Titanium Oxynitride Research Articles

Current Trends in Improving Functional Properties of Intravascular Endoprostheses

Cardiovascular diseases, and in particular, coronary heart disease are the most common cause of death worldwide. Finding the most effective method of treatment seems to be an advanced task. Stenting is a minimally invasive effective way to solve this problem. Immediately with the advent of endoprostheses (stents), there was a problem of repeated vasoconstriction (restenosis) due to neointimal hyperplasia (excessive build-up of the inner shell of the vessel), the causes of which are the release of metal ions from the stent material, damage to the artery wall during implantation, allergic reactions. Initially, they tried to find a solution by searching for the optimal design and material of the stent, as evidenced by the release of more than five hundred models of intravascular endoprostheses differing in design, material, geometric shape, profile, overall dimensions and other parameters. Currently, the most effective way to solve the problems of biocompatibility of stent materials is the formation of coatings on the surface of stents. It is possible to distinguish a number of different intravascular endoprostheses with modifiable coatings: secreting medicinal substances, with biodegradable coatings, with bioactive coatings. The paper presents the results of the analysis of the literature sources of the most advanced research in the field of surface modification of intravascular endoprostheses, which allowed to justify the choice of titanium oxynitride coating as recommended for further optimization and application due to high corrosion resistance, biocompatibility with cells, tissues and fluids of the human body, a good level of adhesion. At the same time there are a number of limiting factors associated with obtaining such coatings while maintaining all structural and technological requirements.

Observation of inherited plasmonic properties of TiN in titanium oxynitride (TiOxNy) for solar-drive photocatalytic applications

This study demonstrates the synthesis of titanium oxynitride (TiOxNy) via a controlled step-annealing of commercial titanium nitride (TiN) powders under normal ambience. The structure of the formed TiOxNy system is confirmed via XRD, Rietveld refinements, XPS, Raman, and HRTEM analysis. A distinct plasmonic band corresponding to TiN is observed in the absorption spectrum of TiOxNy, indicating that the surface plasmonic resonance (SPR) property of TiN is being inherited in the resulting TiOxNy system. The prerequisites such as reduced band gap energy, suitable band edge positions, reduced recombination, and enhanced carrier-lifetime manifested by the TiOxNy system are investigated using Mott-Schottky, XPS, time-resolved and steady-state PL spectroscopy techniques. The obtained TiOxNy photocatalyst is found to degrade around 98% of 10 ppm rhodamine B dye in 120 min and produce H2 at a rate of ∼1546 μmolg−1h−1 under solar light irradiation along with consistent recycle abilities. The results of cyclic voltammetry, linear sweep voltammetry, electrochemical impedance and photocurrent studies suggest that this evolved TiOxNy system could be functioning via plasmonic Ohmic interface rather than the typical plasmonic Schottky interface due to their amalgamated band structures in the oxynitride phase.

The synthesis, surface analysis, and cellular response of titania and titanium oxynitride nanotube arrays prepared on TiAl6V4 for potential biomedical applications

Titania nanotubes are gaining prominence in the biomedical field as implant materials due to their mechanical durability, nano-rough properties, and positive influence on cellular response. This work aimed to synthesize titania and titanium oxynitride (Ti–O–N) nanotubular arrays on TiAl6V4 substrates using an anodic oxidation process followed by annealing in air or by additional nitridation in NH3 atmosphere. Different nanotubular layers of unique morphology and structure were fabricated and investigated using advanced surface analysis and biocompatibility tests. In-depth surface analysis was performed by field emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM), 3D profilometry, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and time-of-flight secondary ion mass spectroscopy (ToF-SIMS). Cell testing using adipose-derived mesenchymal stem cells and human fetal osteoblasts demonstrated good cell viability, high proliferative capacity, and a favorable overall effect on cell morphology for the Ti–O–N nanotubes.

Effect of the Nanorough Surface of TiO2 Thin Films on the Compatibility with Endothelial Cells.

