Bibliografie tematiche / Spectroscopie du lithium

Indice

Articoli di riviste
Tesi
Libri
Capitoli di libri
Atti di convegni
Rapporti di organizzazioni

Letteratura scientifica selezionata sul tema "Spectroscopie du lithium"

Autore: Grafiati

Pubblicato: 19 ottobre 2024

Cita una fonte nei formati APA, MLA, Chicago, Harvard e in molti altri stili

Scegli il tipo di fonte:

Consulta la lista di attuali articoli, libri, tesi, atti di convegni e altre fonti scientifiche attinenti al tema "Spectroscopie du lithium".

Accanto a ogni fonte nell'elenco di riferimenti c'è un pulsante "Aggiungi alla bibliografia". Premilo e genereremo automaticamente la citazione bibliografica dell'opera scelta nello stile citazionale di cui hai bisogno: APA, MLA, Harvard, Chicago, Vancouver ecc.

Puoi anche scaricare il testo completo della pubblicazione scientifica nel formato .pdf e leggere online l'abstract (il sommario) dell'opera se è presente nei metadati.

Articoli di riviste sul tema "Spectroscopie du lithium"

Hanquet, B., B. Tabyaoui, J. C. Caille, M. Farnier e R. Guilard. "Synthèse stéréosélective de (±) boschnialactone, (±) 7-épiteucriumlactone et (±) 7-épiisoiridomyrmécine. Étude de la stéréochimie par spectroscopie de résonance magnétique nucléaire". Canadian Journal of Chemistry 68, n. 4 (1 aprile 1990): 620–27. http://dx.doi.org/10.1139/v90-095.

Testo completo

Abstract (sommario):

The stereoselective syntheses of (±) boschnialactone 1, (±) 7-epiteucriumlactone 2, and (±) 7-epiisoiridomyrmecine 3 are described. Their preparation involved Stetter's reaction followed by nucleophilic addition of lithium enolates of suitable esters. Silylated reagents are used in the lactonisation step and the observed yields are between 63 and 78%. The proposed structural analysis is not in accord with the results of a previous study. The nuclear magnetic resonance data are determined using ID and 2D proton and carbon NMR experiments. Keywords: stereoselective synthesis, boschnialactone, 7-epiteucriumlactone, 7-epiisoiridomyrmecine, 1H and 13C NMR.

Gli stili APA, Harvard, Vancouver, ISO e altri

Seo, Ambrose, Andrew Meyer, Sujan Shrestha, Ming Wang, Xingcheng Xiao e Yang-Tse Cheng. "Observation of the surface layer of lithium metal using in situ spectroscopy". Applied Physics Letters 120, n. 21 (23 maggio 2022): 211602. http://dx.doi.org/10.1063/5.0096546.

Testo completo

Abstract (sommario):

We have investigated the surface of lithium metal using x-ray photoemission spectroscopy and optical spectroscopic ellipsometry. Even if we prepare the surface of lithium metal rigorously by chemical cleaning and mechanical polishing inside a glovebox, both spectroscopic investigations show the existence of a few tens of nanometer-thick surface layers, consisting of lithium oxides and lithium carbonates. When lithium metal is exposed to room air (∼50% moisture), in situ real-time monitoring of optical spectra indicates that the surface layer grows at a rate of approximately 24 nm/min, presumably driven by an interface-controlled process. Our results hint that surface-layer-free lithium metals are formidable to achieve by a simple cleaning/polishing method, suggesting that the initial interface between lithium metal electrodes and solid-state electrolytes in fabricated lithium metal batteries can differ from an ideal lithium/electrolyte contact.

Gli stili APA, Harvard, Vancouver, ISO e altri

Zhang, Li, Tao Qian, Xingyu Zhu, Zhongli Hu, Mengfan Wang, Liya Zhang, Tao Jiang, Jing-Hua Tian e Chenglin Yan. "In situ optical spectroscopy characterization for optimal design of lithium–sulfur batteries". Chemical Society Reviews 48, n. 22 (2019): 5432–53. http://dx.doi.org/10.1039/c9cs00381a.

Testo completo

Abstract (sommario):

Recent advances in optimal design of lithium–sulfur batteries with the aid of in situ optical spectroscopic techniques, including Raman, infrared and ultraviolet-visible spectroscopies, are systematically summarized.

Gli stili APA, Harvard, Vancouver, ISO e altri

Meyer, Lydia, Collin Kinder e Jason Morgan Porter. "Chemometric and Machine Learning Analysis of Lithium Concentration and Solvation Behavior in Li-Ion Battery Electrolytes". ECS Meeting Abstracts MA2022-02, n. 6 (9 ottobre 2022): 618. http://dx.doi.org/10.1149/ma2022-026618mtgabs.

Testo completo

Abstract (sommario):

The demand for batteries is rapidly growing across a range of technologies. The increasingly diverse use cases for batteries require various capabilities, particularly requirements for high energy densities, that are currently unmet by traditional Li-ion batteries. Electrolyte stability proves to be a bottleneck for battery advancement towards energy dense chemistries beyond Li-ion, including metal anodes. In situ spectroscopy tools, such as Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, and X-ray spectroscopy, have provided insight into critical molecular-level interactions in batteries during cycling. These in situ tools have yielded continuous improvement of electrolyte properties. Spectroscopy datasets, however, contain many nuances that challenge meaningful human understanding. Artificial intelligence and chemometric tools can be coupled with in situ spectroscopy to find relevant interpretations of spectral datasets and elucidate complex molecular phenomena. In this research, an analysis was performed on FTIR spectroscopy data from an electrolyte composed of LiPF6 in ethylene carbonate (EC) and ethyl methyl carbonate (EMC) to discern solvation behavior using principal component analysis (PCA) and a convolutional neural network (CNN). PCA pinpointed exact band locations of solvation shifting behavior in the IR spectra and improved understanding of the relationship between lithium concentrations and peak changes. The CNN was trained with spectral datasets of electrolytes with known lithium concentrations and then could predict lithium concentrations from spectral datasets with extraordinarily high accuracy. Additionally, the CNN interpreted FTIR spectral datasets from a graphite half-cell with EC/EMC/LiPF6 electrolyte and accurately determined the lithium concentration in the bulk electrolyte. The CNN also observed lithium depletion events (up to 10% lithium depletion) in the graphite anode during fast-charging cycles of the galvanostatic intermittent titration technique. This research breaks new ground on using advanced computational tools for in situ spectroscopic analysis of battery electrolytes and demonstrates an improved understanding of complex molecular-level phenomena in electrolytes.

Gli stili APA, Harvard, Vancouver, ISO e altri

Cai Jiahua, 才家华, 张保龙 Zhang Baolong, 耿春艳 Geng Chunyan, 郝思博 Hao Sibo, 陈赛 Chen Sai e 吴晓君 Wu Xiaojun. "铌酸锂强场太赫兹非线性时域光谱系统". Chinese Journal of Lasers 50, n. 17 (2023): 1714012. http://dx.doi.org/10.3788/cjl230435.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Muhammad, F. H., A. F. M. Fadzil e Tan Winie. "FTIR and Electrical Studies of Hexanoyl Chitosan-Based Nanocomposite Polymer Electrolytes". Advanced Materials Research 1043 (ottobre 2014): 36–39. http://dx.doi.org/10.4028/www.scientific.net/amr.1043.36.

Testo completo

Abstract (sommario):

Films of hexanoyl chitosan-based polymer electrolytes were prepared using solution casting technique. The interactions between hexanoyl chitosan-lithium perchlorate (LiClO4) and dimethyl carbonate (DMC)-lithium perchlorate (LiClO4) were investigated using Fourier transform infrared spectroscopy (FTIR). The FTIR results showed that there is a possible complexation between the electron donor of hexanoyl chitosan and DMC with lithium salt due to the shifting in the wavenumber and changes in the intensity of the infrared bands. The obtained spectroscopic data has been correlated with the conductivity performance of hexanoyl chitosan-based polymer electrolyte. The ionic conductivity was increased with addition of filler TiO2 and plasticizer DMC to the electrolyte system.

