- Lithium-air and lithium-copper batteries based on a polymer stabilized interface between two immiscible electrolytic solutions (ITIES)
-
We propose and demonstrate the direct application of immiscible aqueous/organic interfaces in lithium-air and lithium-copper batteries. Therefore, the two half-reactions are separated in their respectively favourable electrolytic environments without using any other membranes. In order to prevent water and oxygen from interrupting the reaction in organic phases, we add poly(methyl methacrylate) (PMMA) to propylene carbonate (PC) and investigate its concentration effects using Pt ultramicroelectrodes (UMEs). Pt UMEs provide us the sensitive measure of water contamination as well as the diffusion property of oxygen in the polymer electrolytes. By studying the discharge profiles under various electrolytic conditions, we demonstrate that these batteries are of longer discharge time and higher specific capacity when the polymer electrolyte contains about 10 to 20% of PMMA.
- Wu, Borong,Chen, Xiaohui,Zhang, Cunzhong,Mu, Daobin,Wu, Feng
-
-
Read Online
- Mehrfachbindungen zwischen Hauptgruppenelementen und Uebergangsmetallen. LXII. Alkin-Komplexe der Organorheniumoxide: Redox-Chemie und Nucleophilie der Oxo-Funktion von (η5-Pentamethylcyclopentadienyl)(η2-diphenylethin)oxorhenium(III)
-
The novell ReIII oxo alkyne complexes (η5-C5Me5)Re(=O)(η2-RCCR) (3a-c; R=C6H5, CH3, C2H5) are obtained almost quantitatively by alkaline hydrolysis of the dichloro precursor compounds (η5-C5Me5)ReCl2(η2-RCCR) (4a-c).An X-ray diffraction study has revealed that in the phenyl derivative 3a the alkyne group is best described as a two-electron ligand. 17O NMR spectroscopy shows the remarkable electron deficiency of the terminal oxo group.This oxo function however is sufficiently nucleophilic to be converted into the hydroxo species 2-diphenylalkyne)hydroxo(η5-pentamethylcyclopentadienyl)rhenium(III) tetrafluoroborate (5a) and 2-butyne(2))hydroxo(η5-pentamethylcyclopentadienyl)rhenium(III)> tetrafluoroborate (5b) by O-protonation with HBF4.One-electron oxidation of 3a leads to the dinuclear ReIV species 5-C5Me5)Re(η2-C6H5CCC6H5))2>2+ without loss of the alkyne ligand.The ReV systems (η5-C5Me5)Re(=O)2(η5-RCCR) (2), generated oxidatively, are not stable as they decompose rapidly by eliminating the alkyne ligand.
- Herrmann, Wolfgang A.,Fischer, Roland A.,Amslinger, Wolfgang,Herdtweck, Eberhardt
-
-
Read Online
- Stability of lithium hydride in argon and air
-
The oxidation behaviors of LiH under a high purity argon atmosphere, an argon atmosphere with some O2 and H2O impurities, and ambient air at both room and high temperatures, are investigated using a variety of analytical instruments including X-ray diffractometry, thermogravimetry, mass spectrometry, scanning electron microscopy, and specific surface area analysis. The oxidation behaviors of the ball-milled LiH under different atmospheres are also studied and compared with those without ball milling. It is shown that no oxidation of LiH occurs under a high-purity argon atmosphere. However, oxidation of LiH takes place when the argon atmosphere contains some H2O and O2 impurities. At temperatures higher than ～55 °C, oxidation of LiH proceeds via the reaction of LiH + 1/4 O2 = 1/2 Li2O + 1/2 H2, whereas at room temperature oxidation of LiH is likely caused by the simultaneous reactions of LiH + H2O = LiOH + H2 and LiH + 1/2 O2 = LiOH. The oxidation behavior of LiH in ambient air with a 27% relative humidity can be well described by the Johnson-Mehl - Avrami equation. Furthermore, the ball-milled LiH oxidizes faster than the unmilled one, which is due to the finer particle size and larger surface area of the ball-milled powder.
- Ren, Ruiming,Ortiz, Angel L.,Markmaitree, Tippawan,Osborn, William,Shaw, Leon L.