The cytocompatibility of titanium oxides (TiO2) and oxynitrides (N-TiO2, TiOxNy) thin films depends heavily on the surface topography. Considering that the initial relief of the substrate and the coating are summed up in the final topography of the surface, it can be expected that the same sputtering modes result in different surface topography if the substrate differs. Here, we investigated the problem by examining 16 groups of samples differing in surface topography; 8 of them were hand-abraded and 8 were machine-polished. Magnetron sputtering was performed in a reaction gas medium with various N2:O2 ratios and bias voltages. Abraded and polished uncoated samples served as controls. The surfaces were studied using atomic force microscopy (AFM). The cytocompatibility of coatings was evaluated in terms of cytotoxicity, adhesion, viability, and NO production. It has been shown that the cytocompatibility of thin films largely depends on the surface nanostructure. Both excessively low and excessively high density of peaks, high and low kurtosis of height distribution (Sku), and low rates of mean summit curvature (Ssc) have a negative effect. Optimal cytocompatibility was demonstrated by abraded surface with a TiOxNy thin film sputtered at N2:O2 = 1:1 and Ub = 0 V. The nanopeaks of this surface had a maximum height, a density of about 0.5 per 1 µm2, Sku from 4 to 5, and an Ssc greater than 0.6. We believe that the excessive sharpness of surface nanostructures formed during magnetron sputtering of TiO2 and N-TiO2 films, especially at a high density of these structures, prevents both adhesion of endothelial cells, and their further proliferation and functioning. This effect is apparently due to damage to the cell membrane. At low height, kurtosis, and peak density, the main factor affecting the cell/surface interface is inefficient cell adhesion.

Zinc-doped titanium oxynitride as a high-performance adsorbent for formaldehyde in air

The potential utility of titanium oxynitride doped with 5% zinc (ZnTON) has been investigated as an adsorbent for the treatment of gaseous formaldehyde (FA) using a fixed-bed adsorption system. The adsorption capacity of ZnTON, when estimated at 10%/100% breakthrough (BT) levels from a dry feed gas consisting of 10 Pa FA, was far superior to two reference materials (i.e., commercial P25-TiO2 and activated carbon (AC)) by factors of 1.7/1.3 and 10/2.5, respectively. The adsorption capacity of ZnTON increased with the increase in the initial feeding concentration of FA (5–12.5 Pa), while decreasing with the rising temperature (25–100 oC). An increase in moisture level (0–100% relative humidity) also led to 5.4- and 2.5-fold reductions in adsorption capacity of ZnTON at 10% and 100% BT levels, respectively. Thermodynamically, the adsorption of FA onto ZnTON is an exothermic (ΔHo = - 9.69 kJ.mol-1) to be feasible in nature based on physisorption mechanism. Further, the adsorption of FA onto ZnTON was governed by surface interactions and monolayer surface coverage (Van der Waal's force/electrostatic attraction), as it obeyed the Langmuir isotherm and pseudo-second-order kinetic models. Regeneration tests indicated a positive effect of moisture on FA desorption and durability of ZnTON (i.e., over three adsorption-desorption cycles). This study offers valuable mechanistic insights into the synthesis of an advanced adsorbent for the efficient removal of hazardous volatile organic compounds under near-ambient conditions.

Photoelectrochemical Performance of Strontium Titanium Oxynitride Photo-Activated with Cobalt Phosphate Nanoparticles for Oxidation of Alkaline Water.

Photoelectrochemical (PEC) solar water splitting is favourable for transforming solar energy into sustainable hydrogen fuel using semiconductor electrodes. Perovskite-type oxynitrides are attractive photocatalysts for this application due to their visible light absorption features and stability. Herein, strontium titanium oxynitride (STON) containing anion vacancies of SrTi(O,N)3-δ was prepared via solid phase synthesis and assembled as a photoelectrode by electrophoretic deposition, and their morphological and optical properties and PEC performance for alkaline water oxidation are investigated. Further, cobalt-phosphate (CoPi)-based co-catalyst was photo-deposited over the surface of the STON electrode to boost the PEC efficiency. A photocurrent density of ~138 μA/cm at 1.25 V versus RHE was achieved for CoPi/STON electrodes in presence of a sulfite hole scavenger which is approximately a four-fold enhancement compared to the pristine electrode. The observed PEC enrichment is mainly due to the improved kinetics of oxygen evolution because of the CoPi co-catalyst and the reduced surface recombination of the photogenerated carriers. Moreover, the CoPi modification over perovskite-type oxynitrides provides a new dimension for developing efficient and highly stable photoanodes in solar-assisted water-splitting reactions.

