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554-13-2Relevant articles and documents
Changes of nitrides characteristics in Li-N system synthesized at different pressures
Ignatenko, Oleg V.,Komar, Valery A.,Leonchik, Sergey V.,Shempel, Natalia A.,Ene, Antoaneta,Cantaragiu, Alina,Frontasyeva, Marina V.,Shvetsov, Valery N.
, p. 23 - 27 (2013)
For the Li-N system samples were obtained at pressures of nitrogen from 1 to 10 atm. Energy-dispersive X-ray (EDX) spectrum of a sample of Li-N subjected to degradation shows that lithium nitride turned into carbonate as evidenced by the predominant content of carbon and oxygen. Upon synthesis of lithium nitride at a positive pressure of nitrogen, the b-modification is formed, which can be achieved at a pressure 500 times lower than that described in literature, required to create a high-pressure phase. The increase in carbon content with increasing of synthesis pressure of lithium nitride confirms the change in stoichiometry of its structure formed with high nitrogen content.
A study of binary iron/lithium organometallic complexes as single source precursors to solid state cathode materials for potential Li ion battery application
Khanderi, Jayaprakash,Schneider, J?rg J.
, p. 254 - 259 (2011)
Solid state and solution phase decomposition of organometallic half sandwich and sandwich complexes of type [CpFeCODLi × DME] 1, [CpFeCODLi × TMEDA] 2 and [(Cp)2FeLi2 × 2 TMEDA] 3 (Cp = cyclopentadienyl, COD = 1,5-cyclooctadiene, DME = dimethoxyethane, TMEDA = tetramethylethylenediamine) derived from ferrocene, yield different kinds of lithium ferrites under oxidative and inert conditions. Thermogravimetry (TG) and TG coupled mass spectrometry of these compounds indicate that the decomposition begins above 170 °C for 1, 185 °C for 2 and 190 °C for 3 with removal of all the organic ligands. In the absence of oxygen, compounds 1, 2 and 3 decompose to a mixture of Fe, Fe3C and Li2O/Li 2CO3 at temperatures above 200 °C. Amorphous α-LiFeO2 is formed in the temperature range of 200-400 °C in the presence of oxygen. Crystalline α-LiFeO2 is formed only above 400 °C using 1. Elemental analysis of the LiFeO2 obtained from 1 indicates a drastic decrease in the carbon and hydrogen content with the increase in the oxidation temperature. XRD reveals the presence of Li 2CO3 as second phase formed for precursors 1, 2, and 3 under oxidative conditions. Solution phase decomposition of 2 and 3 in the absence of oxygen followed by annealing at 600 °C yields Li 2Fe3O5, Li5FeO4 and Fe3C depending on the solvent to precursor ratio in contrast to the α-LiFeO2 phase formed under pure solid state decomposition conditions. However, all lithium ferrites (Li2Fe3O 5, Li5FeO4) are converted to α-LiFeO 2 when oxidized above 500 °C. The α-LiFeO2 products were further characterized by IR, XPS, and TEM. Electrochemical analysis of the α-LiFeO2 was performed, showing a moderate initial capacity of 13 mAh/g.
Rodriguez, J. M. Fernandez,Morales, J.,Navas, J.,Tirado, J. L.
, p. 203 - 208 (1988)
Lithium silicate nanosheets with excellent capture capacity and kinetics with unprecedented stability for high-temperature CO2capture
Belgamwar, Rajesh,Maity, Ayan,Das, Tisita,Chakraborty, Sudip,Vinod, Chathakudath P.,Polshettiwar, Vivek
, p. 4825 - 4835 (2021)
An excessive amount of CO2is the leading cause of climate change, and hence, its reduction in the Earth's atmosphere is critical to stop further degradation of the environment. Although a large body of work has been carried out for post-combustion low-temperature CO2capture, there are very few high temperature pre-combustion CO2capture processes. Lithium silicate (Li4SiO4), one of the best known high-temperature CO2capture sorbents, has two main challenges, moderate capture kinetics and poor sorbent stability. In this work, we have designed and synthesized lithium silicate nanosheets (LSNs), which showed high CO2capture capacity (35.3 wt% CO2capture using 60% CO2feed gas, close to the theoretical value) with ultra-fast kinetics and enhanced stability at 650 °C. Due to the nanosheet morphology of the LSNs, they provided a good external surface for CO2adsorption at every Li-site, yielding excellent CO2capture capacity. The nanosheet morphology of the LSNs allowed efficient CO2diffusion to ensure reaction with the entire sheet as well as providing extremely fast CO2capture kinetics (0.22 g g?1min?1). Conventional lithium silicates are known to rapidly lose their capture capacity and kinetics within the first few cycles due to thick carbonate shell formation and also due to the sintering of sorbent particles; however, the LSNs were stable for at least 200 cycles without any loss in their capture capacity or kinetics. The LSNs neither formed a carbonate shell nor underwent sintering, allowing efficient adsorption-desorption cycling. We also proposed a new mechanism, a mixed-phase model, to explain the unique CO2capture behavior of the LSNs, using detailed (i) kinetics experiments for both adsorption and desorption steps, (ii)in situdiffuse reflectance infrared Fourier transform (DRIFT) spectroscopy measurements, (iii) depth-profiling X-ray photoelectron spectroscopy (XPS) of the sorbent after CO2capture and (iv) theoretical investigation through systematic electronic structure calculations within the framework of density functional theory (DFT) formalism.
