Isotopic product rule for solid state lithium nitrate

TheTeller-Redlich type isotopic product rule within the harmonic approximation is found to be satisfactorily applicable to solid state vibrations of anhydrous lithium nitrate,⁶LiNO₃ and⁷LiNO₃.

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Die isotopische Produktenregel für Lithiumnitrat im Festzustand

Zusammenfassung Es wurde festgestellt, daß die Isotopenproduktenregel vomTeller-Redlich-Typ innerhalb der harmonischen Näherung für die Vibrationen von wasserfreiem Lithiumnitrat (⁶LiNO₃ und⁷LiNO₃) im festen Zustand befriedigende Ergebnisse bringt.

     

Diffusion of Li+ ions in concentrated solutions of LiNO3 in 1,3-diaminopropane

The temperature and composition dependences of the self-diffusion coefficient of Li⁺ ions were investigated for concentrated solutions of LiNO₃ in 1,3-diaminopropane by means of the NMR spin-echo technique from 20 to 50°C. The composition dependence of the activation energy shows a bend around 30 mol % LiNO₃. This is consistent with the previous results obtained from the electrical conductivity and the correlation time of the rotational motion of the solvating ions, and suggests that solvent molecules may act as bridges between Li⁺ ions at higher concentrations of LiNO₃.     

Electrochemical behavior of spherical LiNi1/3Co1/3Mn1/3O2 as cathode material for aqueous rechargeable lithium batteries

Spherical LiNi_1/3Co_1/3Mn_1/3O₂ powders have been synthesized from co-precipitated spherical metal hydroxide. The electrochemical performances of the LiNi_1/3Co_1/3Mn_1/3O₂ electrodes in 1 M LiNO₃, 5 M LiNO₃, and saturated LiNO₃ aqueous electrolytes have been studied using cyclic voltammetry and ac impedance tests in this work. The results show that LiNi_1/3Co_1/3Mn_1/3O₂ electrode in saturated LiNO₃ electrolyte exhibits the best electrochemical performance. An aqueous rechargeable lithium battery containing LiNi_1/3Co_1/3Mn_1/3O₂ cathode, LiV_2.9Ni_0.050Mn_0.050O₈ anode, and saturated LiNO₃ electrolyte is fabricated. The battery delivers an initial capacity of 98.2 mAh g⁻¹ and keeps a capacity of 63.9 mAh g⁻¹ after 50 cycles at a rate of 0.5 C (278 mA g⁻¹ was assumed to be 1 C rate).     

The intercalation of cetyltrimethylammonium cations into muscovite by a two-step process: I. The ion exchange of the interlayer cations in muscovite with Li

A new method to prepare alkylammonium ions-intercalated muscovite is reported. It has been obtained in a two-step process: the first step is the inorganic ion exchange, which allows the ion exchange of interlayer cations in muscovite with Li⁺ in a melting condition of LiNO₃. It was found that in the LiNO₃ treatment process most of the interlayer cations were replaced by Li⁺, and a large amount of water entered the interlayer space of muscovite. Therefore the spacing of muscovite (001) plane d₍₀₀₁₎ was enlarged from 19.92 to 24.16 Å, which could allow for the intercalation of organic cations. SEM shows that the LiNO₃ treatments have little effect on the size of muscovite platelets. TEM and FTIR confirm that not only the chemical composition but also the structure of the aluminosilicate layer has not been changed by the LiNO₃ treatments.     

LiNO_3-KNO_3-H_2O三元体系相平衡研究

本文采用等温法分别测定了KNO3-H2O体系的溶解度相图以及LiNO3-KNO3-H2O体系在273.15和298.15K的等温溶解度相图。结果表明在273.15K时LiNO3-KNO3-H2O体系的溶解度等温线有2条分支,对应的固相分别为KNO3和LiNO3·3H2O,共饱点组成为31.55wt%LiNO3和7.07wt%KNO3。该体系在298.15K的等温线有3条分支,对应的固相分别为KNO3,LiNO3和LiNO3·3H2O,2个共饱点组成分别为50.42wt%LiNO3,22.18wt%KNO3,和55.74wt%LiNO3,10.9wt%KNO3。     

Separation of140Ba−140La by reversed phase chromatography using high molecular weight amine

A method has been described for the isolation of radiochemically pure¹⁴⁰La from¹⁴⁰Ba. The tracer¹⁴⁰Ba−¹⁴⁰La is mixed with 6M LiNO₃ solution to make an anionic complex. The solution is then fed into a column (1 cm×0.4 cm) of Kieselguhr impregnated with Aliquat-336.¹⁴⁰La is adsorbed in the column while¹⁴⁰Ba is eluted with 6M LiNO₃. After complete removal of¹⁴⁰Ba,¹⁴⁰La is eluted with 0.002M HNO₃ solution. The purity of¹⁴⁰La is established by both its half-life and γ-spectrum.     