Gli stili APA, Harvard, Vancouver, ISO e altri

Katime-Santrich, Orlando J., Bruno V. Castilho, Carlos A. O. Torres e Germano R. Quast. "Photometric and spectroscopic analysis of the stellar association AB Doradus". Proceedings of the International Astronomical Union 5, S265 (agosto 2009): 370–71. http://dx.doi.org/10.1017/s1743921310000979.

Testo completo

Abstract (sommario):

AbstractWe present the stellar parameters and lithium abundance for 23 stars of the young stellar association AB Doradus, determined by photometry and spectroscopy. The photometric data was obtained at OPD/LNA and/or from the literature and the spectroscopic data was obtained at La silla/ESO and at OPD/LNA. The parameters were determined using photometric calibrations, line ratios, curves of growth and spectral synthesis. Our results confirm that the selected stars are probably association members, showing an uniform metallicity and lithium depletion consistent with 50 Myears

Gli stili APA, Harvard, Vancouver, ISO e altri

Fritzke, Jana Beatrice, Sunita Dey, Christopher A. O'Keefe e Clare P. Grey. "NMR Spectroscopic Investigations of the Performance Limiting Mechanisms of Lithium-Sulfur Batteries". ECS Meeting Abstracts MA2023-02, n. 55 (22 dicembre 2023): 2692. http://dx.doi.org/10.1149/ma2023-02552692mtgabs.

Testo completo

Abstract (sommario):

During the past decades, the development of alternative energy sources has become increasingly important as the growing consumption of non-regenerative fossil energy poses a threat to the environment. Hence, developing of next-generation batteries featuring high capacity, reduced costs and improved safety, such as in lithium-sulfur batteries, is of utmost importance. The benefits of lithium-sulfur batteries have led to widespread efforts to understand the fundamentals of the sulfur redox chemistry that drives their operation, as capacity fade has been observed in almost all Li-S batteries.[1] Therefore, the involved local structural changes that correlate with the (electro)chemical processes need to be unveiled during the operation of Li-S batteries, suitably by in situ and in operando methods. This presentation will demonstrate the development and application of one such (operando) technique: nuclear magnetic resonance (NMR) spectroscopy. NMR spectroscopic measurements allow the probing of the structural changes in a battery during electrochemical cycling. In particular, the application of a non-invasive experimental set-up, which can follow the reaction inside the battery in operando is highly desirable as it provides real-time structural information compared to ex situ analysis.[2] Lithium-sulfur batteries contain various NMR-active nuclear isotopes, like 7Li, 6Li and 33S, which allow the following of the chemical reactions during the charge-discharge process. This includes the transition between elemental sulfur and polysulfides on the cathode side, the formation of the solid-electrolyte interface (SEI) and the metal plating and stripping on the anode side. Herein, we use for the first time a combination of lithium and sulfur in operando NMR spectroscopy to reveal a fundamental understanding of the reaction pathway of lithium-sulfur batteries during the cycling process. Lithium NMR spectroscopy is a powerful technique to apply to batteries, as demonstrated by many previous investigations on different lithium battery systems, since it enables the detection of the chemical environments of lithium species during electrochemical cycling and parasitic reactions in the cell.[3] The great advantage of in operando 7Li NMR spectroscopy is that the 7Li signals of the lithium anode and the deposited metal differ due to the bulk magnetic susceptibility effects and the surface area, bringing the skin depth effect into play. Thus, this method enables a time-resolved and quantitative evaluation of the electrochemical metal deposition during electrochemical cycling. Therefore, it is possible to investigate a critical problem that reduces the cell performance – the formation of lithium dendrites. This lithium deposition is particularly problematic if it occurs uncontrolled and inhomogeneous and the exact mechanism of nucleation and propagation of dendrites is not yet fully understood.[4] The developed technique helps to understand this deposition to improve the safety during cycling. The interpretation of the electrolyte signal in the in operando 7Li spectra is much more difficult because of the overlapping signals. Therefore, in situ 33S and 6Li NMR spectroscopy supports the identification and quantification of (poly-)sulfides during the charge-discharge-process. 33S NMR experiments are rarely reported since 33S is a quadrupolar nucleus characterized by a low natural abundance and magnetogyric ratio, resulting in a very low receptivity. Nevertheless, the developed 33S NMR technique allows the detection of the formation Li2S under in operando conditions.[5] Additional in operando 6Li NMR experiments allow to follow the (poly-)sulfide formation as the spectra yield much sharper lines in asymmetric lithium environments in comparison to 7Li NMR experiments.[6] Thus, these techniques provide complementary results to the 7Li NMR spectroscopic studies and help to elucidate the sulfur redox mechanism in lithium-sulfur batteries. Our developed in situ NMR spectroscopic set-up is a powerful analytical method since real-time qualitative and quantitative detection of different sulfur and lithium species is crucial for understanding the electrochemical process in sulfur batteries. The first time, a combination of in operando lithium and sulfur NMR spectroscopy is presented, providing new insights at the molecular level that are essential for accelerating the development of lithium-sulfur battery technologies. [1] H. Wang, N. Sa, et al., The Journal of Physical Chemistry C 2017, 121, 6011–6017. [2] J. B. Richter, et al., Chemical Communications 2019, 55, 6042–6045. [3] R. Bhattacharyya, et al., Nat Mater 2010, 9, 504–510. [4] A. B. Gunnarsdóttir, et al., J Mater Chem A Mater 2020, 8, 14975–14992. [5] R. Musio, in Annu Rep NMR Spectrosc, 2006, pp. 1–88. [6] L. A. Huff, et al., Surf Sci 2015, 631, 295–300.

Gli stili APA, Harvard, Vancouver, ISO e altri

Bezdomnikov, Alexey A., Liudmila I. Demina, Lyudmila G. Kuz’mina, Galina V. Kostikova, Valeriy I. Zhilov e Aslan Yu Tsivadze. "Study of Lithium-Extraction Systems Based on Benzo-15-Crown-5 Ether and Alkylimidazolium-Based Ionic Liquid". Molecules 28, n. 3 (17 gennaio 2023): 935. http://dx.doi.org/10.3390/molecules28030935.

Testo completo

Abstract (sommario):

The extraction of lithium from aqueous solutions of LiNTf2 and LiCl salts using benzo-15-crown-5 ether (B15C5) as an extractant in [C8mim][NTf2] ionic liquid was studied. The transition of the extractant into the aqueous phase and the distribution of Cl− ions during lithium extraction from LiCl solutions were determined. LiNTf2 complexes with B15C5 with different LiNTf2:B15C5 ratios were isolated for the first time and characterized via X-ray diffraction and IR spectroscopy. Differences in the extraction process of LiCl and LiNTf2 were determined via an infrared spectroscopic study of the extraction systems.

Gli stili APA, Harvard, Vancouver, ISO e altri

Jin, Yan, Lin Zhou, Jianyu Yu, Jie Liang, Wenshan Cai, Huigang Zhang, Shining Zhu e Jia Zhu. "In operando plasmonic monitoring of electrochemical evolution of lithium metal". Proceedings of the National Academy of Sciences 115, n. 44 (15 ottobre 2018): 11168–73. http://dx.doi.org/10.1073/pnas.1808600115.

Testo completo

Abstract (sommario):

The recent renaissance of lithium metal batteries as promising energy storage devices calls for in operando monitoring and control of electrochemical evolution of lithium metal morphologies. While the development of plasmonics has led to significant advancement in real-time and ultrasensitive chemical and biological sensing and surface-enhanced spectroscopies, alkali metals featured by ideal free electron gas models have long been regarded as promising plasmonic materials but seldom been explored due to their high chemical reactivity. Here, we demonstrate the in operando plasmonic monitoring of the electrochemical evolution of lithium metal during battery cycling by taking advantage of selective electrochemical deposition. The relationships between the evolving morphologies of lithium metal and in operando optical spectra are established both numerically and experimentally: Ordered growth of lithium particles shows clear size-dependent reflective dips due to hybrid surface plasmon resonances, while the formation of undesirable disordered lithium dendrites exhibits a flat spectroscopic profile with pure suppression in reflection intensity. Under the in operando plasmonic monitoring enabled by the microscopic morphology of metal, the differences of lithium evolutionary behaviors with different electrolytes can be conveniently identified without destruction. At the intersection of energy storage and plasmonics, it is expected that the ability to actively control and in operando plasmonically monitor electrochemical evolution of lithium metal can provide a promising platform for investigating lithium metal behavior during electrochemical cycling under various working conditions.

