Silicon Metal Research Articles

Utilization of silicon dioxide powder from industrial wastes as novel filler in rubber isolator application

The silicon dioxide powder (SP) was an industrial waste and obtained from the silicon metal industry in Thailand. The effect of SP loading on cure characteristics, mechanical, dynamic and endurance properties in natural rubber were investigated and compared to calcium carbonate (CaCO3) and unfilled natural rubber, respectively. Results revealed that the addition of SP significantly affected the cure characteristics and mechanical properties. An increasing content of SP increased the hardness, modulus, tensile strength and tear strength due to a higher SP-rubber interaction but decreased the elongation at break since higher SP in rubber matrix resulting in lesser mobility of rubber chains. For the curing behavior, the faster cure time was observed since more heat transfer to the compound occurred. The rubber product performance in terms of dynamic and endurance properties of rubber isolator were also determined. It had been found that SP not only improving the damping characteristics but also enhancing the number of cycles until fracture. Moreover, adding the bis-(3-triethoxysilylpropyl)-tetrasulphide (TESPT) showed higher reinforcement efficiency of SP. This can directly react to silanol groups on the SP surface and also reduce hydrogen bonding of SP particles. So, TESPT can reduce accelerator adsorption and SP-SP interaction, leading to better processability. Besides that, TESPT is a sulphur-based rubber silane. It can contribute sulphur atoms from molecule and then form covalent bonds with natural rubber chains which leads to enhance the crosslink density. Influence of filler type on rubber isolator, the SP imparts greater reinforcement than CaCO3. All obtained results suggested that SP can be fully replaced the commercial CaCO3.

Preparation of Hybrid Sol-Gel Materials Based on Living Cells of Microorganisms and Their Application in Nanotechnology.

Microorganism-cell-based biohybrid materials have attracted considerable attention over the last several decades. They are applied in a broad spectrum of areas, such as nanotechnologies, environmental biotechnology, biomedicine, synthetic chemistry, and bioelectronics. Sol-gel technology allows us to obtain a wide range of high-purity materials from nanopowders to thin-film coatings with high efficiency and low cost, which makes it one of the preferred techniques for creating organic-inorganic matrices for biocomponent immobilization. This review focuses on the synthesis and application of hybrid sol-gel materials obtained by encapsulation of microorganism cells in an inorganic matrix based on silicon, aluminum, and transition metals. The type of immobilized cells, precursors used, types of nanomaterials obtained, and their practical applications were analyzed in detail. In addition, techniques for increasing the microorganism effective time of functioning and the possibility of using sol-gel hybrid materials in catalysis are discussed.

A Study on Pyrolysis of Pretreated Automotive Shredder Residue—Thermochemical Calculations and Experimental Work

The automotive shredder residue (ASR) is generated as an inevitable waste after the shredding process of end-of-life vehicles. Typically, the ASR ends up in a landfill in the absence of any existing processing options. The ASR comprises rubber, wood, plastics, textile, metals, and other materials, such as paint and glass (10%), which can be recycled and reused. Given these attributes, the ASR is a potential feedstock for energy production and metal recovery. In this study, ASR was first pretreated because untreated ASR (as received) is fluffy and heterogeneous and, therefore, is difficult to feed into a reactor. Subsequently, the pyrolysis process was conducted with this pretreated ASR for energy recovery. From the thermochemical calculations, an optimized temperature of 500°C was chosen for pyrolysis of the pretreated ASR to ensure that metals would not be further oxidized and polymers could be separated from the metals in the form of volatile gases, oil, and char. Bench-scale pyrolysis tests were conducted on an integrated continuous stirred tank reactor–distillation column pyrolysis system. The product gas composition had hydrogen and methane content of 30% and 26% (v/v), respectively, contributing to the heating value of the gas obtained. The pyrolysis oil was further distilled using fractional distillation apparatus for gasoline and diesel-grade products. The physicochemical characterization of the pretreated ASR pyrolysis oil and its distillates was also carried out. The thermochemical equilibrium predictions showed a similar trend with the experimental pyrolysis results. In addition, the residual char analysis indicated the presence of a significant amount of metals—silicon, titanium, aluminum, and iron. Thus, this work generated information on processing pretreated ASR for the production of fuel and insights on metal recovery that can be recovered from the residual pyrolysis char.

