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All-solid-state batteries (ASSBs) are one of the most forthcoming elements of the electrochemical energy systems of new generation. One of the most attractive perspectives of using all-solid- state batteries as the platform for energy storage is the increased safety, energy density and possible device miniaturization. During the last decades the intensive research of the solid state electrolyte materials has been observed. Among the most investigated and attractive candidates for Li-ion batteries one can distinguish the garnet-structured solid electrolytes, NASICONs, LGPS electrolytes and argyrodites. Despite the ever-growing interest to ASSB technologies there is a room in their chemistry to be explored especially concerning the aspects of the defects, vibrational characteristics, strain- and facet-engineering effects. The aim of this study is to investigate the possible role of composition, disorder and the synthesis details on the Li-ion conductivity and activation energies in garnet-structured solid electrolytes.

Composites based on electrochemically active components, LiFePO4, LiMn2O4 and LiNi0.82Co0.18O2, for the use as cathode materials for lithium-ion batteries were synthesized using ultrasonic treatment. The effects of the sonication mode (series LiFePO4–LiMn2O4) and component ratio (series LiFePO4–LiNi0.82Co0.18O2) on the electrochemical performance of the resulting composites were studied. The obtained composites were examined by scanning electron microscopy and powder X-ray diffraction and tested in coin-type cells with lithium anode. Positive electrodes based on the obtained composites showed enhanced electrochemical performance.

In this work, we consider influence of synthesis procedures, applying coatings, and formation of core-shell structures on the electrochemical performance of Ni-rich and Li-rich oxides. Li-rich Li1.2Mn0.54Ni0.13Co0.13O2 cathode materials synthesized by different synthesis procedures exhibit different electrochemical behavior, especially those obtained by sol-gel combustion method. The TEM findings reveal the presence of monoclinic and trigonal phases in the Li-rich materials synthesized. TEM/ED/EDX microanalysis shows that the C2/m monoclinic phase appears to have a variable composition Li2[M]O3, where [M] = (Mn, Ni, Co). Whence, on the basis of monoclinic phase we can observe a restricted solid solution with 4 h-Wyckoff Mn-cation positions potentially being occupied by the mixture of three 3d-metal cations [M] = (Mn, Ni, Co). The cyclability of Li-rich oxides is improved by thin alumina films deposited by ALD directly on porous electrodes. The better capacity retention of modified electrodes is explained by suppressing reactions with electrolyte accompanied by growth of SEI film on cathode. The core-shell structures with Ni-rich core and gradient shell enriched with Mn were obtained by coprecipitation and applying the shell material onto LiNi0.8Co0.15Al0.05O2 as received. These structures show better cyclability and rate capability in the extended voltage range of 2.5–4.4 V than the core materials.

Lithium-rich transition metal complex oxides of the general composition xLi2MnO3• •(1–x)LiMO2 (M = MnaNibCoc, a + b + c = 1) were synthesized by coprecipitation and modified Pechini method. The influence of the oxide phase composition on their electrochemical performance as cathode materials was studied in lithium half-cells. Effects of the synthetic approach and synthesis conditions on the morphology and electrochemical characteristics of the materials obtained were considered. The composition 0.35Li2MnO3• •0.65LiMn1/3Ni1/3Co1/3O2 demonstrates the highest discharge capacity retention during cycling. The samples with discharge capacity of 290 mA h g–1 were obtained.

Li-rich layered oxides Li1.2Mn0.54Ni0.13Co0.13O2 were synthesized by modified Pechini method using various compositions of the reaction mixture. Difference in the electrochemical performance of cathodes on their basis is explained by different morphology and microstructure of the materials. The porous hierarchical structure favors a better electrochemical performance. The presence of defects, including crystal twins, in the samples is considered to be a major reason that leads to their poor cyclability and rate capability.

Layered Li-rich transition metal oxides are considered among the most promising cathode materials for high energy density lithium-ion batteries. It was studied how the method and conditions of synthesis of Li-rich oxides Li1.2Mn0.54Ni0.13Co0.13O2 affect their electrochemical properties. Coprecipitation methods and modified Pechini process were used. It was shown that it is necessary to carefully choose the synthesis conditions when using the modified Pechini method because of their significant effect on the morphology of Li-rich oxides. Samples were obtained with high electrochemical characteristics: capacity discharge of 260–270 mAh/g (16 mA/g) and 60–70 mAh/g (988 mA/g) within the voltage range of 2.5–4.8 V.