Gli stili APA, Harvard, Vancouver, ISO e altri

Più fonti

Tesi sul tema "Spectroscopie du lithium"

Iezzi, Gianluca. "Cristallochimie des amphiboles à lithium". Orléans, 2001. http://www.theses.fr/2001ORLE2035.

Testo completo

Abstract (sommario):

Le développement de nouvelles méthodes de micro-analyse, a révélé l'importance des éléments légers dans les minéraux majeurs. Li+, cation de petite taille, peut parfois remplacer Na+, mais fréquemment iremplace Mg2+ en sites octaédriques, ce qui implique des substitutions compensatoires. Les amphiboles présentent plusieurs types de sites susceptibles d'accueillir Li+, selon les mécanismes de substitution indiqués ci-dessus. Malgré une bonne connaissance des relations d'ordre à longue distance (LRO) impliquant Li+, fournie par des échantillons naturels, les relations d'ordre à courte distance (SRO), les conditions de stabilité et les relations avec d'autres groupes d'amphiboles étaient inconnues. Un travail expérimental, en conditions hydrothermales, complété par des études en DRX, et des analyses spectrométriques, IRTF et Mössbauer a permis de combler ce manque, sur deux types d'amphiboles à Li+, la holmquistite, avec Li+ en sites [B], et la leakeite, avec Li+ en sites [C]. Les distributions cationiques dans les différents sites ont été déterminées. Les variables utilisées ont été la composition des systèmes, T, P et fO2. La holmquistite Al n'a jamais pu être obtenue dans les conditions adoptées. Par contre, l'introduction de Fe3+ dans le système stabilise sa structure. . On décrit la ferri-ferroholmquistite, amphibole très ordonnée, avec Li+ en sites [B], Fe2+ en sites [C], et Fe3+ exclusivement en sites octaédriques M(2). Les relations d'ordre à courte distance (SRO), dans les ferri-holmquistites obtenues dans différentes conditions expérimentales, et leur évolution le long du join ferro-magnésien ont aussi été étudiées. Enfin, les relations entre clinoamphiboles sodiques et clinoamphiboles à Mg-Mn-Fe-Li ont été établies. La lacune de miscibilité communément admise entre les deux groupes n'existe pas puisqu'un remplacement complet de Na+ par Li+ en sites [B] a pu être obtenu expérimentalement. Finalement, la spectrométrie IRTF montre que dans la leakeite, Li+ est ordonné en sites M(1,3), en accord avec les données précédemment obtenues sur monocristaux naturels.

Gli stili APA, Harvard, Vancouver, ISO e altri

Safrany, Renard Marianne. "Propriétés électrochimiques et réponse structurale du polymorphe gamma'-V2O5 vis-à-vis de l'insertion du lithium et du sodium". Thesis, Paris Est, 2017. http://www.theses.fr/2017PESC1185/document.

Testo completo

Abstract (sommario):

La question du stockage de l’énergie est actuellement au cœur de nombreuses problématiques internationales. Le développement de systèmes de stockage tels que les batteries lithium ion (LIB) et sodium ion (SIB) fait donc l’objet aujourd’hui de nombreuses recherches. Dans ce contexte, les matériaux lamellaires présentant un espace inter-feuillet permettant une insertion d’espèces cationiques semblent idéals dans le cadre d’une utilisation comme matériau d’électrode positive pour ces systèmes LIB et SIB. Parmi ces structures le pentoxyde de vanadium, sous sa forme alpha est un composé modèle présentant de nombreux intérêts pour les batteries au lithium. Ce matériau présente en outre de nombreux polymorphes stables autorisant un large champ d’étude de ce composé.Dans cette thèse, nous nous sommes intéressés au polymorphe gamma’-V2O5 présentant une structure lamellaire à très large inter-feuillet laissant présager une insertion d’espèces cationiques facilitée et donc des performances électrochimiques accrues. Le but de cette thèse a consisté à étudier les propriétés électrochimiques et la réponse structurale de ce composé vis-à-vis de l’insertion des ions lithium et sodium.La première partie de cette thèse propose une analyse bibliographique de l’état de l’art sur les accumulateurs lithium-ion et sodium.Dans une seconde partie les données concernant l’insertion du lithium et du sodium dans le composé alpha-V2O5 sont présentées. Les propriétés électrochimiques et structurales de ce matériau d’insertion permettront de mettre en avant l’intérêt de l’utilisation du polymorphe gamma’-V2O5 comme matériau d’électrode positive pour les systèmes LIB et SIB.Une troisième partie de ce mémoire présente la synthèse et la caractérisation du polymorphe gamma’-V2O5. L’étude complète de ce système est présentée dans le cas de l’insertion du lithium avec une étude des performances électrochimiques, une étude cinétique de la réaction d’insertion réalisée par spectroscopie d’impédance complexe et la description des changements structuraux étudiés pas diffraction des rayons X et par spectroscopie Raman.Dans une quatrième partie, l’insertion électrochimique du sodium dans le polymorphe gamma’-V2O5 est étudiée en suivant la même démarche. Le mécanisme structural impliqué dans le fonctionnement électrochimique est résolu. La formation d’un bronze de vanadium au sodium jamais encore décrit, gamma-Na0,97V2O5, est révélée et la détermination de sa structure est réalisée. Les caractéristiques électrochimiques remarquables de gamma’-V2O5, et notamment sa tension élevée de 3,3V et son excellente stabilité en cyclages, permettent de situer ce composé parmi les cathodes les plus performantes pour batterie au sodium
The question of energy storage is currently at the heart of many international issues. The development of storage systems such as lithium ion (LIB) and sodium ion (SIB) batteries is therefore today the subject of many researches.In this context, layered materials having an interlayer space allowing insertion of cationic species seem ideal in the context of use as a positive electrode material for these LIB and SIB systems. Among these structures, vanadium pentoxide, in its alpha form, is a model compound with many advantages as an attractive cathode material for lithium batteries. This material also has numerous stable polymorphs allowing a wide field of study of this compound.In this thesis we were interested in the gamma'-V2O5 polymorph, which exhibits a layered structure with very large interlayer space allowing an easier insertion. Therefore, increased electrochemical performances are expected for this compound. The aim of this thesis was to study the electrochemical properties and the structural response of this compound toward the insertion of lithium and sodium ions.The first part of this thesis proposes a review of the current literature studies devoted to lithium-ion and sodium batteries.In a second part, a thorough study of the electrochemical lithium and sodium insertion in the alpha-V2O5 phase are depicted. The electrochemical and structural properties of alpha-V2O5 will make it possible to highlight the advantage of using the polymorph gamma'-V2O5 as a positive electrode material for LIB and SIB.The third part of this thesis presents the synthesis and characterization of the gamma'-V2O5 polymorph. The complete study of this system is presented in the case of the insertion of lithium with a study of electrochemical performances, a kinetic study of the insertion reaction carried out by complex impedance spectroscopy and a description of the structural changes studied by X-ray diffraction and by Raman spectroscopy.In the fourth chapter, the insertion of sodium into the polymorph gamma'-V2O5 is studied, using the same approach than that adopted in the case of lithium. The structural mechanism involved during the electrochemical process is solved. The formation of a new sodium vanadium bronze, gamma-Na0.97V2O5 , is revealed and its structural determination is carried out. Due to its remarkable electrochemical characteristics, especially its high voltage of 3,3V and excellent cycling stability, the gamma'-V2O5 oxide ranks among the most performant cathode materials for sodium batteries

Gli stili APA, Harvard, Vancouver, ISO e altri

Dridi, Zrelli Yosra. "Électrochimie et spectroscopie Raman de matériaux d’électrode positive pour batteries Li-ion". Thesis, Paris Est, 2012. http://www.theses.fr/2012PEST1126/document.

