Search

Current lithium-ion batteries have been widely used in portable electronic devices, electric vehicles, and peak power demand. However, the organic liquid electrolytes used in the lithium-ion battery are flammable and not stable in contact with elemental lithium and at a higher voltage. To eliminate the safety and instability issues, solid-state (ceramic) electrolytes have attracted enormous interest worldwide, owing to their thermal and high voltage stability. Among all the solid-state electrolytes known today, the Li-stuffed garnet is one of the most promising electrolytes due to its physical and chemical properties such as high total Li-ion conductivity at room temperature, chemical stability with elemental lithium and high voltage lithium cathodes, and high electrochemical stability window (6 V vs. [Li.sup.+]/Li). In this short review, we provide an overview of Li-stuffed garnet electrolytes with a focus on their structure, ionic conductivity, transport mechanism, chemical stability, and battery applications. Key words: solid electrolytes, Li-rich garnets, ionic conductivity, chemical stability, interface, solid-state Li batteries. Les batteries au lithium-ion actuelles sont largement utilisées dans les appareils électroniques portables et les véhicules électriques ainsi que dans des applications à demande de puissance maximale. Cependant, les électrolytes liquides organiques utilisés dans les batteries au lithium-ion sont inflammables et ne sont pas stables au contact du lithium métal et à des tensions plus élevées. En vue d'éliminer les problèmes de sécurité et de in stabilité, les électrolytes solides (céramiques) ont suscité un intérêt énorme dans le monde entier, en raison de leur stabilité thermique et à haute tension. Parmi tous les électrolytes solides connus à ce jour, le grenat rempli de lithium est l'un des électrolytes les plus prometteurs en raison de ses propriétés physiques et chimiques, notamment la conductivité ionique du lithium total élevée à température ambiante, la stabilité chimique en présence de lithium métal et de cathodes au lithium à haute tension, ainsi que la fenêtre de stabilité électrochimique élevée (6 V vs [Li.sup.+]/Li). Dans ce bref article de synthèse, nous présentons un aperçu des électrolytes à base de grenat rempli de lithium, en nous intéressant à leur structure, à leur conductivité ionique, à leur mécanisme de transport, à leur stabilité chimique et à leurs applications aux batteries. [Traduit par la Rédaction] Mots-clés : électrolytes solides au lithium-ion, grenats riches en Li, conductivité ionique, stabilité chimique, interface, batteries à électrolyte solide au lithium., Introduction All-solid-state batteries (ASSBs) containing a Li metal anode are projected as the ultimate battery technology due to their higher energy density and better safety than the present Li-ion batteries [...]

Background: Smaller hippocampal volumes relative to controls are among the most replicated neuroimaging findings in individuals with unipolar but not bipolar depression. Preserved hippocampal volumes in most studies of participants with bipolar disorder may reflect potential neuroprotective effects of lithium (Li). Methods: To investigate hippocampal volumes in patients with bipolar disorder while controlling for Li exposure, we performed a meta-analysis of neuroimaging studies that subdivided patients based on the presence or absence of current Li treatment. To achieve the best coverage of literature, we categorized studies based on whether all or a majority, or whether no or a minority of patients were treated with Li. Hippocampal volumes were compared by combining standardized differences between means (Cohen d) from individual studies using random-effects models. Results: Overall, we analyzed data from 101 patients with bipolar disorder in the Li group, 245 patients in the non-Li group and 456 control participants from 16 studies. Both the left and right hippocampal volumes were significantly larger in the Li group than in controls (Cohen d = 0.53, 95% confidence interval [CI] 0.18 to 0.88; Cohen d = 0.51, 95% CI 0.21 to 0.81, respectively) or the non-Li group (Cohen d = 0.93, 95% CI 0.56 to 1.31; Cohen d = 1.07, 95% CI 0.70 to 1.45, respectively), which had smaller left and right hippocampal volumes than the control group (Cohen d = -0.36, 95% CI -0.55 to -0.17; Cohen d = -0.38, 95% CI -0.63 to -0.13, respectively). There was no evidence of publication bias. Limitations: Missing information about the illness burden or lifetime exposure to Li and polypharmacy in some studies may have contributed to statistical heterogeneity in some analyses. Conclusion: When exposure to Li was minimized, patients with bipolar disorder showed smaller hippocampal volumes than controls or Li-treated patients. Our findings provide indirect support for the negative effects of bipolar disorder on hippocampal volumes and are consistent with the putative neuroprotective effects of Li. The preserved hippocampal volumes among patients with bipolar disorder in most individual studies and all previous meta-analyses may have been related to the inclusion of Li-treated participants., Introduction Neuroprotective effects of lithium (Li) have been well documented in tissue cultures and animal models. (1,2) Some neuroimaging studies have reported findings suggestive of similar effects of Li in [...]

