Silicon Metal Research Articles

Effect of Microstructure on Chemo-Mechanical Damage Evolution in Aluminum Foil Anodes for Lithium-Ion Batteries

Aluminum-based foil anodes could enable lithium-ion batteries with high energy density comparable to silicon and lithium metal. However, mechanical pulverization and lithium trapping within aluminum tend to cause capacity fading. The complex interplay between these damage modes is not well understood, as well as the role of microstructure on reaction front evolution. Here, we investigate aluminum foils with different compositions and processing conditions to understand how microstructure influences chemo-mechanical degradation. Backscattered electron imaging of ion-milled foil cross sections is used to visualize reaction front evolution and chemo-mechanical degradation. We find that the shape of the reaction front during lithiation is strongly affected by foil composition, defect distribution, and grain size, which, in turn, affects the evolution of chemo-mechanical damage within the foils. Furthermore, a key finding is that the extent of fracture upon delithiation is inversely related to lithium trapping, with foil compositions that exhibit uniform lithiation, and therefore, less fracturing showing greater lithium trapping. Nonreactive precipitate inclusions within alloy foils are also found to induce void formation. This work shows that material design strategies designed to overcome the inverse fracture-lithium trapping relationship could be useful for improving performance. Published by the American Physical Society 2024

Analyzing the lifecycle of solar panels including raw material sourcing, manufacturing, and end-of-life disposal

The lifecycle of photovoltaic systems, encompassing the procurement of raw materials, manufacturing processes, and eventual disposal at the end of their operational lifespan, presents considerable ecological challenges notwithstanding their contribution to the enhancement of renewable energy sources. This research offers an exhaustive examination of the ecological ramifications associated with each phase of the lifecycle of photovoltaic systems. The extraction of essential materials, including silicon, silver, and rare earth metals, necessitates energy-demanding processes and leads to resource depletion, while the manufacturing phase is associated with the emission of greenhouse gases and resource consumption, particularly in the fabrication of crystalline silicon panels. The disposal at the end of life is becoming increasingly significant, as retired panels accumulate, and existing recycling technologies provide minimal recovery of valuable materials. Despite the substantial reduction in greenhouse gas emissions attributable to solar panels throughout their operational lifespan, there is a pressing need for enhancements in material efficiency, manufacturing methodologies, and recycling frameworks to mitigate their lifecycle repercussions. The investigation underscores the imperative for sustainable methodologies, circular economy paradigms, and policy measures to guarantee the enduring environmental sustainability of solar energy.

Aging Retardation of Lead-Acid Batteries by Adjusting Charge Controller Threshold Values in Off-grid Photovoltaic System

Hybrid systems or coupled power plants with energy storage are becoming more and more popular due to the rising need for energy. Researchers have been conducting several experiments to assure longer-lasting battery use due to the increasing widespread use of energy storage and the depletion of resources such as silicon and precious metals. In this study, a simulation study is carried out in PVSyst software on lead-acid batteries, which have a low cycle and a very traditional electrochemical structure. The simulation is realized by scaling Spain’s consumption curve in 2023, taken from the European Network of Transmission System Operators for Electricity (ENTSO-E), together with lead acid batteries and off-grid photovoltaic (PV) modules. After the off-grid system design is created and consumption data is imported, it is aimed to extend battery life by changing the charge-discharge threshold values of the charge controllers. Threshold values are in two categories, high and low, and seventeen different cases are simulated. According to the results of the simulation, the state of charge (SOC) levels of the batteries decreases significantly due to radiation and cloudiness in the winter months and remain high in the spring and summer months. When charge controllers are set to high thresholds levels, they cause gassing currents that rise to an average of 20 amps, while battery life extends up to 5.3 years. When low threshold values are used, negligible levels of oxygen and hydrogen gasses are formed in the battery, but battery life decreases to 4.1 years.

