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Summary Lithium metal electrodeposits in the form of irregular morphological features, loosely termed dendrites, on planar anode substrates. The deposits may lead to rapid battery failure and safety concerns. Due to the highly reducing nature of Li (−3.04 V versus standard hydrogen electrode [SHE]), a solid electrolyte interphase (SEI) inevitably forms at the electrode/electrolyte interface, which regulates the subsequent electrodeposition of Li. Rational design of the chemical, mechanical, and ion transport properties of SEI plays an important role in determining the morphology of electrodeposited metals. We report on using initiated chemical vapor deposition (iCVD) to create ultrathin conformal zwitterionic polymeric interphases with precise thicknesses in the range of 10–500 nm. It was found that zwitterionic moieties are able to tune the solvation environment of the lithium cation at the electrode/electrolyte interface, enabling compact, planar deposition of the lithium metal. These findings provide new directions for designing ionic polymeric interphases for metal anodes.

The synthesis and characterization of the bis(η6 -benzene)lithium cation, the benzene metallocene of the lightest metal, is reported. The boron compound FmesBCl2 [Fmes: 2,4,6-tris(trifluoromethyl)phenyl] reacted with three molar equivalents of the lithio-acetylene reagent Li-C≡C-Fmxyl [Fmxyl: 3,5-bis(trifluoromethyl)phenyl]. Subsequent crystallization from benzene gave the [bis(η6 -benzene)Li]+ cation with the [{FmesB(-C≡C-Fmxyl)3 }2 Li]- anion. This parent [(arene)2 Li]+ cation shows an eclipsed arrangement of the pair of benzene ligands at the central lithium cation with uniform carbon-lithium bond lengths. The corresponding [(η6 -toluene)2 Li]+ and [(η6 -durene)2 Li]+ containing salts were similarly prepared. The bis(arene)lithium cations were characterized by X-ray diffraction, by solid-state 7 Li MAS NMR spectroscopy and their bonding features were analyzed by DFT calculations.

Metal–organic frameworks (MOFs) have emerged as an important, yet highly challenging class of electrochemical energy storage materials. The chemical principles for electroactive MOFs remain, however, poorly explored because precise chemical and structural control is mandatory. For instance, no anionic MOF with a lithium cation reservoir and reversible redox (like a conventional Li-ion cathode) has been synthesized to date. Herein, we report on electrically conducting Li-ion MOF cathodes with the generic formula Li2-M-DOBDC (wherein M = Mg2+ or Mn2+; DOBDC4– = 2,5-dioxido-1,4-benzenedicarboxylate), by rational control of the ligand to transition metal stoichiometry and secondary building unit (SBU) topology in the archetypal CPO-27. The accurate chemical and structural changes not only enable reversible redox but also induce a million-fold electrical conductivity increase by virtue of efficient electronic self-exchange facilitated by mix-in redox: 10–7 S/cm for Li2-Mn-DOBDC vs 10–13 S/cm for the isoreticular H2-Mn-DOBDC and Li2-Mg-DOBDC, or the Mn-CPO-27 compositional analogues. This particular SBU topology also considerably augments the redox potential of the DOBDC4– linker (from 2.4 V up to 3.2 V, vs Li+/Li0), a highly practical feature for Li-ion battery assembly and energy evaluation. As a particular cathode material, Li2-Mn-DOBDC displays an average discharge potential of 3.2 V vs Li+/Li0, demonstrates excellent capacity retention over 100 cycles, while also handling fast cycling rates, inherent to the intrinsic electronic conductivity. The Li2-M-DOBDC material validates the concept of reversible redox activity and electronic conductivity in MOFs by accommodating the ligand’s noncoordinating redox center through composition and SBU design.

Lithium cations were observed to accelerate the hydrolysis of esters with hydroxides (KOH, NaOH, LiOH) in a water/tetrahydrofuran (THF) two-phase system. Yields in the hydrolysis of substituted benzoates and aliphatic esters using the various hydroxides were compared, and the effects of the addition of lithium salt were examined. Moreover, it was presumed that a certain amount of LiOH was dissolved in THF by the coordination of THF with lithium cation and hydrolyzed esters even in the THF layer, as in the reaction by a phase-transfer catalyst.