Long-term neurological deficiencies resulting from hippocampal cytotoxicity induced by cranial irradiation (IR) present a challenge in the treatment of primary and metastatic brain cancers, especially in children. Previously, we showed that lithium protected hippocampal neurons from IR-induced apoptosis and improved neurocognitive function in treated mice. Here, we demonstrate accelerated repair of IR-induced chromosomal double-strand breaks (DSBs) in lithium-treated neurons. Lithium treatment not only increased IR-induced DNA-dependent protein kinase (DNA-PK) threonine 2609 foci, a surrogate marker for activated nonhomologous end-joining (NHEJ) repair, but also enhanced double-strand DNA end-rejoining activity in hippocampal neurons. The increased NHEJ repair coincided with reduced numbers of IR-induced [gamma]-H2AX foci, well-characterized in situ markers of DSBs. These findings were confirmed in vivo in irradiated mice. Consistent with a role of NHEJ repair in lithium-mediated neuroprotection, attenuation of IR-induced apoptosis of hippocampal neurons by lithium was dramatically abrogated when DNA-PK function was abolished genetically in SCID mice or inhibited biochemically by the DNA-PK inhibitor IC86621. Importantly, none of these findings were evident in glioma cancer cells. These results support our hypothesis that lithium protects hippocampal neurons by promoting the NHEJ repair--mediated DNA repair pathway and warrant future investigation of lithium-mediated neuroprotection during cranial IR, especially in the pediatric population., Introduction Cranial irradiation (IR) as part of standard treatment of primary and metastatic brain tumors often results in long-term neurological sequelae, especially in young children (1), (2), (3), (4). Intellectual [...]

ABSTRACT Background Spinocerebellar ataxia type 1 (SCA1) is a dominantly inherited neurodegenerative disorder characterized by progressive motor and cognitive dysfunction. Caused by an expanded polyglutamine tract in ataxin 1 (ATXN1), [...]

To study Li isotopic fractionation during granite differentiation and late-stage pegmatite evolution, Li isotopic compositions and concentrations have been measured for the S-type Harney Peak Granite, the spatially associated Tin Mountain pegmatite, and possible metasedimentary source rocks in the Black Hills, South Dakota. The Harney Peak Granite is isotopically heterogeneous, with [[delta].sup.7]Li varying from -3.1 to +6.6. The [[delta].sup.7]Li values of Proterozoic metasedimentary rocks that are possible sources of the Harney Peak Granite range from -3.1 to +2.5 and overlap with post-Archean shales and the Harney Peak Granite. For the granite suite, there is no correlation between [[delta].sup.7]Li and elements indicative of degrees of granite differentiation (Si[O.sub.2], Li, Rb, etc.). The Li isotopic composition of the Harney Peak Granite, therefore, appears to reflect the source composition. Minerals from the zoned Tin Mountain pegmatite have extremely high Li contents and heavier Li isotopic compositions than the granite or surrounding Black Hills metasedimentary rocks. The heavier compositions may reflect Li isotopic fractionation resulting from extensive crystal-melt fractionation. Lithium concentrations decrease in the order: spodumene (~3.7 wt%), muscovite (0.2 to 2.0 wt%), plagioclase (100-1100 ppm), quartz (30-140 ppm). Plagioclase, muscovite, and spodumene in all zones display a relatively narrow range in [[delta].sup.7]Li of +7.9 to +11.4. In contrast, quartz is isotopically heavier and more variable (+14.7 to + 21.3), with [[delta].sup.7]Li showing an inverse correlation with Li concentration. This correlation reflects the mixing of isotopically heavy Li in quartz and lighter Li in fluid inclusions, as documented by fluid inclusion compositions ([[delta].sup.7]Li = +8.1 to +13.4 and Li of 280 to 3960 ppm). Extrapolation of this trend to an estimated intrinsic Li concentration in quartz of +21. The large difference in [[delta].sup.7]Li between quartz and other minerals may reflect [sup.7]Li preference for less highly coordinated sites, which have higher bond-energies (i.e., the two- or fourfold site in quartz vs. higher coordination number sites in other minerals). Comparison of the Li isotopic composition of fluid inclusions with that of the wall zone of the Tin Mountain pegmatite suggests ~4[per thousand] isotopic fractionation during fluid exsolution, which agrees with the results derived from studies of hydrothermal alteration of basalts. Keywords: Stable isotopes, igneous petrology, pegmatites, fluid phase, lithium, Harney Peak Granite, Tin Montain pegmatite, isotope fractionation