This paper examines the possibilities of using nanoionics principles in developing the technology of novel materials for electrochemical power generation. We analyze data on ceramic membranes with increased oxygen or lithium ion conductivity for cathodes of lithium ion batteries and components of solid oxide fuel cells. It is shown that, to improve the power characteristics of such electrochemical devices, use can be made of completely amorphous nanocomposites produced using synthetic techniques that take into account controlled incommensurability of the structures of interacting components. We assess the potential advantages of using the concepts of “mixed” and nonautonomous phases forming in eutectic and eutectoid systems obtained using electrochemically active inorganic structures.

A method has been proposed for the fabrication of cathode materials for lithium-ion batteries using composites from electrochemically active phases and ultrasonic processing. We have studied the influence of ultrasonic processing medium and intensity on the properties of the materials. The results demonstrate that the composites possess better electrochemical performance than do their constituent components.

Correction for ‘Materials space of solid-state electrolytes: unraveling chemical composition–structure–ionic conductivity relationships in garnet-type metal oxides using cheminformatics virtual screening approaches’ by Natalia Kireeva et al., Phys. Chem. Chem. Phys., 2017, 19, 20904–20918, DOI: 10.1039/c7cp00518k.

This paper discusses some problems of physicochemical analysis and examines the possibility of gaining insight into the mechanisms underlying the crystallization behavior of inorganic alloys. As a model, we use a eutectic T-x system with two phase-forming structural components and limited solid solutions based on them. We demonstrate that the supramolecular theory of eutectics and current views of solid-state determined can be helpful in predicting the forming metastable structural states.

New possibilities to improve the transport characteristics of ceramic electrode materials, which are important for improvement high-energy electrochemical devices, lithium-ion batteries (LIBs), and solid oxide fuel cells (SOFCs), have been determined. Since the full-scale search for new electrochemically active inorganic structures does not promise substantial progress, it is topical to use the possibilities associated with optimizing the structural parameters of already known materials. It is shown that an enhancement in the specific power of these devices associated with an increase in the ionic conductivity of electrode materials can be achieved at the expense of a combination of size effects and experimentally proven effects of amorphization, i.e., the effects of nonautonomic phases formed on the interfaces of composites from incommensurate structural elements. They can provide a substantial increase in the diffusion mobility of lithium and oxygen ions at intergrain and interphase boundaries. Simple experimental methods to obtain such multi-structured nanomaterials based on electrochemically active phases for LIB positive electrodes are proposed.

One characteristic feature that differentiates inorganic host-guest systems of supramolecular chemistry from conventional architectures, which typically build on the use of organic or organoelement ligands, is the necessity of taking into account phase transitions, which may be caused by changes in charges and thermodynamic conditions. This is left out of consideration in the existing postulates of supramolecular chemistry. This paper examines the feasibility of applying the ideology of supramolecular chemistry to inorganic systems.

Intercalated group IVB-VIB metal disulfides and diselenides MX2 (M = Ti, Zr, Nb, Mo) can be obtained by electrochemical reduction of the corresponding MX2 in the presence of tetraalkylammonium salt. An original approach was used, which allowed effective reduction of these insoluble substances in the form of powders suspended in an organic solvent using the standard electrolysis technique in solutions in a one-space electrolyzer with a soluble anode. Using electron transfer mediators in the process afforded intercalated compounds with yields of 60–100%.

This paper examines the possibilities of using nanoionics principles in developing the technology of novel materials for electrochemical power generation. We analyze data on ceramic membranes with increased oxygen or lithium ion conductivity for cathodes of lithium ion batteries and components of solid oxide fuel cells. It is shown that, to improve the power characteristics of such electrochemical devices, use can be made of completely amorphous nanocomposites produced using synthetic techniques that take into account controlled incommensurability of the structures of interacting components. We assess the potential advantages of using the concepts of “mixed” and nonautonomous phases forming in eutectic and eutectoid systems obtained using electrochemically active inorganic structures.

