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Lithium nickel oxide (LNO) is an attractive positive electrode active material for lithium ion batteries (LIBs) due to its high reversible specific capacity and absence of cobalt. Nevertheless, it is prone to structural instabilities that lead to rapid capacity fading, safety concerns and shows in average a lower voltage than mixtures with cobalt, limiting its applicability to date. Herein this study introduces the sulfur‐based electrolyte additive, benzo[d][1,3,2]dioxathiole 2,2‐dioxide (DTDPh), to stabilize the LNO electrode and study its effects on interphase compositions by means of complementary electrochemical and spectroscopic techniques. Obtained results demonstrate an improved galvanostatic cycling performance in terms of cycle life and achievable specific discharge capacity that significantly outperform the common film‐forming additive vinylene carbonate (VC). The cycle life is increased from 102 to 147 cycles compared to the baseline electrolyte and the accumulated discharge energy until end of life is increased by 45%. This study furthermore provides strong evidence of a significant cross‐talk and negative interplay between DTDPh and VC when both are present in the electrolyte formulation. Mechanistic consideration based on density functional theory (DFT) calculations suggest the formation of mobile poly(VC) species, which is supported by the results of post mortem analysis of the resulting interphases. [ABSTRACT FROM AUTHOR]

We investigated the effects of X‐ray beam damage during X‐ray photoelectron spectroscopy measurement on LiNiO2 electrodes. The degree of damage induced by lab‐based and synchrotron X‐ray radiation has been compared between pristine and cycled electrodes, highlighting the role of positive solid electrode–electrolyte interphase to protect the cycled LiNiO2 surface from beam damage. The possible steps to avoid or at least reduce the beam‐induced effects are outlined. [ABSTRACT FROM AUTHOR]

Addressing the oxidation state of functional materials such as transition metal oxides is a current critical challenge and requires new methodologies to characterize their electronic structure within surface to bulk resolution at the nanometer scale. One approach to this issue is the combination of co‐localized soft and hard X‐ray photoelectron spectroscopies for a non‐destructive depth profiling. In this work, we demonstrate the capability to characterize the oxidation state of cobalt in LiCoO2 thin films, a model electrode material in the Li‐ion battery field, within the first 15 nm. The capability of the methodology to address the surface evolution of the cobalt oxidation state is tested through a proof of concept surface modification introduced by Ar‐ion sputtering. To address the cobalt local electronic structure at different depths from the extreme surface, we exploited Auger‐free Hard X‐ray photoelectron spectroscopy (HAXPES) spectra to fit the Co 2p core‐level features in the X‐ray photoelectron spectroscopy (XPS) spectra. This approach may pave the way for a better understanding of the surface electronic structure changes in transition metal oxides driven by their applications in a broad range of technologies. [ABSTRACT FROM AUTHOR]

Using Si as anode materials for Li-ion batteries remain challenging due to its morphological evolution and SEI modification upon cycling. The present work aims at developing a composite consisting of carbon-coated Si nanoparticles (Si@C NPs) intimately embedded in a three-dimensional (3D) graphene hydrogel (GHG) architecture to stabilize Si inside LiB electrodes. Instead of simply mixing both components, the novelty of the synthesis procedure lies in the in situ hydrothermal process, which was shown to successfully yield graphene oxide reduction, 3D graphene assembly production, and homogeneous distribution of Si@C NPs in the GHG matrix. Electrochemical characterizations in half-cells, on electrodes not containing additional conductive additive, revealed the importance of the protective C shell to achieve high specific capacity (up to 2200 mAh.g−1), along with good stability (200 cycles with an average Ceff > 99%). These performances are far superior to that of electrodes made with non-C-coated Si NPs or prepared by mixing both components. These observations highlight the synergetic effects of C shell on Si NPs, and of the single-step in situ preparation that enables the yield of a Si@C-GHG hybrid composite with physicochemical, structural, and morphological properties promoting sample conductivity and Li-ion diffusion pathways. [ABSTRACT FROM AUTHOR]