-
-
Read Online
- The presence of water in the common CeCl3/RLi alkylation system
-
Dehydration of CeCl3(H2O)7 following standard procedures for making the commonly-used CeCl3/RLi reagent forms a material containing water and not anhydrous CeCl3. Heating CeCl3(H2O)7 at 150 °C and 0.03 Torr for 12 h forms a material which has an elemental composition of [CeCl3(H2O)](n), contains water by Karl Fischer analysis, reacts with MeLi to form methane, and crystallizes from THF as [Ce(μ-Cl)3(THF)(H2O)](n) in space group PI? with a = 6.691 (2) A?, b = 7.433(2) A?, c = 10.092(2) A?, α = 84.46(2)°, β = 76.72(2)°, γ = 74.76(3)°, V = 471.0(2) A?3, ρ(calcd) = 2.37 g/cm3, and Z = 2 at T = 158 K. [Ce(μ-Cl)3(THF)(H2O)](n) crystallizes in a layered structure in which eight-coordinate cerium atoms are ligated to terminal water and THF ligands and six bridging chlorides in a distorted square antiprismatic geometry. The THF ligands extend above and below the layers which contain the water molecules. Reactions of 'CeCl3/RLi' must take into account the presence of 1 equiv of water.
- Evans, William J.,Feldman, Jay D.,Ziller, Joseph W.
-
-
Read Online
- Thermal analysis of lithium peroxide prepared by various methods
-
Behavior of lithium peroxide samples at heating in air was studied by the methods of thermogravimetric analysis (TGA) and differential thermal analysis (DTA). In the temperature range from 32 to 82°C all the studied samples we found to react with water vapor forming lithium peroxide monohydrate as confirmed by the methods of chemical analysis and of qualitative X-ray phase analysis. It was found experimentally that in the temperature range from 340 to 348°C lithium peroxide began to decompose into lithium oxide and oxygen, the starting temperature depended on the method of preparation of lithium peroxide. For all the studied samples polymorphism in the temperature range from 25 to 340°C was not detected.
- Ferapontov,Kokoreva,Kozlova,Ul'Yanova
-
-
Read Online
- The standard molar enthalpies of formation of the lithium zirconates
-
The enthalpies of solution of Li2ZrO3, Li6Zr2O7, and Li8ZrO6 in HF*100H2O have been measured.The results have been used to derive the standard molar enthalpies of formation at 298.15 K: ΔfH0m(Li2ZrO3) = -(1742.8 +/- 1.2) k
- Wyers, G. P.,Cordfunke, E. H. P.,Ouweltjes, W.
-
-
Read Online
- Synthesis of the Metastable Cubic Phase of Li2OHCl by a Mechanochemical Method
-
The oxyhalide-based solid electrolyte Li2OHCl usually forms the thermodynamically stable orthorhombic phase at room temperature and shows poor lithium ionic conductivity. Above 35 °C, a structural phase transition into the cubic phase occurs and ionic conductivity is enhanced. In this work, mechanochemical synthesis of Li2OHCl is reported. The as-prepared Li2OHCl formed a cubic Pm3ˉ m structure and showed an ionic conductivity of 2.6 × 10-6 S cm-1 at 25 °C. Once the cubic phase was treated at 200 °C, the orthorhombic Pmc21 structure appeared at 25 °C and the ionic conductivity decreased down to 1.4 × 10-7 S cm-1. Formation of the metastable cubic phase could be explained in terms of low crystallinity of Li2OHCl derived from mechanochemical synthesis.