Testo completo

Abstract (sommario):

Dans ce travail de thèse, la microspectrométrie Raman a été mise à profit pour décrire les changements structuraux induits par la réaction électrochimique d'insertion/désinsertion des ions lithium dans des composés de structure lamellaire LiCoO2 et cubique LiMn2O4 et LiNi0.4Mn1.6O4, utilisés comme électrodes positives dans les batteries Li-ion. L'étude du composé d'électrode LiCoO2 pendant le processus de charge permet de mettre en évidence une région biphasée où la phase initiale coexiste avec une nouvelle phase hexagonale caractérisée par une expansion du paramètre inter-feuillets de l'ordre de 3% et un affaiblissement de la liaison Co-O dans le plan des feuillets. Dans le cas de LiMn2O4, une nouvelle attribution du spectre Raman a pu être proposée. Pendant la charge à 4V, un mécanisme à trois phases (phase initiale LiMn2O4, phase intermédiaire, phase pauvre en lithium) est décrit par spectroscopie Raman alors que la diffraction des RX ne permet pas d'observer la phase intermédiaire dans nos conditions de mesure. L'étude de l'insertion électrochimique du lithium dans LiMn2O4 (région 3V), a permis de montrer pour la première fois par spectroscopie Raman la formation progressive d'une phase tétragonale de composition Li2Mn2O4 qui coexiste avec la phase cubique initiale et qui est pure en fin de décharge. La réversibilité de cette transition structurale a également été démontrée. Dans le cas du composé substitué au nickel, LiNi0.4Mn1.6O4, une attribution complète du spectre Raman est proposée pour la première fois. L'étude par diffraction des RX du matériau en fonction de l'état de charge et de décharge met en évidence une conservation de la structure cubique avec des variations modérées de paramètres de maille. Le spectre Raman présente quant à lui des variations très significatives qui rendent compte de la présence dans des proportions différentes des espèces redox impliquées dans le fonctionnement électrochimique (Mn4+, Mn3+, Ni2+, Ni3+, Ni4+). Une analyse spectrale par décompositions de bandes permet d'identifier et de quantifier les proportions relatives des différents couples redox du nickel. Une réversibilité complète de la signature Raman est observée en décharge. Une application concrète et originale de la spectroscopie Raman a consisté à étudier le mécanisme d'autodécharge qui est observé pour le matériau LiNi0.4Mn1.6O4 complètement chargé. L'évolution des spectres Raman permet de mettre en évidence une réduction rapide et quantitative des ions Ni4+ pendant les premières heures de séjour dans l'électrolyte, puis un processus plus lent de réduction des ions Ni3+. Enfin, pour la première fois également, l'insertion du lithium dans le composé LiNi0.4Mn1.6O4 a été explorée par microspectrométrie Raman et a permis notamment d'identifier l'empreinte Raman de la phase la plus réduite de symétrie tétragonale Li2Ni0.4Mn1.6O4. L'originalité de ce travail a été d'apporter un grand nombre de données Raman expérimentales sur des matériaux d'électrode performants fonctionnant à 4V. De nouvelles attributions ont pu être proposées pour les composés initiaux, et des données vibrationnelles inédites ont été fournies sur les composés formés en charge et en décharge. Dans certains cas, ces données ont permis, sur la base d'une analyse détaillée des spectres Raman par décompositions de bandes, de proposer un raisonnement quantitatif sur l'existence de phases ou d'espèces redox en mélange. Il conviendrait bien sûr de corroborer ces nouvelles données et attributions par des calculs théoriques ab initio capables de simuler les fréquences et les intensités des modes vibrationnels dans les structures hôtes et lithiées
In this work, we show the relevance of Raman spectroscopy as a useful technique to investigate the local changes induced by the electrochemical reaction of intercalation/deintercalation of lithium in positive electrode materials for rechargeable lithium ion batteries.Raman investigations concern three types of high voltage cathode materials (4-5Volts) which are layered LiCoO2 and cubic LiMn2O4 and LiNi0.4Mn1.6O4.During electrochemical deintercalation of LiCoO2, we show the existence of a two phase region where the initial hexagonal phase coexist with a second hexagonal phase with a 3% expansion of the lattice parameter indicating a weakening of the Co-O bond in the Li1-xCoO2 material.On the other hand, a new assignment of LiMn2O4 Raman spectrum was proposed. During the charge in the 4V region, a three region phase (initial LiMn2O4 phase, intermediary phase and poor lithium phase) was described using Raman spectroscopy. RX measurements can not detect this intermediary phase. Lithiated phase Raman signature shows a specific local order: Fd3m for extreme phases and F43m for partially lithiated phase. A rich Raman band spectrum is attributed to this later phase in coherence with literature calculations. Structural changes reversibility is demonstrated. Identification of this intermediary phase as a major component of a cycled electrode, underline the incomplete reduction and explain the important loss of capacity observed during cycling. Raman study of LiMn2O4 electrochemical insertion in the 3V region, has demonstrated for the first time a progressive formation of tetragonal Li2Mn2O4 phase, which is in coexistence with initial cubic phase and is pure at the end of discharge. Structural transition reversibility was also demonstrated.In the case of LiNi0.4Mn1.6O4, the assignment of the Raman spectrum of LiNi0.4Mn1.6O4 is provided for the first time. DRX study in function of the state of charge and discharge, exhibit cubic structure conservation with moderate lattice parameters variations. The Raman spectrum of the spinel oxide exhibits drastic spectral changes during Li extraction. These changes have been directly related to the Mn and Ni oxidation states in the cathode material under operation. It comes out that electrochemical reactions of LiNi0.4Mn1.6O4 are reversible and based on three redox couples of Mn3+/Mn4+, Ni2+/Ni3+, and Ni3+/Ni4+. An original and concrete Raman spectroscopy application is the study of self discharge mechanism of completely charged LiNi0.4Mn1.6O4. Raman spectra evolution exhibits a quantitative Ni4+ reduction during the first hours, and then a slower Ni3+ reduction process. Finally, LiNi0.4Mn1.6O4 lithium insertion has been explored for the first time using Raman spectroscopy, and a tetragonal Li2Ni0.4Mn1.6O4 phase has been identified.The originality of this work is the important number of experimental Raman data of 4V electrode materials. New assignment of initial compound has been proposed and original vibrationnal data of compound during charge/discharge has been presented. These Raman data has permitted to propose a quantitative explanation which must be completed with ab initio calculations to simulate vibrationnal modes frequencies/ intensities

Gli stili APA, Harvard, Vancouver, ISO e altri

Morales, Ugarte Jorge Eduardo. "Etude Operando des accumulateurs au lithium par couplage spectroscopie à photoémission des rayons X et spectroscopie d’impédance". Thesis, Université Grenoble Alpes (ComUE), 2019. http://www.theses.fr/2019GREAI082.

