Increasing Silicon Content Research Articles

Study on the Microstructure, Mechanical Properties, and Corrosion Behavior of 900 °C-Annealed CoCrFeMnNiSix (X = 0, 0.3, 0.6, 0.9) High-Entropy Alloys

In this study, a series of CoCrFeMnNiSix (x = 0, 0.3, 0.6, 0.9) high-entropy alloys (HEAs) were prepared by suspension melting of cold crucible, annealed at 1000 °C, and then quenched at 900 °C. The changes in the microstructure of the HEAs after the addition of Si were analyzed using X-ray diffraction (XRD), metallographic microscope, scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS), and electron backscatter diffraction (EBSD). The hardness, room-temperature friction, and wear behavior, room-temperature compressive properties, and corrosion resistance of the annealed CoCrFeMnNiSix HEAs were also studied. The results show that when the Si content is 0 and 0.3, the annealed CoCrFeMnNiSix HEA exhibits a single face-centered cubic (FCC) structure. As the silicon content increases, a face-centered orthorhombic (FCO) phase appears. At a Si content of 0.9, a hexagonal close-packed (HCP) phase is observed. After heat treatment, the hardness of the CoCrFeMnNiSix HEAs increases continuously with the addition of Si. The HEA with a Si content of 0.9 achieves the highest hardness of 974.8 ± 30.2 HV. The HEA with a Si content of 0.6 reaches the highest compressive strength and yield strength, which are 1990.3 MPa and 1327.5 MPa. When the Si content is 0.9, the HEA shows the smoothest surface after wear, with the best wear resistance, achieving a value of 0.21 mm−1. In the CoCrFeMnNiSix HEAs after 900 °C heat treatment, the HEA with a Si content of 0.6 exhibits the lowest self-corrosion current density of 0.23 µA/cm2 and the highest pitting potential of 157.65 mV, indicating the best corrosion resistance.

Study on the wetting characteristics of liquid-Al/ SiO2 interface with Si content in liquid-Al

Aiming to address the issue of aluminum slag adhering to the interior walls of vacuum lifting ladles in the aluminum electrolysis industry, Molecular dynamics simulations are employed to investigate the wetting behavior and adhesion characteristics of aluminum droplets on silica surfaces. Our findings indicate that with an increase in silicon content within the droplets, wetting diminishes and complete wetting of the silica substrate by aluminum droplets is not achieved. The presence of silicon reduces both the melting point temperature and surface tension of aluminum droplets, leading to a significant increase in contact angle and a corresponding decrease in wettability. Moreover, an elevated silicon content within molten aluminum droplets substantially decreases their interaction energy with the substrate surface. The virtual wall method is applied to examine average separation force and work of separation for detaching aluminum droplets from the substrate, revealing that adhesion characteristics are predominantly governed by mutual adhesive forces. This paper presents an atomic-level analysis elucidating how silicon as an alloying element influences adhesion between liquid aluminum and solid surfaces.

The Specificity of Determining the Latent Heat of Solidification of Cast Hypoeutectic AlSiCu Alloys Using the DSC Method.

Latent heat is commonly measured using Differential Thermal Analysis (DTA) or Differential Scanning Calorimetry (DSC) or calculated using software packages (Thermo-Calc). In this study, the DSC method was used to comprehensively evaluate the accuracy of calculated latent heat for a specific range of cast AlSiCu alloys, considering their solidification under different cooling conditions. The tests involved varying concentrations of two crucial alloying elements: wSi (5, 7, and 9%) and wCu (1, 2, and 4%). All selected alloys were analyzed under three distinct cooling/heating rates: 6, 10, and 50 °C/min. The Thermo-Calc method was used in this work to calculate the latent heats of the investigated alloys. The results obtained show good agreement between the measured and calculated values. The increase in silicon content in the investigated alloys from 4.85% to 9.85% resulted in the increase in latent heat from 407.6 kJ/kg to 467.5 kJ/kg. Higher cooling rates, such as 50 °C/min, resulted in a reduced latent heat release compared to slower rates such as 10 °C/min and 6 °C/min.