Electrochemical Decomposition of Li4SiO4 and Li2TiO3 in Solid-state Thermal Cells
Aceves, Juan M.,West, Anthony R.
, p. 2599 - 2608 (1982)
Cells of the type Au/Li4SiO4/Au and Au/Li2TiO3/Au behave as secondary cells at high temperatures, >/=400 deg C.The cell reactants are created in situ by charging the cells in air at e.g. 1.5 V.Electrochemical decomposition of the solid electrolytes occurs giving, as solid products, Li2CO3 at the negative electrode and Li2SiO3 and TiO2, respectively, at the positive electrode.Under different charging conditions other products may be obtained with the Li2TiO3-containing cell.The products of charging form as a layer on the surfaces of the pellet and the gold electrodes appear to take no part in the reactions.The charged cells have open-circuit voltages in the range 0.4 - 0.5 V at ca. 500 deg C and give discharge currents of e.g. 10 - 100 μA through a 10E4 Ω load resistance for several days.
Thermally driven interfacial degradation between Li7La3Zr2O12 electrolyte and LiNi0.6Mn0.2Co0.2O2 cathode
Kim, Younggyu,Kim, Dongha,Bliem, Roland,Vardar, Gülin,Waluyo, Iradwikanari,Hunt, Adrian,Wright, Joshua T.,Katsoudas, John P.,Yildiz, Bilge
, p. 9531 - 9541 (2020)
Solid-state batteries offer higher energy density and enhanced safety compared to the present lithium-ion batteries using liquid electrolytes. A challenge to implement them is the high resistances, especially at the solid electrolyte interface with the cathode. Sintering at elevated temperature is needed in order to get good contact between the ceramic solid electrolyte and oxide cathodes and thus to reduce contact resistances. Many solid electrolyte and cathode materials react to form secondary phases. It is necessary to find out which phases arise as a result of interface sintering and evaluate their effect on electrochemical properties. In this work, we assessed the interfacial reactions between LiNi0.6Mn0.2Co0.2O2 (NMC622) and Li7La3Zr2O12 (LLZO) as a function of temperature in air. We prepared model systems by depositing thin-film NMC622 cathode layers on LLZO pellets. The thin-film cathode approach enabled us to use interface-sensitive techniques such as X-ray absorption spectroscopy in the near-edge as well as the extended regimes and identify the onset of detrimental reactions. We found that the Ni and Co chemical environments change already at moderate temperatures, on-setting from 500 °C and becoming especially prominent at 700 °C. By analyzing spectroscopy results along with X-ray diffraction, we identified Li2CO3, La2Zr2O7, and La(Ni,Co)O3 as the secondary phases that formed at 700 °C. The interfacial resistance for Li transfer, measured by electrochemical impedance spectroscopy, increases significantly upon the onset and evolution of the detected interface chemistry. Our findings suggest that limiting the bonding temperature and avoiding CO2 in the sintering environment can help to remedy the interfacial degradation.
Time-Resolved Synchrotron Powder X-ray Diffraction Studies on the Synthesis of Li8SiO6 and Its Reaction with CO2
Cova, Federico,Amica, Guillermina,Kohop??, Katja,Blanco, Maria Valeria
, p. 1040 - 1047 (2019)
Lithium oxosilicate was synthesized via the solid-state method using Li2O and SiO2 as starting reactants. In situ synchrotron powder X-ray diffraction (SPRXD) coupled with Rietveld refinement allowed describing the synthesis as a two-step process where Li2O and SiO2 react to form Li4SiO4 and, at higher temperatures, lithium orthosilicate reacts with the remaining Li2O to form Li8SiO6. Time-resolved measurements allowed determining the temperatures at which each phase transformation occurs as well as the time required to complete the synthesis. The CO2 capture properties of Li8SiO6 in the temperature range from room temperature to 770 °C were studied in detail by time-resolved in situ SPXRD. The crystallographic phases present during Li8SiO6 carbonation were identified and quantified via Rietveld analysis. Results showed that, within the temperature range from 200 to 690 °C, Li8SiO6 carbonation produces Li4SiO4 and Li2CO3, while, at temperatures from 690 to 750 °C, a secondary reaction occurs, where previously formed Li4SiO4 reacts with CO2, producing Li2SiO3 and Li2CO3. These findings allowed proposing a mechanism of reaction for Li8SiO6 carbonation in the temperature range that is of interest for high temperature solid-state sorbents.