Testo completo

Abstract (sommario):

Face aux grands défis industriels dans les domaines du stockage électrochimique de l’énergie, un effort de recherche fondamentale sur les matériaux impliqués et leurs interfaces est aujourd'hui indispensable pour un gain en performance, durabilité, sécurité.Dans ce contexte, il est primordial de comprendre les processus interfaciaux mis en jeu qui induisent la dégradation de l’interface lithium métal-électrolyte et entrainent une baisse du rendement Coulombique et favorisent la croissance dendritique.Nous proposons ainsi dans cette thèse une étude couplant des techniques électrochimiques comme la spectroscopie d’impédance avec des techniques d’analyse de surface comme la spectroscopie à photoémission des rayons X pour étudier la réactivité chimique et électrochimiques entre les électrolytes et une électrode de lithium métal.Pour ce faire, un intérêt spécifique a été porté aux électrolytes à base de liquides ioniques, qui ont été proposés comme solvants des sels de lithium, notamment pour leur faible pression de vapeur saturante qui augmente considérablement la sécurité des batteries ainsi conçues.Enfin, ce travail a été consacré en particulier au développement de montages et de mesures operando XPS afin de suivre l’évolution chimique des interfaces à l’intérieur d’une batterie en temps réel
Faced with the major industrial challenges in the field of electrochemical energy storage, a fundamental research effort on the materials involved and their interfaces is nowadays essential for a gain in performance, durability and safety.In this context, it is essential to understand the interfacial processes involved that induce the degradation of the lithium metal-electrolyte interface and lead to a decrease in Coulombic efficiency and promote dendritic growth.In this thesis, we propose a study coupling electrochemical techniques such as impedance spectroscopy with surface analysis techniques such as X-ray photo-emission spectroscopy to study the chemical and electrochemical reactivity between electrolytes and a lithium metal electrode.To this end, special attention has been paid to the ionic liquids based electrolytes, which have been proposed as solvents for lithium salts, particularly for their low saturation vapor pressure, which considerably increases the safety of the batteries thus designed.Finally, this work was devoted in particular to the development of operando XPS assemblies and measurements in order to follow the chemical evolution of the interfaces inside a battery in real time

Gli stili APA, Harvard, Vancouver, ISO e altri

Mignoni, Sabrina. "Investigation par spectroscopie Raman des propriétés photoréfractives et microstructurales de LiNbO3 dopé". Thesis, Metz, 2010. http://www.theses.fr/2010METZ017S/document.

Testo completo

Abstract (sommario):

Le niobate de lithium LiNbO3 (LN) est un excellent matériau pour diverses applications en raison de ses propriétés photoréfractives (PR). Un des enjeux de recherche de ce matériau consiste à réaliser des guides optiques PR performants pour l'optique intégrée. L'objectif de la thèse consiste à déterminer les conditions optimales de réalisation de la diffusion du fer (Fe) dans le LN, par le contrôle de sa microstructure et l'estimation de ses propriétés PR par une seule et même technique, la spectroscopie Raman.Plusieurs échantillons LN:Fe ont été étudiés lors de ce travail. Il s'agit entre autres de contrôler le profil de diffusion du fer, et d'estimer l'influence du traitement oxydant ou réducteur sur les différents cristaux.En effet j'ai pu montrer que la microstructure était modifiée non seulement par l'introduction d'un dopant comme Fe, mais aussi par les divers traitements. J'ai aussi mis en évidence pour la première fois le mécanisme de l'incorporation des ions Fe dans des structures de LN obtenues par diffusion.Par ailleurs, j'ai proposé une nouvelle approche des règles d'activité Raman, qui ainsi peuvent prendre en compte des non linéarités optiques du second ordre, ce qui est en général négligé dans la littérature. J'ai ainsi établi les configurations Raman dans lesquelles, soit les intensités de raies sont amplifiées, soit de nouvelles raies sont activées par un processus non linéaire. Ces prédictions ont été confirmées par des résultats expérimentaux obtenus sur plusieurs échantillons. Enfin, j'ai pu proposer une nouvelle méthode d'estimation de l'efficacité PR permettant de comparer utilement divers échantillons selon leur dopage ou traitement
Lithium niobate LiNbO3 (LN) is an excellent material for various applications in particular thanks to its photorefractive (PR) properties. One of the research goals for this material consists in performing efficient PR optical waveguides for integrated optics.The objective of the thesis is to determine the optimum performing conditions for the iron (Fe) diffusion in LN, by controling its microstructure and estimating its PR properties with only one technique, Raman spectroscopy.Several LN:Fe samples have been studied within this work. The aim is, among others, to control the iron diffusion profile, and to estimate the influence of the oxidizing or reducing treatment on the different crystals.Indeed I was able to show that the microstructure has been affected not only by the introduction of a dopant as Fe, but also by the various treatments. I showed for the first time the mecanism of Fe ions incorporation in LN structures obtained by diffusion.Otherwise, I proposed a new approach of the Raman activity rules, in the way they can take into account optical nonlinearities of the second order, which is generally neglected in litterature. Thus I have established the Raman configurations where, or the intensities of the lines are enhanced, or new lines are activated by a nonlinear process. These predictions have been confirmed by experimental results obtained on many samples. At last, I was able to propose a new method for the estimation of the PR efficiency, allowing to compare usefully several samples according to their doping or treatments

Gli stili APA, Harvard, Vancouver, ISO e altri

Guichard, Jordan. "Etude de l'hydrolyse de l'hydrure de lithium". Thesis, Dijon, 2015. http://www.theses.fr/2015DIJOS050/document.

Testo completo

Abstract (sommario):

L'hydrolyse de LiH à température ambiante et sous faible pression de vapeur d'eau (PH2O < 10 hPa) est d’abord étudiée par thermogravimétrie McBain et spectroscopie infrarouge in situ sur de faibles masses d’échantillon. Puis, afin de se rapprocher des conditions industrielles, l’hydrolyse de LiH est étudiée sur des masses plus importantes, par manométrie en système fermé (PH2O variable) et ouvert (PH2O constante) avec de l'eau lourde. Les produits de la réaction sont caractérisés par diffraction des rayons X et spectroscopie IRTF. Les premières séries d'expériences montrent que le mécanisme se déroule dans un premier temps par la croissance de la couche d’oxyde de lithium Li2O. Puis, quand la couche d’oxyde est suffisamment épaisse, la réaction d’hydrolyse se poursuit par la formation de l’hydroxyde de lithium LiOH pour finir avec la formation de l’hydroxyde de lithium monohydraté LiOH,H2O. La couche externe de Li2O/LiOH formerait une barrière protectrice à la surface de LiH. De plus, grâce à la seconde série d'expériences, il est montré pour la première fois que la réaction d'hydrolyse se déroule en deux étapes : d'abord l'eau est adsorbée à la surface de LiH puis la réaction d'hydrolyse commence. La vitesse de réaction est toutefois extrêmement faible et seule une très petite quantité de LiH est transformée. La cinétique est bien prédite par le modèle du coeur rétrécissant limitée par la diffusion à travers la couche de Li2O et/ou LiOD entourant les particules de LiH. Pour une application pratique, il est conclu que si la poudre de LiH est stockée plusieurs années sous atmosphère contrôlée ou dans un récipient étanche où la pression de vapeur d'eau est inférieure à 0,04 hPa, il n'y a pas de risque majeur de produire LiOH
The hydrolysis of LiH at room temperature and under low water vapor pressure (PH2O < 10 hPa) is investigated by thermogravimetry and FTIR spectroscopy with low sample mass. Then, to be closer to industrial conditions, hydrolysis of LiH is studied by manometry either in closed (adjustable PH2O) or open (constant PH2O) system using larger amounts of sample and heavy water. Products of the reaction are characterized by X-ray diffraction and FTIR spectroscopy. The first set of experiments show that the mechanism of hydrolysis starts with the formation of lithium oxide Li2O. Then, when the oxide layer is sufficiently thick, the hydrolysis reaction is followed by the formation of lithium hydroxide LiOH and afterwards with the formation of lithium hydroxide monohydrate LiOH, H2O. Besides, the Li2O/LiOH outer layer forms a protective barrier on the surface of LiH. The second set of experiments clearly highlights for the first time that the hydrolysis reaction occurs in two steps: first water is adsorbed on the LiH surface and then the hydrolysis reaction starts. The reaction rate is however extremely low and only a very small fraction of LiH is hydrolysed. The kinetic can be well predicted by the shrinking-core model limited by the diffusion through the external ash layer (Li2O and/or LiOH). For practical application, it is concluded that if the LiH powder is stored for several years under a controlled atmosphere or in a sealed container where the vapor water pressure is less than 0.04 hPa, there is no major risk of LiOH formation

Gli stili APA, Harvard, Vancouver, ISO e altri

Seung, Do-Young. "Approche structurale et étude de la conduction ionique de verres à base de thioarsenite de lithium et de verres à formateur mixte, thioborate et thioarsenite de lithium". Bordeaux 1, 1995. http://www.theses.fr/1995BOR10544.