Lithium-sulfur (Li-S) batteries are considered to be one of the next-generation battery candidates and have been widely studied. Despite the obvious advantages of Li-S batteries, there are still many serious problems with sulfur electrode: The active material sulfur (S) and the final product lithium sulfide (Li2S) are both insulators, and the electronic conductivity is poor, so that a large amount of conductive agent must be added to the sulfur electrode; the large difference in density between S and Li2S makes the electrode undergo a huge volume change (about 80%) during the charge and discharge process, which easily leads to the collapse of the sulfur electrode structure, which leads to the degradation of the Li-S batteries performance; the lithium polysulfide produced during charge and discharge has extremely high solubility in ether electrolytes, resulting in the “shuttle effect”. Especially, the “shuttle effect” of lithium polysulfide has caused problems such as poor battery cycle performance, rapid capacity decay and overcharge, which severely restricted the further development and commercial application of Li-S batteries. As a key component of Li-S batteries, electrolyte not only plays a role in transmitting lithium cation (Li+) and conducting internal circuits, but also one of the main factors that determine the overall performance of the battery capacity and cycle stability. Lithium nitrate (LiNO3) has received widespread attention as an electrolyte additive for Li-S batteries, and its mechanism of action has also been studied in depth. However, this article provides a new understanding of the mechanism of LiNO3 additives through deep study and new experimental schemes. In this experimental scheme, the Li metal anode recycled by electrolyte containing LiNO3 additive and fresh sulfur electrode was used to reassemble the battery with the electrolyte without the LiNO3 additive; the sulfur electrode recycled by electrolyte containing LiNO3 additive and fresh Li metal anod were used to reassemble the battery with the electrolyte without the LiNO3 additive; both batteries have serious overcharging during the charging process, and the shuttle of polysulfide anions occurs. This shows that the mechanism of LiNO3 inhibiting the “shuttle effect” is not just to form SEI film. Through the ion migration number test, it is found that after adding LiNO3 additive, the migration number of Li+ increases, resulting in a significant decrease in the migration of polysulfide anions. It can be concluded that another effect of adding LiNO3 additives is to increase the migration number of Li+, thereby reducing the migration number of anions and effectively inhibiting the “shuttle effect”. At present, the components of gunpowder (sulfur, nitrate, carbon) are concentrated in Li-S batteries, which may be potentially dangerous during commercial use. According to the new discovery of the role of LiNO3 additives in Li-S batteries in this work, future research work can be based on the migration number theory to find other electrolyte additives that can promote the migration number of lithium ions and interact with polysulfide anions. LiNO3 additives, thereby reducing the potential dangers of Li-S batteries in use.

Single-ion-conducting polymer electrolytes are attractive to use in lithium batteries as the transference number of the lithium cation approaches unity. This helps prevent concentration gradients a...

The dehydrogenation of 2,3-butanediol (BDO) to 3-hydroxybutanone (HBO) was studies over Li cation-doped CuZnAl catalysts. The catalyst samples were characterized by XRD, XPS, H -TPR and SEM techniques. The characterization results showing that doping with Li cation obviously modified the surface morphology of CuZnAl catalysts; decreased the reduction temperature of CuZnAl catalysts; and finally increased the amount of Cu active sites. The reaction results showing that, Li modified CuZnAl catalysts obviously enhanced the selectivity of the dehydrogenation of BDO to HBO by inhibiting the dehydration of BDO. The Li(2%)–Cu(44%)–Zn(38%)–Al(16%) exhibited the highest activity for dehydrogenation of BDO, with the conversion rate of BDO is 72.4% and the selectivity of HBO is 95.9% at 260°C. This catalyst shows excellent stability for more than 100h without significant deactivation. 2

Polyoxometalates (POMs) have been proposed as electromaterials for lithium-based batteries because they provide access to multiple electron transfer reactions coupled to fast lithium ion transport ...