Unusual electrochemical properties of boron and silicon Co-doped diamond electrodes

Boron-doped diamond (BDD) films exhibit exceptional physicochemical properties and have been utilized in numerous fields. As a common impurity in diamond, silicon is inevitably introduced into the diamond lattice during certain growth process. However, there are limited reports on the impact of silicon co-doping on the electrochemical properties of BDD electrodes. In this paper, we prepared a series of BDD electrodes with various silicon contents and made a systematic evaluation of these electrodes in terms of physicochemical properties. The results indicated that silicon and boron co-doped diamond (SiBDD) electrodes displayed a broader potential window and lower background current compared to the pure BDD electrode. Additionally, we observed that the electron transfer rate of the electrodes in the inner ([Fe(CN)6]3−/4−) redox systems exhibited a rising trend with increasing silicon content, whereas the electron transfer rate of the outer ([Ru(NH3)6]3+/2+) redox systems displayed contrasting trend. Surface analyses and electrochemical measurements results suggested that the unusual phenomena might stem from the alterations in surface functional groups and carrier density of the electrode inducing by silicon co-doping. In general, our results demonstrate, for the first time, that Si co-doping can influence the surface functional groups and carrier behavior of BDD electrodes, thereby altering the electrode's electrochemical performance. This provides new insights for the design of high-performance diamond electrodes.

Influence of nanofiller surface treatment on mechanical properties of pyrolyzed ceramic nanocomposites

The brittleness and limited plastic deformation of ceramics restrict their applications. In this work, the effects of pristine (CNTP), functionalized (CNTOH, CNTCOOH) and silanized MWCNTs on the mechanical properties of Silicon Carbide obtained by pyrolyzing polycarbosilane SMP-10 were studied. Functionalization with 3-glycidoxypropyltrimethoxy was analyzed through dispersion stability, zeta potential, and EDS analyses, revealing increased silicon content and colloidal stability in silanized MWCNTs. However, silanized MWCNTs led to reduced mechanical properties in composites, while untreated MWCNTs (CNTP, CNTOH, CNTCOOH), showed a substantial increase in modulus by 74.2 %, 86.9 %, and 30.5 %, respectively. The observed enhancement in mechanical properties exceeded the outcomes predicted by the rule of mixtures, suggesting notable morphological changes induced by MWCNTs. Potential underlying factors including toughening mechanisms and changes in porosity were evaluated and discussed in depth. Composites with untreated MWCNTs showed nearly a two-fold increase in fracture toughness. This work shows a streamlined approach for the development of ceramic nanocomposites (CNCs), achieving significant improvement in mechanical properties through pyrolysis, surpassing traditional methods reliant on densification processes. These findings demonstrate the substantial potential of CNCs, enhancing their suitability for advanced engineering applications.

Fully Consolidated Deposits from Oxide Dispersion Strengthened and Silicon Steel Powders via Friction Surfacing

Abstract The objective of this work is to study the ability of friction surfacing to deposit metal alloys that are difficult to process with traditional methods. Creep and neutron irradiation resistant oxide dispersion strengthened (ODS) materials cannot be produced via conventional casting route due to insolubility of the oxidic and metallic alloy constituents, causing unintended inhomogeneous oxide dispersion and material behavior. Increasing silicon content of Iron-Silicon (Fe-Si) improves electromagnetic properties but embrittles the material significantly and the fusion based manufacturing methods unable to process this steel. The solid-state nature of the friction surfacing process offers a potential alternative processing route to enable wider usage of difficult to process alloy systems. Both ODS and Fe-Si materials are available in powder forms. While the existing literature in friction surfacing focuses on depositing composites by incorporating small quantities powders through holes in consumable rod, this is a first study that shows a large charge of powder can be converted to a homogeneous fully consolidated deposit in friction surfacing. A novel methodology is used that incorporates the high portion of powder feedstock into hollow consumable friction surfacing rods (up to 35% volume fraction). It was found that fully consolidated deposits can be produced with powder feedstocks using proposed methodology. A recrystallized, homogeneous, equiaxed microstructure was observed in Fe-Si 6.8 wt% and a new generation FeAlOY ODS alloy deposits processed with hollow stainless-steel friction surfacing rods. Both powder and rod material plasticize and deposit without bulk intermixing.

