Solid State Reaction Of Li2CO3 Research Articles

Non-isothermal reaction mechanism and kinetic analysis for the synthesis of monoclinic lithium zirconate (m-Li2ZrO3) during solid-state reaction

Non-isothermal reaction mechanism and kinetic analysis for the synthesis of monoclinic lithium zirconate (m-Li2ZrO3) were investigated by processing of TG-DTA, along with XRD, DLS, and HRTEM. For this purpose, the solid-state reaction of Li2CO3 with ZrO2 was carried out by TG-DTA at different heating rates (10, 20, and 30 °C/min) from room temperature to 1100 °C. The thermal data was used to calculate the kinetic parameters by two types of isoconversional methods: Flynn-Wall-Ozawa (FWO) and Kissinger-Akahira-Sunose (KAS). The reaction mechanism was determined by the model-fitting method, applying the Coats-Redfern (CR) approximation to the different solid-state reaction models. The results confirmed the formation of pure m-Li2ZrO3, consists of semispherical particles of about 490 nm, using a very short reaction time. The average activation energy obtained by FWO and KAS methods were 274.73 and 272.50 kJ/mol, respectively. It was found that the formation of m-Li2ZrO3 from Li2CO3 with ZrO2 is governed by the three-dimensional diffusion mechanism. Based on these results, a microscopic reaction model of the formation of m-Li2ZrO3 was proposed.

Formula omitted]:[formula omitted]: The highly sensitive probe for the low-temperature lifetime-based luminescence thermometry

In this work, the potential of Li1.8Na0.2TiO3:Mn4+ for the lifetime-based luminescence thermometry is assessed. The material is prepared by the solid-state reaction of Li2CO3, Na2CO3, and nanostructured TiO2 at 800 °C, and its monoclinic structure (space group C2/c) is confirmed by X-ray diffraction analysis. In this host, Mn4+ provides strong absorption around 330 nm and 500 nm due to 4A2g → 4T1g and 4A2g→ 4T2g electric dipole forbidden and spin-allowed electron transitions, respectively, and emits around 679 nm on account of 2Eg→4A2g spin forbidden electron transition. Temperature dependences of emission intensity and emission decay are measured over the 10–350 K range. Due to the low value of energy of 4T2g level (20000 cm−1), the strong emission quenching starts at low-temperatures which favors the use of this material for the luminescence thermometry. It is demonstrated that the quite large value of relative sensitivity (2.27% K−1@330 K) facilitates temperature measurements with temperature resolution better than 0.15 K, and with the excellent repeatability.

ChemInform Abstract: Improved Electrochemical Performance of Ag‐Modified Li4Ti5O12 Anode Material in a Broad Voltage Window.

AbstractLi4Ti5O12/Ag composites are prepared by solid state reaction of Li2CO3, TiO2, and AgNO3 (air, 850 °C, 15 h).

ChemInform Abstract: The Structural and Electrochemical Impact of Li and Fe Site Substitution in LiFePO4.

AbstractLi1‐3y[VyFe]PO4 (y = 0, 0.025, 0.05, 0.1, 0.2) is synthesized by solid state reaction of Li2CO3, FeC2O4, NH4H2PO4, and NH4VO3 (8.5% H2/He, 550 °C, 10 h).

ChemInform Abstract: LiCo2As3O10: A New Structure with Interconnected Tunnels.

AbstractThe new title compound is prepared by solid state reaction of Li2CO3, CoCl2·6H2O, and NH4H2AsO4 (Li:Co:As = 1:1:3, porcelain crucible; 1.

ChemInform Abstract: Solid‐State Synthesis of Li4Ti5O12 for High Power Lithium Ion Battery Applications.

AbstractLarge scale (15 kg) preparation of Li4Ti5O12 is performed by solid state reaction of Li2CO3 and anatase‐phase TiO2 (molar ratio of 4.05:5).

Microstructure and Electrochemical Properties of Lithium Titanate Particles Prepared by Solid State Reaction of Li and Spherical TiO<sub>2</sub> Powders

Li4Ti5O12 powders were synthesized via the solid state reaction of Li2CO3 and spherical composite powders of carbon and TiO2 (denoted by C/TiO2) with different microstructures. These C/TiO2 powders were synthesized by spray pyrolysis using various organic acid aqueous solutions. The particle characteristics of the resulting carbon composite Li4Ti5O12 (denoted by C/Li4Ti5O12) powders were determined using SEM, XRD, and DTA-TG. DTA-TG showed that the carbon content of all Li4Ti5O12 powders. was around 3 wt%. XRD revealed that the spinel structure (Fd3m) was obtained by heating at 750 °C under N2 atmosphere. The initial rechargeable capacity of the C/Li4Ti5O12 powders formed using citric acid was approximately 170 mAh/g at 1 C. The rechargeable capacity of the C/Li4Ti5O12 powders decreased with an increase in the rechargeable rate. The anodes maintained over 90% of their initial discharge capacity after 200 cycles at 1 C. The C/Li4Ti5O12 powders also demonstrated high cycle stability at 50 °C. It was found that rechargeable capacity was influenced by the particles microstructure, but cycle stability did not depend on the microstructure.