Testo completo

Abstract (sommario):

Une nouvelle famille de verres du système As2S3-Li2S-Lil a été étudiée. Ils présentent une conductivité ionique élevée. Une étude de l'ordre local par différentes techniques a permis de proposer des hypothèses structurales. L'étude cristallographique d'un nouveau compose Li3AsS3 a permis, d'autre part, une étude structurale comparative avec le verre de même composition. L'évolution des propriétés physiques de ces verres (conductivité ionique, température de transition vitreuse, densité), a été correlée à leurs compositions. Un petit domaine vitreux a été mis en évidence dans le système As2S3-B2S3-Li2S comportant deux sulfures formateurs. La caractérisation de ces matériaux a permis de proposer des hypothèses structurales liées à leur homogènéité.

Gli stili APA, Harvard, Vancouver, ISO e altri

Fleutot, Benoit. "Amélioration des performances des microbatteries au lithium : corrélation entre la structure locale et la conductivité ionique d’électrolytes solides amorphes". Thesis, Bordeaux 1, 2010. http://www.theses.fr/2010BOR14162/document.

Testo completo

Abstract (sommario):

Les microbatteries sont des microsources d’énergie adaptées à l’alimentation des microsystèmes tels que l’horloge à temps réel des téléphones portables, les étiquettes intelligentes RFID…. Pour pouvoir être considéré comme un composant classique de la microélectronique, la microbatterie doit être compatible avec le processus de soudure de type solder-reflow qui atteint une température de 260 °C pendant quelques secondes. Au cours de cette thèse, nous nous sommes focalisés sur l’étude de couches minces de LiPON (oxynitrure de phosphate de lithium) utilisé comme électrolyte solide qui est le matériau limitant pour une application à basse température en établissant des relations entre sa composition, sa structure et ses performances électriques. Ayant observé une baisse des performances après traitement thermique, nous avons proposé un matériau présentant une meilleure stabilité. Nous avons également étudié la compatibilité des autres couches ainsi que l’empilement complet de la microbatterie vis-à-vis du solder-reflow
Microbatteries are energy sources well-adapted to power microsystems such as the real time clock of mobile phones, smart tags RFID. To be considered as a microelectronic component, the microbattery must be compatible with the solder-reflow process which reaches a temperature of 260 °C during few seconds. During this Ph-D, various thin films of LiPON (lithium phosphate oxynitride) used as amorphous solid electrolyte have been prepared by sputtering. As this material presents limited performances for an application of the microbattery at low temperature, we have investigated the influence of its composition and local structure on its electrical performances. In addition, a decrease of its performances has been noticed after solder-reflow. In this work, we have proposed a new material, much more thermally stable. Finally, we have studied the compatibility of other active layers as well as the all-solid-state microbattery towards the solder-reflow

Gli stili APA, Harvard, Vancouver, ISO e altri

Dollé, Mickael. "Etude par spectroscopie d'impédance électrochimique, couplée à la microscopie électronique, d'interfaces de batteries au lithium et à ions lithium". Amiens, 2002. http://www.theses.fr/2002AMIE0207.

Testo completo

Abstract (sommario):

Les interfaces lithium/électrolyte polymère et carbone/électrolyte ont une importance primordiale sur les performances des batteries au lithium et à ions lithium. L'objectif de ce travail était d'acquérir une meilleure compréhension de ces interfaces dans le but d'optimiser leur fonctionnement. Pour cela, des mesures d'impédance électrochimique 3 électrodes dans des cellules de configurations variées ont été mises au point et un microscope électronique à balayage (MEB) a été amélioré afin de permettre l'étude in situ de l'interface lithium/électrolyte polymère. L'influence de la température et du régime de formation sur la nature chimique et l'épaisseur de la couche de passivation formée à l'interface carbone/électrolyte a ainsi été démontrée tout comme l'importance des conditions de formation sur les performances des matériaux carbonés. L'étude par spectroscopie d'impédance électrochimique a alors été étendue à des batteries LiCoO2/graphite en configuration plastique. Enfin, l'influence de la densité de courant sur la morphologie des dendrites à l'interface lithium/électrolyte polymère a été confirmée et les premières observations par MEB de la croissance de dendrites en direct ont été obtenues. L'ensemble des résultats a permis de mieux comprendre chacune des interfaces étudiées et ainsi de proposer des mécanismes

Gli stili APA, Harvard, Vancouver, ISO e altri

Zhang, Wanjie. "Etude des interfaces de batteries lithium-ion : application aux anodes de conversion". Thesis, Pau, 2014. http://www.theses.fr/2014PAUU3024/document.

Testo completo

Abstract (sommario):

Les matériaux dits de conversion à base de Sb et Sn, utilisés comme électrodes, apparaissent comme des composés particulièrement intéressants compte tenu de leur forte capacité théorique. Le matériau TiSnSb a été récemment développé en tant qu’électrode négative pour batteries lithium-ion. Ce matériau est capable d’accueilir, de façon réversible, 6,5 Li par unité formulaire, ce qui correspond à une capacité spécifique de 580 mAh/g. Dans le domaine des batteries lithium-ion, les propriétés de l’interface électrode/électrolyte (« solid electrolyte interphase », SEI), formant une couche de passivation protectrice à la surface des électrodes sont considérées comme essentielles pour les performances au sens large des batteries. Cet aspect représente le sujet majeur traité dans ce travail de thèse. Dans cet optique, nous avons tout d'abord étudié les propriétés électrochimiques de l'électrode TiSnSb sous divers aspects, dont les effets du régime de cyclage, l’influence de la nature des additifs au sein de l’électrolyte ainsi que l’utilisation de liquides ioniques à température ambiante (RTILs). En particulier, un système d'électrolyte à base de RTILs a été développé et optimisé vis-à-vis des performances électrochimiques. Afin de caractériser l’interface électrode-électrolyte, deux techniques de caractérisation majeures ont été utilisées : la Spectroscopie Photoélectronique à Rayonnement X (XPS) et la Spectroscopie d'Impédance électrochimique (EIS). Cette étude a permis de cibler certains paramètres essentiels liant les aspects performances électrochimiques à la nature de l’interface électrode-électrolyte
In the past decades, the need for portable power has accelerated due to the miniaturization of electronic appliances. It continues to drive research and development of advanced energy systems, especially for lithium ion battery systems. As a consequence, conversion materials for lithium-ion batteries, including Sb and Sn-based compounds, have attracted much intense attention for their high storage capacities. Among conversion materials, TiSnSb has been recently developed as a negative electrode for lithium-ion batteries. This material is able to reversibly take up 6.5 Li per formula unit which corresponds to a specific capacity of 580 mAh/g. In the field of lithium-ion battery research, the solid electrolyte interphase (SEI) as a protective passivation film formed at electrode surface owing to the reduction of the electrolyte components, has been considered as a determinant factor on the performances of lithium-ion battery. Thus it has been a focused topic of many researches. However, little information can be found about the formation and composition of the SEI layer formed on TiSnSb conversion electrode at this time. With the aim to investigate the influences of the SEI layer on the performances of composite TiSnSb electrode, we first studied the electrochemical properties of the electrode from various aspects, including the effects of cycling rates, electrolyte additives, as well as room temperature ionic liquids (RTILs). Especially, a RTILs-based electrolyte system was developed and optimized by evaluating its physicochemical properties to be able to further improve the performances of TiSnSb electrode. In order to characterize the SEI layer formed at electrode surface, we performed X-ray photoelectron spectroscopy (XPS) and electrochemical impedance spectroscopy (EIS). This study allowed to target some essential parameters concerning electrochemical performances linked with the nature of the solid electrolyte interphase.*

Gli stili APA, Harvard, Vancouver, ISO e altri

Più fonti

Libri sul tema "Spectroscopie du lithium"

Fergani, Hadi. Determination of lithium in geological samples by using atomic absorption spectroscopy. Sudbury, Ont: Laurentian University, 1991.

