Mechanism of Silicon Electrode Aging upon Cycling in Full Lithium-Ion Batteries

International audienc

Cephalosporin Hypersensitivity: Descriptive Analysis, Cross-reactivity, and Risk Factors

International audienceBackground: Cephalosporins, which belong to the beta-lactam therapeutic class, are increasingly used throughout the world. Few large studies on this issue have been conducted, and most of them have been performed as part of penicillin hypersensitivity studies.Objective: We described our 26-year experience exploring cephalosporin drug hypersensitivity, from which we identified epidemiological and cross-reactivity data.Methods: We included 476 patients who reported drug hypersensitivity reaction (DHR) to cephalosporin and underwent an allergy workup between January 1992 and July 2018 in the Allergy Unit of the University Hospital of Montpellier (France). According to their structural side chain R1 homology, we worked with 4 classes of cephalosporins. Logistic regression analysis was used to search for risk factors for hypersensitivity to cephalosporin (positive skin test [ST] or drug provocation test [DPT] results).Results: Cephalosporin hypersensitivity was proven in 22.3% of the patients referred in our Unit, according to positive ST (51.9%) or DPT to the culprit drug (48.1%). One in 5 patients were children, and cephalosporin hypersensitivity was confirmed in 15% (47.6% of them by means of ST). In the cephalosporin hypersensitive population, initial reactions were mostly immediate (68.9%) and anaphylactic (72.7%). Cross-reactivity with aminopenicillins was the most frequent pattern of cross-reactivity. In multivariate analysis, immediate reactions (odds ratio [OR] = 3, 95% confidence interval [CI] [1.6-5.5], P < .001), anaphylactic shock (OR = 6.5, 95% CI [3.3-13.1], P < .001) and anaphylaxis (OR = 3.1, 95% CI [1.6-6.1], P < .001), and multiple reactions to the same or several cephalosporins (OR = 2.0, 95% CI [1-3.5], P = .04) were statistically associated with confirmed DHR. DPT was generally safe, but elicited anaphylaxis in 20% of patients. Systemic reactions during skin testing occurred in 9.1% of positive patients, almost always related to anaphylactic index reactions. Nonimmediate confirmed DHR to cephalosporins were rare and occurred in less than 10% of the positive patients.Conclusion: Almost a quarter of the tested patients were confirmed as hypersensitive to cephalosporins; sensitivity of skin testing was 51.9%, and thus, half of the positive patients needed a DPT to prove the diagnosis

Cephalosporin Hypersensitivity: Descriptive Analysis, Cross-Reactivity, and Risk Factors

International audienc

Improved electrochemical performance for high voltage spinel LiNi0.5Mn1.5O4 modified by supercritical fluid chemical deposition

International audienceAmong candidates at the positive electrode of the next generation of Li-ion technology and even beyond post Li-ion technology as all-solid-state batteries, spinel LiNi0.5Mn1.5O4 (LNMO) is one of the favorites. Nevertheless, before its integration into commercial systems, challenges still remain to be tackled, especially the stabilization of interfaces with the electrolyte (liquid or solid) at high voltage. In this work, a simple, fast, and cheap process is used to prepare a homogeneous coating of Al2O3 type to modify the surface of the spinel LNMO: the supercritical fluid chemical deposition (SFCD) route. This process is, to the best of our knowledge, used for the first time in the battery field. Significantly improved performance was demonstrated vs those of bare LNMO, especially at high rates and for highly loaded electrodes

Improved electrochemical performance for high voltage spinel LiNi0.5Mn1.5O4 modified by supercritical fluid chemical deposition

International audienceAmong candidates at the positive electrode of the next generation of Li-ion technology and even beyond post Li-ion technology as all-solid-state batteries, spinel LiNi0.5Mn1.5O4 (LNMO) is one of the favorites. Nevertheless, before its integration into commercial systems, challenges still remain to be tackled, especially the stabilization of interfaces with the electrolyte (liquid or solid) at high voltage. In this work, a simple, fast, and cheap process is used to prepare a homogeneous coating of Al2O3 type to modify the surface of the spinel LNMO: the supercritical fluid chemical deposition (SFCD) route. This process is, to the best of our knowledge, used for the first time in the battery field. Significantly improved performance was demonstrated vs those of bare LNMO, especially at high rates and for highly loaded electrodes