The synthesis and spectral and structural descriptions of two salts of formulas {[Li][Li(H2O)(μ-CN)3]}[W(CN)3(bpy)] (1) and {Li}{[Li(μ-CN)2][Li(μ-CN)3]μ-Cl}[W(CN)(bpy)]·2H2O (2) were described. The structural investigation shows the influence of the size and charge of Li+ on the nature of the CN−/Li+ interaction and thus on the structure of the compounds. Both salts crystallize in the triclinic P space group with very similar cell parameters (a, b and c differ by no more than 0.05 A, α, β and γ less than 1°, and cell volume less than 4 A3) in spite of the different complex formulas. In 1, two different lithium cations are observed. Only one compensates the anion charge, while the second one is tetrahedral and forms a complicated 1D network via three nitrogen atoms of cyano ligands trans to a bpy molecule. The molecular wires connect neighbouring molecules only by weak intermolecular interactions. In 2, the 2D structure, with layers connected only by π–π stacking interactions, is observed. Lithium cations are involved in bonds with the nitrogen of cyano ligands.

Deprotonation of the fluorenyl-tethered imidazolinium salt [9-(C13H9)C2H4N(CH)C2H4N(2,4,6-Me3C6H2)][BF4] gave a spirocyclic compound that reacted with a synergic mixture of LiPh/LiN(SiMe3)2 or LinBu/LiN(SiMe3)2 to give a dilithium complex incorporating a bridging N(SiMe3)2 ligand. In contrast, deprotonation of the imidazolium salt [9-(C13H9)C2H4N(CH)C2H2N(Me)][Br] instead yielded the free NHC, which reacted with nBuLi to form a dimeric, NHC-bridged dilithium complex. Addition of LiN(SiMe3)2 led to coordination and the formation of a dilithium complex with a bridging N(SiMe3)2 ligand, which was characterised in the solid state as a 1D coordination polymer. The reaction of 1,3-bis(2,6-diisopropylphenyl)-4,5-dihydroimidazol-2-ylidene (SIPr) with lithium indenide and lithium fluorenide gave soluble species with terminal binding of the NHC to the lithium cation and η5 coordination of indenyl or fluorenyl. A symmetrical bridging mode for an NHC donor was therefore observed only if a tethered fluorenyl anion was present with no additional amide ligand.

International audience; We report herein the synthesis of a new NHC-stabilised borane complexe featuring a weakly coordinating anion, namely a pentaorganosilicate, on the NHC backbone. The synthesis can be achieved from a zwitterionic abnormal silicate-imidazolium adduct by deprotonation with a strong base followed by quenching with a borane transfer agent. Alternatively, the IPr-BH 3 complex can also be deprotonated and the resulting vinylanion is trapped by a tetravalent spirosilane. The first structural data on a lithium derivative of an anionic NHC-borane complex functionalized by a silicate have been obtained and reveal an interaction between the three hydrogens of the borane and the lithium cation. Assessment of the reactivity highlights the higher hydridicity of the anionic NHCborane compared to the parent IPr-BH 3. Finally, electronic properties of this new species have been evaluated by means of DFT calculations and the presence of the silicate on the NHC backbone raises the HOMO which can in part explain the high hydride-donor abilities. This is consistent with the smooth reduction of an aldehyde without Lewis acid additive.

MP2/aug-cc-pVTZ calculations were carried out on complexes wherein the proton or the lithium cation is located between π-electron systems, or between π-electron and σ-electron units. The acetylene or its fluorine and lithium derivatives act as the Lewis base π-electron species similarly to molecular hydrogen, which acts as the electron donor via its σ-electrons. These complexes may be classified as linked by π-H∙∙∙π/σ hydrogen bonds and π-Li∙∙∙π/σ lithium bonds. The properties of these interactions are discussed, and particularly the Lewis acid units are analyzed, because multi-center π-H or π-Li covalent bonds may occur in these systems. Various theoretical approaches were applied here to analyze the above-mentioned interactions—the Quantum Theory of Atoms in Molecules (QTAIM), the Symmetry-Adapted Perturbation Theory (SAPT) and the Non-Covalent Interaction (NCI) method.