Hydrogen-bond-rich composite membrane with improved conductivity and selectivity for flow battery

Flow batteries have gained remarkable attention for large scale energy storage due to high safety and high efficiency. Membrane is the key component of the flow battery, directly affecting the efficiency and power density of the battery. However, the membrane development faces the challenge of the trade off between ion conductivity and ion selectivity. Herein, we propose a strategy to break the trade off, that is to improve the ion conductivity by creating rich hydrogen bonding networks in the membrane and maintain the ion selectivity via the spatial effect of the nanoparticles. A hydrogen-bond-rich composite membrane is prepared by incorporating the titanium oxynitride (TiON) nanoparticles into the SPEEK matrix, where TiON will form –OH and –NH2 functional groups on the surface of nanoparticles in the aqueous solution. The interaction between water molecules and –OH or –NH2 functional groups forms continuous and rich hydrogen bonding networks in the composite membrane, which remarkably improves the ion conductivity of the membrane. As a result, the iron chromium flow battery with SPEEK/TiON composite membrane exhibits excellent performance, with an energy efficiency of 82.7% at the current density of 80 mA/cm2, which was 4.4% higher than that with the commercial Nafion 212 membrane.

Study of epsilon-near-zero response in Al substituted titanium oxynitride thin films using computational and experimental investigations

Titanium oxide (TiO2) is considered as an important semiconductor material due to having promising tuneable optoelectronic, thermoelectric, and photovoltaic applications. First-principles calculations based on the density functional theory were used to elucidate the effect of dopant on various properties. Thin films have been fabricated using a reactive magnetron sputtering. X-ray diffraction analysis displayed the formation of the rutile phase of Titania in thin films. Atomic force and scanning electron microscopy revealed the growth of uniform, smooth, and well distributed granular thin films. Photoluminescence intensity was observed to decrease with an increase in dopant concentration. Experimentally obtained energy bandgap of the un-doped and doped TiO2 thin film samples was found to decrease and observed as 2.90 eV for pure Titania and 0.85 eV for maximum dopant contents. The present study exhibited that prepared oxynitrides thin films with epsilon near zero response are suitable candidate for enhanced optoelectronic and thermoelectric applications.

Air-based sputtering deposition of titanium oxynitride-based single, gradient, and multi-layer thin films for photoelectrochemical applications

Titanium oxynitride (TiNxOy) thin films exhibiting tunable physical and chemical properties can be used in many fields. Air-based sputtering deposition of the films with diverse O/N ratios was employed to produce gradient and multilayer films. By solely altering the air/Ar flow ratio, obtained TiNxOy films could change from a crystalline to a mainly amorphous feature. Moreover, the carrier concentration, Hall mobility, and hence resistivity of the films could be modified to a large range. The optical bandgaps of the films could also be tailored to a wide extent. Based on these results, the gradient TiNxOy layer and TiNxOy/TiN(O) multilayer were also deposited on TiN(O)-coated glass substrates for the assessment of photoelectrochemical performance. Compared with the TiNxOy/TiN(O) bilayer with the best photoelectrochemical performance, the photoelectrochemical currents of gradient TiNxOy films could be improved from 99 ± 2 μA⋅cm−2 to 164 ± 2 μA⋅cm−2 by taking advantage of bandgap engineering. Additionally, the photoelectrochemical currents of TiNxOy/TiN(O) multilayer were further improved to 175 ± 6 μA⋅cm−2. This is mainly due to conductive nano TiN(O) layers providing multiple high-transport paths while allowing light transmission. The enhancement mechanisms of the gradient and multilayer films have also been elaborated.

Modulation of Structural, Electronic, and Optical Properties of Titanium Nitride Thin Films by Regulated In Situ Oxidation

Epitaxial titanium nitride (TiN) and titanium oxynitride (TiON) thin films have been grown on sapphire substrates using a pulsed laser deposition (PLD) method in high-vacuum conditions (base pressure <3 × 10-6 T). This vacuum contains enough residual oxygen to allow a time-independent gas phase oxidation of the ablated species as well as a time-dependent regulated surface oxidation of TiN to TiON films. The time-dependent surface oxidation is controlled by means of film deposition time that, in turn, is controlled by changing the number of laser pulses impinging on the polycrystalline TiN target at a constant repetition rate. By changing the number of laser pulses from 150 to 5000, unoxidized (or negligibly oxidized) and oxidized TiN films have been obtained with the thickness in the range of four unit cells to 70 unit cells of TiN/TiON. X-ray photoelectron spectroscopy (XPS) investigations reveal higher oxygen content in TiON films prepared with a larger number of laser pulses. The oxidation of TiN films is achieved by precisely controlling the time of deposition, which affects the surface diffusion of oxygen to the TiN film lattice. The lattice constants of the TiON films obtained by x-ray diffraction (XRD) increase with the oxygen content in the film, as predicted by molecular dynamics (MD) simulations. The lattice constant increase is explained based on a larger electrostatic repulsive force due to unbalanced local charges in the vicinity of Ti vacancies and substitutional O. The bandgap of TiN and TiON films, measured using UV-visible spectroscopy, has an asymmetric V-shaped variation as a function of the number of pulses. The bandgap variation following the lower number of laser pulses (150-750) of the V-shaped curve is explained using the quantum confinement effect, while the bandgap variation following the higher number of laser pulses (1000-5000) is associated with the modification in the band structure due to hybridization of O2p and N2p energy levels.