- Yamamoto, Takayuki,Shiba, Hinata,Mitsukuchi, Naohiro,Sugumar, Manoj Krishna,Motoyama, Munekazu,Iriyama, Yasutoshi
-
-
Read Online
- The Effect of Water on Quinone Redox Mediators in Nonaqueous Li-O2 Batteries
-
The parasitic reactions associated with reduced oxygen species and the difficulty in achieving the high theoretical capacity have been major issues plaguing development of practical nonaqueous Li-O2 batteries. We hereby address the above issues by exploring the synergistic effect of 2,5-di-tert-butyl-1,4-benzoquinone and H2O on the oxygen chemistry in a nonaqueous Li-O2 battery. Water stabilizes the quinone monoanion and dianion, shifting the reduction potentials of the quinone and monoanion to more positive values (vs Li/Li+). When water and the quinone are used together in a (largely) nonaqueous Li-O2 battery, the cell discharge operates via a two-electron oxygen reduction reaction to form Li2O2, with the battery discharge voltage, rate, and capacity all being considerably increased and fewer side reactions being detected. Li2O2 crystals can grow up to 30 μm, more than an order of magnitude larger than cases with the quinone alone or without any additives, suggesting that water is essential to promoting a solution dominated process with the quinone on discharging. The catalytic reduction of O2 by the quinone monoanion is predominantly responsible for the attractive features mentioned above. Water stabilizes the quinone monoanion via hydrogen-bond formation and by coordination of the Li+ ions, and it also helps increase the solvation, concentration, lifetime, and diffusion length of reduced oxygen species that dictate the discharge voltage, rate, and capacity of the battery. When a redox mediator is also used to aid the charging process, a high-power, high energy density, rechargeable Li-O2 battery is obtained.
- Liu, Tao,Frith, James T.,Kim, Gunwoo,Kerber, Rachel N.,Dubouis, Nicolas,Shao, Yuanlong,Liu, Zigeng,Magusin, Pieter C. M. M.,Casford, Michael T. L.,Garcia-Araez, Nuria,Grey, Clare P.
-
-
Read Online
- The effect of 3D carbon nanoadditives on lithium hydroxide monohydrate based composite materials for highly efficient low temperature thermochemical heat storage
-
Lithium hydroxide monohydrate based thermochemical heat storage materials were modified with in situ formed 3D-nickel-carbon nanotubes (Ni-CNTs). The nanoscale (5-15 nm) LiOH·H2O particles were well dispersed in the composite formed with Ni-CNTs. These composite materials exhibited improved heat storage capacity, thermal conductivity, and hydration rate owing to hydrogen bonding between H2O and hydrophilic groups on the surface of Ni-CNTs, as concluded from combined results of in situ DRIFT spectroscopy and heat storage performance test. The introduction of 3D-carbon nanomaterials leads to a considerable decrease in the activation energy for the thermochemical reaction process. This phenomenon is probably due to Ni-CNTs providing an efficient hydrophilic reaction interface and exhibiting a surface effect on the hydration reaction. Among the thermochemical materials, Ni-CNTs-LiOH·H2O-1 showed the lowest activation energy (23.3 kJ mol-1), the highest thermal conductivity (3.78 W m-1 K-1) and the highest heat storage density (3935 kJ kg-1), which is 5.9 times higher than that of pure lithium hydroxide after the same hydration time. The heat storage density and the thermal conductivity of Ni-CNTs-LiOH·H2O are much higher than 1D MWCNTs and 2D graphene oxide modified LiOH·H2O. The selection of 3D carbon nanoadditives that formed part of the chemical heat storage materials is a very efficient way to enhance comprehensive performance of heat storage activity components.
- Li, Shijie,Huang, Hongyu,Li, Jun,Kobayashi, Noriyuki,Osaka, Yugo,He, Zhaohong,Yuan, Haoran
-
-
Read Online
- Anti-Perovskite Li-Battery Cathode Materials
-
Through single-step solid-state reactions, a series of novel bichalcogenides with the general composition (Li2Fe)ChO (Ch = S, Se, Te) are successfully synthesized. (Li2Fe)ChO (Ch = S, Se) possess cubic anti-perovskite crystal structures, where Fe and Li are completely disordered on a common crystallographic site (3c). According to Goldschmidt calculations, Li+ and Fe2+ are too small for their common atomic position and exhibit large thermal displacements in the crystal structure models, implying high cation mobility. Both compounds (Li2Fe)ChO (Ch = S, Se) were tested as cathode materials against graphite anodes (single cells); They perform outstandingly at very high charge rates (270 mA g-1, 80 cycles) and, at a charge rate of 30 mA g-1, exhibit charge capacities of about 120 mA h g-1. Compared to highly optimized Li1-xCoO2 cathode materials, these novel anti-perovskites are easily produced at cost reductions by up to 95% and, yet, possess a relative specific charge capacity of 75%. Moreover, these iron-based anti-perovskites are comparatively friendly to the environment and (Li2Fe)ChO (Ch = S, Se) melt congruently; the latter is advantageous for manufacturing pure materials in large amounts.