In contrast to the extensive knowledge of lithium cation affinities and basicities, the thermochemistry of microsolvated lithium cations is much less explored. Here, we determine the relative stabilities of Li(A,B)n+ complexes, n = 2 and 3, by monitoring their gas-phase reactions with A and B substrate molecules, A/B = Me2O, Et2O, tetrahydrofuran, and MeCN, in a three-dimensional quadrupole-ion trap mass spectrometer. Kinetic analysis of the observed ligand displacement reactions affords equilibrium constants, which are then converted into Gibbs reaction energies. In addition, we use high-level quantum chemical calculations to predict the structures and sequential ligand dissociation energies of the homoleptic Li(A)n+ complexes, n = 1–3. As expected, the ligands dissociate more easily from complexes in higher coordination states. However, the very nature of the ligand also matters. Ligands with different steric demands can, thus, invert their relative Li+ affinities depending on the coordination state of the metal center. This finding shows that microsolvation of Li+ can result in specific effects, which are not recognized if the analysis takes into account only simple lithium cation affinities and basicities.

The authors report on 7Li, 19F, and 1H pulsed field gradient NMR measurements of 26 organosilyl nitrile solvent-based electrolytes of either lithium bis(trifluorosulfonyl)imide (LiTFSI) or lithium hexafluorophosphate. Lithium transport numbers (as high as 0.50) were measured and are highest in the LiTFSI electrolytes. The authors also report on solvent blend electrolytes of fluoroorganosilyl (FOS) nitrile solvent mixed with ethylene carbonate (EC) and diethyl carbonate. Solvent diffusion measurements on an electrolyte with 6% FOS suggest both the FOS and EC solvate the lithium cation. By comparing lithium transport and transference numbers, The authors find less ion pairing in FOS nitrile carbonate blend electrolytes and difluoroorganosilyl nitrile electrolytes.

Mass spectrometric analysis of lignin for developing biomaterials requires advances of characterization techniques. Positive ion mass spectrometry of lignin model compounds using lithium has recently been explored as a viable alternative to current negative mode techniques. To date, little is known about the impact of lithium adduct ion formation on relative response factors of lignin and lignin decomposition products. In this contribution, we report estimates of lithium cation basicity for synthetic monolignols H, G and S using Cooks’ kinetic method on a linear quadrupole ion trap mass spectrometer. Optimized geometries and interaction energies have also been calculated by DFT methods to quantify the electrostatic cation coordination. Based on a combination of experimental and computational evidence, lithium appears to preferentially bind to the phenol and methoxy substituents on the aromatic ring of monolignols. The strength of this interaction increases with the number of methoxy substituents (S > G > H). This work serves as a basis of understanding for future work in developing lithium adducted lignin mass spectrometric analytical methods.

We demonstrate that lithium metal is sparingly soluble in poly(ethylene oxide) (PEO). 7Li NMR shows that when a PEO sample is placed in contact with lithium metal at elevated temperatures, a lithium species dissolves and diffuses into the bulk polymer. A lithium/PEO/lithium electrochemical cell, containing no lithium salts, shows increasing conductivity over time when annealed at 120 °C. Chronoamperometry shows that the annealed cell obeys Ohm’s law, implying that conduction occurs without the development of concentration gradients. To explain the results, it is proposed that atomic lithium dissolves into PEO, where it exists as a lithium cation and free electron. The dissolution of lithium also affects the phase behavior of block copolymer electrolytes. These observations explain the strong adhesion between lithium metal and PEO and have important implications for lithium metal battery systems that contain PEO-based electrolytes.