Stability and activity of titanium oxynitride thin films for the electrocatalytic reduction of nitrogen to ammonia at different pH values.

The production of ammonia for agricultural and energy demands has accelerated research for more environmentally-friendly synthesis options, particularly the electrocatalytic reduction of molecular nitrogen (nitrogen reduction reaction, NRR). Catalyst activity for NRR, and selectivity for NRR over the competitive hydrogen evolution reaction (HER), are critical issues for which fundamental knowledge remains scarce. Herein, we present results regarding the NRR activity and selectivity of sputter-deposited titanium nitride and titanium oxynitride films for NRR and HER. Electrochemical, fluorescence and UV absorption measurements show that titanium oxynitride exhibits NRR activity under acidic conditions (pH 1.6, 3.2) but is inactive at pH 7. Ti oxynitride is HER inactive at all these pH values. In contrast, TiN - with no oxygen content upon deposition - is both NRR and HER inactive at all the above pH values. This difference in oxynitride/nitride reactivity is observed despite the fact that both films exhibit very similar surface chemical compositions - predominantly TiIV oxide - upon exposure to ambient, as determined by ex situ X-ray photoelectron spectroscopy (XPS). XPS, with in situ transfer between electrochemical and UHV environments, however, demonstrates that this TiIV oxide top layer is unstable under acidic conditions, but stable at pH 7, explaining the inactivity of titanium oxynitride at this pH. The inactivity of TiN at acidic and neutral pH is explained by DFT-based calculations showing that N2 adsorption at N-ligated Ti centers is energetically significantly less favorable than at O-ligated centers. These calculations also predict that N2 will not bind to TiIV centers due to a lack of π-backbonding. Ex situ XPS measurements and electrochemical probe measurements at pH 3.2 demonstrate that Ti oxynitride films undergo gradual dissolution under NRR conditions. The present results demonstrate that the long-term catalyst stability and maintenance of metal cations in intermediate oxidation states for pi-backbonding are critical issues worthy of further examination.

Correlating Oxidation State and Surface Ligand Motifs with the Selectivity of CO2 Photoreduction to C2 Products

AbstractThe design for non‐Cu‐based catalysts with the function of producing C2+ products requires systematic knowledge of the intrinsic connection between the surface state as well as the catalytic activity and selectivity. In this work, photochemical in situ spectral surface characterization techniques combined with the first principle calculations (DFT) were applied to investigate the relationships between the composition of surface states, coordinated motifs, and catalytic selectivity of a titanium oxynitride catalyst. When the catalyst mediates CO2 photoreduction, C2 product selectivity is positively correlated with the surface Ti2+/Ti3+ ratio and the surface oxidation state is regulated and controlled by coordinated motifs of N−Ti‐O/V[O], which can reduce the potential dimerization energy barriers of *CO−CO* and promote spontaneous formation of the subsequent *CO−CH2* intermediate. This phenomenon provides a new perspective for the design of heterogeneous catalysts for photoreduction of CO2 into useful products.

Correlating Oxidation State and Surface Ligand Motifs with the Selectivity of CO2 Photoreduction to C2 Products.

The design for non-Cu-based catalysts with the function of producing C2+ products requires systematic knowledge of the intrinsic connection between the surface state as well as the catalytic activity and selectivity. In this work, photochemical in-situ spectral surface characteristic technique combined with the first principle calculations (DFT) were applied to investigate the relationships among the composition of surface states, coordinated motifs, and catalytic selectivity of the titanium oxynitride catalyst. By adopting the process of CO2 photoreduction, we found that C2 product selectivity is positively correlated with the surface Ti2+/Ti3+ ratio while the surface oxidation state is regulated and controlled by coordinated motifs of N-Ti-O/V[O], which can reduce the potential dimerization energy barriers of *CO-CO* and promote the spontaneous formation of the subsequent *CO-CH2* intermediate. On the contrary, relatively high or low N/O coordination ratios will cause imbalance of coordination motifs in reducing surface states and abate the hydrogenation barriers of the methoxy group, thus facilitating methane formation. Such phenomenon provides a new design perspective and by such, researchers make a step close to the accurate production of photo-transformed CO2 products.