- Lai, Kwing To,Antonyshyn, Iryna,Prots, Yurii,Valldor, Martin
-
-
Read Online
- Determination of the role of Li2O on the corrosion of lithium hydride
-
Lithium hydride (LiH) will efficiently react with moisture, forming lithium hydroxide (LiOH) on the surface. Typically, diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy is used for studying the surface corrosion reaction. The presence of a surface lithium oxide (Li2O) layer will enhance hydroxide formation kinetics; however, interference in the DRIFT spectrum prevents the role of Li2O on the reaction kinetics from being fully understood. In the current study, Raman spectroscopy has been used to follow the reaction of LiH with moisture, with particular focus on the Li2O vibrational signature. Three vibrations were observed for Li2O after thermal decomposition of LiOH on the LiH surface in contrast to the single vibration at 515 cm-1 for pure Li2O powder. The multiple peaks are indicative on multiple Li2O chemical domains and are likely the substrate through which unstable LiOH domains are formed during subsequent hydrolysis of the LiH/Li2O system.
- Sifuentes, Adalis,Stowe, Ashley C.,Smyrl, Norm
-
-
Read Online
- Ionic structure in the aqueous electrolyte glass LiCl · 4D2O
-
The difference methods of neutron diffraction and isotopic substitution were applied to Li+ and Cl- in the aqueous lithium chloride glass LiCl · 4D2O at 120 K (the glass transition Tg = 150 K). Results for the ionic hydration show that structural changes are more evident for the Cl- coordination than for the Li+ coordination. At the level of the anion-anion structure there is an appreciable increase in the nearest-neighbour coordination number over that in the liquid which suggests a greater degree of correlation between the Cl- anion and the water molecules. A model of the ionic structure is proposed to explain the relative ease of glassification of concentrated aqueous lithium chloride solutions.
- Ansell,Dupuy-Philon,Jal,Neilson
-
-
Read Online
- Hydrogen production via thermochemical water-splitting by lithium redox reaction
-
Hydrogen production via thermochemical water-splitting by lithium redox reactions was investigated as energy conversion technique. The reaction system consists of three reactions, which are hydrogen generation by the reaction of lithium and lithium hydrox
- Nakamura, Naoya,Miyaoka, Hiroki,Ichikawa, Takayuki,Kojima, Yoshitsugu
-
-
Read Online
- Extended Chemical Flexibility of Cubic Anti-Perovskite Lithium Battery Cathode Materials
-
Novel bichalcogenides with the general composition (Li2TM)ChO (TM = Mn, Co; Ch = S, Se) were synthesized by single-step solid-state reactions. These compounds possess cubic anti-perovskite crystal structure with Pm3m symmetry; TM and Li are disordered on the crystallographic site 3c. According to Goldschmidt tolerance factor calculations, the available space at the 3c site is too large for Li+ and TM2+ ions. As cathode materials, all title compounds perform less prominent in lithium-ion battery setups in comparison to the already known TM = Fe homologue; e.g., (Li2Co)SO has a charge density of about 70 mAh g-1 at a low charge rate. Nevertheless, the title compounds extend the chemical flexibility of the anti-perovskites, revealing their outstanding chemical optimization potential as lithium battery cathode material.
- Lai, Kwing To,Antonyshyn, Iryna,Prots, Yurii,Valldor, Martin
-
supporting information
p. 13296 - 13299
(2018/10/31)
-
- Standard enthalpies of formation of Li, Na, K, and Cs thiolates
-
The standard enthalpies of formation of alkaline metals thiolates in the crystalline state were determined by reaction-solution calorimetry. The obtained results at 298.15 K were as follows: δfH°m(MSR, cr)/kJ mol-1 = -259.0 ± 1.6 (LiSC2H5), -199.9 ± 1.8 (NaSC2H5), -254.9 ± 2.4 (NaSC4H9), -240.6 ± 1.9 (KSC2H 5), -235.8 ± 2.0 (CsSC2H5). These results where compared with the literature values for the corresponding alkoxides and together with values for δfH° m(MSR, cr) were used to derive a consistent set of lattice energies for MSR compounds based on the Kapustinskii equation. This allows the estimation of the enthalpy of formation for some non-measured thiolates.
- Leal, Joao P.