Review on porous materials for the thermal stabilization of proteins

Proteins, the key components of vaccines, enzymes and many types of therapeutics, are sensitive to denaturing and loss of structure when exposed to high temperatures. One way to thermally stabilize proteins is through immobilization on a porous support. In this review, a comparative analysis of the literature reports on the most relevant porous materials for protein thermal stability is presented. The materials fall into two main categories: inorganic porous materials and organic polymer materials. Inorganic porous materials for protein immobilization include metal oxides (e.g., aluminum oxides, and iron oxides), silicon dioxides, activated carbons and metal organic frameworks. Organic polymer materials include both natural and synthetic polymers, with natural polymers (e.g., agarose, chitosan and alginate) being by far the most widely studied type of material for enzyme immobilization. Support materials, support surface chemical modification agents, and degree of thermal stability are discussed in detail. The review may be helpful in selecting the optimum support material and surface modification process for a given protein to increase thermal stability. • Comprehensive review on thermal stabilization of proteins on porous materials with 166 sources from 1955 to the present. • Applications discussed include catalyst immobilization, vaccine and protein therapeutic thermal stability and drug delivery. • Inorganic and organic porous materials mentioned. • Includes silicas, activated carbons, aluminum oxides, iron oxides, metal organic frameworks, natural and synthetic polymers. • Includes over 60 biomolecules consisting of proteins, enzymes and vaccine conjugates.

K2O-Metakaolin-Based Geopolymer Foams: Production, Porosity Characterization and Permeability Test.

In this paper, four near-net shaped foams were produced via direct foaming, starting from a benchmark metakaolin-based geopolymer formulation. Hydrogen peroxide and metallic silicon were used in different amounts as blowing agents to change the porosity from meso- to ultra-macro-porosity. Foams were characterized by bulk densities ranging from 0.34 to 0.66 g cm−3, total porosity from 70% to 84%, accessible porosity from 41% to 52% and specific surface area from 47 to 94 m2 g−1. Gas permeability tests were performed, showing a correlation between the pore features and the processing methods applied. The permeability coefficients k1 (Darcian) and k2 (non-Darcian), calculated applying Forchheimer’s equation, were higher by a few orders of magnitude for the foams made using H2O2 than those made with metallic silicon, highlighting the differing flow resistance according to the interconnected porosity. The gas permeability data indicated that the different geopolymer foams, obtained via direct foaming, performed similarly to other porous materials such as granular beds, fibrous filters and gel-cast foams, indicating the possibility of their use in a broad spectrum of applications.

Controllable Synthesis of Silicon‐Based Nanohybrids for Reliable Surface‐Enhanced Raman Scattering Sensing

Comprehensive SummaryInterface between metallic nanoparticles and dielectric silicon substrate can strongly confine electromagnetic field (EM‐field) through its localized surface plasmons, together contributing great surface‐enhanced Raman scattering (SERS) enhancement. Typically, silicon‐based nanohybrids (metallic nanoparticles in situ grown on silicon substrate) have been widely employed as SERS‐active substrates in sensing platforms for the detection of chemical and biological analytes. Silicon‐based nanohybrids with surface plasmons allow amplifying Raman signals that associate molecular binding events by several orders of magnitude. Together with interfacial architectures for the specific binding of target analyte on the silicon‐based nanohybrid surface, silicon‐based nanohybrid‐enhanced Raman scattering represents a promising method for increasing reliability and sensitivity. This review affords a presentation to the basics of SERS enhancement of silicon‐based nanohybrid, illustrates current advances in controllable synthesis of silicon‐based nanohybrid substrates, and outlines current implementations to sensors for reliable detection of ultralow amounts of analytes. What is the most favorite and original chemistry developed in your research group?The design and fabrication of silicon‐based platform for long‐term bioimaging and reliable biosensing analysis.What is the most important personality for scientific research?Cooperation and conscientiousness.What are your hobbies? What's your favorite book(s)?Music. History book.Who influences you mostly in your life?Family and supervisors.What is your favorite journal(s)?Nature serials, JACS, Angew. Chem., etc.Could you please give us some advices on improving Chinese Journal of Chemistry?Publishing original and significant discoveries.