A Robust Static Model of Basic Oxygen Furnace for Analyzing Emerging Steelmaking Scenarios

A robust static model, which incorporates emerging steelmaking scenarios in terms of solid charge mix with the given hot metal in basic oxygen furnace process, is developed. It employs mass and enthalpy balances to comprehend nonequilibrium conditions, considering four key empirical parameters: iron loss, post‐combustion ratio, heat loss, and undissolved lime content in slag, which are fine‐tuned using plant data through a multivariate approach, ensuring the reliability. The model is validated in a basic oxygen furnace (BOF) shop using data from over 4000 heats, achieving a strike rate of ≈77% for input lime prediction within ±1 ton and ≈80% for input oxygen prediction within ±600 Nm3. Model implementation in BOF shop provides valuable guidance to the operators, resulting in the reduction of average oxygen and lime consumption by 139 Nm3 and 652 kg heat−1, respectively. The model also enables the determination of the maximum scrap utilization of ≈16% for 0.8% silicon and ≈14% for 0.6% silicon in hot metal, respectively. The model aids in calculating the maximum tap temperature for varying hot metal silicon and iron ore addition. Overall, the model optimizes primary steelmaking, enhancing efficiency, reducing resource consumption, and offering insights into alternative iron sources like direct reduced iron.

Know-How of the Effective Use of Carbon Electrodes with a through Axial Hole in the Smelting of Silicon Metal

This article describes elements of the know-how of using carbon electrodes produced using the technology of molding around a rod when smelting silicon metal. Application of our know-how will dramatically increase the competitiveness of silicon metal production. Experts’ concerns regarding the use of such electrodes were that such electrodes have a through axial hole. This significantly reduces the mechanical strength of such electrodes, which can presumably lead to problems associated with the breakage of the working side of the electrode, which is immersed in the smelting space of the furnace under the charge layer. Industrial testing of such electrodes was carried out in a 30 MVA furnace of “Tau-Ken Temir” LLP. During testing, we used an approach previously developed by our team for working with a furnace in the process of smelting silicon metal. In particular, we used an interval between top treatments of about 30 min and adhered to the principles of balanced smelting, i.e., provided a balance between the intensity of the uniform supply of the charge into the furnace and the current active electrical power. Industrial testing carried out over four weeks confirmed the stability of the operation of cheaper carbon electrodes with a through axial hole. The recovery of silicon into finished products was also improved to 88–89% and the specific energy consumption was reduced to 11.2–12.1 MWh/t of silicon metal from the initial value 14,752 MWh/t. Thus, we received additional evidence for the effectiveness of our approach in furnace operating compared to an approach based on the ultimate provision of gas and permeability of the furnace top due to excessively intense processing of the top and an uncontrolled, uneven supply of charge to the furnace.

Physicochemical processes during solidification and the peculiarities of structure formation in aerated concretes using metallic silicon as a gas generator

The results of research on the structure and phase composition of non-autoclaved aerated concrete with a density of 550–750 kg/m3 using metallic silicon as a gas generator are presented. The peculiarities of the structure formation of aerated concrete products and the mineralogical composition of their hydration products were investigated. It was established that increasing the content of metallic silicon in aerated concrete leads to an increase in the pore space of the compositions. The results of diffractometric and thermal analysis methods for establishing the phase composition of aerated concrete compositions with metallic silicon as a gas generator are also presented. Analysis of XRD patterns and derivatograms showed that the aerated concrete samples under investigation contain a binder component, obermorite (5CaO6SiO25.5H2O); xonotlite (6CaO6SiO2H2O); -dicalcium silicate hydrate (2CaOSiO2H2O); and hillebrandite (2CaOSiO21.17H2O). It was established that increasing the amount of metallic silicon as a gas generator stimulates an increase in the content of hydrated phases in aerated concrete compositions.