Lithium metal electrodes have been submitted to a long-term storage in contact with carbonated-based electrolyte at different temperatures, with the aim of gaining more understanding on the impact of aging conditions on the lithium metal surface. To do so, the evolution of lithium surface∣electrolyte interface has been monitored via electrochemical impedance spectroscopy, X-ray photoelectron spectroscopy and FE-SEM techniques, to correlate the change of the interface properties with the chemical and morphological modifications at the electrode’s surface. After this aging, lithium electrodes were galvanostatically cycled in symmetric Li∣Li coin cell configuration at 10, 25 and 45 °C. Through this approach, a better cycling stability was observed in those cells stored at 45 °C, which can be ascribed to the more compact lithium electrodeposition than that observed in the rest of cells previously aged at lower temperatures. These results indicate that calendar at high temperature condition benefits lithium electrode performance, which can be attributed to a homogeneous passivation of the metal surface with fluorine and/or phosphate-based compounds, following XPS measurements, which can improve the behaviour of the solid electrolyte interface. [ABSTRACT FROM AUTHOR]

The timely arrival of novel materials plays a key role in bringing advances to society, as the pace at which major technological breakthroughs take place is usually dictated by the discovery rate at which novel materials are identified within chemical space. High‐throughput experimentation and computation strategy, now widely considered as a watershed in accelerating the discovery and optimization of novel materials in virtually every field, enables simultaneous screening, synthesis and characterization of large arrays of different material classes toward identification of the lead candidates for given system and targeted application. However, the ability to acquire data, through the continued advancement of automation platforms and workflows especially in the field of battery research and development, often outpaces the ability to optimally leverage obtained data for improved decision‐making. Closing this gap inevitably calls for adapted algorithms, development of reliable predictive models and enhanced integration with machine learning, deep learning, and artificial intelligence. This Review aims to highlight state‐of‐the‐art achievements along with an assessment of current and future challenges as well as resulting perspectives toward accelerated development of advanced battery electrolytes and their interfaces. [ABSTRACT FROM AUTHOR]

Driven by the continuous search for improving performances, understanding the phenomena at the electrode/electrolyte interfaces has become an overriding factor for the success of sustainable and efficient battery technologies for mobile and stationary applications. Toward this goal, rapid advances have been made regarding simulations/modeling techniques and characterization approaches, including high‐throughput electrochemical measurements coupled with spectroscopies. Focusing on Li‐ion batteries, current developments are analyzed in the field as well as future challenges in order to gain a full description of interfacial processes across multiple length/timescales; from charge transfer to migration/diffusion properties and interphases formation, up to and including their stability over the entire battery lifetime. For such complex and interrelated phenomena, developing a unified workflow intimately combining the ensemble of these techniques will be critical to unlocking their full investigative potential. For this paradigm shift in battery design to become reality, it necessitates the implementation of research standards and protocols, underlining the importance of a concerted approach across the community. With this in mind, major collaborative initiatives gathering complementary strengths and skills will be fundamental if societal and environmental imperatives in this domain are to be met. [ABSTRACT FROM AUTHOR]

Lithium-rich disordered rocksalt Li2TiS3 offers large discharge capacities (>350 mAh·g−1) and can be considered a promising cathode material for high-energy lithium-ion battery applications. However, the quick fading of the specific capacity results in a poor cycle life of the system, especially when liquid electrolyte-based batteries are used. Our efforts to solve the cycling stability problem resulted in the discovery of new high-energy selenium-substituted materials (Li2TiSexS3−x), which were prepared using a wet mechanochemistry process. X-ray diffraction analysis confirmed that all compositions were obtained in cation-disordered rocksalt phase and that the lattice parameters were expanded by selenium substitution. Substituted materials delivered large reversible capacities, with smaller average potentials, and their cycling stability was superior compared to Li2TiS3 upon cycling at a rate of C/10 between 3.0–1.6 V vs. Li+/Li. [ABSTRACT FROM AUTHOR]

Chlorine oxoanions with different oxidation states are introduced in order to correlate the degree of oxidation with the electronic structures of the carbon nanotubes (CNTs). The density functional theory calculations have shown that physisorption is involved at a high oxidation state and selective doping on the metallic nanotubes is seen, whereas chemisorptions have played a key role in modifying the electronic structures of the CNTs at a low oxidation state.