Transformative potential: Utilizing Teos-modified mugwort for sustainable construction

Exploring innovative materials derived from natural sources holds significant promise in pursuing sustainable construction practices. This study investigates the modification of mugwort (Artemisia dubia Wall.) with TEOS (tetraethyl orthosilicate) and its application as a sustainable reinforcement material in construction applications. It aims to integrate the plant's inherent strength with TEOS-enhanced mechanical properties and assess the feasibility of incorporating TEOS-modified mugwort into a lime-based matrix. The modified mugwort and its lime-based composite characterisation were conducted using FTIR, SEM-EDS, thermogravimetric analysis, compressive strength tests, and nitrogen adsorption analysis. FTIR analysis showcases significant structural enhancements post-modification, corroborated by SEM-EDS findings indicating increased silicon content. Peaks at 2915, 2845, and 1256 cm⁻¹ confirm successful modification with octadecyl amine and Si-C bond integration. Silica-related peaks at 1052, 801, and 456 cm⁻¹ indicate the presence of Si-O-Si structures. SEM analysis observes the presentation of Si as a layer confirming line scan position results, and EDS analysis findings indicate an increased silicon content of 15.16 %. Thermogravimetric analysis of modified samples displayed improved stability at low temperatures and more significant mass loss at high temperatures (72.01 % for modified and 28.91 % for unmodified samples) due to the decomposition of new chemical components. Nitrogen adsorption measurements reveal enhanced porosity in modified mugwort, suggesting diverse applications. The surface area of modified mugwort increased by 85 % compared to unmodified samples. Compressive strength analyses underscore the material's suitability for construction, with modified samples exhibiting denser structures at 8.5 % and higher strength at 13.3 % compared to unmodified samples. Macrostructure analysis further supports this, highlighting enhanced compatibility with binding materials. Overall, modified mugwort emerges as a versatile, eco-friendly reinforcement material with improved mechanical and thermal properties, poised for various applications in sustainable construction.

Demonstration of Microwave Resonators and Double Quantum Dots on Optimized Reverse-Graded Ge/SiGe Heterostructures.

One of the most promising platforms for the realization of spin-based quantum computing are planar germanium quantum wells embedded between silicon-germanium barriers. To achieve comparably thin stacks with little surface roughness, this type of heterostructure can be grown using the so-called reverse linear grading approach, where the growth starts with a virtual germanium substrate followed by a graded silicon-germanium alloy with an increasing silicon content. However, the compatibility of such reverse-graded heterostructures with superconducting microwave resonators has not yet been demonstrated. Here, we report on the successful realization of well-controlled double quantum dots and high-quality coplanar waveguide resonators on the same reverse-graded Ge/SiGe heterostructure.

Grown Silicon Iron Oxide by DC- RF Magnetron Co-Sputtering Technique

In this study, the structure of silicon iron oxide (Si:Fe2O3) was grown using co-sputtering. The Si:Fe2O3 film was grown on glass substrates at a pressure of 8.5 mTorr and a temperature of 450°C for 35 minutes. Optical measurements have revealed that the band gap of the structure ranges from 2.54 to 2.73 eV. The roughness values of the films in AFM images are Ra 3.08 nm and Sa 2.7 nm for Si:Fe2O3, and Ra 1.88 nm and Sa 2.09 nm for Fe2O3, respectively. As can be seen from the XPS figures, the change in binding energy is attributed to electron exchange among silicon, iron, and oxygen. In the iron-silicon oxide structure, the energy increases slightly as a result of the chemical environment. XRD measurements indicate that the size of crystal grains decreases gradually with an increase in silicon content. The Si4+ ion has a strong tendency to distribute itself within the tetrahedral region of spinel-like structures. The behavior of the structure is influenced by the stoichiometry of oxygen. The consistent results from both XRD and SEM images indicate that the crystal grain sizes gradually decrease as the silicon content increases.