Cerca il testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Bullen, Peter Stanley. Domain Broadening in Periodic Poling of Thinned Lithium Niobate and Spectroscopic Methods for Whole Blood Analysis. [New York, N.Y.?]: [publisher not identified], 2019.

Cerca il testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Garbarino, John R. Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory: Determination of dissolved arsenic, boron, lithium, selenium, strontium, thallium, and vanadium using inductively coupled plasma-mass spectrometry. Denver, Colo: U.S. Geological Survey, 1999.

Cerca il testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Lithium, magnesium, calcium, strontium, and barium in waters and sewage effluents by atomic absorption spectrophotometry, 1987. London: H.M.S.O., 1987.

Cerca il testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Capitoli di libri sul tema "Spectroscopie du lithium"

Sebban, Muriel, Laure Guilhaudis e Hassan Oulyadi. "Spectroscopic Advances in Structural Lithium Chemistry: Diffusion-Ordered Spectroscopy and Solid-State NMR". In Lithium Compounds in Organic Synthesis, 85–122. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2014. http://dx.doi.org/10.1002/9783527667512.ch4.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Zhang, Jianbo, Shangshang Wang e Kei Ono. "Electrochemical Impedance Spectroscopy". In Microscopy and Microanalysis for Lithium-Ion Batteries, 301–50. Boca Raton: CRC Press, 2023. http://dx.doi.org/10.1201/9781003299295-11.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Jones, Amanda C. "Spectroscopic Advances in Organolithium Reactivity: The Contribution of Rapid-Injection NMR (RINMR)". In Lithium Compounds in Organic Synthesis, 53–84. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2014. http://dx.doi.org/10.1002/9783527667512.ch3.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Alcántara, Ricardo, Pedro Lavela, Carlos Pqérez Vicente e José L. Tirado. "Applications of Mössbauer Spectroscopy in The Study of Lithium Battery Materials". In Mössbauer Spectroscopy, 552–63. Hoboken, New Jersey: John Wiley & Sons, Inc., 2013. http://dx.doi.org/10.1002/9781118714614.ch28.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Zuerch, Michael. "Ultrafast Second-Harmonic XUV Spectroscopy: A Novel Probe for Symmetry". In Springer Proceedings in Physics, 169–76. Cham: Springer International Publishing, 2024. http://dx.doi.org/10.1007/978-3-031-47938-0_16.

Testo completo

Abstract (sommario):

AbstractExtreme-ultraviolet second-harmonic generation spectroscopy (XUV-SHG) is a novel spectroscopy that enables probing element-selective symmetry-broken states. This renders XUV-SHG especially useful to study surfaces, interfaces, and symmetry-broken bulk states in otherwise complex chemical environments. In a string of recent works, XUV-SHG was successfully applied to study the role of lithium in various compounds. One of the most striking recent results studied the role of Li symmetry-breaking displacement causing the emergence of polarity in the polar metal LiOsO3. Furthermore, the directional dependence of the SHG process allows geometry specific measurements. Given the femtosecond nature of the probe pulses, one can readily envision this method to be applied to study interfacial carrier dynamics in complex in-operando environments that are difficult to probe with conventional ultrafast methods.

Gli stili APA, Harvard, Vancouver, ISO e altri

Dedryvere, R., S. Denis, J. Olivier-Fourcade e J. C. Jumas. "Lithium Insertion Mechanism in Copper Indium Tin Sulfospinels Studied by 119Sn Mössbauer Spectroscopy and Rietveld Analysis". In Materials for Lithium-Ion Batteries, 577–80. Dordrecht: Springer Netherlands, 2000. http://dx.doi.org/10.1007/978-94-011-4333-2_43.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Handke, Miroslaw, e Marek Nocuń. "Vibrational Spectroscopy of Lithium Silicates and Aluminosilicates in Crystalline Form". In Progress in Fourier Transform Spectroscopy, 507–10. Vienna: Springer Vienna, 1997. http://dx.doi.org/10.1007/978-3-7091-6840-0_124.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

van Wijngaarden, W. A., e G. A. Noble. "Precision Laser Spectroscopy of Li+ and Neutral Lithium". In Precision Physics of Simple Atoms and Molecules, 111–29. Berlin, Heidelberg: Springer Berlin Heidelberg, 2008. http://dx.doi.org/10.1007/978-3-540-75479-4_7.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Pruneri, V., S. D. Butterworth, J. Webjörn, P. St J. Russell e D. C. Hanna. "Green-Light Generation from Picosecond Pulses Via First-Order Quasi-Phase-Matched Lithium Niobate". In Ultrafast Processes in Spectroscopy, 365–67. Boston, MA: Springer US, 1996. http://dx.doi.org/10.1007/978-1-4615-5897-2_82.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Deliyannis, C. P., J. R. King e A. M. Boesgaard. "Lithium in the Old Open Cluster M 67: Constraints for the Cause of the Boesgaard Li Gap". In Wide-Field Spectroscopy, 201–4. Dordrecht: Springer Netherlands, 1997. http://dx.doi.org/10.1007/978-94-011-5722-3_33.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Atti di convegni sul tema "Spectroscopie du lithium"

Mashburn, Carter, Kristina Chang, Tsung-Han Wu, Luis Ledezma, Ryoto Sekine, Alireza Marandi e Scott A. Diddams. "Towards UV-Visible Dual-Comb Spectroscopy with Lithium Niobate Nanophotonic Waveguides". In CLEO: Science and Innovations, SW4F.3. Washington, D.C.: Optica Publishing Group, 2024. http://dx.doi.org/10.1364/cleo_si.2024.sw4f.3.

Testo completo

Abstract (sommario):

We present a dual-comb spectrometer that employs thin-film lithium niobate nanophotonic waveguides for UV-visible light generation. The potential for broadband and high-resolution spectroscopy spanning 350-850 nm is explored.

Gli stili APA, Harvard, Vancouver, ISO e altri

Kishkin, Krasimir, Dimitar Arnaudov, Kaspars Kroics e Vladimir Dimitrov. "Comparison of the Characretistics of a Lithium Ion and a Lithium Titanate Oxide Battery by Impedance Spectroscopy". In 2024 23rd International Symposium on Electrical Apparatus and Technologies (SIELA), 1–5. IEEE, 2024. http://dx.doi.org/10.1109/siela61056.2024.10637828.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Engleman, R., L. J. Radziemski e J. W. Brault. "Reanalysis of 6Li I and 7Li I transitions using hollow cathode Fourier transform spectra". In Fourier Transform Spectroscopy. Washington, D.C.: Optica Publishing Group, 1995. http://dx.doi.org/10.1364/fts.1995.ffd3.

Testo completo

Abstract (sommario):

The spectrum of neutral lithium remains of considerable interest to both theorists and experimentalists. There have been attempts to calculate from first principles the energy levels, hyperfine parameters and isotope shifts (see for example Ref. 1); thus, good experimental values are important for comparison. The abundance of lithium is a key indicator for the age of a star; thus, accurate information on the stronger lithium lines becomes important in certain astrophysical problems.

Gli stili APA, Harvard, Vancouver, ISO e altri

de Almeida, Jose M. M. M., Antonio M. P. P. Leite e Jaymin Amin. "Spectroscopy of doped lithium niobate". In Symposium on Integrated Optoelectronics, a cura di Shibin Jiang. SPIE, 2000. http://dx.doi.org/10.1117/12.382863.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Baxter, G. W., Y. He e B. J. Orr. "A pulsed, injection-seeded optical parametric oscillator system based on periodically poled lithium niobate for high-resolution spectroscopy". In The European Conference on Lasers and Electro-Optics. Washington, D.C.: Optica Publishing Group, 1998. http://dx.doi.org/10.1364/cleo_europe.1998.cfh3.

Testo completo

Abstract (sommario):

Optical parametric oscillator (OPO) and amplifier (OPA) devices are recognised as versatile coherent tunable spectroscopic sources. This is borne out by our previous work on OPOs based on bulk (3-barium borate (BBO) [1] and lithium niobate (LNB) [2], in which tunability and optical bandwidth are achieved by injection seeding with single-mode tunable diode lasers (TDL). We now report a new modular spectroscopic system, as depicted in Figure 1: a TDL-seeded OPO based on periodically poled lithium niobate (PPLN) plus a bulk-LNB OPA.