Impact of nonlinear radiation on magnetohydrodynamic flow of hybrid nanofluid with heat source effect

This investigation is performed to deliberate the novel significance of nonlinear thermal radiation effect on magnetohydrodynamic flow of Casson hybrid nanoliquid caused by a curved stretching sheet. The flow and thermal transport nature of three different hybrid nanoliquids in the stimulus of viscous dissipation, nonlinear radiation and magnetic force is discussed numerically. The novelty of this work is to obtain the simultaneous solutions for three different types of hybrid nanoliquids, they are obtained by suspending titanium alloy (Ti6Al4vs.) is composed of titanium, aluminum and vanadium in the ratio of 90:6:4 respectively and aluminium alloy (AA7075) is compossed of Aluminum, Zinc, Magnesium and Copper nanoparticles in the ratio of 90:6:3:1 respectives with added metals Silicon, Ferrous and Magnesium. in three various working liquids viz. methanol, ethylene glycol and engine oil. The flow governing PDE's are transmuted into ODE's with suitable similarity transformation and solved by using Runge-Kutta and Newton's approach. Numerical outcomes of flow and temperature profiles are presented via graphical trends, also skin friction coefficient and rate of thermal transfer are illustrated via tabulated values. Major outcomes reveals that, inclusion of hybrid nanometer sized particles in pedestal liquid lead to an large hike in thermal transfer performance. Importantly, thermal transport rate and temperature profiles of the hybrid nanoliquid rises with improving nonlinear radiation values and these results are significant in nonlinear radiation case as compared with linear radiation case.

Lithium Silicates in Anode Materials for Li-Ion and Li Metal Batteries

The structural and interfacial stability of silicon-based and lithium metal anode materials is essential to their battery performance. Scientists are looking for a better inactive material to buffer strong volume change and suppress unwanted surface reactions of these anodes during cycling. Lithium silicates formed in situ during the formation cycle of silicon monoxide anode not only manage anode swelling but also avoid undesired interfacial interactions, contributing to the successful commercialization of silicon monoxide anode materials. Additionally, lithium silicates have been further utilized in the design of advanced silicon and lithium metal anodes, and the results have shown significant promise in the past few years. In this review article, we summarize the structures, electrochemical properties, and formation conditions of lithium silicates. Their applications in advanced silicon and lithium metal anode materials are also introduced.

A Triangle Hybrid Plasmonic Waveguide with Long Propagation Length for Ultradeep Subwavelength Confinement

Facing the problems of ohmic loss and short propagation length, the application of plasmonic waveguides is limited. Here, a triangle hybrid plasmonic waveguide is introduced, where a cylinder silicon waveguide is separated from the triangle prism silver waveguide by a nanoscale silica gap. The process of constant optimization of waveguide structure is completed and simulation results indicate that the propagation length could reach a length of 510 μm, and the normalized mode area could reach 0.03 along with a high figure of merit 3150. This implies that longer propagation length could be simultaneously achieved along with relatively ultra-deep subwavelength mode confinement due to the hybridization between metallic plasmon polarization mode and silicon waveguide mode, compared with previous study. By an analysis of fabrication errors, it is confirmed that this waveguide is fairly stable over a wide error range. Additionally, the excellent performance of this is further proved by the comparison with other hybrid plasmonic waveguides. Our work is significant to manipulate light waves at sub-wavelength dimensions and enlarge the application fields, such as light detection and photoelectric sensors, which also benefit the improvement of the integration of optical devices.

Room Temperature Enhancement of Electronic Materials by Superacid Analogues.

Treatment with the superacid bis(trifluoromethanesulfonyl)amide (sometimes known as TFSA, TFSI, or HNTf2) enhances the properties of a wide range of optoelectronic materials, resulting in longer effective carrier lifetimes and higher photoluminescence quantum yields. We have conducted a multimaterial study treating both crystalline silicon and transition metal dichalcogenide (TMDC) monolayers and few-layer flakes with solutions formed from TFSA and a range of compounds with related chemical structures with different Lewis acidities, in order to elucidate the factors underpinning the TFSA-related class of enhancement treatments. We adopt dichloromethane (DCM) as a common solvent as it provides good results at room temperature and is potentially less hazardous than TFSA-dichloroethane (DCE) heated to ∼100 °C, which has been used previously. Kelvin probe experiments on silicon demonstrate that structurally similar chemicals give passivating films with substantially different charge levels, with the higher levels of charge associated with the presence of CF3SO2 groups resulting in longer effective lifetimes due to an enhancement in field-effect passivation. Treatment with all analogue solutions used results in enhanced photoluminescence in MoS2 and WS2 compared to untreated controls. Importantly we find that MoS2 and WS2 can be enhanced by analogues to TFSA that lack sulfonyl groups, meaning an alternative mechanism to that proposed in computational reports for TFSA enhancement must apply.

