- An ESR and ENDOR study of irradiated 6Li-formate
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Lithium formate (6LiOOCH·H2O), 95% 6Li enrichment, combined with an exchange of crystallization water with D2O was investigated. The ESR spectrum of the radiation induced free radicals stable at room temperature
- Komaguchi,Matsubara,Shiotani,Gustafsson,Lund,Lund
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Read Online
- Thermal and spectroscopic study of dehydration of lithium formate monohydrate single-crystals
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Differential scanning calorimetry (DSC) and thermogravimetric analysis (TG) of lithium formate monohydrate (LiHCOO·H2O) were performed in the temperature range 300-700 K. The DSC/TG measurements show that the dehydration process to anhydrous li
- Mouaine,Becker,Carabatos-Nedelec
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Read Online
- A Stable Lithium–Oxygen Battery Electrolyte Based on Fully Methylated Cyclic Ether
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Ether-based electrolytes are commonly used in Li–O2 batteries (LOBs) because of their relatively high stability. But they are still prone to be attacked by superoxides or singlet oxygen via hydrogen abstract reactions, which leads to performance decaying during long-term operation. Herein we propose a methylated cyclic ether, 2,2,4,4,5,5-hexamethyl-1,3-dioxolane (HMD), as a stable electrolyte solvent for LOBs. Such a compound does not contain any hydrogen atoms on the alpha-carbon of the ether, and thus avoids hydrogen abstraction reactions. As the result, this solvent exhibits excellent stability with the presence of superoxide or singlet oxygen. In addition the CO2 evolution during charge process is prohibited. The LOB with HMD-based electrolyte was able to run up to 157 cycles, 4 times more than with 1,3-dioxolane (DOL) or 1,2-dimethoxyethane (DME) based electrolytes.
- Huang, Zhimei,Zeng, Haipeng,Xie, Meilan,Lin, Xing,Huang, Zhaoming,Shen, Yue,Huang, Yunhui
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supporting information
p. 2345 - 2349
(2019/02/01)
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- The carboxylic acid lithium salt of boron trifluoride complex -
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PROBLEM TO BE SOLVED: To provide a new electrolyte solution, a method for manufacturing the electrolyte solution, an electrolyte suitable for manufacturing the electrolyte solution, and a method for manufacturing the electrolyte, and to provide a gel electrolyte and a solid electrolyte using the electrolyte.SOLUTION: A method for manufacturing lithium carboxylate salt-boron trifluoride complex includes a step for mixing lithium carboxylate salt (A), boron trifluoride and/or boron trifluoride complex (B) and a solvent (C) and reacting the lithium carboxylate salt (A), the boron trifluoride and/or boron trifluoride complex (B); and a step for removing the solvent (C) and impurities originated from the boron trifluoride and/or boron trifluoride complex (B) from a reaction solution obtained after the reaction. The lithium carboxylate salt-boron trifluoride complex manufactured by the method, and an electrolyte solution, a gel electrolyte and a solid electrolyte obtained by using the complex are provided.
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Paragraph 0101
(2018/05/03)
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- The Effect of Water on Quinone Redox Mediators in Nonaqueous Li-O2 Batteries
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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.
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p. 1428 - 1437
(2018/02/09)
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- Coordination environments and π-conjugation in dense lithium coordination polymers
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The understanding of lithium-oxygen coordination systems is important for making better lithium conductors as well as active materials for lithium ion batteries. Here, we report a systematic investigation on coordination environments in lithium coordination polymers (LCPs) through the syntheses and analyses of six new crystals composed of lithium ions and anthraquinone (aq) derivative anions, where the negative charges are distributed in π-conjugation systems. Their structures were determined by single-crystal X-ray diffraction to be (1) [Li2(23dcaq)(H2O)] in space group P21/c, (2) [Li(23dcaqH)] in P21/c, (3) [Li2(15dhaq)(H2O)2] in P21/c, (4) [Li2(14dhaq)(H2O)2] in Pnma, (5) [Li(14dhaqH)(H2O)] in P212121 and (6) [Li(14hnaq)(H2O)] in P212121 (23dcaq2- = 2,3-dicarboxy-aq, 14dhaq2- = 1,4-dihydroxy-aq, 15dhaq2- = 1,5-dihydroxy-aq and 14hnaq- = 1-hydroxy-4-nitro-aq). Through the comprehensive structure analysis of these materials as well as other LCPs, we found that when considering the longest C-O bond in the π-conjugation system of an anionic organic molecule and its coordination to a Li ion, there is a weak inverse relationship between the C-O and Li-O bond lengths. In addition, despite exhibiting optical band edges below 2 eV and 1D π-stacking connectivity, conductivity measurements on single crystals of 1-6 confirmed that they are all electronic insulators. We rationalize this finding on the basis of π-orbital delocalization, which is more restricted in the aq-based LCPs compared to known semiconducting hybrid materials.
- Tominaka, Satoshi,Yeung, Hamish H.-M.,Henke, Sebastian,Cheetham, Anthony K.
