Early postnatal exposure to lithium in vitro induces changes in AMPAR mEPSCs and vesicular recycling at hippocampal glutamatergic synapses

Lithium is an effective mood stabilizer but its use is associated with many side effects. Electrophysiological recordings of miniature excitatory postsynaptic currents (mEPSCs) mediated by glutamate receptor AMPA-subtype (AMPARs) in hippocampal pyramidal neurons revealed that CLi (therapeutic concentration of 1 mM lithium, from days in vitro 4-10) decreased the mean amplitude and mean rectification index (RI) of AMPAR mEPSCs. Lowered mean RI indicate that contribution of Ca2+-permeable AMPARs in synaptic events is higher in CLi neurons (supported by experiments sensitive to Ca2+-permeable AMPAR modulation). Co-inhibiting PKA, GSK-3 beta and glutamate reuptake was necessary to bring about changes in AMPAR mEPSCs similar to that seen in CLi neurons. FM1-43 experiments revealed that recycling pool size was affected in CLi cultures. Results from minimum loading, chlorpromazine treatment and hyperosmotic treatment experiments indicate that endocytosis in CLi is affected while not much difference is seen in modes of exocytosis. CLi cultures did not show the high KCl associated presynaptic potentiation observed in control cultures. This study, by calling attention to long-term lithium-exposure-induced synaptic changes, might have implications in understanding the side effects such as CNS complications occurring in perinatally exposed babies and cognitive dulling seen in patients on lithium treatment.

Lithium metal borate (LiMBO3) family of insertion materials for Li-ion batteries: a sneak peak

Rechargeable lithium-ion battery remains the leading electrochemical energy-storage device, albeit demanding steady effort of design and development of superior cathode materials. Polyanionic framework compounds are widely explored in search for such cathode contenders. Here, lithium metal borate (LiMBO3) forms a unique class of insertion materials having the lowest weight polyanion (i. e., BO33-), thus offering the highest possible theoretical capacity (ca. 220 mAh/g). Since the first report in 2001, LiMBO3 has rather slow progress in comparison to other polyanionic cathode systems based on PO4, SO4, and SiO4. The current review gives a sneak peak to the progress on LiMBO3 cathode systems in the last 15 years highlighting their salient features and impediments in cathode implementation. The synthesis and structural aspects of borate family are described along with the critical analysis of the electrochemical performance of borate family of insertion materials.

Energy-savvy solid-state and sonochemical synthesis of lithium sodium titanate as an anode active material for Li-ion batteries

Lithium sodium titanate insertion-type anode has been synthesized by classical solid-state (dry) and an alternate solution-assisted (wet) sonochemical synthesis routes. Successful synthesis of the target compound has been realized using simple Na- and Li-hydroxide salts along with titania. In contrast to the previous reports, these energy-savvy synthesis routes can yield the final product by calcination at 650 -750 degrees C for limited duration of 1-10 h. Owing to the restricted calcination duration (dry route for 1-2 h and wet route for 1-5 h), they yield homogeneous nanoscale lithium sodium titanate particles. Sono-chemical synthesis reduces the lithium sodium titanate particle size down to 80-100 nm vis-a-vis solid-state method delivering larger (200-500 nm) particles. Independent of the synthetic methods, the end products deliver reversible electrochemical performance with reversible capacity exceeding 80 mAh.g(-1) acting as a 1.3 V anode for Li-ion batteries. (C) 2015 Elsevier B.V. All rights reserved.

Role of Fuel on Cation Disorder in Magnesium Aluminate (MgAl2O4) Spinel Prepared by Combustion Synthesis

Magnesium aluminate spinel (MgAl2O4) forms an interesting system having tetrahedral and octahedral voids filled with near similar sized divalent Mg2+ and trivalent Al3+ cations. Structural disorder (e.g., Mg-Al antisite defects) can be tuned by synthetic conditions. This study reports the evolution of Mg/Al disorder in MgAl2O4 prepared by combustion synthesis using different types of fuels. The effect of nature of fuel and the final calcination temperature (600 degrees C-900 degrees C for 9h) on degree of cation ordering has been investigated combining powder X-ray (XRD) and neutron (NPD) diffraction. The results indicate very high degree of inversion in the samples crystallized at low annealing temperature, which on further annealing reduces toward the thermodynamically stable values. Raman spectroscopy, probing MgO4, and AlO4 tetrahedral bonds, confirmed the results at a local level.