Objective: Previous studies have suggested that oxidative stress may play a role in the pathophysiology of bipolar disorder (BD). Moreover, recent studies indicate that lithium and valproate exert neuroprotective effects [...]

Objective: Lithium remains the most widely used treatment for bipolar disorder; however, the molecular mechanisms underlying its therapeutic actions have not been fully elucidated. We studied the in-vivo effect of [...]

Regulation and dysregulation of intracellular calcium (Ca2+) signaling via the inositol 1,4,5-trisphosphate receptor (Ins[P.sub.3]R) has been linked to many cellular processes and pathological conditions. In the present study, addition of [...]

The mechanisms of ion and electron transport in nanostructured insertion electrode materials such as metal oxide electrochromics and/or Li ion batteries are described. Some sort of relaxation process is expected to take place in the domain response, during the insertion of Li ions into nanostructure-based electrodes.

Lithium has long been a primary drug used to treat bipolar mood disorder, even though the drug's therapeutic mechanisms remain obscure. Recent studies demonstrate that lithium has neuroprotective effects against glutamate-induced excitotoxicity in cultured neurons and in vivo. The present study was undertaken to examine whether postinsult treatment with lithium reduces brain damage induced by cerebral ischemia. We found that s.c. injection of lithium dose dependently (0.5-3 mEq/kg) reduced infarct volume in the rat model of middle cerebral artery occlusion/reperfusion. Infarct volume was reduced at a therapeutic dose of 1 mEq/kg even when administered up to 3 h after the onset of ischemia. Neurological deficits induced by ischemiawere also reduced by daily administration of lithium over 1 week. Moreover, lithium treatment decreased the number of neurons showing DNA damage in the ischemic brain. These neuroprotective effects were associated with an up-regulation of cytoprotective heat shock protein 70 (HSP70) in the ischemic brain hemisphere as determined by immunohistochemistry and Western blotting analysis. Lithium-induced HSP70 up-regulation in the ischemic hemisphere was preceded by an increase in the DNA binding activity of heat shock factor 1, which regulates the transcription of HSP70. Physical variables and cerebral blood flow were unchanged by lithium treatment. Our results suggest that postinsult lithium treatment reduces both ischemia-induced brain damage and associated neurological deficits. Moreover, the heat shock response is likely to be involved in lithium's neuroprotective actions. Additionally, our studies indicate that lithium may have clinical utility for the treatment of patients with acute stroke. cerebral ischemia | heat shock factor 1 | heat shock protein | neuroprotection | DNA damage

The study of the C 1SIGMA+ excited electronic state of 6LiH and 7LiD isotopomers is presented. A pulsed optical-optical double resonance fluorescence depletion spectroscopic technique is used for this purpose.

There is considerable interest in synthetic ionophores with high affinity and selectivity for [Li.sup.+]. But so far, compounds that selectively bind [Li.sup.+] in the presence of other alkali and alkaline earth metal ions are rare and current approaches toward this goal are often accompanied with substantial synthetic efforts. Here we describe a trinuclear ruthenium metallamacrocyclic complex (1) that was obtained by self-assembly of ruthenium halfsandwich complexes and 3-hydroxy-2-pyridone ligands. This complex was shown to be an extremely potent receptor for LiCl with an affinity high enough to extract LiCl from water. The selectivity of this receptor is exceptional: even in the presence of a large excess of [Na.sup.+], [K.sup.+], [Ca.sup.+], [Ca.sup.2+], and [Mg.sup.2+], [Li.sup.+] was extracted exclusively. The [Li.sup.+]/[Na.sup.+] selectivity ratio was determined to be higher than 1,000:1. Compared with other synthetic ionophores, the receptor 1 offers two additional advantages: (i) the synthesis can be accomplished in one step by using simple starting materials; and (ii) the presence of lithium ions can be detected electrochemically. Complex 1 is therefore a very attractive candidate for the construction of a [Li.sup.+]-specific chemosensor.