Achieving Cycling Stability in Anode of Lithium-Ion Batteries with Silicon-Embedded Titanium Oxynitride Microsphere.

Surface coating approaches for silicon (Si) have demonstrated potential for use as anodes in lithium-ion batteries (LIBs) to address the large volume change and low conductivity of Si. However, the practical application of these approaches remains a challenge because they do not effectively accommodate the pulverization of Si during cycling or require complex processes. Herein, Si-embedded titanium oxynitride (Si-TiON) was proposed and successfully fabricated using a spray-drying process. TiON can be uniformly coated on the Si surface via self-assembly, which can enhance the Si utilization and electrode stability. This is because TiON exhibits high mechanical strength and electrical conductivity, allowing it to act as a rigid and electrically conductive matrix. As a result, the Si-TiON electrodes delivered an initial reversible capacity of 1663 mA h g-1 with remarkably enhanced capacity retention and rate performance.

Interaction mechanism of transition metal phthalocyanines on transition metal nitride supports

We investigated the electronic interactions between transition metal phthalocyanine (TMPc’s) on a refractory transition metal nitride support, specifically copper phthalocyanine (CuPc) on titanium nitride (TiN). X-ray Photoelectron Spectroscopy (XPS) results suggest a presence of a few nanometer native oxide layer on the surface of the TiN nanoparticles, which consists of TiN, TiO2, and Titanium oxynitrides (TixOyNz). A TiNCuPc nanocomposite was synthesized via a simple mixing method due to the strong binding between CuPc and TiN confirmed by density functional theory (DFT) calculations. Both XPS data and DFT calculations revealed an electron transfer from TiN substrate to CuPc molecule. The nature of charge transfer is not influenced by the presence of an oxide layer on the surface of TiN. Substantial deviations are however found between photoelectron emission microscopy (PEEM) measured work function for TiN (4.68 eV) and theoretically calculated work function for pristine stoichiometric TiN (2.63 eV). This behavior is attributed to the presence of an oxide layer on the TiN surface. TiNCuPc composite system has a work function value between those of TiN and CuPc. Our studies open up an opportunity to apply a new class of materials based on transition metal phthalocyanine/transition metal nitride composites to catalysis and optoelectronic devices.

Integral Algorithms to Evaluate TiO2 and N-TiO2 Thin Films’ Cytocompatibility

Titanium oxide (TiO2) and oxynitride (N-TiO2) coatings can increase nitinol stents' cytocompatibility with endothelial cells. Methods of TiO2 and N-TiO2 sputtering and cytocompatibility assessments vary significantly among different research groups, making it difficult to compare results. The aim of this work was to develop an integral cytocompatibility index (ICI) and a decision tree algorithm (DTA) using the "EA.hy926 cell/TiO2 or N-TiO2 coating" model and to determine the optimal cytocompatible coating. Magnetron sputtering was performed in a reaction gas medium with various N2:O2 ratios and bias voltages. The samples' morphology was studied by scanning electron microscopy (SEM) and Raman spectroscopy. The cytocompatibility of the coatings was evaluated in terms of their cytotoxicity, adhesion, viability, and NO production. The ICI and DTA were developed to assess the cytocompatibility of the samples. Both algorithms demonstrated the best cytocompatibility for the sample sputtered at Ubias = 0 V and a gas ratio of N2:O2 = 2:1, in which the rutile phase dominated. The DTA provided more detailed information about the cytocompatibility, which depended on the sputtering mode, surface morphology, and crystalline phase. The proposed mathematical models relate the cytocompatibility and the studied physical characteristics.

Iridium Stabilizes Ceramic Titanium Oxynitride Support for Oxygen Evolution Reaction.

Decreasing iridium loading in the electrocatalyst presents a crucial challenge in the implementation of proton exchange membrane (PEM) electrolyzers. In this respect, fine dispersion of Ir on electrically conductive ceramic supports is a promising strategy. However, the supporting material needs to meet the demanding requirements such as structural stability and electrical conductivity under harsh oxygen evolution reaction (OER) conditions. Herein, nanotubular titanium oxynitride (TiON) is studied as a support for iridium nanoparticles. Atomically resolved structural and compositional transformations of TiON during OER were followed using a task-specific advanced characterization platform. This combined the electrochemical treatment under floating electrode configuration and identical location transmission electron microscopy (IL-TEM) analysis of an in-house-prepared Ir-TiON TEM grid. Exhaustive characterization, supported by density functional theory (DFT) calculations, demonstrates and confirms that both the Ir nanoparticles and single atoms induce a stabilizing effect on the ceramic support via marked suppression of the oxidation tendency of TiON under OER conditions.