Gettering in silicon photovoltaics: A review

A key efficiency-limiting factor in silicon-based photovoltaic (PV) devices is the quality of the silicon material itself. With evolving cell architectures that better address other efficiency-loss channels in the device, the final device efficiency becomes increasingly sensitive to the contaminants in the silicon wafer bulk. However, due to cost constraints, silicon materials for PV are inherently less pure and further contamination during device fabrication is commonly found, especially in mass production environments. Metallic impurities are ubiquitous and abundant, and they are strong efficiency-loss channels in the device if not removed. Gettering is the process of removing metallic impurities to a less harmful region of the device, and is therefore an essential aspect of the cell fabrication process. This article presents an up-to-date review of the gettering techniques and processes in silicon solar cells, providing a complete picture of the possible gettering sinks and routes in various cell architectures. The article starts by explaining the common nomenclatures in gettering and summarising recent updates to the solubility and diffusivity data of the common 3d transition metals in silicon. Then the three-step gettering process (release, diffusion, capture) is explained, and its implications for solar-grade cast-grown silicon (in terms of release) and various cell architectures (in terms of diffusion) are discussed. The main focus of the article is to summarise and review the various capture approaches in the context of silicon PV. These include phosphorus diffusion, boron diffusion, selective doping via ion implantation, state-of-the-art polycrystalline-silicon/oxide passivating contact structures, dielectric films (silicon nitride and aluminium oxide), aluminium alloying, surface damaged regions including black silicon, and internal gettering in cast-grown silicon by existing crystallographic defects. Their gettering effects, current understanding of the gettering mechanisms, modelling, improvement strategies, implementation in processing and potential impacts on cell performance are reviewed.

Palladium clusters, free and supported on surfaces, and their applications in hydrogen storage.

Palladium is a late transition metal element in the 4d row of the periodic table. Palladium nanoparticles show efficient catalytic activity and selectivity in a number of chemical reactions. In this paper, we review the structural and electronic properties of palladium nanoclusters, both isolated and deposited on the surface of different substrates. Careful experiments and extensive calculations have been performed for small Pd clusters which provide ample information on their properties. Work on large Pd clusters is less abundant and more difficult to perform and interpret. Cluster deposition is a method to modify material surfaces for different applications, and we report the known results for the deposition of Pd clusters on the surfaces of a number of interesting substrates: carbonaceous substrates like graphene and some layered novel materials related to graphene, metal oxide substrates, silicon and silicon-related substrates and metallic alloy substrates. Emphasis is placed on revealing how the structural, electronic and magnetic properties change when the clusters are deposited on the substrate surfaces. Some examples of chemical reactions catalyzed by supported Pd clusters and nanoparticles are reported. An issue discussed in detail is the influence of Pd on the storage of hydrogen in porous materials. Experimental work shows that the amount of stored hydrogen increases when the absorbing material is doped with Pd atoms, clusters and nanoparticles, and a spillover mechanism from the metal particle to the substrate is usually accepted as the explanation. To shed light on this issue, a critical analysis based on density functional simulations of the mechanisms of hydrogen spillover in perfect and defective graphene doped with palladium clusters is presented.

Power Relay Based Multiple Device Cryogenic Characterization Method and Results

Cryogenic power electronics is a promising technology due to their high efficiency and high power density characteristics. As the key element of power electronic systems, semiconductor performance should be evaluated under cryogenic temperatures. Liquid nitrogen or liquid helium are usually adopted to achieve cryogenic temperatures. Traditionally, only one semiconductor can be evaluated at one time under different temperatures, which is time-consuming and not energy-friendly. To enable multiple-device characterization at one time under different temperatures, a novel power relay based characterization circuit and corresponding control strategy are described. With the aid of the proposed circuit, multiple devices can be characterized by controlling the power relays. The introduced parasitics by the power relays are minimized through paralleling, which has negligible influence on the device under test (DUT). Cryogenic characterization results of the gate driver, power relay, and semiconductors are presented. Both silicon (Si) metal–oxide–semiconductor field-effect transistor (MOSFET) and silicon carbide (SiC) MOSFETs are characterized and their performances are discussed.