Author(s): Fechner, Uli; de Graaf, Chris; Torda, Andrew E; Gussregen, Stefan; Evers, Andreas; Matter, Hans; Hessler, Gerhard; Richmond, Nicola J; Schmidtke, Peter; Segler, Marwin HS; Waller, Mark P; Pleik, Stefanie; Shea, Joan-Emma; Levine, Zachary; Mullen, Ryan; van den Broek, Karina; Epple, Matthias; Kuhn, Hubert; Truszkowski, Andreas; Zielesny, Achim; Fraaije, Johannes Hans; Gracia, Ruben Serral; Kast, Stefan M; Bulusu, Krishna C; Bender, Andreas; Yosipof, Abraham; Nahum, Oren; Senderowitz, Hanoch; Krotzky, Timo; Schulz, Robert; Wolber, Gerhard; Bietz, Stefan; Rarey, Matthias; Zimmermann, Markus O; Lange, Andreas; Ruff, Manuel; Heidrich, Johannes; Onlia, Ionut; Exner, Thomas E; Boeckler, Frank M; Bermudez, Marcel; Firaha, Dzmitry S; Holloczki, Oldamur; Kirchner, Barbara; Tautermann, Christofer S; Volkamer, Andrea; Eid, Sameh; Turk, Samo; Rippmann, Friedrich; Fulle, Simone; Saleh, Noureldin; Saladino, Giorgio; Gervasio, Francesco L; Haensele, Elke; Banting, Lee; Whitley, David C; Oliveira Santos, Jana Sopkova-de; Bureau, Ronan; Clark, Timothy; Sandmann, Achim; Lanig, Harald; Kibies, Patrick; Heil, Jochen; Hoffgaard, Franziska; Frach, Roland; Engel, Julian; Smith, Steven; Basu, Debjit; Rauh, Daniel; Kohlbacher, Oliver; Boeckler, Frank M; Essex, Jonathan W; Bodnarchuk, Michael S; Ross, Gregory A; Finkelmann, Arndt R; Goller, Andreas H; Schneider, Gisbert; Husch, Tamara; Schutter, Christoph; Balducci, Andrea; Korth, Martin; Ntie-Kang, Fidele; Gunther, Stefan; Sippl, Wolfgang; Mbaze, Luc Meva'a

Considering chalcogenide transport processes with a participation of indium and indium sulfides in the closed system it was found that non-isothermal conditions are insufficient for a noticeable reversible indium transfer. The main reason for this fact was considered as a deficiency of indium halides with a high oxidation degree of indium which are in the equilibrium in the vapor with condensed indium or its lower sulfides. To provide chemical transport that is impossible in the usual experimental conditions a new way was proposed and applied implying dilution of a charge (source or getter of indium) with inactive diluent. One of the probable diluents is gold. The probability of reversible and selective chemical transport was proved for indium in the system “indium sulfides – vapor of In chlorides – (Au–In) charge”. Conditions for performing the non-destructive composition control of indium sulfides in the non-destructive chemical transport were determined.

Changes in inorganic systems associated with the formation of metastable states and their relaxation are considered using supramolecular theory of eutectics. After analysis of the existing theories and concepts describing possible transition mechanisms of nonequilibrium amorphous structures to a crystalline state, the conclusion that there is poor correspondence of experimental data to those theories is made. Owing to the complexity of relaxation processes, it was proposed to divide the objects of investigation into groups considering the different interaction potentials and size parameters of substructures. Inorganic binary eutectic systems were classified as a special group. The peculiarities of the relaxation processes in quenched non-autonomous phases are shown in a few examples with consideration of characteristic temperatures and time.

New data in favor of the supramolecular theory of eutectics are given. It is shown that, on the basis of metastable states appearing in eutectic compositions, new materials having a functional purpose can be obtained. The concept that explains the pseudo-single-phase character and defect structure of such states allows these specific features to be used for obtaining a composite cathode material for rechargeable lithium-ion batteries. On the basis of postulates of the theory and a series of experimental data, a technique for the synthesis of such a material is developed; the efficiency of its application is shown.

We have studied the effect of surface modification with aluminum hydroxide and alumina-boehmite mixtures on the electrochemical performance of an equimolar LiCoO2/LiMn2O4 composite cathode material. A process has been developed for the deposition of aluminum hydroxide nanocoatings using ultrasonic processing. Al(OH)3 nanocoatings, as well as alumina-boehmite nanocoatings, considerably improve the cyclability of the composite in an extended voltage range (up to 4.5 V) in comparison with the unmodified material, with an insignificant reduction in specific capacity in the first cycles. Both types of coatings markedly improve the cyclability of the composite at high current rates in comparison with the unmodified composite.

A process has been developed for surface modification of an equimolar LiCoO2-LiMn2O4 composite with a mixture of alumina (Al2O3) and boehmite (AlO(OH)). The alumina: boehmite ratio and pH value have been optimized in order to achieve adequate surface adhesion between the coating and powder and good homogeneity of the nanocoatings. The effects of ultrasonic processing, coating conditions, and thermal annealing have been examined. The results demonstrate that the nanocoatings considerably improve the cyclability of the composite in an extended voltage range (up to 4.5 V) in comparison with the unmodified material and slightly increase its average discharge voltage.