Effect of hydrogen flow rate on properties of silicon oxycarbide thin films via hot wire chemical vapor deposition

AbstractThis study explores the impact of hydrogen flow as a carrier gas on silicon oxycarbide thin films produced via hot wire chemical vapor deposition (HWCVD) using tetraethyl orthosilicate as a precursor. Systematically varying the hydrogen flow rates, the influence on thin film composition, microstructure, and optical properties is investigated. Employing diverse characterization techniques, such as X‐ray diffraction, field‐emission scanning electron microscopy (FE‐SEM), energy‐dispersive X‐ray spectroscopy, Fourier‐transform infrared (FTIR), X‐ray photoelectron spectroscopy (XPS), ellipsometry, and photoluminescence (PL) spectroscopy, it is revealed that there is a correlation between hydrogen flow rate and thin film elemental composition. Higher hydrogen flow rates result in increased silicon content and reduced contributions of oxygen and carbon. FE‐SEM images show agglomerates with improved homogeneity at higher flow rates. FTIR spectra highlight distinctive vibrational modes, including Si–H bonds. XPS confirms the emergence of Si–H bonds at elevated hydrogen flow rates. Ellipsometry indicates increased thickness and refractive index. PL spectra exhibit a broadband across the visible spectrum, influenced by hydrogen‐related defects and electronic transitions. This study provides findings for optimizing HWCVD parameters to tailor thin films for specific applications, emphasizing the important role of hydrogen flow as a carrier gas.

Synthesis of equiaxed Si3N4 from Si(NH)2 by adding seeds formed by in situ nitridation of silicon

High-quality Si3N4 powder is a prerequisite for the preparation of high-performance Si3N4 ceramics. In this paper, Si3N4 powders with regular morphology were successfully prepared by pyrolysis of Si(NH)2 using silicon as a nucleation inducing agent. The mechanism of the silicon in regulating the morphology and particle size of Si3N4 powders was investigated. The results show that when Si(NH)2 is pyrolyzed directly at 1500 °C under N2 atmosphere, the products are mainly whiskers accompanied by some particles with irregular shape. In the presence of silicon, the powder particles exhibit a regular hexagonal prismatic morphology. With the increase of silicon content, the whisker content decreases obviously, and the whisker disappears completely when the silicon content exceeds 10 %. Furthermore, the particle size of Si3N4 powder decreases with the increase of silicon content, and the particle size is the smallest when the silicon content is 15 wt%, which is about 802 nm. The nucleation and growth process of Si3N4 powder particles can be divided into three stages. Firstly, silicon reacts with N2 to form Si3N4 nuclei. Then, amorphous Si3N4 partially decomposes to form Si(g) and SiO(g) and grows on the formed Si3N4 nuclei as the temperature increased. Finally, undecomposed amorphous Si3N4 spontaneously nucleates and grows of the solid-phase diffusion mechanism. Ultimately, all the powders show equiaxial regular morphology. Preferential nitridation of silicon to form Si3N4 nuclei provides nucleation sites for vapor-phase products, which is the key to inhibiting whisker formation and regulating the particle size of Si3N4 powders.

Silicon regulation of the interface microstructure and shear strength of rheological cast-rolling aluminum/steel composite plates

This study reports the preparation of medium-thickness aluminum/steel composite plates with different diffusion layers using rheological cast-rolling technology. The thermodynamic software and first-principles were employed to determine the effects of different silicon contents on the solidification process and mechanical properties of the 6061 aluminum/steel composite plates. The research revealed that the Fe2Al5 phase on the steel side possessed a tongue-like preferential growth at a silicon content of less than 1.2 wt%. A granular Al–Fe–Si phase was formed on the aluminum side of the diffusion layer when the silicon content exceeded the saturation solubility (1.8 wt%), which completely suppressed the tongue-like preferential growth of the Fe2Al5 phase. First-principles calculations revealed that the matrixes showed superior toughness in comparison to binary intermetallic compounds (IMCs), while the toughness of binary IMCs surpassed that of ternary IMCs. The mechanical properties showed that the shear strength of the sample prepared by rheological cast-rolling was higher than that of composite casting and close to that of composite rolling, reaching a maximum value of 73.4 MPa. The shear strength initially increased and then decreased with an increase in isothermal diffusion time, and the fracture location was transferred from the loose FeAl3 to the Fe2Al5 phase. An increase in silicon content resulted in a slight increase in the microhardness of the diffusion layer, a delay of the peak value of the shear strength, and a reduction in the gradient of the shear strength. A substantial decrease in peak shear strength was observed when the silicon content reached 1.8 wt%.