Dependence of electrochemical properties of spinel LiMn2O4 on Li2CO3 with micro-flaky, micro-flower and nanorod morphologies
Li, Lang,Sui, Jinsong,Huang, Rui,Xiang, Wei,Qin, Wei
, p. 42289 - 42295 (2017)
Herein, the dependence of spinel LiMn2O4 on Li2CO3 with micro-flaky, micro-flower and nanorod morphologies is investigated. The results show that the as-synthesized LiMn2O4 with micron sized Li2CO3 as raw materials have a much higher discharge capacity than that of the one prepared with nano sized Li2CO3. It delivers an initial charge capacity of 110.1, 105.2 and 104.9 mA h g-1 followed by a discharge capacity of 109.1, 103.9 and 104.2 mA h g-1 with the micro-flower, nanorod and micro-flaky Li2CO3 morphologies, respectively, at room temperature (about 99% of the charge capacity is discharged). The smaller specific surface area is found in the spinel LiMn2O4 with micron sized Li2CO3, resulting in a better stable electrochemical performance in LiMn2O4 with micro-flower and micro-flaky Li2CO3. Their capacities are maintained at 99.2 mA h g-1 and 94.2 mA h g-1 after 100 cycles at 1C rate. The capacity retention was more than 90% at the 100th cycle with the micron-sized Li2CO3. Moreover, the as-synthesized spinel LiMn2O4 with micro-flower Li2CO3 retained more than 95% of its initial discharge capacity (92 mA h g-1) after 200 cycles at 2C rate. The cubic spinel structure was detected after 200 cycles of LiMn2O4 at 2C rate.
Selective production of acetone in the electrochemical reduction of CO2 catalyzed by a Ru-naphthyridine complex
Mizukawa, Tetsunori,Tsuge, Kiyoshi,Nakajima, Hiroshi,Tanaka, Koji
, p. 362 - 363 (1999)
The controlled potential electrolysis of [Ru(bpy)(napy)2(CO)2](BF4)2 (1; bpy = 2,2'-bipyridine, napy = 1,8-naphthyridine) in the presence of LiBF4 in CO2-saturated DMSO at -1.65 V (vs. Ag/Ag+) produced CO and Li2CO3 [Eq. (a)], while similar electrolysis in the presence of (CH3)4NBF4 resulted in formation of acetone together with (CH3)3N and {(CH3)4N}2CO3 [Eq. (b)]. This represents the first almost selective generation of acetone upon electrochemical reduction of CO2. The selectivity is ascribed to depression of reductive cleavage of the Ru-CO bond of 1 due to an attack of the nonbonded nitrogen atom of napy at the carbonyl carbon atom.
Reaction mechanisms of Li0.30La0.57TiO3 powder with ambient air: H+/Li+ exchange with water and Li2CO3 formation
Boulant, Anthony,Bardeau, Jean Francois,Jouanneaux, Alain,Emery, Joel,Buzare, Jean-Yves,Bohnke, Odile
, p. 3968 - 3975 (2010)
The proton/lithium exchange property of the lithium lanthanum titanate Li0.30La0.57TiO3 (named LLTO) is shown to occur at room temperature under ambient air. The 1H and 7Li MAS NMR, TGA analysis and IR spectroscopy techniques are used to probe reaction mechanisms. XRPD analysis gives evidence of the topotactic character of this exchange reaction. As for exchange in aqueous solution, it is shown that Li 0.30La0.57TiO3 is able to dissociate water on the grain surface and then to exchange H+ for Li+ into the perovskite structure. Lithium hydroxide is then formed on the grain surface and afterwards reacts with CO2 contained in air to form Li 2CO3. It is shown that this mechanism is reversible. When the aged sample (aging in air for 5 months at room temperature) is annealed at 400°C for two hours, the initial LLTO sample is totally recovered, a mass loss is observed and the carbonate signal in IR spectra disappears, demonstrating the reversibility of the carbonation reaction process.
Colloidal-crystal-templated synthesis of ordered macroporous electrode materials for lithium secondary batteries
Yan, Hongwei,Sokolov, Sergey,Lytle, Justin C.,Stein, Andreas,Zhang, Fan,Smyrl, William H.