-
experimental part
p. 441 - 446
(2010/08/04)
-
- Isotope effects in the kinetics of simultaneous H and D thermal desorption from Pd
-
The kinetics of simultaneous hydrogen and deuterium thermal desorption from PdHxDy has been investigated. A novel experimental approach for the study of the transition state (TS) characteristics of the surface recombination reaction is proposed based on the analysis of the H and D partitioning into H2, HD and D2 molecules. It has been found that the hydrogen molecular isotopes distribution is determined by the energy differences of the corresponding TS of the atom-atom recombination reactions. On the other hand, the mechanisms and activation energies of the desorption process have been obtained. At 420 K, the desorption reaction changes from a surface recombination limiting mechanism during desorption from β-PdHxDy to a reaction limited by the rate of β to α phase transformation during the two phase coexistence. Surface recombination reaction becomes again rate limiting above 480 K, due to a change in the catalytic properties of the Pd surface. TS energies obtained from the kinetic analysis of the thermal desorption spectra are in good accordance with those obtained from the analysis of the H2, HD and D2 distributions. Anomalous TS energies have been observed for the H-D recombination reaction, which may be related to the heteronuclear character of this molecule.
- Leardini,Fernández,Bodega,Sánchez
-
p. 116 - 127
(2008/10/09)
-
- Monomeric alkoxo and amido methylnickel(II) complexes. Synthesis and heterocumulene insertion chemistry
-
Fluoride displacement from the complex Ni(Me)(F)(dippe) by LiOR or LiNRR′ provides an efficient method for the synthesis of the corresponding mononuclear Ni(II) alkoxo or amido complexes. These complexes undergo addition reactions to heterocumulenes (CO2, PhNCO, PhNCS), leading to the formal insertion of these molecules into the Ni-O or Ni-N bonds. The dialkylamido complexes decompose through β-hydrogen elimination processes, which selectively afford η2-imine Ni(O) compounds.
- Campora, Juan,Matase, Inmaculada,Palma, Pilar,Alvarez, Eleuterio,Graiff, Claudia,Tiripicchio, Antonio
-
p. 3840 - 3849
(2008/10/09)
-
- Nanoporous crystalline material CsLiB6O10
-
CsLiB6O10 crystals up to 60 × 40 × 20 mm in dimensions were prepared by top-seeded solution growth, and their interaction with water was studied. The crystals were found to be subject to hydration followed by hydrolysis, during which
- Kononova,Kokh,Fedorov,Ferapontova,Zakalyukin,Tkachenko
-
p. 1264 - 1269
(2008/10/08)
-
- Thermal Decomposition of the Perchlorate Ion in LiClO4-LiOH Melts
-
Decomposition of perchlorate ion ClO4 in LiClO4 : LiOH = 1 : 0.5, 1 : 1, 1 : 2, and 1 : 3 melts is studied. According to DTA data, the onset temperature of rapid decomposition of LiClO4 decreases by 30, 50, 80, and 100°C, respectively, when in these melts. In the range 350 to 400°C, the thermal process consists of two consequent reactions: LiClO4 → LiClO3 → LiCl. The decomposition of LiClO4 in the 1 : 3 melt is described by a first-order rate equation virtually in the whole range of extents of reaction with the Arrhenius parameters Ea = 53.9 kcal/mol and A = 1.1 × 1016 min-1. For the LiOH · LiClO4 melt, the first-order law is valid to α ～ 0.5 with the same activation energy, but a slightly smaller frequency factor. The maximum concentration of the intermediate compound LiClO3 varies from 0.23 in the 1 : 0.5 melt to 0.48 in the 1 : 2 melt and then remains unchanged as the hydroxide concentration increases. The position and height of the maxima suggest that LiClO3 decomposes approximately 1.5 times faster than LiClO4 in the 1 : 0.5 melt. In the 1 : 1 melt, the decomposition rates of the compounds are approximately equal. In the 1 : 2 and 1: 3 melts, the chlorate decomposes 1.5 to 2 times more slowly than the perchlorate. For the first time, an inhibitor of the alkali-metal chlorate decomposition has been found: pure LiClO3 decomposes faster than in hydroxide melts.