Is silicon worth it? Modelling degradation in composite silicon–graphite lithium-ion battery electrodes

The addition of silicon into graphite lithium-ion battery anodes has the potential to increase cell energy density. However, understanding the complex degradation behaviour in these composite systems remains a research challenge. Here, we developed a coupled electrochemical–mechanical model of a composite silicon/graphite electrode, including stress-driven crack formation and solid electrolyte interphase layer growth for each material, validated with experimental degradation data from an LG M50T cell. The model reveals self-limiting loss of silicon due to decreasing stress in the silicon as the silicon activity shifts to a lower state-of-charge. Higher C-rates can lead to lower degradation due to lower phase utilisation as voltage cut-offs are reached earlier. Increasing silicon content can reduce the stress in the silicon by distributing reaction current density over more material. Using this model, we explored whether the extra capacity from silicon is generally ‘worth’ the faster degradation compared to graphite-only electrodes. The model shows if you use the silicon, you lose it, as the higher initial capacity is rapidly lost with regular high depth-of-discharge events. However, silicon does have value if it enables full graphite utilisation without range anxiety; if high depth-of-discharge events are minimised then graphite’s superior longevity can be utilised while exploiting silicon’s high specific capacity. The model is integrated into PyBaMM (an open-source physics-based modelling platform); providing the research community and industry with the capability to reproduce our results and further explore the dynamic lifetime behaviour of composite electrodes.

Influence of silicon content on high temperature tribology performance of TiAlCrSiN coatings

A series of TiAlCrSiXN coatings with various silicon contents were fabricated on Si(100) and 304 stainless steel substrates using a radiofrequency magnetron sputtering system, aiming to examine the effects of various Si content on wear behaviors at room temperature and 700 °C. The addition of silicon notably increased the coatings' hardness from 21 GPa to 29 GPa, attributed to significant compressive residual stress (−3.4 GPa) that inhibited dislocation movement. Room temperature wear tests revealed that wear rates varied between 0.6 and 3.7 (10−6mm3N−1 m−1) with increasing silicon content. The lowest wear rate is observed at a silicon content of 3.1 at.%, which is associated with an ideal residual stress of −1.2 GPa. This stress level played a crucial role in preventing crack propagation and delamination, thus enhancing wear protection. At 700 °C, the coatings' wear resistance was mainly governed by their oxidation resistance, with the most resistant coatings exhibiting wear rates from 1.6 to 4.4 (10−6mm3N−1 m−1). The silicon addition promoted the formation of an amorphous Si3N4 phase, serving as an oxygen diffusion barrier, thus enhancing resistance to oxidation at elevated temperatures. The findings suggest that TiAlCrSiN coatings offer a promising solution for advanced tribological applications, demonstrating improved performance at temperatures up to 700 °C.

Oxidation-Resistant Coatings Based on High-Entropy Alloy (MoTaNbZrHf)SiB with Increased Silicon Content, Deposited by Magnetron Sputtering

Oxidation-Resistant Coatings Based on High-Entropy Alloy (MoTaNbZrHf)SiB with Increased Silicon Content, Deposited by Magnetron Sputtering

Modelling and characterization of the silicon effect on the oxidation of novel SiNb cast irons

