80 research outputs found
Reversible Intercalation of Fluoride-Anion Receptor Complexes in Graphite
We have demonstrated a route to reversibly intercalate fluoride-anion receptor complexes in graphite via a nonaqueous electrochemical process. This approach may find application for a rechargeable lithium–fluoride dual-ion intercalating battery with high specific energy. The cell chemistry presented here uses graphite cathodes with LiF dissolved in a nonaqueous solvent through the aid of anion receptors. Cells have been demonstrated with reversible cathode specific capacity of approximately 80 mAh/g at discharge plateaus of upward of 4.8 V, with graphite staging of the intercalant observed via in situ synchrotron X-ray diffraction during charging. Electrochemical impedance spectroscopy and 11B nuclear magnetic resonance studies suggest that co-intercalation of the anion receptor with the fluoride occurs during charging, which likely limits the cathode specific capacity. The anion receptor type dictates the extent of graphite fluorination, and must be further optimized to realize high theoretical fluorination levels. To find these optimal anion receptors, we have designed an ab initio calculations-based scheme aimed at identifying receptors with favorable fluoride binding and release properties
Entanglements of race and migration in the (open) city: Analytical and normative tensions of the sociological imagination
This article considers the interface of taxonomies of race and migration crystallised through the materialities of the contemporary city in the shadow of the 7th anniversary of the Grenfell Tower fire. It draws on multi-method empirical research that interrogates the notion of the open city. The article proposes that ‘entanglement’ and ‘contaminations’ of material and cultural formations confound some claims made in the name of the good city, recognising what Marilyn Strathern might describe as the recursive ‘contamination’ of normative and empirical evidence. The article argues that it is imperative to excavate the normative domain of the empirical, and curate the empirical realisation of the normative, in rethinking a truly global sociological imagination. It concludes by suggesting that one way of approaching this is through a more forensic understanding of what is taken as ‘evidence’ in social sciences that should inform an interdisciplinary urban studies
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Politicization, postpolitics and the open city: Openness, closedness and the spatialisation of the political
The idea of the open city has been used both conceptually and analytically to understand the politics of the city. The contrast between the open city and the closed city relies, in part, upon an understanding of the global systems that enfold cities and, consequently, the politics that are – and are not – afforded cities. Notions such as the postpolitical city depend not on temporality where the city has ceased to be political, but a spatialisation of politics where the (properly) political has become excluded by the closed systems that envelope cities. In this paper, we explore analytical and theoretical responses to the horror of the Grenfell Tower fire to disclose the ways that different critiques of neoliberalism and racial capitalism deploy and rely upon different conceptions of the open and closed systems of the city. Rather than settle for the open/closed binary, we seek to understand how different forms of openness and closedness afford/constrain the politicisation (and depoliticization) of city life – and its catastrophes
Evolution of microscopic heterogeneity and dynamics in choline chloride-based deep eutectic solvents
Deep eutectic solvents (DESs) are an emerging class of non-aqueous solvents that are potentially scalable, easy to prepare and functionalize for many applications ranging from biomass processing to energy storage technologies. Predictive understanding of the fundamental correlations between local structure and macroscopic properties is needed to exploit the large design space and tunability of DESs for specific applications. Here, we employ a range of computational and experimental techniques that span length-scales from molecular to macroscopic and timescales from picoseconds to seconds to study the evolution of structure and dynamics in model DESs, namely Glyceline and Ethaline, starting from the parent compounds. We show that systematic addition of choline chloride leads to microscopic heterogeneities that alter the primary structural relaxation in glycerol and ethyleneglycol and result in new dynamic modes that are strongly correlated to the macroscopic properties of the DES formed
Lithium sulfur and lithium oxygen batteries: New frontiers of sustainable energy storage
Lithium sulfur and lithium oxygen batteries are predicted to be high-energy rechargeable systems of choice for emerging applications, such as modern electronics and electric vehicles. Despite the several issues hindering their diffusion, the two attractive systems are rapidly evolving, and achieving high performances and targets, which were only partially expected in the past few years. Lithium sulfur batteries have been recently introduced into the energy storage market, while practical prototypes of lithium oxygen cells are already emerging, thus indicating the high level achieved by these systems. Therefore, we report herein an overview of recent studies of the reaction mechanism which allowed the development of Li/S and Li/O2batteries. We show and discuss the latest advances, in terms of electrochemical performances and characteristics, in order to shed light on the feasibility of the two important, cheap and environmentally compatible energy storage systems
Bamboo Planning Project proposal to the Mellon Foundation
Project Bamboo (2008-2012) was a cyberinfrastructure initiative for the arts and humanities, funded by the Andrew W. Mellon foundation. This was the initial proposal to the Mellon Foundation for the planning project, submitted January 2008
Bamboo Technology Proposal to the Mellon Foundation
Project Bamboo (2008-2012) was a cyberinfrastructure initiative for the arts and humanities, funded by the Andrew W. Mellon foundation. This is the grant proposal for the technical implementation phase of Project Bamboo (intended phase 1)
A novel polymer electrolyte membrane for application in solid state lithium metal battery
Polyethylene oxide (PEO), dimethyl sulphoxide (DMSO) and lithium trifluoromethanesulfonate (LiCF3SO3) salts are combined into a composite polymer electrolyte studied for application in lithium metal battery. FTIR measurements and AFM images are used to reveal the structure and morphology of the polymer electrolyte, while electrochemical impedance spectroscopy (EIS), chronoamperometry and voltammetry are employed for determining the electrolyte conductivity, lithium transference number, chemical and electrochemical stability, respectively. The data reveal a suitable conductivity and lithium transport, i.e., δ above 10−4S cm−1and tLi+about 0.5, at moderate temperature, which allow the use of the membrane and a LiFePO4olivine cathode in an efficient lithium metal cell delivering a capacity of 130 mAh g−1at about 3.4 V, and operating at 50 °C. This relatively low operating temperature, the good electrochemical properties, and the polymer configuration of the PEO-DMSO-LiCF3SO3membrane suggest it as a viable solution for application in high energy lithium metal battery
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