Preparation of muscovite with ultrahigh specific surface area by chemical cleavage

The specific surface area of a muscovite sample increases drastically after exposure to a LiNO₃ solution, e.g., from 3.4 m²/g, corresponding to platelets of ca. 200 silicate layers, to 295 m²/g (platelets of ca. 2–3 silicate layers) after treatment at 180°C under atmospheric pressure for 46 h. The efficiency of the cleavage process decreases with decreasing temperature (down to 50°C). The LiNO₃/H₂O weight ratio is also very important: at 130°C and a reaction time of 46 h, for instance, a value in the range of 1.7–1.8 leads to the highest specific surfaces. The cleaved products have the form of strong papers that disperse readily in water. During the cleaving procedure, not only the particle thickness, but also the diameter decreases. There is no evidence of damage or partial dissolution of the silicate structure after cleavage, by IR spectroscopy and yield. The use of LiCl also leads to an increase in specific surface area, but the effect is weaker than in the case of LiNO₃. Treatment with some other alkaline and alkaline earth nitrates and chlorides did not increase the specific surface area of muscovite significantly.     

Cation exchange extraction of neptunium(V) and protactinium(V) from molten nitrate salt

Cu-di-(2-ethylhexyl)phosphate was used as the cation exchange extractant from molten nitrate salt. IR absorption spectra of di-(2-ethylhexyl)phosphoric acid and Cu-di-(2-ethylhexyl)phosphate were compared and it was proved that the acidic form of the extractant is not Cu-di-(2-ethylhexyl)-phosphate. Using LiNO₃−NH₄NO₃ eutectic melt, it was shown that the back-extraction of Cu²⁺ is a cation exchange reaction. Np(V) and Pa(V) were extracted by Cu-di-(2-ethylhexyl)phosphate from LiNO₃−NaNO₃−KNO₃ eutectic melt. The distribution ratio of Np(V) was greater than that of Pa(V) on the contrary of their distribution ratios in the aqueous extraction system. A possible cation exchange extraction reaction was proposed for the extraction of Np(V).     

Quaternary reciprocal system Li,K‖F,Br,NO<Subscript>3</Subscript>

The quaternary reciprocal system Li,K‖F,Br,NO₃ was described and studied for the first time. The system was partitioned into simplexes by writing an adjacency matrix and solving a logical expression. The partition was confirmed by the results of differential scanning calorimetry of two partitioning triangles (LiF-KBr-KNO₃ and LiF-KBr-LiNO₃) and three stable triangles (LiBr-LiF-KBr-LiNO₃, LiNO₃-LiF-KNO₃-KBr, and KF-LiF-KNO₃-KBr). The compositions (mol %) and melting points of quaternary eutectics of the system Li,K‖F,Br,NO₃ were determined: E ₁ ^□ (4.0% LiF, 48.0% LiNO₃, 17.28% KBr, 30.7% LiBr, T _melt = 186°C), E ₂ ^□ (7.35% LiF, 47.53% KNO₃, 2.0% KBr, 43.12% LiNO₃, T _melt = 102°C), and E ₃ ^□ (2.0% LiF, 84.28% KNO₃, 0.98% KBr, 12.74% KF, T _melt = 280°C).     

Anionization of volatile molecules on the surface of electrolytic solutions exposed to high electric fields

The anionization of molecules supplied from the gas phase onto a negatively charged [Cl]^? or [NO₃]^? ion donating surface has been investigated. The charged surface was prepared by exposing an aqueous solution of LiCl (or LiNO₃) and polyethylene oxide to a high external field as is done in negative ion field desorption mass spectrometry. The ionization of some monosaccharides and adenosine by [Cl]^? and [NO₃]^? attachment and of some acids by proton abstraction is reported.     