The oxidation behavior of novel xSiNb cast irons designed for use as exhaust manifold material is studied by computational alloy thermodynamics and oxidation tests. Computational alloy thermodynamics is applied to determine the oxidation behavior of novel xSiNb cast irons (x: 4, 5, 6 and 7wt.%) designed as alternative exhaust materials to commercial SiMo ductile cast iron. In the modelling studies, the types and amounts of the oxides formed on the surface, depending on the oxygen partial pressure, are investigated at 750 and 850 °C and the findings reveal that as the silicon content increases the amount of Si-rich Fe2SiO4 phase increases that acts as a protective barrier. Oxidation tests are carried out in two stages to verify the modelling studies. Initially, thermogravimetric analyses are carried out at 800 °C to determine the oxidation kinetics of xSiNb cast irons and the results indicate that oxidation kinetics are reduced as silicon content increases. Then, oxidation tests are carried out at 750, 800 and 850 °C for 24h in dry air atmosphere to characterize the oxides formed on the surfaces and cross-sections of cast irons. Characterization studies show that (i) a thinner oxide layer is formed on the surface as silicon content increases, (ii) the oxide layer consists of an outer and an inner layer, (iii) the inner layer has more silicon content compared to the outer layer. All findings indicate that xSiNb cast irons have potential for high temperature applications and can be preferred to SiMo ductile cast iron.

Biochar application improves the yield, lodging resistance, and lignin synthesis mechanism in rice

AbstractBiochar application elicits positive environmental and agricultural impacts owing to its physicochemical properties; however, the mechanism of biochar in regulating the lodging resistance in rice remains unclear. The present study was conducted to investigate the effects of biochar application on rice yield, lodging‐related traits, and enzymes activity and gene expression related to lignin biosynthesis in two rice (Oryza sativa L.) cultivars, that is, Shennong 265 and Akihikari. The biochar treatments were: 0 (B1), 5 (B2), 10 (B3), 20 (B4), and 40 (B5) t/ha. Results depicted that compared with B1, the B2 and B3 treatments improved the rice yield by 8.36%–27.62% and decreased the lodging index by 7.72%–24.14% for both rice cultivars, respectively. The increase in rice yield was mainly due to an increase in chlorophyll content, net photosynthesis, and dry matter at the heading stage. The reduced lodging index in B2 and B3 was mainly owing to an increase in stem lignin and silicon content by 28.55%–62.80% and 16.27%–50.09%, respectively, that was possibly linked to an increase in lignin synthase activity and its gene expression, that is, phenylalanine ammonia lyase, caffeic acid 3‐O‐methyltransferase, 4CL3 (where 4CL is 4‐coumarate: CoA ligase), and CCR20 (where CCR is cinnamyl coenzyme A reductase). Furthermore, the numbers of large and small vascular bundles were the highest in B2 and B3 treatment for both rice cultivars. However, excess biochar applications had an inhibitory effect on rice yield. Overall, biochar application at 5–10 t/ha is an appropriate dosage to improve lodging resistance and rice yield.

Hydrothermal precipitation of hematite from the model solution of zinc hydrometallurgical extraction

Abstract The effect of temperature and silicon concentration on iron precipitation and morphology of hematite particles was discussed. The results showed that increase of initial silicon centration will lead to the decrease of iron removal efficiency, and the Fe content decreases and S content increases in hematite. Increasing temperature is beneficial to increase iron removal rate and Fe content in hematite, but increasing temperature can not decrease silicon content in hematite. The content of Si in precipitate is proportional to the concentration of silicon in solution. Silicon is adsorbed on the surface of hematite in the form of silicic acid. Hematite particle was agglomerated microsphere. Increasing concentration of silicon will increase the disorder degree of hematite crystallization. With the increase of silicon concentration, the agglomeration of hematite particle was more obvious, and the average particle size of hematite particles increased. At 175 °C, the morphology of iron precipitation particles are composed of flake particles and rhomboid massive particles, but when the temperature rises to 195 °C, the agglomeration phenomenon is obvious, small flake particles agglomerate into microspherical aggregates.

Wpływ krzemu na rozwój i zarodnikowanie grzybów entomopatogenicznych

Silicon is used in the cultivation of agricultural plants as an element that has a positive effect on the development of plants and increases their resistance to stress. It supports the plant’s defense systems, protecting against the penetration of pathogens. Increased silicon content in the environment may have a negative impact on other soil organisms. The aim of the experiment was to demonstrate the ef­fect of using a silicon preparation in various doses on the development of entomopathogenic fungi of the genera Beauveria, Cordyceps and Metarhizium on artificial media. A varied effect of the silicon preparation on the development of fungi have been demonstrated. It was found that at a low dose, the preparation had a positive effect on the production of spores in fungi of the genera Beauveria sp. and Cordyceps sp. In the case of Metarhizium sp., a positive effect on the growth of mycelium was demonstrated, with a simultaneous strong limiting effect of silicon on spore formation.