Carbon black (CB) filled elastomers are structurally complex materials that offer unique properties at different length scales. They have tremendous potential applications in a number of fields including the automotive and aerospace industries and for designing innovative smart materials such as artificial muscles but their applications remain limited primarily due to inadequate understanding of their unique mechanical properties. Here, using the Berkovich technique to probe the surface mechanical properties at different scales the nanoindentation response of a series of composites made by homogeneously dispersed CB nanoparticles inside a semicrystalline copolymer matrix has been explored. While the measured loading part of the force–displacement curves is well described by Meyer's empirical power relation, the inverted methodology (IM) approach to deal with the unloading part has been considered and its outcome has been compared with that obtained from the standard Oliver–Pharr's method. The results were consistent with the observed increase of hardness when the applied displacement decreases for all composite samples over a large range of CB volume fraction. Zhang and Xu's model is demonstrated to produce experimentally consistent explanation of this indentation size effect. X‐ray photoelectron spectroscopy (XPS) spectra also show composition gradients with depth up to 100 nm. Furthermore, the effect of CB content, surface features, and length scale‐dependent deformation on the hardness–displacement behavior have been considered. These findings highlight the possibility of attaining a diverse set of mechanical properties by a better understanding of the nanoindentation response of CB filled elastomers which can be useful for material selection and design improvements in a number of practical applications. [ABSTRACT FROM AUTHOR]

A novel well-defined precatalyst for ammonia-selective catalytic reduction of NOx (NH3-SCR), namely, [W(≡CtBu)(CH2tBu)3]/CeO2, was prepared by surface organometallic chemistry and then characterized. Due to the high dispersion of the active phase, this catalyst showed excellent activity after calcination at 500 °C, described by up to 99% conversion of NOx, high N2 selectivity, broad operation temperature window (225–500 °C), and extremely high durability for the selective catalytic reduction of NOx with NH3. [ABSTRACT FROM AUTHOR]

The dependence of the induced morphological layer variations on the processing conditions and parameters during injection molding of polymers is analyzed through a robust numerical framework of the complete microinjection molding cycle. Predicted temperature, heat transfer and viscous dissipation, spherulite diameters, and shear rates provide sufficient clarifications to develop a deeper understanding of the complex evolution of the induced thicknesses of layers. The evolution of the structure of polyoxymethylene (POM) under strong strain rates and high thermal gradients is investigated while flowing along an expanding flow configuration composed of three steps of increasing thickness. High and low mold temperatures and injection velocity levels are tested according to the design of the experiment method (DOE). Morphological development in each zone was examined to provide the induced crystalline layer thickness in the longitudinal as well as the transverse directions using polarized light microscopy (PLM). The thickness of the layers strongly depends on the local thickness of the stepped‐part and on the abrupt dimensional changes. The variation of bulk tensile properties obtained by dynamic mechanical analysis (DMA) is related to the thermomechanical history experienced by the melt. [ABSTRACT FROM AUTHOR]

The present paper reports the energy loss near-edge structure (ELNES) study of monoclinic HfO2 (m-HfO2) and tantalum doped m-HfO2 (Ta0.1Hf0.9O2) thin films prepared by radio frequency magnetron co-sputtering method. A change in the O K-ELNES spectra was observed as the amount of dopant increases. In order to precise the common features and the differences as a function of Ta defect nature (substitutional or interstitial) in HfO2, the O K-ELNES were commented with respect to density functional theory calculations implemented in Vienna ab initio simulation package code. The calculated Ta doped HfO2 band structure showed that substitutional tantalum is the dominant defect and the spectral differences between doped and non-doped HfO2 are mainly originated from the change in the local cation distribution around the oxygen atoms. [ABSTRACT FROM AUTHOR]

