectureWISElectrical Engineering, Mathematics and Computer Scienc
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe 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
Ca3(PO4)2-incorporated poly(ethylene oxide)-based nanocomposite electrolytes for lithium batteries. Part II. Interfacial properties investigated by XPS and a.c. impedance studies
No full textCalcium phosphate incorporated poly(ethylene oxide)-based nanocomposite electrolytes for lithium batteries. I. Ionic conductivity and positron annihilation lifetime spectroscopy studies
No full textThe vanishing author in computer-generated works: a critical analysis of recent Australian case law
No full textAbstract
The use of software is ubiquitous in the creation of many copyright works, yet the requirement in copyright law that every work have a human author who engages in independent intellectual effort means that its use may prevent copyright subsistence. Several recent Australian cases have refocused attention on authorship as an essential criterion of copyright subsistence, and these cases suggest that much computer-produced output may be authorless and thus lack copyright protection. This article, the first in a two-part series, analyses how each case deals with the question of authorship of computer-produced works and why the use of software diminishes copyright protection for a significant number of computer-generated works. The article critiques the application of conventional notions of human authorship developed in the pre-computer age to modern productions and suggests alternative approaches to authorship that satisfy both the major objectives of copyright policy and the need to adapt to the computer age. The article argues that, without a broader judicial approach to authorship of computer-generated works, Parliament must remedy the lacuna in protection for these ‘authorless’ works. Possible solutions for reform are suggested. In a forthcoming article, the author comprehensively examines those reform proposals
Diffusive author(s), cohesive author: Analysis of S/N (1994)
No full textThis study indicates the ways in which various aspects of the author(s) are brought forth in Dumb type’s performance art, the S/N production. Previous research has suggested a non-hierarchical organization of Dumb type and the absence of a “privileged author” in Dumb type’s collaborative work, S/N. However, the results that I have investigated from member’s interviews on the creative process of S/N along with my analysis of the recorded images of S/N, indicate a different aspect of the author(s). First, S/N was created through, so to speak, the collective ideas of the members of Dumb type. Further, S/N has at least nine quotations from previous performances, installations, and printed writings, besides the work-in-progress technique. Explicating one of the “author functions” as given by Michel Foucault, each text has plural subjects of the author. However, it has been revealed from members’ interviews that Teiji Furuhashi had a decision-making role in selecting the members’ ideas within the performance. Since then, S/N has had plural subjects of creation; however, Furuhashi is one of the subjects of creation along with the “privileged author.” S/N has plural authors (diffusive authors) yet at the same time, it has a “privileged author,” Teiji Furuhashi (cohesive author)
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