Unraveling Effects of Current Density and Silicon on Silicon-Graphite Composite Anodes By in-Situ Synchrotron X-Ray Diffraction

The development of lithium-ion batteries (LIBs) with high capacity and rate capabilities is imperative to meet energy demands for both transport and grid storage in the future. Due to its relative abundance and excellent cycling stability, state of the art LIBs contains graphite as the main anode component. However, graphite suffers from a low theoretical specific capacity of 372 mAhg-1 [ 1 ]. Alternatively, silicon (Si) has emerged as a promising energy-dense anode material with a theoretical specific capacity 10 times higher than graphite, but their widespread application is impeded by low electrical conductivity and extremely poor cycling stability due to large volume variations when alloying with lithium during electrochemical cycling [ 2 ]. Interestingly, silicon-graphite (SiG) composites have been pinpointed as promising options for producing improved anodes, which aims to combine graphite’s high electronic conductivity and structural stability with silicon’s high specific capacity. As expected, increasing the silicon content of SiG anodes reduces the cycling stability [3]. Optimization of SiG with respect to silicon content and utilization of silicon is not straightforward, and a comprehensive analysis on the effect of variations of silicon content and current density on SiG andoes is key. To investigate these interactions, in-situ synchrotron X-ray diffraction (XRD) analysis of composite anodes with varying silicon content at increasing c-rates was performed.In situ experiments were performed at BM01 of the European Synchrotron Radiation Facility (ESRF). An in-situ electrochemical cell consisting of two current collectors, in which the lower current collector is made of brass and the upper current collector is made of stainless steel, was utilized [ 4 ]. A half-cell was then assembled between the two current collectors in a coin cell configuration using lithium metal as the counter electrode and a glass fiber separator. 1M LIFSI in 1:1 vol EC: DMC was used as the liquid electrolyte. The current collectors each have a thin single crystal sapphire window that is mostly transparent to X-ray but have distinct signals that can be masked out in post-processing. To avoid diffraction signal from the underlying copper current collector of the electrode, the composite anode consists of electrodes cast on copper foil as well as a free-standing section. The assembled cell was galvanostatically cycled between 1 V and 50 mV while XRD data was acquired. In this study 4 different electrodes containing 0, 20 %wt., 30 %wt. and 70 %wt. of Si in the active material of the electrode were cycled at C/5, C/2, 1C and 2C rates.Analysis of the XRD results showed that tracking of the evolution of graphite main reflections during electrochemical cycling while completely avoiding the copper signal has been achieved. The degree of graphite lithiation was tracked by following the distinct 002, 100 and 110 peaks of graphite where phase transitions to LiC12 and LiC6 can be identified. Consistent with the results of other studies, graphite has been found to be both lithiated and delithiated at lower potentials than silicon [ 3 ]. Increasing silicon content was found to decrease the degree of graphite lithiation as silicon will be preferentially lithiated. Increasing the current density was found to reduce the overall degree of lithiation of graphite as the specific capacity decreases and the material is not sufficiently lithiated to undergo the expected phase transitions. This study has therefore unraveled the effect of silicon content and current density on composite anode behavior which could allow for the design of better next-generation composite anodes. Tarascon, J.-M. & Armand, M. Issues and challenges facing rechargeable lithium batteries. Nature 414, 359–367 (2001). Ashuri, M., He, Q. & Shaw, L. L. Silicon as a potential anode material for Li-ion batteries: where size, geometry and structure matter. Nanoscale 8, 74–103 (2015). Moyassari, E. et al. The Role of Silicon in Silicon-Graphite Composite Electrodes Regarding Specific Capacity, Cycle Stability, and Expansion. J. Electrochem. Soc. 169, 010504 (2022). Drozhzhin, O. A. et al. An electrochemical cell with sapphire windows for operando synchrotron X-ray powder diffraction and spectroscopy studies of high-power and high-voltage electrodes for metal-ion batteries. J. Synchrotron Radiat. 25, 468–472 (2018). Figure 1