Physicochemical processes during solidification and the peculiarities of structure formation in aerated concretes using metallic silicon as a gas generator

The results of research on the structure and phase composition of non-autoclaved aerated concrete with a density of 550–750 kg/m3 using metallic silicon as a gas generator are presented. The peculiarities of the structure formation of aerated concrete products and the mineralogical composition of their hydration products were investigated. It was established that increasing the content of metallic silicon in aerated concrete leads to an increase in the pore space of the compositions. The results of diffractometric and thermal analysis methods for establishing the phase composition of aerated concrete compositions with metallic silicon as a gas generator are also presented. Analysis of XRD patterns and derivatograms showed that the aerated concrete samples under investigation contain a binder component, obermorite (5CaO6SiO25.5H2O); xonotlite (6CaO6SiO2H2O); -dicalcium silicate hydrate (2CaOSiO2H2O); and hillebrandite (2CaOSiO21.17H2O). It was established that increasing the amount of metallic silicon as a gas generator stimulates an increase in the content of hydrated phases in aerated concrete compositions.

Physicochemical processes during solidification and the peculiarities of structure formation in aerated concretes using metallic silicon as a gas generator

Physicochemical processes during solidification and the peculiarities of structure formation in aerated concretes using metallic silicon as a gas generator

Q.ANTUM NEO with LECO Exceeding 25.5 % cell Efficiency

In recent years, we have developed the Q.ANTUM NEO solar cell, a rear-passivated double-sided contact solar cell that achieves power conversion efficiencies exceeding 25.5 %. Our streamlined and cost-efficient process leverages the proprietary Laser Enhanced Contact Optimization (LECO) technology. The LECO process has undergone extensive optimization and has been successfully implemented in both our pilot line and mass production facilities, resulting in significant improvements in solar cell efficiency. LECO facilitates a novel formation of the contact interface between the silicon surface and metallization, leading to remarkably low j0,met values (as low as 160 fA cm−2). The contact resistivity of 20 μm wide contacts on a high sheet resistance emitter is below 1 mΩ cm2, with minimal impact on fill factor (FF) and overall cell efficiency. Rigorous reliability tests, including TC600 and DH3000, demonstrate module degradation well below 5%rel. Our champion cell conversion efficiency achieved in the pilot line using LECO technology reaches 25.6 %, accompanied by a notable open-circuit voltage exceeding 730 mV.

Environmental impact assessment of the manufacture and use of N- type and P-type photovoltaic modules in China

For a long time, solar power has been considered a clean and non-polluting energy source because it absorbs sunlight without consuming other energy or materials and does not emit pollutants. Nevertheless, the manufacturing and end-of-life stages of solar power systems leave an environmental footprint and produce pollutants. Hence, a global perspective on photovoltaic (PV) systems using life cycle assessment methodology is necessary. Here, we investigated the life cycle impacts of P- and N-type PV modules in terms of their energy consumption, carbon emissions, and human toxicity potential. In addition, the energy payback durations of P- and N-type PV modules were computed. In this study, we used the Life Cycle Assessment Basic Database from the National Engineering Laboratory of Industrial Big Data Application Technology at Beijing University of Technology to create a life cycle assessment model for N-type PV modules. Subsequently, we performed a life cycle assessment of Chinese silicon N-type- and P-type PV modules. The research system encompassed the production processes for metallic silicon materials, solar-grade silicon materials, silicon wafers, cells and modules, utilization, recycling, and other interrelated processes. We found that the production and processing of silicon-to-solar-grade polysilicon feedstock were crucial stages that significantly affected the energy consumption and environment of P- and N-type PV modules in China. The high electricity consumption of this process, combined with the dominance of coal power in China's electricity structure, contributed to the substantial energy consumption and environmental impacts of the PV modules. Therefore, this stage is critical for the low-carbon and environmentally sustainable manufacturing of N-type PV modules in China. Carbon emissions for both the P-type and N-type PV modules were lower only during the cell production phase but higher during the other stages when compared to the P-type and N-type PV modules. The n-type bifacial PV modules yielded the highest return on investment in terms of energy. Different regions and installation types have a substantial impact on the carbon emissions of P-type and N-type PV modules. Projections indicate that the potential to lower carbon emissions from n-type PV modules will increase by 2060.