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p. 398 - 406
(2016/01/16)
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- An aqueous rechargeable formate-based hydrogen battery driven by heterogeneous Pd catalysis
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The formate-based rechargeable hydrogen battery (RHB) promises high reversible capacity to meet the need for safe, reliable, and sustainable H2 storage used in fuel cell applications. Described herein is an additive-free RHB which is based on repetitive cycles operated between aqueous formate dehydrogenation (discharging) and bicarbonate hydrogenation (charging). Key to this truly efficient and durable H2 handling system is the use of highly strained Pd nanoparticles anchored on graphite oxide nanosheets as a robust and efficient solid catalyst, which can facilitate both the discharging and charging processes in a reversible and highly facile manner. Up to six repeated discharging/charging cycles can be performed without noticeable degradation in the storage capacity.
- Bi, Qing-Yuan,Lin, Jian-Dong,Liu, Yong-Mei,Du, Xian-Long,Wang, Jian-Qiang,He, He-Yong,Cao, Yong
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supporting information
p. 13583 - 13587
(2015/02/19)
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- Lithium-based metal organic frameworks
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An object of the present invention relates to a porous metal organic framework comprising at least one first organic compound and ions of at least one metal, with the skeleton of the framework being formed at least partly by the at least one first organic compound coordinating at least partly in a bidentate fashion to at least two ions of the at least one metal, where the at least one metal is lithium and the at least one first compound is derived from formic acid or acetic acid. Also provided a process for preparing the porous metal organic framework and its use for gas storage or separation.
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Page/Page column 5
(2014/09/17)
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- CO2-"Neutral" hydrogen storage based on bicarbonates and formates
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Let the circle be unbroken! One ruthenium catalyst generated in situ facilitates the selective hydrogenation of bicarbonates and carbonates, as well as CO2 and base, to give formates and also the selective dehydrogenation of formates back to bicarbonates. The two reactions can be coupled, leading to a reversible hydrogen-storage system. dppm=1,2- bis(diphenylphosphino)methane. Copyright
- Boddien, Albert,Gaertner, Felix,Federsel, Christopher,Sponholz, Peter,Mellmann, Doerthe,Jackstell, Ralf,Junge, Henrik,Beller, Matthias
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p. 6411 - 6414
(2011/08/05)
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- Reactions in the rechargeable lithium-O2 battery with alkyl carbonate electrolytes
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The nonaqueous rechargeable lithium-O2 battery containing an alkyl carbonate electrolyte discharges by formation of C3H 6(OCO2Li)2, Li2CO3, HCO2Li, CH3CO2Li, CO2, and H 2O at the cathode, due to electrolyte decomposition. Charging involves oxidation of C3H6(OCO2Li)2, Li2CO3, HCO2Li, CH3CO2Li accompanied by CO2 and H2O evolution. Mechanisms are proposed for the reactions on discharge and charge. The different pathways for discharge and charge are consistent with the widely observed voltage gap in Li-O2 cells. Oxidation of C3H6(OCO 2Li)2 involves terminal carbonate groups leaving behind the OC3H6O moiety that reacts to form a thick gel on the Li anode. Li2CO3, HCO2Li, CH3CO 2Li, and C3H6(OCO2Li)2 accumulate in the cathode on cycling correlating with capacity fading and cell failure. The latter is compounded by continuous consumption of the electrolyte on each discharge.
- Freunberger, Stefan A.,Chen, Yuhui,Peng, Zhangquan,Griffin, John M.,Hardwick, Laurence J.,Barde, Fanny,Novak, Petr,Bruce, Peter G.
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body text
p. 8040 - 8047
(2011/06/27)
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- Germanium(II) hydride mediated reduction of carbon dioxide to formic acid and methanol with ammonia borane as the hydrogen source
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LGeOC(O)H (3) (L = CH{(CMe)(2,6-iPr2C6H 3N)}2), from the straightforward conversion of LGeH (2) with CO2, reacts with LiH2NBH3 giving 2 and LiOC(O)H (4), while the corresponding reaction of 3 with H3NBH 3 after aqueous workup releases 2 and CH3OH (5). This opens the possibility to use hydride 2 as a mediator in the reduction of carbon dioxide to formic acid and methanol.
- Jana, Anukul,Tavcar, Gasper,Roesky, Herbert W.,John, Michael
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experimental part
p. 9487 - 9489
(2011/01/07)
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- Mn(III) containing ferrites in the system Li0.5Fe(2.5-x)Mn(x)O4
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The decomposition of freeze-dried Li-Mn(II)-Fe(III)-formate precursors at temperatures in the region of 600°C - 900°C in air yields complex oxides Li0.5Fe(2.5-x)Mn(x)O4 (0 x 1.5) with cubic spinel structure. These ferrites contain Mn(III) ions on octahedral sites of the spinel lattice. The cation distribution and the properties ofthe single phase Li-Mn-ferrites with x = 0.5, 1.0 and 1.5 were studied by X-ray powder diffraction, infrared spectroscopy, (57)Fe-Moessbauer sp ectroscopy and magnetization measurements. In contrast to the lithium ferrite (li0.5Fe2.5O4, x = 0), where the Li ions only occupy octahedral sites, the Li ions in the Li-Mn-ferrites are found on both octahedral and tetrahedral cationic positions of the spinel lattice.