ChemInform Abstract: Synthesis and Relative Optical Properties of Eu3+/Tb3+‐Activated Li3InB2O6.

AbstractThe new title phosphors are prepared by solid state reaction of Li2CO3, In2O3, Eu2O3, Tb4O7, and H3BO3 (1.

ChemInform Abstract: Crystal Structure of Li4ZnTeO6 and Revision of Li3Cu2SbO6.

AbstractLi4ZnTeO6 is synthesized by solid state reaction of Li2CO3, ZnO, and TeO2 (850 °C, 4 h) and characterized by X‐ray and neutron diffraction.

ChemInform Abstract: Phase Transition and Conduction Mechanism of Rare Earth Based Tungsten‐Bronze Compounds.

AbstractPolycrystalline materials Li2Pb2Ln2W2Ti4 Nb4O30 (Ln: Y, Eu) are synthesized by solid state reaction of Li2CO3, TiO2, Nb2O5, WO3, PbO, and Ln2O3 (alumina crucible, 1100 °C, 4 h).

ChemInform Abstract: Synthesis and Thermoelectric Properties of the Novel A‐Site Deficient Zn0.5Rh2O4 Compound.

AbstractThe new thermoelectric title material is obtained from Li0.5Zn0.5Rh2O4 (obtained by solid state reaction of Li2CO3, Rh2O3, and ZnO in air at 1000 °C for 24 h) by immersion into an aqueous solution of K2S2O8 (1 and 10 d).

Electrochemical Properties of Li1.1V0.75W0.075Mo0.075O2/Graphite Composite Anodes for Lithium-ion Batteries

Novel type Li1.1V0.9-2xWxMoxO2 powders were prepared by a solid-state reaction of Li2CO3, V2O3, WO2 and MoO2 precursors in a nitrogen atmosphere containing 10 mol % hydrogen gas, and assessed as anode materials in lithium-ion batteries. The specific charge and discharge capacities of the Li1.1V0.9-2xWxMoxO2 anodes were higher than those of the bare Li1.1V0.9O2 anode. The cyclic efficiency of these anodes was approximately 73.3% at the first cycle, regardless of the presence of W and Mo doping. The composite anode, which was composed of Li1.1V0.75W0.075Mo0.075O2 (20 wt %) and natural graphite (80 wt %), demonstrated reasonable specific capacity, high cyclic efficiency, and good cycling performance, even at high rates without capacity fading. based on this material could be enhanced significantly because of its low working potential of < 0.3 V vs. Li/Li + during the charge and discharge reactions. The potential of this material as a high-density anode electrode has prompted intensive research on its structure and valence state. Li1.1V0.9O2 has an ordered layered crystalline structure with Li + and V +3 ions occupying alternate (111) planes, and exhibits a hexagonal structure. 8,9 After lithium intercalation, Li1.1V0.9O2 is converted to Li2.1V0.9O2, corresponding to the P-3m1 space group, and the oxidation state of vanadium ions is reduced from V(III) to V(II). The layered structure of Li1.1V0.9O2, gives it a relatively low volume change of 25% during the cycling process compared to that of highly capacitive silicon or tin-based anode materials. On the other hand, the electrochemical properties of Li1.1V0.9O2 might be insufficient for high-current applications owing to its low conductivity. Therefore, surface modification or other treat- ment methods should be applied to enhance the rate cap- ability. Metal doping is one of the most effective methods for improving the electrochemical properties of Li1.1V0.9O2. W and Mo-based oxide materials are used as dopants for Li1.1V0.9O2, which is used as an anode material in lithium-ion batteries. 10,11 These metals are suitable for the preparation of high-density anodes because of their high intrinsic density, low cost and non-toxic environment. In this study, a simple solid-state reaction was used to prepare a conducting Li1.1V0.9-2xWxMoxO2 anode material using a metal doping process. The electrochemical proper- ties of the anodes of these lithium-ion batteries were ex- amined using a range of analytical techniques. Experimental

ChemInform Abstract: Crystal Structure and Properties of a New Mixed‐Valence Compound LiMn2TeO6 and the Survey of the LiMM′XO6 Family (X: Sb or Te).

AbstractThe new compound LiMn2TeO6 is synthesized by solid state reaction of Li2CO3, Mn2O3, and TeO2 (600 °C for 3—6 h and 750—800 °C for 2—3 h).

ChemInform Abstract: Preparation, Crystal Structure and Photoluminescence of Lithium Magnesium Manganese Borate Solid Solutions, LiMg1‐xMnxBO3.

AbstractThe title compounds are prepared by solid state reaction of Li2CO3, MgO, MnO, and H3BO3 (Ar, 800 °C, 12 h).