Enhancement of lithium ion conduction in the cubic rare earth oxide

A new type of lithium ion conducting solid electrolyte based on a cubic rare earth oxide was developed by co-doping LiNO₃ and KNO₃ into a (Gd_1−xNd_x)₂O₃ solid, which possesses large interstitial open spaces within the structure. Among the samples prepared, 0.6(Gd_0.4Nd_0.6)₂O₃–0.16LiNO₃–0.24KNO₃ exhibits the highest lithium ion conductivity of 8.05 × 10⁻² and 1.35 × 10⁻³ S cm⁻¹ at 400 and 100 °C, respectively, which is comparable to that of the LISICON materials. Pure Li⁺ ion conduction was successfully demonstrated by the dc electrolysis method.     

Vibrational Spectra of the Molten Nitrate/Platinum Electrode Interfacial Region

Raman spectra and IR reflection-absorption spectra are measured for the interfacial region between a platinum electrode and molten NaNO₃, KNO₃, and binary eutectic LiNO₃–KNO₃. The design of high-temperature spectroelectrochemical cells used in recording vibrational spectra of the region is described. Effects of electrode potential on the NO^- ₃ion inner-vibrational spectra are studied.     

Pd(OAc)2/M(NO3)n (M = Cu(II), Fe(III); n = 2, 3): Kinetic investigations of an alternative Wacker system for the oxidation of natural olefins

Pd-catalyzed oxidative coupling of camphene by dioxygen afforded mainly a diene, which subsequently underwent oxidation to a ring-expanded β,γ-unsaturated ketone with LiNO₃ as reoxidant. However, the instability of LiNO₃ results to the decomposition of NO₃⁻ ions which subsequently deactivates the catalyst. The present investigation describes the oxidation of terpenes catalyzed by Pd(OAc)₂/M(NO₃)_n (M = Cu(II), Fe(III); n = 2 or 3), using dioxygen as final oxidant. Fe(III) and Cu(II) effectively stabilize the nitrate reoxidant as determined by the significant increase of both catalytic activity and stability of the system. Turnover frequency suggests that Fe(III) is the most efficient co-catalyst. Moreover, it is established that the co-catalysts NO₃⁻, Cu(II) and especially Fe(III) ions, change the product distribution (diene/ketone) remarkably. Their involvement in the rate-determining step was investigated and the results of the kinetic investigations clarified important aspects of Pd(II)-catalyzed oxidation reactions. The described protocol offers an alternative to the traditional Wacker system which uses CuCl₂ as co-catalyst and is not effective in promoting the oxidation of bicycle olefins.     

LiNO3-Based Electrolytes via Electron-Donation Modulation for Sustainable Nonaqueous Lithium Rechargeable Batteries

LiPF₆ as a dominant lithium salt of electrolyte is widely used in commercial rechargeable lithium-ion batteries due to its well-balanced properties, including high solubility in organic solvents, good electrochemical stability, and high ionic conductivity. However, it suffers from several undesirable properties, such as high moisture sensitivity, thermal instability, and high cost. To address these issues, herein, we propose an electron-donation modulation (EDM) rule for the development of low-cost, sustainable, and electrochemically compatible LiNO₃-based electrolytes. We employ high donor-number solvents (HDNSs) with strong electron-donation ability to dissolve LiNO₃, while low donor-number solvents (LDNSs) with weak electron-donation ability are used to regulate the solvation structure to stabilize the electrolytes. As an example, we design the LiNO₃-DMSO@PC electrolyte, where DMSO acts as an HDNS and PC serves as an LDNS. This electrolyte exhibits excellent electrochemical compatibility with graphite anodes, as well as the LiFePO₄ and LiCoO₂ cathodes, leading to stable cycling over 200 cycles. Through spectroscopy analyses and theoretical calculation, we uncover the underlying mechanism responsible for the stabilization of these electrolytes. Our findings provide valuable insights into the preparation of LiNO₃-based electrolytes using the EDM rule, opening new avenues for the development of advanced electrolytes with versatile functions for sustainable rechargeable batteries.     