Multi-scale characterization of submicronic NASICON-type solid electrolyte Li1.3Al0.3Ti1.7(PO4)3 degraded by spark plasma sintering

One of the most promising and developed disruptive technology of energy storage for the future is all solid-state batteries. The NASICON phase LATP (Li1.3Al0.3Ti1.7(PO4)3) is widely studied especially thanks to its high ionic conductivity and mechanical strength. However, high temperature densification is required to obtain a dense and conductive material. Here we explore the fast sintering by Spark Plasma Sintering (SPS) of submicronic LATP particles, and the impact of the heating rate on the physico-chemical and transport properties of the pristine powder. High-speed rate for the sintering process induces particles’ growth, avoiding any reduction of titanium. The impurity AlPO4 plays a major role on the conductivity, depending on its content but also on its distribution within the composite, either as a coating (surface modification) or as crystalline particles within the grain boundaries. An intimate understanding of the ceramic composites was achieved using combination of advanced characterization techniques to get a multi-scale description of the material, from the pristine to the sintered states, from the surface to the bulk, and from the atomic long range to the local scales. Sharing these fundamental results is essential, with among other motivations, the spreading of our interpretation of complex spectroscopic results (Electronic Spin Resonance (ESR) spectroscopy, solid-state Nuclear Magnetic Resonance (NMR) spectroscopy and X-ray Photoelectron Spectroscopy (XPS)), key for characterization of reactivities at interfaces in this work and in others.Laboratory of excellency for electrochemical energy storag

Multi-scale characterization of submicronic NASICON-type solid electrolyte Li1.3Al0.3Ti1.7(PO4)3 degraded by spark plasma sintering

International audienceOne of the most promising and developed disruptive technology of energy storage for the future is all solid-state batteries. The NASICON phase LATP (Li1.3Al0.3Ti1.7(PO4)3) is widely studied especially thanks to its high ionic conductivity and mechanical strength. However, high temperature densification is required to obtain a dense and conductive material. Here we explore the fast sintering by Spark Plasma Sintering (SPS) of submicronic LATP particles, and the impact of the heating rate on the physico-chemical and transport properties of the pristine powder. High-speed rate for the sintering process induces particles’ growth, avoiding any reduction of titanium. The impurity AlPO4 plays a major role on the conductivity, depending on its content but also on its distribution within the composite, either as a coating (surface modification) or as crystalline particles within the grain boundaries. An intimate understanding of the ceramic composites was achieved using combination of advanced characterization techniques to get a multi-scale description of the material, from the pristine to the sintered states, from the surface to the bulk, and from the atomic long range to the local scales. Sharing these fundamental results is essential, with among other motivations, the spreading of our interpretation of complex spectroscopic results (Electronic Spin Resonance (ESR) spectroscopy, solid-state Nuclear Magnetic Resonance (NMR) spectroscopy and X-ray Photoelectron Spectroscopy (XPS)), key for characterization of reactivities at interfaces in this work and in others

A standard for sharing data from vineyard experiments

To facilitate the sharing and interoperability of data collected by many different experimenters and structures, a standardized description of the data acquisition context has been set in the form of a data schema. This data schema defines the entities and the attributes to describe them. This data schema is available online, under an open license CC0 1.0 Universal, with a user’s guide

Grands hommes vus d'en bas

Ce dossier propose d’aborder les images des grands hommes sous une perspective inédite. Par contraste avec les analyses déjà nombreuses consacrées à l’iconographie officielle, il s’agit de décaler le regard pour examiner comment la figure des hommes d’État fait l’objet d’appropriations qui échappent au registre de l’officiel tout en prenant appui sur lui. Ce changement de perspective permet de saisir les grands hommes non plus « par le haut », tels qu’ils se donnent à voir dans leur grandeur officielle, mais « par le bas », du point de vue des acteurs subordonnés. Ces usages populaires des icônes politiques impliquent un jeu souvent ambigu avec le monde officiel. Selon les cas, il pourra s’agir de capter, de cannibaliser, de moquer, d’accommoder ou d’apprivoiser le pouvoir à travers ses effigies. Les usages populaires de la figure du grand homme constituent en définitive des actes d’invention qui ne laissent pas indemne le modèle officiel. Acheter ce numéro en lign