Применение бентонитовой глины в качестве гидроизоляционного материала

Purpose: analytical study of usability bentonite is a natural mineral with high waterproofing and adsorption properties in various fields. Methods: methods of comparative analysis, synthesis, generalization, analogy were used. Results: this article examines various applications of bentonite, allowing to position bentonite as a universal material, which is widely used in various industries due to its unique properties. The advantages of bentonite over other waterproofing materials are noted, including environmental friendliness, durability, efficiency and economy. The properties of bentonite clay have been studied, the ability of which to swell and create a waterproofing barrier in contact with water makes it an effective material for protection against moisture. It is indicated that the high frost resistance of bentonite is ensured due to the complex structure of the material consisting of metal oxide atoms and silicon atoms, which form a dense structure. The interlayer space in which the exchange cations are concentrated is the physical and physicochemical basis for the sorption activity of bentonite clay rocks. Bentonite has been found to be of value in its self-healing properties, as is the case when used at negative temperatures. This is due to its molecular structure. The microscopic particles that make up bentonite have a negative charge, they are able to adsorb water molecules. Practical significance: waterproofing works are carried out in many areas of construction. However, bentonite materials are not widely used. In this aspect, the article describes in detail such waterproofing materials as bentonite mats, clay lock, injectable bentonite waterproofing. The authors believe that the demand for the use of bentonite as a reliable and promising means of waterproofing in the construction industry will increase.

Prospects of silicide contacts for silicon quantum electronic devices

Metal contacts in semiconductor quantum electronic devices can offer advantages over doped contacts, primarily due to their reduced fabrication complexity and lower temperature requirements during processing. Some metals can also facilitate ambipolar device operation or form superconducting contacts. Furthermore, a sharp metal–semiconductor interface allows for contact placement in close proximity to the active device area avoiding damage caused by dopant implantation. However, in the case of gate-defined quantum dots in intrinsic silicon, the formation of a Schottky barrier at the silicon–metal interface can lead to large, nonlinear contact resistances at cryogenic temperatures. We investigate this issue by examining hole transport through metal oxide-semiconductor transistors with platinum silicide contacts on intrinsic silicon substrates. We extract the contact and channel resistances as a function of temperature and improve the cryogenic conductance of the device by more than an order of magnitude by implementing meander-shaped contacts. In addition, we observe signatures of enhanced transport through localized defect states, which we attribute to platinum clusters in the depletion region of the Schottky contacts that form during the silicidation process. These results showcase the prospects of silicide contacts in the context of cryogenic quantum devices and address associated challenges.

Metallic Sb-stabilized porous silicon with stable SEI and high electron/ion conductivity boosting lithium-ion storage performance

Metallic Sb-stabilized porous silicon with stable SEI and high electron/ion conductivity boosting lithium-ion storage performance

Facile room temperature synthesis of size-controlled spherical silica from silicon metal via simple sonochemical process

The waterglass or St o¨ ber method is commonly used to synthesize spherical colloidal silica; however, these methods have some disadvantages, such as complicated processes for the removal of sodium ions and expensive and energy-consuming raw materials such as tetraethoxysilane (TEOS). In this study, size-controlled spherical colloidal silica was synthesized from silicon metal at room temperature using an ultrasound process with hydrazine monohydrate as the solvent. Silicon metal dissolves easily in hydrazine monohydrate under ultrasound irradiation, and spherical colloidal silica can be synthesized by adding alcohol to this precursor solution. By changing the concentration or type of alcohol, size-controlled colloidal silica 20–200 nm in size could be easily obtained. In addition, finer and more monodisperse particles were produced by low-frequency ultrasound irradiation, which had a higher stirring effect at the particle formation stage. The present method is effective because size-controlled colloidal silica can be synthesized at room temperature using only silicon metal, hydrazine, and alcohol as raw materials, without complicated processes or expensive and energy-consuming raw materials such as TEOS or tetramethoxysilane (TMOS).