Voltammetry was used to study the charge state of molybdenum disulfide nanoparticles in single-layer aqueous dispersions obtained by hydration of LiMoS2. MoS2 nanoparticles were shown to have a negative charge. Nanodispersed MoS2 can be used to deposit Cu-MoS2 coatings. The influence of some deposition parameters (electrolyte composition, current mode) on the coating composition was determined.

The stability and specific properties of metastable states in multicomponent systems are considered in terms of supramolecular chemistry. Some logical, theoretical, and experimental evidences are presented in favor of the supramolecular concept of eutectics allowing for the interaction between incommensurate substructures. A possibility of self-assembly of interacting initial substructures and formation of nonautonomous phases in melt is shown.

The notion of a soliton as a quasiparticle in the Frenkel–Kontorova system is substantiated. This allows the use of the diffusive model for the description of the processes of soliton creation and disappearance at the chain ends. The Frenkel–Kontorova model is modified through the addition of barriers with certain height and concentration to the pinning profile of the potential energy surface for the soliton motion along the chain. The ratio of the relaxation times in ideal and defective systems is estimated, and it is shown that the relaxation rate can be reduced by ten and higher orders of magnitude under quite reasonable assumptions.

The T - x phase diagram of the In-S system has been studied by differential thermal analysis and x-ray diffraction between 300 and 1150 ° C. The compounds identified in this temperature range are InS, In 6 S 7 , In 3 S 4 , and In 2 S 3 . We have determined the temperatures of the monotectic equilibrium L 1 (In) + InS = L 2 ; peri- tectic equilibria involving InS, In 6 S 7 , and In 3 S 4 ; and polymorphic transformations of InS and In 2 S 3 . Our results demonstrate that raising the cooling rate to a certain level leads to a sharp transition from near-equilibrium to metastable phase relations in the In-S system.

We have prepared composite cathode materials based on two electrochemically active compounds, LiCoO2 and LiMn2O4, and investigated their properties. The results indicate that the discharge capacities of all the materials studied exceed the additivity rule values calculated from the discharge capacities of the starting materials. The effect of heat treatment on the physicochemical properties of the composites is analyzed.

In this study, some features that distinguish inorganic supramolecular host-guest objects from traditional architectures are considered. Crystalline inorganic supramolecular structures are the basis for the development of new functional materials. Here, the possible changes in the mechanism of crystalline inorganic supramolecular structure self-organization at high interaction potentials are discussed. The cases of changes in the host structures and corresponding changes in the charge states under guest intercalation, as well as their impact on phase stability and stoichiometry are considered. It was demonstrated that the deviation from the geometrical and topological complementarity conditions may be due to the additional energy gain from forming inorganic supramolecular structures. It has been assumed that molecular recognition principles can be employed for the development of physicochemical analysis and interpretation of metastable states in inorganic crystalline alloys.

The main concepts of the theory of eutectics are analysed. The most essential results of investigations on eutectic alloys of inorganic compounds are surveyed. Evidence in favour of the supramolecular concept of eutectics is presented. This concept takes into account interactions of incommensurate substructures and gives an insight into the mechanisms of formation of supramolecular eutectic assemblies in boundary regions ('non-autonomous phases'). Using the static one-dimensional Frenkel — Kontorova model for finite systems, it is shown that the consideration of these mechanisms in terms of supramolecular chemistry simplifies analysis of the behaviour of inorganic eutectic systems in the course of crystallisation under conditions both close to and far from equilibrium, including crystallization upon quenching and under external actions. The supramolecular concept bridges gaps between the definitions 'compound', 'eutectic' and 'solution' in physicochemical analysis. The bibliography includes 83 references.

Differential scanning calorimetry and temperature-dependent magnetic susceptibility measurements demonstrate that the misfit layer compounds (SnS)1.15(TaS2) and (PbS)1.14(TaS2) undergo a few phase transitions between 2 and 700 K. The transitions are interpreted as due to the incommensurability of the suprastructure components. The heat capacity data indicate that the properties of the misfit layer compounds do not obey the additivity rule.

Incommensurability of interacting sublattices in inorganic suprastructures can lead to formation of defects, including fragmentation of one of the sublattices. A theoretical approach is proposed, which is based on the analytical and numerical studies of the static one-dimensional Frenkel–Kontorova model for chains of finite length. This approach provides the possibility of relating geometric and energy parameters of the interacting sublattices to the values of bond deformations that arise. These deformations, in turn, may result in the fragmentation of one of the sublattices and formation of imperfect structures.