Gli stili APA, Harvard, Vancouver, ISO e altri

Isler, R. C. "Spectroscopic techniques for studying magnetic fusion plasmas". In OSA Annual Meeting. Washington, D.C.: Optica Publishing Group, 1989. http://dx.doi.org/10.1364/oam.1989.wy3.

Testo completo

Abstract (sommario):

Magnetic fusion plasmas have temperatures ranging from several tens of electron volts at the edge up to several kiloelectron volts at the center. Electron densities typically vary from 1 to 10 × 1013/cm3. Spectroscopic techniques using wavelengths from the x-ray through the visible regions are employed to measure a number of parameters.1 These quantities include, but are not restricted to, plasma temperatures, radiated power, impurity content and transport, radial electric fields as inferred from plasma rotation, neutral hydrogen densities, and rotational transforms of magnetic fields. In addition to passive spectroscopy, active techniques are used for enhancing spectroscopic capabilities. Introduction of trace amounts of nonintrinsic impurities by laser ablation, excitation by charge exchange between energetic hydrogen beams incident on highly ionized impurities, laser-induced fluorescence, and excitation of lithium introduced in a beam or as a pellet have all been employed for making one or more types of measurement. In particular, charge exchange from hydrogen beams has become widely adopted as the standard method of measuring ion temperatures, plasma rotation, and concentrations of fully ionized low-Z impurities.2

Gli stili APA, Harvard, Vancouver, ISO e altri

Sarkas, H. W., S. T. Arnold, Jackie Hendricks, V. L. Slager e Kit Bowen. "Photoelectron spectroscopy of lithium dimer anion". In OE/LASE'93: Optics, Electro-Optics, & Laser Applications in Science& Engineering, a cura di Cheuk Yiu Ng. SPIE, 1993. http://dx.doi.org/10.1117/12.143090.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

ChiuHuang, Cheng-Kai, Chuanzhen Zhou e Hsiao-Ying Shadow Huang. "Exploring Lithium-Ion Intensity and Distribution via a Time-of-Flight Secondary Ion Mass Spectroscopy". In ASME 2013 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/imece2013-63013.

Testo completo

Abstract (sommario):

For high rate-capability and low cost lithium-ion batteries, the prevention of capacity loss is one of major challenges facing by lithium-ion batteries today. During electrochemical processes, lithium ions diffuse from and insert into battery electrodes accompanied with the phase transformation, where ionic diffusivity and concentration are keys to the resultant battery capacity. In the current study, we first compare voltage vs. capacity curves at different C-rates (1C, 2C, 6C, 10C). Second, lithium-ion distributions and intensity are quantified via the Time-of-Flight Secondary Ion Mass Spectroscopy (ToF-SIMS). The result shows that voltage vs. capacity relations are C-rate dependent and larger hystereses are observed in the higher C-rate samples. Detailed quantification of lithium-ion intensity for the 1C sample is conducted. It is observed that lithium-ions are distributed uniformly inside the electrode. Therefore, the current study provides a qualitative and quantitative data to better understand C-rate dependent phenomenon of LiFePO4 battery cells.

Gli stili APA, Harvard, Vancouver, ISO e altri

Donnelly, T. D., T. E. Glover, E. A. Lipman, M. Hofer, R. W. Falcone, L. Da Silva, S. Morwka e D. C. Eder. "Experiments with Short-Wavelength Lasers Driven by Ultra-Short Pulse, High-Intensity Lasers". In High Resolution Fourier Transform Spectroscopy. Washington, D.C.: Optica Publishing Group, 1994. http://dx.doi.org/10.1364/hrfts.1994.wb2.

Testo completo

Abstract (sommario):

A multi-terawatt laser was used to generate and characterize plasmas appropriate for recombination pumped x-ray lasers. Thomson scattering was used to determine the electron and ion temperatures on a sub-picosecond time-scale. A recombination pumped x-ray laser on the Lyman-alpha transition of H-like lithium was also studied.

Gli stili APA, Harvard, Vancouver, ISO e altri

Qi, Zhi-mei, Lichao Zhang e Ning Xue. "Design of a High-resolution Static Fourier Transform Spectrometer on Thin-film Lithium Niobate Substrate". In Fourier Transform Spectroscopy. Washington, D.C.: OSA, 2021. http://dx.doi.org/10.1364/fts.2021.fw3d.3.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Rapporti di organizzazioni sul tema "Spectroscopie du lithium"

Benn, D., R. Linnen e T. Martins. Evaluating white mica as an indicator mineral for lithium bearing pegmatites, Wekusko Lake pegmatite field, Manitoba, Canada. Natural Resources Canada/CMSS/Information Management, 2021. http://dx.doi.org/10.4095/328982.

Testo completo

Abstract (sommario):

This project investigates the potential use of white micas as an indicator mineral within Li-bearing pegmatites and the potential of field portable techniques, such as Raman spectroscopy and Laser Induced Breakdown Spectroscopy (LIBS) as real-time techniques in exploration. The pegmatites in the Wekusko Lake field, Manitoba, Canada, display five zones of varying mineralization. White micas display two textures in the field (primary igneous and secondary) and four textures were identified by backscattered electron imaging (poor zonation, rimmed, patchy and exsolution). The white micas were analysed by Electron Probe Micro-Analysis (EPMA) and Laser Ablation Induction-Coupled Plasma Mass Spectroscopy (LA-ICP-MS) and the results show a strong correlation in the Li content of the white mica and the whole rock Li2O obtained from the assays of drill core. The K/Rb vs. Cs contents of the white mica indicate that the most prospective dikes contain moderate to highly evolved grains. The use of portable Raman Spectrometer, while useful for mineral identification, was not able to detect a significant Li signature at the concentrations tested (1500-6000 ppm).

Gli stili APA, Harvard, Vancouver, ISO e altri

Tachikawa, Hiroyasu. In situ Raman spectroscopy of lithium electrode surface in ambient temperature lithium secondary battery. Final report. Office of Scientific and Technical Information (OSTI), settembre 1992. http://dx.doi.org/10.2172/10160397.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Augustsson, Andreas. Soft X-ray emission spectroscopy of liquids and lithium batterymaterials. Office of Scientific and Technical Information (OSTI), ottobre 2004. http://dx.doi.org/10.2172/878312.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Barbour, R., Sunghyun Kim, D. Tryk e D. A. Scherson. In situ spectroscopic applications to the study of rechargeable lithium batteries. Final report. Office of Scientific and Technical Information (OSTI), agosto 1993. http://dx.doi.org/10.2172/10105605.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Gofer, Y., R. Barbour, Yuyan Luo, In Tae Bae, Lin-Feng Li e D. A. Scherson. In situ spectroscopic applications to the study of rechargeable lithium batteries. Final report. Office of Scientific and Technical Information (OSTI), luglio 1996. http://dx.doi.org/10.2172/409896.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Kilroy, W. P., S. A. Chmielewski e D. W. Bennett. Investigation of Li/SO2 Cell Hazards. 3. Raman Spectroscopy of Lithium Dithionite. Fort Belvoir, VA: Defense Technical Information Center, settembre 1988. http://dx.doi.org/10.21236/ada205756.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Scherson, D., e G. Chottiner. Ex-situ and in-situ spectroscopic studies of the passive film on lithium in non-aqueous solvents. Office of Scientific and Technical Information (OSTI), ottobre 1990. http://dx.doi.org/10.2172/6009064.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Kopasz, J. P., C. E. Johnson e J. Ortiz-Villafuerte. An investigation of the desorption of hydrogen from lithium oxide using temperature programmed desorption and diffuse reflectance infrared spectroscopy. Office of Scientific and Technical Information (OSTI), aprile 1995. http://dx.doi.org/10.2172/114938.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Offriamo sconti su tutti i piani premium per gli autori le cui opere sono incluse in raccolte letterarie tematiche. Contattaci per ottenere un codice promozionale unico!