Specific contact resistivity reduction in amorphous IGZO thin-film transistors through a TiN/IGTO heterogeneous interlayer

Oxide semiconductors have gained significant attention in electronic device industry due to their high potential for emerging thin-film transistor (TFT) applications. However, electrical contact properties such as specific contact resistivity (ρC) and width-normalized contact resistance (RCW) are significantly inferior in oxide TFTs compared to conventional silicon metal oxide semiconductor field-effect transistors. In this study, a multi-stack interlayer (IL) consisting of titanium nitride (TiN) and indium-gallium-tin-oxide (IGTO) is inserted between source/drain electrodes and amorphous indium-gallium-zinc-oxide (IGZO). The TiN is introduced to increase conductivity of the underlying layer, while IGTO acts as an n+-layer. Our findings reveal IGTO thickness (tIGTO)-dependent electrical contact properties of IGZO TFT, where ρC and RCW decrease as tIGTO increases to 8 nm. However, at tIGTO > 8 nm, they increase mainly due to IGTO crystallization-induced contact interface aggravation. Consequently, the IGZO TFTs with a TiN/IGTO (3/8 nm) IL reveal the lowest ρC and RCW of 9.0 × 10−6 Ω·cm2 and 0.7 Ω·cm, significantly lower than 8.0 × 10−4 Ω·cm2 and 6.9 Ω·cm in the TFTs without the IL, respectively. This improved electrical contact properties increases field-effect mobility from 39.9 to 45.0 cm2/Vs. This study demonstrates the effectiveness of this multi-stack IL approach in oxide TFTs.

Active dual-control electromagnetically induced transparency analog in metal- vanadium dioxide-photosensitive silicon hybrid metamaterial

We investigate an active dual-control metamaterial leveraging electromagnetically induced transparency (EIT), exploiting near-field interactions between electric and magnetic dipole resonances. Our hybrid strip element, combining metal and vanadium dioxide, generates electric dipole resonance, while split-ring resonators integrating metal and photosensitive silicon induce magnetic dipole resonance. Simulations confirm coupling validity and demonstrate dynamic adjustability of EIT via temperature and light intensity changes. EIT modulation transitions between transparent and non-resonant states due to temperature fluctuations, or resonant states with varying light intensity. Temperature adjustments dominate when both factors are altered. Analysis via a coupled oscillator model reveals modulation of damping rates as the origin of disappearance curve variations. This innovative design enhances tunable EIT metamaterial versatility, with implications for high transmission ratios and adaptable slow-light effects in terahertz applications.

MEMS flexible conformal hydrophone based on heterogeneous integration technology

PurposeHuman-induced marine environmental noise, such as commercial shipping and seismic exploration, is concentrated in the low-frequency range. Meanwhile, low-frequency sound signals can achieve long-distance propagation in water. To meet the requirements of long-distance underwater detection and communication, this paper aims to propose an micro-electro-mechanical system (MEMS) flexible conformal hydrophone for low-frequency underwater acoustic signals. The substrate of the proposed hydrophone is polyimide, with silicon as the piezoresistive unit.Design/methodology/approachThis paper proposes a MEMS heterojunction integration process for preparing flexible conformal hydrophones. In addition, sensors prepared based on this process are non-contact flexible sensors that can detect weak signals or small deformations.FindingsThe experimental results indicate that making devices with this process cannot only achieve heterogeneous integration of silicon film, metal wire and polyimide, but also allow for customized positions of the silicon film as needed. The success rate of silicon film transfer printing is over 95%. When a stress of 1 Pa is applied on the x-axis or y-axis, the maximum stress on Si as a pie-zoresistive material is above, and the average stress on the Si film is around.Originality/valueThe flexible conformal vector hydrophone prepared by heterogeneous integration technology provides ideas for underwater acoustic communication and signal acquisition of biomimetic flexible robotic fish.