We have investigated the core levels and the valence band of (Ge2Sb2Te5)1-x(In3Sb1Te2)x quaternary phase system (IGST) by means of x-ray photoelectron spectroscopy. A systematic shift of Sb 3d and Ge 2p core-level peaks toward lower binding energies side was observed with increasing indium amount, whereas the In 3d and Te 3d core peaks showed less change. The Sb 3d and Ge 2p core-level shift is attributed to an increase in the electronic charge of p-electrons dependent of indium amount. The valence band spectra show a distinct change in the sp configuration with indium concentration change. The change in the local bonding as the indium amount increase has a profound impact on both local atomic arrangement and amorphous-to-crystalline transformation temperature. The difference in the photoemission spectra have been discussed according to a simple structural model suggesting that the Na site in IGST can be occupied by Te, Sb, In, and vacancy, whereas in GST it is occupied only by Te. [ABSTRACT FROM AUTHOR]

The x-ray photoelectron spectroscopy technique is employed to explain the valence bond, as well as the electronic structure of the [([Ge.sub.2][Sb.sub.2][Te.sub.5]).sub.1-x][([In.sub.3]Sb[Te.sub.2]).sub.x] quaternary phase system. A change in the indium concentration is shown to highly affect the valence bond spectra of the system.

Thermal nitridation is adopted to modify [Li.sub.4][Ti.sub.5][O.sub.12] to make it electronically more conductive. Electrochemically induced [Li.sub.4+[delta]][Ti.sub.5][O.sub.15] with a TiN surface layer has increased the electrochemical properties at high current densities.

The modulation of optical properties of single-walled carbon nanotubes (SWCNTs) by Au[Cl.sub.3] doping is examined. The large work function shift has forced the Fermi level of the SWCNTs to be located deep in the valence band, thus invoking a new asymmetric transition in the absorption spectroscopy from a deeper level to newly generated empty states.

The electronic structures of single-walled carbon nanotubes (SWCNTs) were tailored by using various electron-donating and -withdrawing groups in solvents with various aromatic and aliphatic backbones. The results from the experiments suggest that the electronic structures of SWCNTs could be modified by a solvent treatment.

The linear, two-coordinate and isostructural heteroleptic [M(IPr){N(SiMe3)2}] (IPr = 1,3-bis(diisopropylphenyl)-imidazol-2-ylidene), formally MI complexes (M = Co, 3; Fe, 4) were obtained by the reduction of [M(IPr)Cl{N(SiMe3)2}] with KC8, or [Co(IPr){N(SiMe3)2}2] with mes*PH2, mes* = 2,4,6-tBu3C6H2. The magnetism of 3 and 4 implies CoII and FeII centres coupled to one ligand-delocalized electron, in line with XPS and XANES data; the ac susceptibility of 4 detected a pronounced frequency dependence due to slow magnetization relaxation. Reduction of [Fe(IPr)Cl{N(SiMe3)2}] with excess KC8 in toluene gave the heteronuclear ‘inverse-sandwich’ Fe–K complex 7, featuring η6-toluene sandwiched between one Fe0 and one K+ centre. [ABSTRACT FROM AUTHOR]

Copper/copper oxide (Cu/Cu2O) electrodes are known to display interesting electrocatalytic performances for the reduction of CO2, and thus, deserve further investigation for optimization. Here, we show that the addition of nitrogen- based organic additives greatly improves the activity of these electrodes (higher current densities, greater selectivity, and higher faradaic yields). The best effector is found to be tetramethyl cyclam. For example, electrolysis at -2.0 V versus Fc+/Fc in CO2-saturated DMF/H2O (99:1, v/v) in the presence of this effector results in formic acid with almost 90% faradaic yield. SEM and XPS analysis of the electrode surface reveals that the organic additive promotes the formation of active Cu0 nanoparticles from Cu2O during electrolysis. This simple approach provides a straightforward strategy toward the optimization of Cu/Cu2O electrodes. [ABSTRACT FROM AUTHOR]