Ultra-small sulphur nanoparticles configured inside a flexible organic mixed conducting network as a cathode for lithium-sulphur batteries

The major challenges in Li-S batteries are the formation of soluble polysulphides during the reversible conversion of S-8 <-> Li2S, large changes in sulphur particle volume during lithiation and extremely poor charge transport in sulphur. We demonstrate here a novel and simple strategy to overcome these challenges towards practical realization of a stable high performance Li-S battery. For the first time, a strategy is developed which does away with the necessity of pre-fabricated high surface area hollow-structured adsorbates and also multiple nontrivial synthesis steps related to sulphur loading inside such adsorbates. A lithiated polyethylene glycol (PEG) based surfactant tethered on ultra-small sulphur nanoparticles and wrapped up with polyaniline (PAni) (abbreviated as S-MIEC) is demonstrated here as an exceptional cathode for Li-S batteries. The PEG and PAni network around the sulphur nanoparticles serves as an efficient flexible trap for sulphur and polysulphides and also provides distinct pathways for electrons (through PAni) and ions (through PEG) during battery operation. Contrary to the cathodes demonstrated based on various carbon-sulphur composites, the mixed conducting S-MIEC showed an extremely high loading of 75%. The S-MIEC exhibited a stable capacity of nearly 900 mA h g(-1) at the end of 100 cycles at a 1C current rate.

Structural evolution and second harmonic properties of lithium niobate-tantalate nanocrystals embedded in a borate glass

Nano-crystals of LiNbxTa1 (-) O-x(3) were evolved by subjecting melt-quenched 1.5Li(2)O-2B(2)O(3)-xNb(2)O(5)-(1 - x)Ta2O5 glasses (where x = 0, 0.25, 0.5, 0.75 and 1.00) to a controlled 3-h isothermal heat treatment between 530 and 560 degrees C. Detailed X-ray diffraction and Raman spectral studies confirmed the formation of nano-crystalline LiNbxTa1 (-) O-x(3) along with a minor phase of ferroelectric and non-linear optic Li2B4O7. The sizes of the nanocrystals evolved in the glass were in the range of 19-37 nm for x = 0-0.75 and 23-45 nm for x = 1.00. Electron microscopic studies confirmed a transformation of the morphology of the nano-crystallites from dendritic star-shaped spherulites for x = 0 to rod-shaped structures for x = 1.00 brought about by a coalescence of crystallites. Broad Maker-fringe patterns (recorded at 532 nm) were obtained by subjecting the heat-treated glass plates to 1064 nm fundamental radiation. However, an effective second order non-linear optic coefficient, d(eff), of 0.45 pm/V, which is nearly 1.2 times the d(36) of KDP single crystal, was obtained for a 560 degrees C/3 h heat-treated glass of the representative composition x = 0.50 comprising 37 nm sized crystallites. (C) 2015 Elsevier B.V. All rights reserved.

Structural evolution and second harmonic properties of lithium niobate-tantalate nanocrystals embedded in a borate glass

Nano-crystals of LiNbxTa1 (-) O-x(3) were evolved by subjecting melt-quenched 1.5Li(2)O-2B(2)O(3)-xNb(2)O(5)-(1 - x)Ta2O5 glasses (where x = 0, 0.25, 0.5, 0.75 and 1.00) to a controlled 3-h isothermal heat treatment between 530 and 560 degrees C. Detailed X-ray diffraction and Raman spectral studies confirmed the formation of nano-crystalline LiNbxTa1 (-) O-x(3) along with a minor phase of ferroelectric and non-linear optic Li2B4O7. The sizes of the nanocrystals evolved in the glass were in the range of 19-37 nm for x = 0-0.75 and 23-45 nm for x = 1.00. Electron microscopic studies confirmed a transformation of the morphology of the nano-crystallites from dendritic star-shaped spherulites for x = 0 to rod-shaped structures for x = 1.00 brought about by a coalescence of crystallites. Broad Maker-fringe patterns (recorded at 532 nm) were obtained by subjecting the heat-treated glass plates to 1064 nm fundamental radiation. However, an effective second order non-linear optic coefficient, d(eff), of 0.45 pm/V, which is nearly 1.2 times the d(36) of KDP single crystal, was obtained for a 560 degrees C/3 h heat-treated glass of the representative composition x = 0.50 comprising 37 nm sized crystallites. (C) 2015 Elsevier B.V. All rights reserved.

In Situ NMR Insights into the Electrochemical Reaction of Cu3P Electrodes in Lithium Batteries

This study reports a multinuclei in situ (real-time) NMR spectroscopic characterization of the electrochemical reactions of a negative Cu3P electrode toward lithium. Taking advantage of the different nuclear spin characteristics, we have obtained real-time P-31 and Li-7 NMR data for a comprehensive understanding of the electrochemical mechanism during the discharge and charge processes of a lithium battery. The large NMR chemical shift span of P-31 facilitates the observation of the chemical evolutions of different lithiated and delithiated LixCu3-xP phases, whereas the quadrupolar line features in Li-7 enable identification of asymmetric Li sites. These combined NMR data offer an unambiguous identification of four distinct LixCu3-xP phases, Cu3P, Li0.2Cu2.8P, Li2CuP, and. Li3P, and the characterization of their involvement in the electrochemical reactions. The NMR data led us to propose a delithiation process involving the intercalation of metallic Cu-0 atomic aggregates into the Li2CuP structure to form a Cu-0-Li2-xCu1-xP phase. This process might be responsible for the poor capacity retention in Cu3P lithium batteries when cycled to a low voltage.