- Nikitina,Nikitina,Rosolovskii
-
p. 1157 - 1161
(2008/10/08)
-
- Alkalimetal Trialkylhydroxyborates and (Alkalimetaloxy)dialkylboranes
-
Et3B (1) and 9-Et-9-BBN (2) react with alkalimetal hydroxides (LiOH, NaOH, KOH) to yield the alkalimetal hydroxytriorganoborates M-3 and M-4, resp.Heating (about 100 deg C) of the borates, catalyzed by NaHBEt3, leads to elimination of ethane with formation of the boranes MOBEt2 (M-5, M = Na, K) or MOBC8H14 (M-7, M = Li, Na, K), which associate to compounds with BOB, BOM, or MOM bridge bonds.At temperatures higher than 160 deg C (without catalyst), M-3 (M = Li, Na) and Li-4 dissociate.Na-4 is dehydroborated with formation of H2 and NaOB(Et)C8H13 (Na-9).From K-7 and ClSiMe3 9-Me3SiO-9-BBN (10) is obtained.Na-9 reacts with ClSiMe3 to give a mixture of the unsaturated mixed borane 11 and the mixed diboroxane 12.The degree of the association of the alkalimetal compounds were determined by the specific electric conductivity measurements (κ) and by 17O-NMR spectroscopy.Key Words: Borates, trialkyl-, hydroxy- / Alkalimetal hydroxides / BC protolysis, BH-borate catalysis / Boranes, (alkalimethaloxy)dialkyl- / Dimers with BOB bonds, MOM bonds / 1,3,2-Diboroxanes, organosubstituted
- Koester, Roland,Seidel, Guenter,Wrackmeyer, Bernd
-
p. 617 - 626
(2007/10/02)
-
- Structural modifications induced by proton exchange in γ-LiFeO2
-
The tetragonal crystalline modification of LiFeO2 was subjected to partial proton exchange reactions by hydrothermal treatment at 160°C in distilled water. The product after 1-day treatment had a Li/Fe ratio of ca. 0.15. A partial displacement
- Barriga, C.,Morales, J.,Tirado, J. L.
-
p. 997 - 1002
(2008/10/08)
-
- Organometallic compounds of the lanthanides. 42. Bis(dimethoxyethane)lithium bis(cyclopentadienyl)bis(trimethylsilyl)lanthanide complexes
-
The trichlorides of Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu react with NaC5H5 in tetrahydrofuran in the presence of dimethoxyethane (dme) with formation of bis(cyclopentadienyl)lanthanide chloride complexes of the types (C5H5)2Ln(μ-Cl)2Na(dme). The reactions of these organolanthanide halide complexes with (trimethylsilyl)lithium in dme yield compounds of the type [Li(dme)2][(C6H5)2Ln(SiMe 3)2] (Ln = Sm, Dy, Ho, Er, Tm, Lu). (C5H5)2Sm(μ-Cl)2Na(dme) reacts with (trimethylgermyl)lithium in dme/pentane with formation of [Li(dme)3][(C5H5)3SmClSin(C 5H5)3] (7a). The new compounds have been characterized by elemental analyses and IR and NMR spectra. The structure of [Li(dme)3][(C5H5)3SmClSm(C 5H5)3] (7a) has been elucidated through complete X-ray analysis. The crystals are monoclinic with a = 14.00 (1) A?, b = 13.38 (2) A?, c = 23.49 (3) A?, β = 93.37 (9)°, space group P21/n, Z = 4, and R = 0.0411 for 4671 reflections. The [Cp3SmClSmCp3]- anion consists of two Cp3Sm unite bridged by a chlorine atom with Sm-Cl distances of 2.827 (2) and 2.798 (2) A?.
- Schumann, Herbert,Nickel, Siegbert,Loebel, J?rg,Pickardt, Joachim
-
p. 2004 - 2009
(2008/10/08)
-
- LITHIUM ION CONDUCTION IN SUBSTITUTED Li//5MO//4, M equals Al, Fe.
-
The ionic conductivity of substituted Li//5AlO//4 and Li//5FeO//4 phases was measured by a complex impedance method. The high-temperature beta phase was obtained in quenched Li//5AlO//4 but not in Li//5FeO//4. The Zn-substituted quenched samples form beta
- Esaka, T.,Greenblatt, M.
-
p. 164 - 171
(2008/10/08)
-