Model Predictive Control of Molten Iron and Slag Quality Indices in a Large-scale Ironmaking Blast Furnace using a Hybrid Dynamic Model*

The stable operation and the optimal thermal control of industrial blast furnaces are challenging due to the complexity of the multi-phase and multi-scale physical and chemical phenomena, the presence of fast and extremely slow dynamics with latency periods of more than 8 hours, the absence of direct measurements of key inner variables, and the occurrence of a wide range of unknown disturbances. Industrial blast furnaces are still operated in a semi-automated manner and the quality of the control depends on the skills and dedication of the operators. Model-based control schemes, operated either in closed-loop or as advisory systems, are an obvious option to achieve a smooth and energetically efficient operation of blast furnaces. This work proposes a hybrid dynamic model-based optimizing control scheme for achieving the desired operational objectives by tightly controlling the hot metal silicon content ([Si]) and the slag basicity (SB) at their desired set-points. These two variables are key product quality indices and indicators of the internal thermal status of the blast furnace process. Within the proposed framework, the optimizer regulates the fast dynamics of the blast furnace to counteract the unmeasured disturbances that are caused by the variations in the solid feed, subject to operational constraints. Simulation results on a large-scale industrial blast furnace demonstrate the potential of the proposed approach for an improved operation of the blast furnace process.

Temporal Hypergraph Attention Network for Silicon Content Prediction in Blast Furnace

Online dynamic prediction of the hot metal silicon content in the blast furnace ironmaking process is crucial for stabilizing the furnace condition and improving the molten iron quality. However, due to the complex nonlinear correlations and time-varying time lags between silicon content and process variables, silicon content prediction is a challenging task. To tackle the problem, we propose a novel silicon content prediction method, called temporal hypergraph attention network (T-HyperGAT), which is combined the hypergraph attention network (HyperGAT) and the gated recurrent unit (GRU) network. Specifically, the Hyper-GAT is used to capture the high-order correlations of input features and perform equal-dimensional feature transformation to maintain the temporality of input features, and the GRU network is used to capture the time-series characteristics of transformed input features to overcome the time-varying time lags of process variables. Then the T-HyperGAT model can capture high-order correlations and time-series characteristics from complex industrial data. The effectiveness of the proposed T-HyperGAT method is verified by actual blast furnace ironmaking process data from a blast furnace in China.

Predictive modeling of the hot metal silicon content in blast furnace based on ensemble method

The silicon content of the hot metal is not only an important indicator of the quality of the hot metal and blast furnace (BF) operation but also reflects the level of energy utilization and the thermal state within a BF. It is important to develop an accurate prediction model for hot metal silicon content. In present study, two models for predicting hot metal silicon content are developed based on two ensemble learning methods, random forest regression (RFR) and extreme gradient boosting (XGBoost). First, Box plot was used to visualize the collected data and determine extreme outliers in the raw data. Extreme outliers are replaced with null value, and all null value are filled by linear interpolation. Secondly, feature selection is performed using recursive feature elimination. Cross-validation is performed to optimize machine learning hyperparameters and having a robust accuracy measure. Based on this, two hot metal silicon content prediction models are developed. Finally, the prediction results of the two models are compared and evaluated. The results show that both ensemble learning models show good prediction performance in predicting hot metal silicon content, but the prediction performance of the RFR model is better than that of the XGBoost model and reaching 98.77%.

An Investigation on the Mechanical Properties of Aluminium 6061 Alloy Reinforced with Boron Carbide and Silicon Carbide