The abundance and distribution of B and Li in metasedimentary rocks and in the Harney Peak Granite (HPG) in the Black Hills, South Dakota, U.S.A., elucidate the behavior of these two elements during (1) regional metamorphism that began at ~1760 Ma; (2) subsequent contact metamorphism associated with emplacement of the HPG and associated pegmatites at ~1715 Ma; and (3) anatexis leading to production of the granite. There is no clear evidence for changes in B and Li concentrations with progressive regional metamorphism of the metapelites from chlorite-biotite grade up to staurolite grade. Rocks outside the pegmatite aureole that surround the HPG have average B contents of ~80 ppm. There is no correlation of B with other elements in the pelitic schists, which indicates that none of the major phases is the dominant host for B. Boron content is mainly controlled by small amounts of randomly distributed tourmaline that was identified in alpha-track maps of thin sections. In the aureole of the granite, B concentrations are depleted in many samples. The depletion is attributed to consumption of tourmaline during interaction of the rocks with alkalic fluids. The average Li contents in metapelites far away from the HPG are also ~80 ppm. Near the HPG, Li concentrations reach roughly 190 ppm, indicating significant metasomatism by fluids that emanated from the granite and pegmatites. The concentrations of B and Li in the low-grade metapelites are sufficient to explain their abundances in the HPG, if the granite formed by partial melting of the metapelites and if there was total breakdown of tourmaline. Stabilization of tourmaline in leucogranites is not necessarily related to sources enriched in B, but may be related to its competition for Fe and Mg with biotite.

Research has been conducted on the N-substituted beta-enamino acid derivatives. The preparation of these derivatives via 2-alkyl-oxa(thia)zolines reaction with imidoylbenzotriazoles in the presence of LDA is described.

Research has been conducted on the methyl group deprotonation on silicon group. The methodology for this deprotonation based on the intramolecular pyridyl group coordination is discussed.

Research has been conducted on lithium. The isolation of the genes that improve cell growth though their overexpression under high LiCl concentrations in order to understand lithium therapy has been performed.

Research into the ionic conductivity of lithium hexafluorophosphate (LiPF6) and the behaviour of solvated Li+ ion species in organic solvents is presented. The high solubility of LiPF6 in propylene carbonate and the high viscosity of the solution are considered.

The reaction between lithium dicyclohexylamide and N,N-dibutylformamide and other disubstituted formamides generates dilithiated intermediate with a lithiated carbon atom bonded to N, O, and a carbonyl functionality as shown by (sup)13C nuclear magnetic resonance and gas chromatography analyses.

Issues concerning the solvation of the Li+ ion with tetrahydrofuran, acetone and diethyl ester in the gas phase are discussed. Fourier transform ion cyclotron resonance spectrometry measurements produce absolute solvent-binding energies that can be used as reference values.

A new study investigates the conduction properties of gel polymer electrolytes comprising lithium imide salts, LiN(CF3SO2)2, LiN(C2F5SO2)2 and PVFD-HFP copolymers.

Research has been conducted on the oxidative homocouplings of lithium enolates. A radical coupling mechanism that explains their stereoselectivity is discussed.

Research has been conducted on the reaction with lithium alkynylselenolate anions. Results indicate that at room temperature they give alpha-zirconated vinylselenolate intermediates.

Research has been conducted on the protected tetrazole ring that functions as an activating group for nucleophilic aromatic substitution reactions. The possibility of a protecting group strategy development for tetrazoles is discussed.

An investigation of the structural and energetic details of small binary B/Li clusters is presented. The structural diversity of these clusters is large and is different from those of Li/C clusters and diboranes.

Research has been conducted on the diastereoselective addition of organolithium to imines. The usage of a chiral alpha-naphthylethyl group as a chiral auxiliary is discussed.

Research has been conducted on lithium enolates of alpha-hydroxy ketones. The authors evaluate them for asymmetric aldol reactions in the presence of lithium chloride.