- Bonsdorf, G.,Schaeffer, K.,Langbein, H.
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- The Polymorphism of Alkali Metal Formates, Part 3. A Raman Spectroscopic, X-Ray and Thermoanalytical Study of the Polymorphism of Lithium Formate
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The crystal structure of anhydrous lithium formate, published recently by Kansikas and Hermansson, is in fact that of a quenchable high-temperature modification (LiHCOO-I).The low-temperature modification LiHCOO-II can be obtained by thermal dehydration of the monohydrate, LiHCOO*H2O, or by drying it over P4O10.LiHCOO-II persists up to 228 deg C, at which temperature it transforms to LiHCOO-I, which in turn is stable up to its melting point at 272 deg C.LiCOO-I is also the modification which crystallizes when a melt of lithium formate is cooled down, in spite of the fact that solidification occurs only at 165 deg C, i.e. at a temperature well within the stability region of LiHCOO-II.The Raman spectra of the different forms of lithium formate are discussed in some detail.Single crystal of LiHCOO-II, obtained by slow evaporation of a saturated solution of anhydrous LiHCOO in absolute methanol, are hexagonal, space group P63, whith a = 14.915(2) Angstroem, c = 5.543(1) Angstroem and Z = 18.All lithium atoms are tetrahedrally coordinated by oxygen.The LiO4 tetrahedra are connected by corner-sharing and by bridging formate groups to form a complicated three dimensional network comprising tunnels running along .No indications for an at least partial occupation of these tunnels have been found.Keywords: Lithium Formate, Polymorphism, Raman Spectra, Crystal Structure
- Mueller, Kerstin,Heyns, Anton M.,Range, Klaus-Juergen,Zabel, Manfred
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p. 238 - 246
(2007/10/02)
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- Photolysis of Alkali Hexa(formato)ferrates(III) in Solution
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Photolysis of alkali hexa(formato)ferrates(III) in solution and solid phase has been investigated.The formation of iron(II) species has been detected by UV spectroscopy.Solid state photopysis does not show the formation of Fe(II) species.
- Brar, A. S.,Brar, S.,Sandhu, S.
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- Reversible formation of Pt2(μ-H)2H(PEt3)4+ and Pt2(μ-H)H2(PEt3)4+ from the cis and trans isomers of dihydrobis(triethylphosphine)platinum(II)
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Irradiation of Pt(C2O4)L2, where L = P(C2H5)3, in CH3CN solvent under a hydrogen atmosphere produces [Pt2(μ-H)2HL4][O2CH], 1[O2CH], and CO2. Dimer 1 can also be prepared by the condensation reaction between PtH2L2 (a 90:10 trans:cis equilibrium mixture) and PtH(S)L2+, where S = a solvent such as acetone. When PtD2L2 is used in the reaction, deuterium is only incorporated into the bridging positions. Analyses of the spin and isotopic distribution patterns in the 31P, 1H, and 195Pt NMR spectra establish a solution geometry for 1 based on a cis-PtH2L2 molecule bound to the PtHL2+ fragment. The solution chemistry of 1 depends dramatically on the counterion. Basic anions X = I-, OCH3-, and O2CH- generate small equilibrium concentrations of PtH2L2, PtHXL2, and [PtH(S)L2]X. For example, 1[O2CH] reacts completely in the presence of C2H4 to yield Pt(C2H4)L2 whereas 1[B(C6H5)4] exhibits no such reactivity. Complex 1 efficiently catalyzes the decomposition of formic acid at 25°C; however, formate ion must be added in excess to promote the reaction. Monomers appear to be the active catalysts. The species 1[OH] formed by the addition of H2O to PtH2L2 also catalyzes the hydration of acetonitrile to acetamide. A symmetrical isomer, Pt2(μ-H)H2L4+ (2), of dimer 1 can be generated by the UV photolysis of Pt(C2O4)L2 in methanol. It appears that the initially formed trans-PtH(OCH3)L2 complex undergoes β-hydride abstraction to stereoselectively yield trans-PtH2L2. This species is trapped by trans-PtH(OCH3)L2 or [trans-PtH(S)L2][CH3O] to form 2 before isomerization to cis-PtH2L2 (and thereby 1) takes place. Dimer 2 is thermodynamically unstable with respect to 1, and bases such as pyridine or I- catalyze the isomerization. The relationship between the structures, fluxionality, and reactivity properties of 1, 2, and related dinuclear hydrido complexes is discussed. Lack of facile exchange between bridging and terminal hydrides in 1 and 2 is attributed to the trans disposition of terminal hydrogen to the bridging hydrogens.
- Paonessa, Ralph S.,Trogler, William C.
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p. 1038 - 1048
(2008/10/08)
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