, p. A1102-A1107 (2003)
This paper presents a general method of preparing three-dimensionally ordered macroporous (3DOM) electrode materials, including both cathode materials (V2O5 and LiNiO2) and an anode material (SnO2). The method is based on templated precipitation of inorganic precursors within a colloidal crystal of poly(methyl methacrylate) spheres and subsequent chemical conversion. 3DOM electrodes possess several features of interest in the design of novel battery materials, such as high accessible surface areas, continuous networks, and structural features on the nanometer scale. Optimal synthesis conditions and structural features of 3DOM electrode materials are described on the basis of X-ray diffraction, scanning electron microscopy, nitrogen adsorption, and chemical analysis.
Selective CO2 Splitting by Doubly Reduced Aryl Boranes to Give CO and [CO3]2?
von Grotthuss, Esther,Prey, Sven E.,Bolte, Michael,Lerner, Hans-Wolfram,Wagner, Matthias
, p. 16491 - 16495 (2018)
Alkali metal salts M2[1] (M=Li, Na) of doubly reduced 9,10-dimethyl-9,10-dihydro-9,10-diboraanthracene (1) instantaneously add the C=O bond of CO2 across their boron centers to furnish formal [4+2]-cycloadducts M2[2]. If only 1 equiv of CO2 is supplied, these products are stable. In the presence of excess CO2, however, C?O bond cleavage occurs and an O2? equivalent is transferred to CO2 to furnish CO and [CO3]2?. With M=Li, Li2CO3 precipitates and the neutral 1 is liberated such that it can be reduced again to establish a catalytic cycle. With M=Na, [CO3]2? remains coordinated to both boron atoms in a bridging mode (Na2[4]). A mechanistic scenario is proposed, based on isolated intermediates and model reactions.
MOSSBAUER STUDY OF THE THERMAL DECOMPOSITION OF ALKALI TRIS(OXALATO)FERRATES(III).
Brar,Randhawa
, p. 153 - 156 (1985)
The thermal decomposition of alkali (Li,Na,K,Cs,NH//4) tris(oxalato)ferrates(III) has been studied at different temperatures up to 700 degree C using Mossbauer, infrared spectroscopy, and thermogravimetric techniques. The formation of different intermedia
H2O-induced self-propagating synthesis of hierarchical porous carbon: A promising lithium storage material with superior rate capability and ultra-long cycling life
Liang, Chu,Liang, Sheng,Xia, Yang,Chen, Yun,Huang, Hui,Gan, Yongping,Tao, Xinyong,Zhang, Jun,Zhang, Wenkui
, p. 18221 - 18229 (2017)
Hierarchical porous carbon (HPC) has attracted much attention in tackling global environmental and energy problems. For the state-of-the-art routes to synthesize HPC from organic compounds, the emission of carbon dioxide (CO2) and gaseous pollutants is inevitable during thermal carbonization. Herein, we report an environmentally benign and high-yield route to synthesize HPC from CO2via H2O-induced self-propagating reactions. By introducing an initiator of H2O, CO2 can react with lithium hydride (LiH) to produce HPC in 13 seconds at low temperatures. The as-synthesized HPC exhibits an interconnected micro-meso-macropore network structure with a high porosity of 83%. The formation mechanism of HPC is discussed on the basis of the conversion reactions from CO2 to C and the gas blowing effect in producing hierarchical porosity. The HPC evaluated as an anode material for lithium-ion batteries not only delivers a high reversible capacity of ～1150 mA h g-1 at a current density of 0.2 A g-1, but also exhibits superior rate capability (～825 mA h g-1 at 1.0 A g-1) and excellent cycling properties (up to 2000 cycles). This research opens a new avenue both to synthesize HPC from CO2 on a large scale and to mitigate greenhouse gas from the atmosphere.
The Alkali Metal Salts of Methyl Xanthic Acid
Liebing, Phil,Schmeide, Marten,Kühling, Marcel,Witzorke, Juliane
, p. 2428 - 2434 (2020/06/17)
Methyl xanthates of the type M(SSC-OMe) (M = Li–Cs) are readily formed when carbon disulfide is reacted with the corresponding alkali metal hydroxides in methanol exposed to air, or with the alkali metal methoxides in dry methanol or THF under exclusion of air. The reactions are easily monitored by 13C NMR spectroscopy. The Na, K, Rb, and Cs salt could be isolated in high yields, while the Li salt decomposed upon attempted isolation. All compounds are readily complexed by crown ethers and form isolable 1:1 adducts, including the elusive Li salt. All products were studied by NMR (1H, 13C, and alkali metal nuclei) and IR spectroscopy, and most of them where structurally characterized by single-crystal X-ray diffraction. Li(SSC-OMe)(12c4) (12c4 = [12]crown-4) and Cs(SSC-OMe)(18c6) (18c6 = [18]crown-6) represent the first structurally characterized lithium and caesium xanthate complexes, respectively.