The question of the number of carbonate molecules in the first coordination shell of the lithium cation is outstanding. This query has been already answered for cyclic carbonates like ethylene carbonate (EC), demonstrating a coordination number of 4. In this work, we attempt to solve such a problem for three linear carbonates including dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), and diethyl carbonate (DEC). For this purpose, we have calculated various Li+–carbonate clusters with the coordination number from 1 to 4 by using density functional theory at the B3LYP/6-31+G (d, p) level. A discussion has been made on favoring of Li+···O=C interaction over Li+···OC2 interaction in the coordination process of carbonates to the lithium cation. The IR spectra of the optimized clusters have been also computed to improve understanding of the Li+ interaction with the carbonyl group of the solvent. Thermodynamic functions of the coordination process such as Gibbs free energy (ΔG), heat of formation (ΔH), and entropy (ΔS) as well as binding energy (Ebin) have been obtained to explain the effect of alkyl chain of carbonates on the coordination. Our calculations show that the number of linear carbonate solvents coordinated directly to the lithium cation can be up to 3. Furthermore, it is observed that the interaction strength of the studied three solvents with Li+ is in the sequence DEC > EMC > DMC. This indicates that the dissociation constant of a lithium salt as an effective parameter for lithium-ion batteries could be higher in diethyl carbonate.

For the first time, the effect of minor structural changes to the electrolyte salt on solution properties is investigated experimentally. It was achieved by decomposition of the overall changes into individual components. It allowed to obtain information on the contradicting effects influence on the final result. This study is focused on comparison of two lithium salts: lithium 4,5-dicyano-2-(trifluoromethyl) imidazolide (LiTDI) and lithium 4,5-dicyano-2-(pentafluoroethyl) imidazolide (LiPDI). LiTDI is a very promising salt for lithium-ion battery application. PDI− anion differs from TDI− only in length of perfluorinated alkyl chain. Triethylene glycol dimethyl ether (triglyme) solutions of both salts in a wide range of concentrations were prepared. Triglyme was chosen as a solvent due to number of oxygen atoms which allows for fulfilment of lithium cation coordination sphere. Use of such similar salts in a model system allows us to find the correlation between salt structure and properties of electrolyte. Conductivity, viscosity, lithium transference number, thermal properties and FTIR spectra were measured for all solutions. Ionic fractions were also estimated by Fuoss-Kraus formalism. Obtained results showed that electrochemical properties of electrolyte are result of several opposing factors. Transference numbers are mostly dependent on association. We have also observed interesting correlation between thermal properties and conductivity.

Cooperativity is an important and ubiquitous concept whose origin is still not well appreciated. Using the new quantitative measure of this concept that we recently proposed, in this work, we investigate the origin of negative cooperativity for two ionic systems, either a lithium cation or fluorine anion embedded in an argon cluster with up to 20 argon atoms. This measure is found to be strongly correlated with thermochemistry quantities like enthalpy and Gibbs free energy. Dependences of negative cooperativity on density functionals and basis set are examined. Two energy decomposition schemes are employed to investigate the origin of the cooperativity effect. Quantities from the information-theoretic approach have also been utilized to pinpoint the origin. We find that the characteristics of negative cooperativity for ionic clusters is its strong correlation with information gain and Renyi entropy, which are closely related to nucleophilicity, nucleophilicity, and quantum entanglement. These results should shed new light in appreciating cooperativity effect and its impact on chemical reactivity in many chemical and biological systems.

Compounds containing biguanide moiety, such as buformin, phenformin, and metformin are well recognized for their antihyperglycaemic action. Imeglimin is a dihydro-1,3,5-triazine that can be conside...

The density functional theory method at the M06-2X/6-31G(d,p) level was used to calculate the optimal geometry and thermodynamic parameters of formation of the Li+CF3SO3− and Li+@C60(CF3SO3−) ion pairs, as well as topological characteristics of the electron density distribution in the critical point (3,‒1) of bonds between lithium cation endofullerene Li+@C60, and the triflate anion in a vacuum and in chlorobenzene.

According to DFT/M06-2X/6-311G(d,p) calculations, the binding energy of the lithium cation with benzene and polycyclic aromatic hydrocarbons of the general formula C6n2H6n (n = 2–5) increases in the order C6H6 < C24H12 < C54H18 < C96H24 < C150H30 and tends for saturation. The Li+···C6n2H6n bonds are characterized by a considerable dynamic instability and predominant π contribution.