Nitrogen- and TiN-modified Li4Ti5O12: one-step synthesis and electrochemical performance optimization

It is believed that a TiN coating can increase the electrical conductivity, and consequently the performance, of an electrode. In this work, a simple one-step synthesis of nitrogen- and TiN-modified Li4Ti5O12, i.e. solid-state reaction of Li2CO3 and TiO2 anatase in an ammonia-containing atmosphere, is introduced. The reducing ammonia atmosphere could cause the partial reduction of Ti4+ to Ti3+ and the doping of nitrogen into the Li4Ti5O12 lattice, in addition to the formation of the TiN phase. By controlling the ammonia concentration of the atmosphere and using a slight Ti excess in the reactants, Li4Ti5O12, nitrogen-doped Li4Ti5O12, or TiN-coated nitrogen-doped Li4Ti5O12 were obtained. Both the electrical conductivity and the TiN thickness were closely related to the ammonia concentration in the atmosphere. Synthesis under reducing atmosphere also resulted in powders with a different plate shape particulate morphology from that synthesized in air, and such plate-shape powders had an ultrahigh tap density of ∼1.9 g cm−3. Interestingly, the formation of TiN was not beneficial for capacity improvement due to its insulation towards lithium ions, unlike the nitrogen doping. The sample prepared under 3% NH3–N2, which was free of TiN coating, showed the best electrode performance with a capacity of 103 mA h g−1 even at 20 C with only 3% capacity decay after cycling 100 times.

Synthesis and Electrochemical Properties of Lithium Titanate Anode Materials Powders by Solid State Reaction of Li and Spherical TiO&lt;sub&gt;2&lt;/sub&gt; Powders

Li4Ti5O12 powders were synthesized by solid state reaction of Li2CO3 and spherical composite powders of carbon and TiO2 (denoted as C/TiO2). C/TiO2 powders were synthesized by spray pyrolysis of using lactic acid aqueous solution. The particle characteristics of Li4Ti5O12 powders were determined by SEM, XRD and DTA-TG. DTA-TG showed that the carbon content was around 8 wt% in Li4Ti5O12 powders. XRD revealed that the spinel structure (Fd3m) was obtained by heating at 750 °C under N2 atmosphere. The first rechargeable capacity of Li4Ti5O12 anode was about 160 mAh/g at 1 C. That of Li4Ti5O12 anode decreased to 90 mAh/g at 20 C. The rechargeable capacity of Li4Ti5O12 anode decreased with increasing the rechargeable rate, but 81% of initial discharge capacity of Li4Ti5O12 anode was retained after 200 cycles at 1C

ChemInform Abstract: Synthesis, Structure, and Properties of Li2Pb2CuB4O10 with Isolated [CuB4O10]6‐ Units.

AbstractThe title compound is prepared by solid state reaction of Li2CO3, PbO, CuO, and H3BO3 in air (550—650 °C, 2—3 d).

Electrochemical Characteristics of Lithium Vanadium Oxide for Lithium Secondary Battery

The pure crystalline Li1.1V0.9O2 powder has been prepared by a simple solid state reaction of Li2CO3 and V2O3 precursors under nitrogen gas containing 10 mol % hydrogen gas flow. The structure of Li1.1V0.9O2 powder was analyzed using Xray diffraction (XRD) and scanning electron microscope (SEM). The stoichiometric Li1.1V0.9O2 powder was used as anode active material for lithium secondary batteries. Its electrochemical properties were investigated by cyclic voltammetry and constant current methods using lithium foil electrode. The observed specific discharge capacity and charge capacity were 360 mAh/g and 260 mAh/g during the first cycle, respectively. In addition, the cyclic efficiency of this cell was 72.2% in the first cycle. The specific capacity of Li1.1V0.9O2 anode rapidly declines as the current rate increases and retains only 30 % of the capacity of 0.1C rate at 1C rate. The crystallinity of the Li1.1V0.9O2 anode decrease as discharge reaction proceeds. However, the relative intensity of main peaks was almost recovered when the cell was charged up to 1.5 V.

Li2ZrO3분리막의 제조와 이산화탄소 선택투과 전후의 기계적 특성 평가

In this study, we investigated Li₂ZrO₃ membrane as a candidate material for high-temperature CO₂ separation and evaluated mechanical property. Li₂ZrO₃ powder was synthesized by solid state reaction of Li₂CO₃ and ZrO₂. Then we fabricated Li₂ZrO₃ tape using tape casting method. Dense Li₂ZrO₃ membrane prepared by sintering at 1600℃ for 2 h after pressing Li₂ZrO₃ tape using lamination machine. Mechanical properties before and after CO₂ absorption of fabricated Li₂ZrO₃ membrane such as Hertzian indentation, Vickers hardness and 3-point bending testing were evaluated.

A novel one-pot metathesis route for the synthesis of double perovskites, Ba3MM′2O9(M = Mg, Ni, Zn; M′ = Nb, Ta) with 1 : 2 ordering of M and M′ atoms

Solid state reaction of Li2CO3, MC2O4·2H2O (M = Mg, Ni, Zn), M′2O5 (M′ = Nb, Ta) and BaCl2 in stoichiometric quantities at 900–1100 °C in air provides a convenient one-pot synthesis route for 1 : 2 B-site ordered double perovskite oxides, Ba3MM′2O9, that find application in microwave telecommunications.