Amidinato- and triazenido-bridged binuclear complexes of palladium and platinum

The reaction of [M2Cl2(mu-Cl)(2)(PR3)(2)] (M=Pd or Pt; PR3=PEt3, PBu3, PMe2Ph, PMePh2) with lithium amidinate or sodium triazenide gave binuclear complexes containing amidinato- or triazenido-bridges, [M2Cl2(mu-ArNENAr)(2)(PR3)(2)] (E=CH, CMe or N). These complexes were characterized by elemental analysis and NMR (H-1, P-31 or Pt-195) data. The structures of two complexes, [(PdCl2)-Cl-2(mu-PhNC(Me)NPh)(2)(PMe2Ph)(2)] (10) and [Pt2Cl2(mu-PhNNNPh)(2)(PEt3)(2)] (11) were established by single crystal X-ray structural analyses. The Pt-195 NMR data Show coupling between two metal centers in the cis triazenido-bridged complex. The corresponding amidinate bridged complex does not show coupling. The role of the bridging ligand in mediating interaction between the metal centers is probed through Extended Huckel Theory (EHT) calculations. It is suggested that M-M interactions are primarily affected by the bridging ligands

Studies on the target conditioning for deposition of $LiCoO_{2}$ films

Deposition of good quality thin films of Lithium Cobalt Oxide (LiCoO2), by sputtering is preceded by target conditioning, which dictates the surface composition, morphology and electrochemical performance of the deposited film. Sputtering from a Virgin target surface, results in films with excess of the more reactive elements. The concentration of these reactive elements in the films decreases until the system reaches a steady state after sufficient sputtering from the target. This paper discusses the deposition kinetics in terms of target conditioning of LiCoO2. The composition, morphology and texturing of deposited film during various hours of sputtering were analyzed using X-ray photoelectron Spectroscopy (XPS) and Field Emission Scanning electron microscopy (FESEM). The compositional stability is not observed in the films formed during the initial hours or Sputtering from the fresh target, which becomes stable after several hours of sputtering. The Li and Co concentration in the Films deposited subsequently is found to be varying and possible causes are discussed. After the compositional stability is reached, electrochemical analysis of LiCoO2 thin films was performed, which shows a discharge capacity of 129 mu Ah/cm(2).

Gibbs Energy of Formation of Cobalt Divanadium Tetroxide

The Gibbs energy of formation of V2O3-saturated spinel CoV2O4 has been measured in the temperature range 900–1700 K using a solid state galvanic cell, which can be represented as Pt, Co + CoV2O4 + V2O3/(CaO) ZrO2/Co + CoO, Pt. The standard free energy of formation of cobalt vanadite from component oxides can be represented as CoO (rs) + V2O3 (cor) → CoV2O4 (sp), ΔG° = −30,125 − 5.06T (± 150) J mole−1. Cation mixing on crystallographically nonequivalent sites of the spinel is responsible for the decrease in free energy with increasing temperature. A correlation between “second law” entropies of formation of cubic 2–3 spinels from component oxides with rock salt and corundum structures and cation distribution is presented. Based on the information obtained in this study and trends in the stability of aluminate and chromite spinels, it can be deduced that copper vanadite is unstable.

Critical Cation Balance In B-]Z Transition - Role Of Li+

The sodium salt of poly(dG-dC) is known to exhibit a B + Z transition in the presence of various cations and 60% alcohol. We here show that the lithium salt of poly(dG-dC) does not undergo B 4 Z transition in the presence of 60% alcohol since Li’ with its large hydration shell cannot stabilize the Z-form. On the other hand, high concentrations of Mg2* or micromolar concentrations of the cobalt hexamine complex which are known to stabilize the Z-form can compete with Li+ for charge neutraIization and hence bring about a B--t Z transition in the same polymer. From the model building studies the mode of action of the cobalt-hexamine complex in stabilizing the Z-form is postulated.

Twin roller quenching technique and preparation of glasses of high melting ionic solids

A rapid quenching technique with a quenching rate of roughly 106°C/sec has been developed to prepare glassy samples of ABO3 type materials. Glasses of potassium lithium niobate have been prepared by this technique. These glasses have been characterized by x-ray diffraction, electron diffraction and differential scanning calorimetry techniques to assess the quality of the obtained glasses.

Studies on the reactions of thionyl fluoride

Thionyl fluoride undergoes quantitative oxidation with chloramine-T and reduction with lithium aluminium hydride and sodium borohydride. At elevated temperatures, (>150°C) it reacts with metals such as copper, silver, zinc and lead forming the corresponding metal sulphides, fluorides and sulphur dioxide. With the respective metal oxides, the metal fluorides and sulphur dioxide are formed.

7Li Spin-flip satellites in the EPR sectra of NH3+ -doped LiKSO4

EPR spectra of lithium potassium sulfate doped with NH3+ have been recorded at 9.05 GHz. A pair of satellites can be seen symmetrically situated on either side of the main lines. The separation of the satellite lines from the main line corresponds to the 7Li NMR frequency. The distance of the interacting 7Li nucleus from the unpaired electron in NH3+ is estimated to be 3.29 Å.