A series of halogen bonding and chalcogen bonding phenanthroline containing heteroditopic macrocyclic receptors exhibit cooperative recognition of lithium halide (LiX) ion-pairs. Quantitative 1H NMR ion-pair titration experiments in CDCl3 : CD3CN (1 : 1, v/v) reveal a co-bound lithium cation switches on halide anion binding, most notably with the halogen bonding host system. The employment of bis- iodo- and telluromethyl-triazole sigma–hole donor motifs endows contrasting halide anion selectivity and binding affinity, with the halogen bonding ditopic host capable of exclusively binding lithium chloride whereas the chalcogen bonding ditopic receptor displays notable selectivity for lithium iodide over lithium bromide. Preliminary solid–liquid extraction experiments demonstrate the potential of sigma–hole mediated ion-pair recognition as a promising strategy for lithium salt recovery.

As the world transitions away from fossil energy to green and renewable energy,electrochemical energy storage increasingly becomes a vital component of the mix to conduct thistransition. The central goal in developing next-generation batteries is to maximize gravimetric andvolumetric energy density, battery cycle life and improve safety. All solid-state batteries using asolid electrolyte and a lithium metal anode represent one of the most promising technologies thatcan achieve this goal. Highly conductive solid electrolytes (>10 mS·cm-1) are the key componentto remove the safety concerns inherent with flammable organic liquid electrolyte and achieve highenergy density by enabling high active material loading. Considering a range of inorganic solidelectrolytes that haven been developed to date, sulfide solid electrolytes exhibit highest ionicconductivity that even surpasses that of conventional organic liquid electrolytes. Argyrodite-structured sulfide solid electrolytes are one of the most promising materials in this class and arecurrently the dominantly used solid electrolyte for all solid-state battery fabrication. Argyroditesolid electrolytes are particularly appealing, owing to their ultra-high Li-ion conductivity, quasistablesolid electrolyte interphase (SEI) formed with Li metal and their ability to be prepared viascalable solution-assisted synthesis approaches. These factors are all vital for commercialapplications.In this Account, we afford an overview of our recent development of several argyroditesuperionic conductors, including Li6.6Si0.6Sb0.5S5I (24 mS·cm-1), Li6.6Ge0.6P0.4S5I (18 mS·cm-1) andLi5.5PS4.5Cl1.5 (12 mS·cm-1), and a comprehensive understanding of the origin of the underlyinghigh conductivity: namely sulfide/halide anion site-disorder and Li cation site disorder. A highdegree of sulfide/halide anion site-disorder (changes in anion distribution) modifies the anioniccharge that in turn strongly influences the lithium distribution. A more inhomogeneous chargedistribution in anion-disordered systems generates a spatially diffuse and delocalized lithiumdensity resulting in faster ionic transport. Lithium cation site-disorder generated by increasing Licarrier concentration through aliovalent substitution, creates high-energy interstitial sites for Liion diffusion which activate concerted ion migration and flatten the energy landscape for Li iondiffusion. This enables high conductivity in Li-rich argyrodite superionic conductors. Theseconcepts are also expected to promote rational new solid electrolyte design and fundamentalunderstanding of the structure - ion transport relationships in inorganic ionic conductors.Collectively, a comprehensive and deep understanding of the interphase formation betweenargyrodite solid electrolytes and cathode active materials/Li metal, and the failure mechanism ofall solid-state batteries with argyrodite solid electrolytes, will lead to the bottom-up engineering of the cathode/anode-solid electrolyte interfaces, which will accelerate the development of safe, highenergy density all solid-state lithium batteries.