To achieve high-mobility and high-reliability oxide thin film transistors (TFTs), ZnON has been investigated following an anion control strategy based on the substitution of oxygen with nitrogen in ZnO. However, as nitrogen possesses, compared to oxygen, a low reactivity with Zn, the chemical composition of ZnON changes easily, causing in turn a degradation of both the performance and the stability. Here, we have solved the issues of long-time stability and composition nonuniformity while maintaining a high channel mobility by adopting the argon plasma process, which can delay the reaction of oxygen with Zn-O-N; as a result, owing to the formation of very fine nano-crystalline structure in stable glassy phase without changes in the chemical composition, the material properties and stability under e-radiation have significantly improved. In particular, the channel mobility of the ZnON TFTs extracted from the pulsed IV method was measured to be 138 cm²/V s. [ABSTRACT FROM AUTHOR]

We present versatile ZnOxNy applicable to a wide range of imaging/display devices. A well-optimized ZnOxNy material exhibits high mobility exceeding 100 cm2/Vs, bandgap of 1.3 eV and nanocrystalline microstructure with multiphase. Accordingly, the performance of ZnOxNy-based device can be adjustable to meet the requisite of future electronic/photonic device elements. [ABSTRACT FROM AUTHOR]

Carbon serves as one of the best coating materials for the cathode in lithium ion batteries. This is because it can solve two main problems, which are surface deterioration and poor electrical conductivity. However, the conventional carbon coating procedures and, chemical carbonization processes, are especially difficult to implement for the oxide cathode, which could thereby deteriorate the oxide structure. We prepared a new dry 100 nm-thick homogeneous multi-walled carbon nanotube (MWCNT) coating on the high-capacity oxide cathode material, Li1.17Ni0.17Co0.1Mn0.56O2, by applying shear stress without breaking down the crystal structure or morphology of the cathode. The electronic conductivity of the carbon composite with the coated sample is 170 mS cm−1, which is over 40 times as much as the conductivity of the pristine cathode containing the same amount of carbon. In addition, at a high current condition of 2450 mA g−1, a specific capacity of 103 mA h g−1 is observed even with 3 percent of the carbon (in weight) constituting the coated MWCNT. The unconventionally improved performances are explained by the suppression of the electronic resistance and surface charge transfer resistance by electrochemical analyses. [ABSTRACT FROM AUTHOR]

5-Hydroxy-1H-indazole (HI) is investigated as an effective film-forming additive for an over-lithiated layered oxide (OLO) positive electrode. The protective film that is generated by oxidative decomposition of the additive (HI) prior to the carbonate electrolyte is thin and less resistive. As a result, a full cell comprised of OLO/graphite in the HI-added electrolyte gives a better cycling performance. [ABSTRACT FROM AUTHOR]

Does the Li4Ti5O12 electrode need a carbon additive in lithium-ion batteries? We answered this question in our previous work by showing that the partially reduced Ti4+ on the surface of Li4Ti5O12 could provide enough electronic conductivity to initiate the electrochemical process. In this work, we discuss the generally accepted fact that a solid electrolyte interphase (SEI) is hardly formed on the surface of the Li4Ti5O12 electrode owing to its high redox potential by using the carbon-free Li4Ti5O12 electrode to exclude the influences of carbon. In contrast to the previous argument, Li4Ti5O12 was found to have certain reactivity towards electrolytes at room and high temperature (60 °C). Moreover, in the presence of carbon in the electrode (i.e. the conventional electrode formulation), the reactivity of the electrode towards an electrolyte was significantly increased at high temperatures. These results were discussed based on surface analyses and electrode morphology observation before and after cycling, and correlated with the electrochemical performance. [ABSTRACT FROM AUTHOR]