Lithium Nitrate Regulated Sulfone Electrolytes for Lithium Metal Batteries

The electrolytes in lithium metal batteries have to be compatible with both lithium metal anodes and high voltage cathodes, and can be regulated by manipulating the solvation structure. Herein, to enhance the electrolyte stability, lithium nitrate (LiNO₃) and 1,1,2,2-tetrafuoroethyl-2′,2′,2′-trifuoroethyl(HFE) are introduced into the high-concentration sulfolane electrolyte to suppress Li dendrite growth and achieve a high Coulombic efficiency of >99 % for both the Li anode and LiNi_0.8Mn_0.1Co_0.1O₂ (NMC811) cathodes. Molecular dynamics simulations show that NO₃⁻ participates in the solvation sheath of lithium ions enabling more bis(trifluoromethanesulfonyl)imide anion (TFSI⁻) to coordinate with Li⁺ ions. Therefore, a robust LiN_xO_y−LiF-rich solid electrolyte interface (SEI) is formed on the Li surface, suppressing Li dendrite growth. The LiNO₃-containing sulfolane electrolyte can also support the highly aggressive LiNi_0.8Mn_0.1Co_0.1O₂ (NMC811) cathode, delivering a discharge capacity of 190.4 mAh g⁻¹ at 0.5 C for 200 cycles with a capacity retention rate of 99.5 %.     

New process for low temperature preparation of LiNi1−xCoxO2 Cathode material for lithium cells

LiNi_1−yCo_yO₂ has been prepared at a temperature as low as 400 °C by molten ion exchange using a βNi_1−yCO_yOOH and either LiNO₃ or LiOH. The mechanism of these reactions was clarified using DTA and TG analyses. The material prepared using the LiNO₃ is well crystallized because the reaction takes place in viscous state since LiNO₃ melts and then reacts with the oxyhydroxide. However, in the case of using LiOH, a solid-solid diffusion reaction takes place and leads to a material with broad XRD peaks. The electrochemical characteristics of these materials were evaluated and compared with those prepared by the usual processes at high temperature.     

Metal nitrate/fuel mixture reactivity and its influence on the solution combustion synthesis of γ-LiAlO<Subscript>2</Subscript>

The reactivity of LiNO₃ and Al(NO₃)₃ with respect to urea and β-alanine was investigated. Experimental results proved that β-alanine is a more suitable fuel for LiNO₃, whereas urea seems to be more adequate for Al(NO₃)₃. Based on the different metal nitrate/fuel mixture reactivity, nanocrystalline γ-LiAlO₂ powders were prepared by solution combustion synthesis using a fuel mixture of urea and β-alanine. This fuel mixture yielded single-phase nanocrystalline γ-LiAlO₂ (32.6 nm) directly from the combustion reaction. The resulted powder had a specific surface area of 3.2 m²/g and no supplementary annealing was required. On the other hand, pure γ-LiAlO₂ could not be obtained by using a single fuel (urea, β-alanine) unless annealing at 900 °C for 1 h was performed.     

A lithium‐organic framework as a fluorescent sensor for detecting aluminum (III) ion

Due to the low coordination number and the relatively weak coordination ability, it is a great challenge to introduce Li⁺ into the construction of metal–organic frameworks (MOFs). Here, one Li‐based metal–organic framework (Li‐MOF), [Li₄L(DMF)₂]_n ( HNU‐31 ), is constructed by the assembly of LiNO₃ and 5‐(bis(4‐carboxybenzyl)amino)isophthalic acid (H₄L) ligand, which possesses a 3D framework, and can be serve as a luminescent sensor for detecting Al³⁺ ion with the detection limit of 4 × 10^?6 M.     

Enthalpies of solution and of crystallization of lithium nitrate and of lithium nitrate trihydrate in water at 25°C

The enthalpies of crystallization of LiNO₃ and LiNO₃–3H₂O from aqueous solutions at 25°C, measured by a calorimetric method and determined from the previously published data on the concentration dependence of the enthalpy of solution, are reported. The results are compared with the values obtained from the concentration dependences of the activity coefficients and from the temperature dependences of the solubilities. The enthalpy of solution at infinite dilution and the enthalpy of hydration are given.     

Li,K∥F,NO3 and Li,K∥Cl,NO3 three-component reciprocal systems

Phase equilibria in Li,K∥F,NO₃ and Li,K∥Cl,NO₃ three-component reciprocal systems were studied by differential scanning calorimetry (DSC). Eutectic compositions (mol %) in the Li,K∥F,NO₃ system were determined to be as follows: 5.0 LiF, 10.0 KF, and 85.0 KNO₃ with T _m = 281°C and 48.5 KNO₃, 44.0 LiNO₃, and 7.5 LiF with T _m = 105°C. Eutectic compositions (mol %) in the Li,K∥Cl,NO₃ system were determined to be as follows: 10.0 LiCl, 32.1 KCl, and 57.9 LiNO₃ with T _m = 147°C and 44.5 KNO₃, 45.0 LiNO₃, and 10.5 KCl with T _m = 97°C.