Different concentrations of lithium bis(trifluoromethylsulfonul)imide, nona(ethylene glycol) dimetacrylate and propylene carbonate have been studied by means of single- and double- quantum filtered spectra. Results indicate that the solvent acts as a competitive ligand.

Research has been conducted on the lithiation at the 2-position of the purine ring. The use of 6-chloro-9-(2,3-O-isopropylidene-5-O-trityl-beta-D-ribofuranosyl)-8-(triisopropylsilyl)purine during lithiation is discussed.

Research has been conducted on the alpha-alkoxylithium reagents. Experiments include reduction and in situ acetylation of 1,3-dioxanes-4-ones.

Research has been conducted on the mechanism of the Horner-Wadsworth-Emmons (HWE) reaction. Results indicate that HWE reaction of lithium enolate occurs with the addition of lithium enolate to aldehyde.

Electron beam evaporation of reduced TiO2 was used to obtain thin smooth anatase TiO2 films. When deposited on electron beam evaporated amorphous titanium, these films show a preferential (004) orientation. Several optical and electrochemical techniques were used to study electrochemical lithium insertion into these films. A coloration efficiency of 13 cm2 C-1, which was twice as high as that reported for TiO2 films grown by chemical vapor deposition, was found.

The intramolecular Diels-Alder reaction of iminium ions was studied in polar media such as 5.0 M lithium perchlorate-diethyl ether and water. Results showed that the polar solvent of choice for such intramolecular imino Diels-Alder reactions is water. The main problem with the use of 5.0 M lithium perchlorate in diethyl ether is that weak acids in highly polar media such as 5.0 M LiClO4*Et2O become strong acids and protonation of the tethered dienes with concomitant diene isomerization is competitive with cycloaddition.

A Co K-edge X-ray absorption spectroscopy near-edge structure study of chemically and electrochemically Li ion extracted LiyCo0.85Al0.15O2 compounds revealed that the extraction results to an increase in the average oxidation state of the Co ion and the local structural distortion around the Co atom. The Li ion insertion/extraction processes were found to be reversible for three cycles. A Co K-edge X-ray absorption spectroscopy fine structure examination revealed that chemical and electrochemical extractions resulted to a decrease of the interatomic distance for each bond pair.

Research was conducted to examine the glasses of lithium phosphate of the formula xLi2O-(1-x)P2O5 using molecular dynamics stimulation. The existence of two different oxygen coordinations corresponding to BO and NBO was demonstrated by the MD simulation of the glasses while the modifying effect of lithium oxide and the formation of various phosphate P(super n) units was ascertained. Results suggest that the Li+ ion migration and bond flips are not directly coupled.

Research was conducted to examine two protocols for introduction of electrophiles at the 4-position of 1-hydroxypyrazoles. One involves the deprotonation of 4-bromo-1-((tert-butyldiphenylsilyl)oxy)pyrazole with LDA to generate the 5-lithio derivative. The other involves the treatment of 4-bromo-1-hydroxypyrazole with excess LDA and trimethylsilyl chloride to produce 3,5-bis(trimethylsilyl)4-bromo-1-hydroxypyrazole. Results indicate that 4-lithio-1-lithoxypyrazoles can be generated by bromine-lithium exchange in the presence of silyl protecting groups at C-5 or at C-3 and C-5.

The electronic structure of lithium varies significantly from nearly free-electron behaviour at high pressure. It is predicted that lithium undergoes a symmetry-breaking distortion at high pressures, leading to a paired ground state. The distortion is introduced within face-centred cubic but has more extensive applicability. The initial distortion is linked with the Jahn-Teller mechanism, while further distortion leading to the pairing is determined by the delicate balance between exclusionary band-structure effects and exchange.

Highly accurate ab initio computations with specially designed basis sets were performed for Li4. The molecule became a particularly soft system, with a very anisotropic dipole polarizability and a very large second dipole hyperpolarizability. The computational aspects were examined with respect to the extension of quantum chemical studies to large lithium clusters. The values obtained for the mean dipole polarizability were systematically higher compared to previously reported experimental static value for this essential quantity.

A study on lithium salt systems investigated two factors which contribute to the establishment of a high ambient temperature conductivity in an ionic liquid. These factors are, namely, a high fluidity and a high conductivity/viscosity decoupling index. One aim of the study was to discover factors that determine the decoupling index on one hand and the glass transition temperature and fragility on the other hand for liquid salt mixtures which do not crystallize at ambient temperature.