Abstract: Aluminium alloys are widely utilised in the aerospace and automobile industries due to their low density and strong mechanical qualities, as well as their superior corrosion and wear resistance and low thermal coefficient of expansion as compared to traditional metals and alloys. These material’s superior mechanical qualities and inexpensive production costs make them an appealing alternative for a wide range of scientific and technical applications. In this study, we strive to present a literature review on the overall performance of reinforced composites created by the stir casting method, as well as the effect of process factors on the properties of Aluminium-based MMC. The literature review framework in this paper provides a clear overview that the process parameters play important role for optimum properties of Aluminium based Metal Matrix Composites. As reinforcing elements in Metal Matrix Composites, Boron Carbide and Silicon Carbide play an important role. The MMCs were successfully produced using the liquid metallurgy process. Scanning electron microscopy was used to examine the morphology and microstructure of Al-B4C and Al-SiC composites. The addition of 2, 4 and 6 wt% B4C and SiC particles increased several mechanical parameters such as ultimate tensile strength and hardness. It was also discovered that the mechanical behaviour of B4C particulates AMC is superior to that of SiC particulates AMC. Keywords: Aluminum, Metal matrix composite, SiC, B4C, Tensile test, Hardness test and SEM Analysis.

Thermophysical Properties of Aluminium of Grade A5N and Its Alloys Doped with Silicon, Copper and Rare-Earth Metals

Thermophysical Properties of Aluminium of Grade A5N and Its Alloys Doped with Silicon, Copper and Rare-Earth Metals

Determining the influence of the microstructure and phase composition of glass-metal-ceramic coatings on their basic physical-technical properties

Given the development of new heat-resistant nickel alloys that operate at temperatures up to 1,250 °C, as well as the introduction of additive technologies for the production of various parts, it is a relevant task to devise new compositions of highly heat-resistant coatings. Determining the influence of the phase composition of glass-metal-ceramic coatings on its basic properties could improve the effectiveness of protecting those parts that operate under extreme conditions. Therefore, it is promising to conduct a study aimed at establishing the relationship between the microstructure and phase composition of glass-metal-ceramic coatings and the main physical-technical characteristics. This study's results have established that the most high-quality coatings were obtained on the basis of non-crystallizing glass. Such glass is characterized by a temperature coefficient of linear expansion of 92·10-7 degrees-1, a glass transition temperature of 625 °C, and surface tension of 260·10-3 N/m at 850 °C. These properties contribute to the formation of a defect-free coating, providing uniform spreading and high-quality adhesion to the substrate. The resulting optimal coating is characterized by the adhesion strength of 98 %, the thermal resistance (mode 950↔20 °C) of 50 cycles, and the high heat resistance (a weight gain after 100 h in the temperature range of 1,000‒1,050 °C) of 0.03 g/m2·h. Coatings with a minimum amount of glass bonding are distinguished by uniformity and high quality. The optimal ratio of phases "glass:metal-ceramic composition" is 10:90. The structure of the recommended coating is uniform, characterized by the homogeneous distribution of components, the absence of cracks, visible defects, and high quality. The phase composition of the coating after firing is represented by crystals of metallic nickel and silicon, as well as a small amount of residual glass phase.

Metallic Tin Nanoparticle-Reinforced Tin-Doped Porous Silicon Microspheres with Superior Electrochemical Lithium Storage Properties

Improving the electronic conductivity and drastic volume expansion is attractive and challenging for constructing high-performance Si-based anode materials for lithium-ion batteries. Herein, tin-doped porous silicon microspheres embedded with tin nanoparticles (Sn–PSi@Sn) are fabricated from easily available low-cost silicon–aluminum alloy precursors through a simple and scalable strategy with a chemical replacement/etching and a low-temperature annealing process. The 3D porous framework structure of Sn–PSi@Sn microspheres may buffer severe volume expansion during the electrochemical cycling and shorten the transport paths of Li+ ions. The doping of Sn atoms in the Si crystal lattice can lead to a lattice expansion in silicon, reinforce the electronic and ionic conductivities, and minimize the effect of Li trapping, which is advantageous for enhancing the rate performance and improving the initial Coulombic efficiency. The Sn nanoparticles anchoring in porous silicon microspheres may further improve the conductivity and structure stability of Sn–PSi@Sn composites. Based on the density functional theory calculation results, the effects of partial substitution of Sn into the Si lattice mentioned above have been successfully confirmed. As a consequence, the as-prepared tin-doped porous silicon microspheres embedded with tin nanoparticles show a high reversible capacity (1165.6 mA h g–1 at the 400th cycle at 1 A g–1), excellent rate properties (1433.4 mA h g–1 at a high rate of 2.5 A g–1), and superior cycling performance at an ultrahigh rate (910.9 mA h g–1 at the 500th cycle even at a high current density of 4 A g–1). This work provides a promising strategy to design high-performance anode composites.