The valence band structures and ionization energies of pentacene layers grown on poly (3,4-ethylenedioxythiophene) polymerized with poly (4-styrenesulfonate) (PEDOT:PSS) and Au electrodes were characterized using in situ ultraviolet photoemission spectroscopy. The pentacene layers grown on Au films consist of amorphous phase and round oval grains regardless of the pentacene deposition temperature, whereas the pentacene deposited on PEDOT:PSS films showed highly distinctive ordered structures depending on the deposition conditions. The pentacene layer (thickness: 30 rim) grown on PEDOT:PSS at room temperature (RT) showed a highly crystalline thin film phase (001) and typical terrace-like structure, but that grown on PEDOT:PSS at I00°C consists of a weakly oriented thin film/bulk mixed phase with a disordered grain structure. However, irrespective of the molecular ordering structure, the pentacene layers grown on PEDOT:PSS films showed nearly the same hole-injection barriers (0.40 ~ 0.45 eV) at both interface ( I 0 nm) and bulk regions (30 nm). On the basis of the correlation between the molecular ordering and device characteristics, we conclude that the carrier transport at pentacene/electrode interface relies more on the hole-injection barrier than on the ordering of the pentacene layer grown on the electrode. [ABSTRACT FROM AUTHOR]

Nitrogen in a thin HfO2−xNx layer was observed in the form of dinitrogen molecules by atom probe microscope measurements. To evaluate the chemical state, an ab initio calculation based on monoclinic HfO2 was performed with using oxygen vacancy models combined with interstitial or substitutional nitrogen. The formation of a hafnium dinitrogen complex near the oxygen vacancy was found to considerably lower the system energy. This result contrasts the substitutional nitrogen complex passivating the oxygen vacancy level in the cubic structure and suggests that the structural stability enhanced by the oxygen vacancy-dinitrogen complex restrains the formation of grain boundaries in amorphous HfO2, which are responsible for the large leakage current. [ABSTRACT FROM AUTHOR]

The effects of Ar ion and Ar gas cluster ion beam (GCIB) sputtering processes on the core-level structure, valence band structure and work function of poly (3,4-ethylenedioxythiophene) polymerized with poly (4-styrenesulfonate) (PEDOT:PSS) and multi wall casbon nanotube (MWNT)IPEDOT:PSS films were characterized by photoemission spectroscopy and atomic forced microscopy. The depth profiles of X-ray photoemission and ultraviolet spectroscopy with Ar ion sputtering process confirmed that Ar ion sputtering process highly causes damage on the surface potential and valence band structure as well as core-level structure of PEDOT:PSS film. However, on the contrary to Ar ion sputtering, Ar GCIB sputtering process at each acceleration voltage did not induce any transition of chemical bonding State in PEDOT:PSS film and therefore, the atomic composition of Ar GCIB sputtered PEDOT:PSS film was also nearly same with that of as-dep. PEDOT:PSS film. Furthermore, the valence band structure and work function of organic composite films were not damaged by Ar GCIB sputtering process so that the energy band diagram between PEDOT:PSS and fluorine doped tin oxide films was clearly settled using valence band structure and work function of Ar GCIB sputtered PEDOT:PSS film. [ABSTRACT FROM AUTHOR]

We report the transformation of electronic structures of sp2 graphene to sp3 graphene by UV-light-assisted oxidation. Two distinctive oxidation mechanisms were observed during this metal-insulator transition: (i) At low-oxidation regime, p-doping behavior by oxygen species extracting electrons from graphene and (ii) at high-oxidation regime, n-doping behavior by electron-hopping via strongly localized oxide states. We also found that the dominant oxygen-related functional group by UV-light-assisted oxidation was an epoxide group rather than hydroxyl group, which differed from conventional graphite oxide. [ABSTRACT FROM AUTHOR]