A study on lithium halides in water was conducted to carry out a simple comparison of the extremes of the liquid state for two common lithium salt systems where concentrated solutions approaching the dihydrate could be investigated in both molten and supercooled states. The experimental results suggest the types of systems where higher boiling points might be obtained without undue increase on the glass transition temperature and, therefore, the viscosity.

A study was conducted to analyze the lithium ion pair acidities of the N,N-dialkylamides and the aggregation of the lithium enolates in THF. A Buchi melting point equipment was utilized to determine the melting points.The starting materials were purified by crystallization or distillation before use. Results indicated that the lithium ion pair acidities support pK's that range from 20 to 22 units.

A study was conducted to analyze the catalytic influence of lithium perchlorate in diethyl ether. Chemical and spectroscopic experiments were performed to carry out the analysis. Gas chromatography was performed using the hewlett-packard 5890 GC system. Nuclear magnetic resonance spectra were then determined on the Bruker AC 250 and 400 MHz spectrometers. Results indicated that lithium perchlorate functions as a weak Lewis acid in diethyl ether.

A laser-desorption mass-spectrometer microprobe has been developed to profile Li distributions on the crevice surfaces of Cr-plated rolled-joint hubs. A single laser pulse is used to desorb and ionize the surface species followed by detection of [Li.sup.+] in a time-of-flight mass spectrometer. Images of the surface Li distribution are obtained with a resolution of

The reduction of N-methoxycarbonyl-1H-azepine-2,7-dicarboxaldehyde (I) in tetrahydrofuran with 6Li or 7Li generated anion radicals that are closely associated with the lithium cations. The nonequivalency in all the protons in I-*,Li+ is attributed to the closer approach of the Li+ to one of the carbonyls and a twist of the ester carbonyl group toward the Li+. MO calculations showed that the nitrogen is puckered above the twisted plane of the ring in both the neutral molecule and the I-*,Li+.

Cluster model calculations at the Hartree-Fock/6-31G(d) level were carried out to study the local coordination environments of Li+ and Na+ ions in single- and mixed-alkali silicate glasses. Results indicated that the average coordination number of alkali cations increases from Li to Na and each alkali cation is located in individual sites in the single- and mixed-alkali clusters. There is also significant site mismatch during the hopping of the alkali cations.

Density functional methods were used to measure the dipole polarizability and the hardness of a series of lithium clusters doped with hydrogen. The mean polarizability was found to decrease when hydrogen atoms are increased in a given lithium cluster. The decrease is attributed to the metal-insulator transition. The resulting hardness variations proved that the hydrogen-saturated clusters are the most stable.

Research was conducted to examine the cycloaddition of cyclopentyne with spiro(2.4)hepta-4,6-diene. The objective was to prepare two additional precursors precursors whose decomposition to cyclopentyne could be done without the presence of lithium cations. Results provide strong evidence demonstrating the intervention of lithium-containing complexes when the cycloalkyne is produced through alkyllithium chemistry.

The dynamics of transfer of TMEDA-coordinated lithium between the two allyl faces was obtained independently through 13C nuclear magnetic resonance line shape investigations of diastereotopic geminal methylsilyl groups strategically integrated close to the chiral lithium in the organometallic species. With rising temperature, the 13C shift between these methyls was progressively averaged because of faster rates of lithium transfer.

The pulse-gradient spin-echo nuclear magnetic resonance measurement of the self-diffusion coefficients of the anion, lithium ion and solvent in lithium bis(trifluromethanesulfonyl)imide solvent systems was performed to study the 14 different organic solvents commonly used as electrolytes in lithium batteries. Results showed that the solvents can be classified into three groups. The first consists of cyclic carbonates and esters. The second consists of triglyme, diglyme and dimethoxyethane. The last includes a linear carbonate, cyclic ethers and diethoxyehtane.

Research was conducted to examine novel electrochemical techniques based on a filament-type and an array-type microelectrodes. The objective was to analyze in situ the conductance change of a carbon particle and its composite film during electrochemical lithium insertion/extraction reactions. Results provide evidence that microelectrode-based techniques are a unique and effective method in the study of battery active materials from both practical and fundamental standpoints.