Lithium metal is among the most promising anodes for the next generation of batteries due to its high theoretical energy density and high capacity. Challenges such as extreme reactivity and lithium dendrite formation have kept lithium metal anodes away from practical applications. However, the underlying mechanisms of Li ion deposition from the electrolyte solution onto the anode surface are still poorly understood due to their inherent complexity. In this work, density functional theory calculations and thermodynamic integration via constrained molecular dynamics simulations are conducted to study the electron and ion transfer between lithium metal slab and the electrolyte in absence of an external field. We explore the effect of the solvent chemistry and structure, distance of the solvated complex from the surface, anion-cation separation, and concentration of Li-salts on the deposition of lithium ions from the electrolyte phase onto the surface. Ethylene carbonate (EC), 1,2-dimethoxyethane (DME), 1,3-dioxolane (DOL), and mixtures of them are used as solvents. These species compete with the salt anion and the Li cation for electron transfer from the surface. It is found that the structure and properties of the solvation shell around the lithium cation has a great influence on the ability of the cation to diffuse as well as on its surrounding electron environment. DME molecules allow easier motion of the lithium ion compared with EC and DOL molecules. The slow growth approach allows the study of energy barriers for the ion diffusion and desolvation during the deposition pathway. This method helps elucidating the underlying mechanisms on lithium-ion deposition and provides a better understanding of the early stages of Li nucleation.

Lithium cations have been shown to impart an electrostatic Stark effect on molecules bound to mesoporous metal oxides commonly used in dye-sensitized solar cells. Herein, using the Barrera-Crivelli-Loeb theoretical model accompanied by Time Dependent Density Functional Theory calculations, we examined the influence that lithium cations have on the performance of dye-sensitized solar cells that incorporate [Ru(dmb)2(dcbH)]2+ sensitizers, where dmb is 4,4′-dimethyl-2,2′-bipyridine and dcbH is 4,4′-dicarboxylic acid-2,2′-bipyridine was examined. Simulations suggest that an enhanced photocurrent occurs in the presence of lithium cations, which is attributed to the photochemical generation of an excited-state dye–lithium adduct. In this adduct, a lithium cation is interacting with the carbonyl moieties of the dcbH ligands, which results in a bathochromic shift of the [Ru(dmb)2(dcbH)]2+ metal-to-ligand charge-transfer spectral band. This shift in absorption can be canceled by introducing a hypothetical dipolar electric field of 7.3 MV/cm, in good agreement with experimentally reported values for Stark effects observed under solar excitation of TiO2 functionalized with these types of sensitizer molecules. This indicates that lithium cations not only interact with the metal-oxide semiconductor, as shown previously, but also interact directly with the dye upon photoexcitation, something that should be considered when designing and evaluating new sensitizers.

Ionic liquids have gained immense popularity in recent decades due to a combination of unique properties. Despite the widespread use of ionic liquids mixtures with aprotic dipolar solvents in electrochemistry, it remains relevant to predict their macroscopic, primarily transport, properties based on the microscopic picture of the entire set of interparticle interactions in such systems. The method of molecular dynamics simulation (MDS) is one of the most powerful tools for solving problems of this kind. However, one of the unsolved problems of the classical MDS of ion-molecular systems is the correct accounting of polarization effects. Recently it was proposed to use a variation of the effective ion charges in solutions to solve this task. This paper presents the results of the MDS structural and dynamic properties of 1-butyl-3-methylimidazolium (BmimBF4) and lithium (LiBF4) tetrafluoroborates solutions in propylene carbonate (PC) at 298.15 K in NPT ensemble using GROMACS and MDNAES software packages. The possibility of reproducing the experimental dynamic properties (diffusion coefficients of cations and solvent, viscosity, and electrical conductivity) of binary systems based on mixtures of ionic liquids with PC in a wide concentration range was shown. Polarization effects were taken into account by reducing the partial charges of the ion atoms. The structure of the solvation shell of cations was studied within the framework of radial distribution functions, distribution of coordination numbers and the presence of hydrogen bonds between the organic cation and solvent molecules. The results point to stronger and more structured solvation shell of the Li+ cation compared to Bmim+, which is consistent with the conclusions about the mobility of these cations. The reorientation times of propylene carbonate molecules and their lifetimes in the framework of the first solvation shells of the cations are several times higher for the lithium cation.