Controlling the lifetime of biodegradable electronics: from dissolution kinetics to trigger acceleration

Biodegradable electronics have revolutionized the field of medical devices by offering inherent advantages such as natural disintegration after a useful functional period, thereby eliminating the need for removal surgery. This paradigm shift addresses challenges with long-term implantation, the risks of secondary surgeries, and potential complications, offering a safer and more patient-friendly approach to temporary implantable devices. This review delves into the dissolution kinetics of materials and strategies for lifetime control providing a comprehensive overview of recent advancements in biodegradable electronics. Understanding the kinetics is crucial for meeting the required functional lifetime for implantable medical applications, which varies based on application scope and target diseases. The dissolution kinetics of silicon and biodegradable metals form the core of the discussion, focusing on recent studies aimed at controlling the dissolution rate and enhancing properties. The exploration extends to ideas for accelerating material degradation or initiating on-demand degradation in biodegradable electronics after stable function. Additionally, the compilation of encapsulation layer materials and strategies enhances understanding of how to improve the stable operation time of devices. Emphasis is placed on efforts to adjust the lifetime of biodegradable electronics, particularly in medical applications.

Evolution of Ti2O3 and mullite in Si-Al2O3-fused mullite containing Ti2O3 composite at 1600 °C

Si-Al2O3-fused mullite containing Ti2O3 composite was sintered at 1600 °C in N2. Changes in the structure and activity of fused mullite containing Ti2O3 raw material during the coupled reaction of metallic silicon and Ti2O3 are explored. The mechanism of regulating the phase composition and microstructure of the composite with the changes of Ti2O3 and fused mullite is also revealed. At high temperatures and low oxygen partial pressures, the stability of fused mullite decreases and decomposes to form SiO(g) and alumina-rich mullite. SiO(g) reacts with N2 to form Si3N4, which solidifies with mullite to form X-Sialon, further optimizing the phase composition. With the transformation of Ti2O3 to Ti(C,N)ss, the inhibitory effect of Ti3+ on the growth and development of fused mullite disappears, and the morphology of the fused mullite is gradually transformed from a dense structure to a classical elongated columnar morphology. A model for the mechanism of non-oxide formation and the regulation of micro-morphology is developed.

Round-the-Clock and Continuous Generation of Hydrogen and Oxygen

The main methods of industrial hydrogen production are: steam restructuring of methane and natural gas; coal gasification; biotechnology; water electrolysis. The most efficient method for producing pure hydrogen and oxygen is to produce pure hydrogen and oxygen in a photoelectrochemical cell. A photoelectrochemical cell produces hydrogen and oxygen directly from solar energy. In a photoelectrochemical cell, a combined anode, made from silicon semiconductor and metal mesh with large cells, submerged in water electrolyte solution, agitated by four photons of light, forms an oxygen molecule, which in the form of a gas bubble lifts from the surface of anode to the free surface of the water electrolyte solution. Two hydrogen cations, formed because of the dissociation of water, reaching the cathode, form a gaseous hydrogen molecule, which, turn into an electrolysis bubble, lifts from surface of cathode to the free surface of the water electrolyte solution. The article presents a new method for round-the-clock and continuous generation of hydrogen and oxygen, using a developed photoelectrolyzer-generator, taking a horizontally located combine anode, made from silicon semiconductor and metal mesh with large cells and burnt graphite cathode (electrolysis base) at the bottom of the photoelectrolyzer-generator; a membrane from fire hose material, located between electrodes; device, regulating the gap between the electrodes. Round-the-clock and continuous production of hydrogen and oxygen in the photoelectrolyzer-generator is ensured by using lamp, including LED with a daylight battery charger as a useful electrical load, which brightens the combined anode, made from silicon semiconductor and metal mesh with large cells at night until the morning and by continuously filling the photoelectrolyzer-generator with water.