Manifestation of the Enhanced Photovoltaic Performance in Eco-Friendly AgBiS2 Solar Cells Using Titanium Oxynitride as the Electron Transport Layer

In this study, titanium oxynitride with empirical composition of TiON is developed using a sol–gel and ammonia-gas-assisted thermal nitridation process. The obtained TiON phase is employed as the photoanodic electron transport layer (ETL) in a silver bismuth sulfide (AgBiS2) quantum-dot-sensitized solar cell (QDSSC) device and compared to a QDSSC consisting of commercial TiO2 as the ETL. The obtained X-ray photoelectron spectroscopy spectra and Mott–Schottky plots of the samples suggested that the valence and conduction bands of TiON are significantly shifted (EVB = 2.9 eV and ECB = −0.3 eV) with respect to that of TiO2 (EVB = 1.88 eV and ECB = −0.51 eV), which eventually decreased its band gap energy to 2.46 eV compared to TiO2 (3.2 eV). A decrease in the charge transfer resistance (Rct = 38.2 Ω) and improvement in carrier lifetime (τ = 5.3 ms) are observed in the developed TiON device. The work also endorses the use of eco-friendly green quantum dots of AgBiS2 as photoabsorbers in solar cells. Although the photovoltaic performance is not found to be greater, the demonstration of the enhanced performance of the TiON-based device with ∼50% enhancements, owing to its improved open circuit voltage and current density by 20 and 35%, is achieved in this work. Titanium oxynitride can, hence, be considered a suitable alternative to existing commercial TiO2 in all applications that involve solar energy conversion.

Exceptional long-term stability of titanium oxynitride nanoparticles as non-carbon-based electrodes for aerated saline water capacitive deionization

Carbon-based capacitive deionization (CDI) electrodes suffer from long-lasting stability challenges due to sets of parasitic side reactions, including the high oxidation rate of the electrodes during the desalination process. Consequently, it is essential to identify, design, and fabricate novel electrodes that overcome such challenges to achieve robust and high desalination performance. This work reports on the fabrication and utilization of titanium oxynitride (TixOyNz) nanoparticles as stable non‑carbon-electrodes for capacitive deionization. The oxynitride nanoparticles were synthesized via a simple template-free approach and fully characterized using XRD, XPS, Raman, SEM, and BET techniques. Moreover, the fabricated electrodes were electrochemically evaluated via cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS) techniques. The electrode exhibited a pseudocapacitance behavior with a specific capacitance of 150 F/g. A symmetric configuration CDI setup was constructed, enabling the investigation of the effect of different flow rates and voltages. Remarkably, the TixOyNz CDI cell revealed a salt adsorption capacity (SAC) of up to 56.6 mg/g with fast adsorption kinetics. Moreover, the electrodes retained ~100% of its initial SAC even after 1960 cycles over 110 days of continuous testing. Furthermore, several post- characterization techniques such as XPS, XRD, FTIR, and potential of zero charge have been deeply studied and analyzed to unravel the observed exceptional stability of the tested electrodes.

Engineering High-Performance SiOx Anode Materials with a Titanium Oxynitride Coating for Lithium-Ion Batteries.

Micron-sized silicon oxide (SiOx) has been regarded as a promising anode material for new-generation lithium-ion batteries due to its high capacity and low cost. However, the distinct volume expansion during the repeated (de)lithiation process and poor conductivity can lead to structural collapse of the electrode and capacity fading. In this study, SiOx anode materials coated with TiO0.6N0.4 layers are fabricated by a facile solvothermal and thermal reduction technique. The TiO0.6N0.4 layers are homogeneously dispersed on SiOx particles and form an intimate contact. The TiO0.6N0.4 layers can enhance the conductivity and suppress volume expansion of the SiOx anode, which facilitate ion/electron transport and maintain the integrity of the overall electrode structure. The as-prepared SiOx-TiON-200 composites demonstrate a high reversible capacity of 854 mAh g-1 at 0.5 A g-1 with a mass loading of 2.0 mg cm-2 after 250 cycles. This surface modification technique could be extended to other anodes with low conductivity and large volume expansion for lithium-ion batteries.