We evaluated the Coulombic interactions of the lithium cation in the separator membrane of lithium secondary batteries in terms of the morphological factors of the separator membrane and the solvat...

The self-diffusion coefficients of the lithium cation (D(Li+)) and counter anion (D(anion)) in the molten lithium amide, such as lithium bis(fluorosulfonyl)amide (Li[FSA]) and lithium fluorosulfonyl(trifluoromethylsulfonyl)amide (Li[FTA]), were measured by a pulsed-gradient spin-echo nuclear magnetic resonance (PGSE-NMR) method. Relationships between viscosity and the resulting self-diffusion coefficient (the D(Li+) is 1.4×10–11 m2·s–1 and the D(anion) is 5.5×10–12 m2·s–1 for the Li[FSA] and the D(Li+) is 1.7×10–12 m2·s–1 and the D(anion) is 6.6×10–13 m2·s–1 for the Li[FTA]), the Li[FTA] and Li[FSA] have a stronger intercalation between ions than the high temperature lithium molten salts. However, their ionic conductivities are higher than those estimated by D(Li+) and D(anion), specifically, that of the Li[FTA] is three times higher. Therefore, the Li[FTA] would have special conductive behavior, which leads to the superionic nature on the Walden Plot and high rate performance against much high viscosity ...

Differential ion mobility spectrometry (DIMS) can be used to separate isomeric and isobaric ions, which are difficult to distinguish with mass spectrometry alone. Three peaks were observed while performing DIMS-MS for both lithium cationized glucose and lithium cationized levoglucosan. Glucose has a large number of potential structures for its small size. The different peaks could be caused by differences in glucose anomericity, pyranose versus furanose forms, ring conformation, or the lithium cation binding site. However, the bicyclic structure of levoglucosan is more constrained and less likely to result in different structures than glucose. The three peaks for both compounds were found to originate from the monomer, post-DIMS fragmentation of a homodimer, and post-DIMS fragmentation of a heterodimer with a common contaminant, erucamide. This post-DIMS fragmentation occurs in the ion transfer optics and can lead to erroneous conclusions about the peaks in a DIMS spectrum where dimers are present. Dimers are commonly observed when using metal cationization, where over 10% of the glucose and levoglucosan was observed as a lithium cation bound dimer, even at concentrations as low as 0.1 μM.

For lithium halides, LiX (X = Cl, Br and I), hydrates with a water content of 1, 2, 3 and 5 moles of water per formula unit are known as phases in aqueous solid–liquid equilibria. The crystal structures of the monohydrates of LiCl and LiBr are known, but no crystal structures have been reported so far for the higher hydrates, apart from LiI·3H2O. In this study, the crystal structures of the di- and trihydrates of lithium chloride, lithium bromide and lithium iodide, and the pentahydrates of lithium chloride and lithium bromide have been determined. In each hydrate, the lithium cation is coordinated octahedrally. The dihydrates crystallize in the NaCl·2H2O or NaI·2H2O type structure. Surprisingly, in the tri- and pentahydrates of LiCl and LiBr, one water molecule per Li+ ion remains uncoordinated. For LiI·3H2O, the LiClO4·3H2O structure type was confirmed and the H-atom positions have been fixed. The hydrogen-bond networks in the various structures are discussed in detail. Contrary to the monohydrates, the structures of the higher hydrates show no disorder.

Li6-xZr2-xAxO7 (A = Nb, Ta) system with 0 &lt, x &lt, 0.30 is synthesized by glycine-nitrate method. Boundaries of solid solutions based on monoclinic Li6Zr2O7 are determined, temperature (200–600 °C) and concentration dependences of conductivity are investigated. It is shown that monoclinic Li6Zr2O7 exhibits better transport properties compared to its triclinic modification. Li5.8Zr1.8Nb(Ta)0.2O7 solid solutions have a higher lithium-cation conductivity at 300 °C compared to solid electrolytes based on other lithium zirconates due the “open” structure of monoclinic Li6Zr2O7 and a high solubility of the doping cations.