In this study, some features that distinguish inorganic supramolecular host-guest objects from traditional architectures are considered. Crystalline inorganic supramolecular structures are the basis for the development of new functional materials. Here, the possible changes in the mechanism of crystalline inorganic supramolecular structure self-organization at high interaction potentials are discussed. The cases of changes in the host structures and corresponding changes in the charge states under guest intercalation, as well as their impact on phase stability and stoichiometry are considered. It was demonstrated that the deviation from the geometrical and topological complementarity conditions may be due to the additional energy gain from forming inorganic supramolecular structures. It has been assumed that molecular recognition principles can be employed for the development of physicochemical analysis and interpretation of metastable states in inorganic crystalline alloys.

Li1 – x Mn2 – y Co y O4(x= 0–0.06, y= 0–0.15) spinels were prepared by solid-state reactions and sol–gel processing and were characterized by x-ray diffraction and scanning electron microscopy. The spinels offer satisfactory electrochemical performance and are potentially attractive as cathode materials for rechargeable lithium batteries.

Data on a new class of inorganic incommensurate intergrowth suprastructures, viz., layered misfit compounds, are surveyed and systematised. Physical properties of misfit suprastructures are discussed. Possible mechanisms of the effects of the electronic structure and incommensurability on the structural elements of suprastructures and on their recognition in molecular ensembles are considered. The general criteria for self-organisation of incommensurate suprastructures are proposed and conditions for the fragmentation of one of the sublattices (i.e., conditions for the formation of nanocomposites) are given. The bibliography includes 82 references.

(2000). Oxidizing Intercalation of Layered Structures. Materials Technology: Vol. 15, No. 2, pp. 155-160.

A combined X-ray and electron microscopy analysis was used for structure and microstructure characterisation of the newly synthesized layered compound TaReSe 4 . This compound crystallizes in the hexagonal system with lattice parameters a = b =3.32130(4), c =12.95910(16) A and α = β =90°, γ =120° (space group P 6 3 / mmc , Z =1, D x =9.161 g/cm 3 ). X-ray powder structure refinement confirmed TaReSe 4 as a full structural analogue of 2H-WSe 2 . The defect structure of TaReSe 4 is characterized by the presence of a number of rotation twins with twist angles 9.43°, 13.17°, 17.89°, 21.78°, and 27.79°. Apart from these, a high density of 2D-defects was observed in the (0001) plane. In some cases these results in the formation of an almost periodical “superlattice” with a period along the c axis of about 60 A. A simple geometrical theory for the rotations- (R-) twins on the hexagonal lattice has been developed as well. Experimental results on R-twins fit very well the predicted ones based on an explicit formulae derived in this work. Along with the main phase a small admixture of a superstructure phase ( a ′≈ b ′≈2 a , c ′≈ c /2 and epitaxially grown on TaReSe 4 was found. It was identified from selected area diffraction patterns as the triclinic ReSe 2 phase. A self-consistent structure-physical model for the coexistence of R-twins, 2D-defects and prismatic cluster defects in the material is proposed and discussed in view of the experimental results.

The published data on oxide materials as positive electrodes for lithium-ion batteries are described systematically. The mechanisms of structural changes in cathode materials occurring during the operation of lithium-ion batteries and the problems concerned with their selection are discussed. Modern trends in optimising cathode materials and lithium-ion batteries on the whole are considered. The bibliography includes 167 references.

Data on a new class of inorganic incommensurate intergrowth suprastructures, viz., layered misfit compounds, are surveyed and systematised. Physical properties of misfit suprastructures are discussed. Possible mechanisms of the effects of the electronic structure and incommensurability on the structural elements of suprastructures and on their recognition in molecular ensembles are considered. The general criteria for self-organisation of incommensurate suprastructures are proposed and conditions for the fragmentation of one of the sublattices (i.e., conditions for the formation of nanocomposites) are given. The bibliography includes 82 references.

The development of a new area of thermochemistry (the calorimetry of fluorination reactions) is reviewed. The high reactivity of fluorine offers some important advantages over alternative reagents, but at the same time it introduces some experimental difficulties. We have attempted to generalise the practical problems of fluorine calorimetry by systematically examining a number of specific thermochemical investigations by the most widely adopted modification of the method: fluorine bomb calorimetry. Current developments and possible new applications are reviewed, and the basic experimental procedures and apparatus are described. 86 references.

The mechanisms of the phase transitions in the AaMX2-type intercalates (A-metal, MX2-layered dichalcogenide matrix) occurring upon a change in the stoichiometry (a) are studied. It is shown that maximal stoichiometric ratios, and trends of structural changes in intercalates are determined by stabilization of conduction bands (“electronic stabilization”) of intercalates.