Stripping Process Research Articles

Cold Sintering Halide-in-Oxide Composite Solid-State Electrolytes with Enhanced Ionic Conductivity.

All-solid-state batteries (ASSBs) have attracted increasing attention for next-generation electrochemical energy storage due to their high energy density and enhanced safety, achieved through the use of nonflammable solid-state electrolytes (SSEs). Oxide-based SSEs, such as Li1.3Al0.3Ti1.7(PO4)3 (LATP), are notable for their high ionic conductivity and excellent chemical and electrochemical oxidation stability. Nevertheless, their brittle mechanical properties and poor interface contact with electrode materials necessitate high-temperature and long-duration sintering or postcalcination processes, limiting their processability for real-world applications. Additionally, the formation of secondary phases can detrimentally affect the ionic conductivity of LATP electrolytes. Emerging halide-based SSEs offer reliable deformation for practical processing while maintaining high ionic conductivity. In this work, we report a transient liquid-assisted cold sintering process to integrate oxide-based LATP as the matrix and halide-based Li3InCl6 as the conductive boundary phase into a halide-in-oxide ceramic composite electrolyte at a low processing temperature of 150 °C. This composite structure significantly reduces interface resistance, effectively addressing ion-transport depletion across the boundaries between LATP particles. Consequently, the cosintered LATP-Li3InCl6 composite SSE exhibits a high ionic conductivity of 1.4 × 10-4 S cm-1 at ambient temperature. Furthermore, the symmetric Li|LATP-Li3InCl6·nDMF|Li cell demonstrates stable stripping and plating processes for 1600 h at 55 °C (0.1 mA cm-2) and 1200 h at 100 °C (1 mA cm-2). This work represents the first demonstration of halide-oxide ceramic composite SSEs that combine the advantages of oxides and halides for high-performance SSBs.

Superionic conducting vacancy-rich β-Li3N electrolyte for stable cycling of all-solid-state lithium metal batteries.

The advancement of all-solid-state lithium metal batteries requires breakthroughs in solid-state electrolytes (SSEs) for the suppression of lithium dendrite growth at high current densities and high capacities (>3 mAh cm-2) and innovation of SSEs in terms of crystal structure, ionic conductivity and rigidness. Here we report a superionic conducting, highly lithium-compatible and air-stable vacancy-rich β-Li3N SSE. This vacancy-rich β-Li3N SSE shows a high ionic conductivity of 2.14 × 10-3 S cm-1 at 25 °C and surpasses almost all the reported nitride-based SSEs. A Li- and N-vacancy-mediated fast lithium-ion migration mechanism is unravelled regarding vacancy-triggered reduced activation energy and increased mobile lithium-ion population. All-solid-state lithium symmetric cells using vacancy-rich β-Li3N achieve breakthroughs in high critical current densities up to 45 mA cm-2 and high capacities up to 7.5 mAh cm-2, and ultra-stable lithium stripping and plating processes over 2,000 cycles. The high lithium compatibility mechanism of vacancy-rich β-Li3N is unveiled as intrinsic stability to lithium metal. In addition, β-Li3N possesses excellent air stability through the formation of protection surfaces. All-solid-state lithium metal batteries using the vacancy-rich β-Li3N as SSE interlayers and lithium cobalt oxide (LCO) and Ni-rich LiNi0.83Co0.11Mn0.06O2 (NCM83) cathodes exhibit excellent battery performance. Extremely stable cycling performance is demonstrated with high capacity retentions of 82.05% with 95.2 mAh g-1 over 5,000 cycles at 1.0 C for LCO and 92.5% with 153.6 mAh g-1 over 3,500 cycles at 1.0 C for NCM83. Utilizing the vacancy-rich β-Li3N SSE and NCM83 cathodes, the all-solid-state lithium metal batteries successfully accomplished mild rapid charge and discharge rates up to 5.0 C, retaining 60.47% of the capacity. Notably, these batteries exhibited a high areal capacity, registering approximately 5.0 mAh cm-2 for the compact pellet-type cells and around 2.2 mAh cm-2 for the all-solid-state lithium metal pouch cells.

Design, perspectives, and challenges of modification strategies for alkali metal anodes

Abstract. The alkali metal anode has emerged as a focal point of research due to its extremely low oxidation-reduction potential and high theoretical specific capacity. However, challenges such as unstable solid electrolyte interphase (SEI), infinite volume expansion, and uncontrollable dendrite growth result in low coulombic efficiency and irreversible losses during the deposition and stripping processes. To address these issues, various effective strategies have been proposed to protect the alkali metal anode and achieve dendrite-free growth. In this review, we summarize recent advancements in enhancement strategies for alkali metal anodes, including the construction of three-dimensional current collectors and interface engineering. Specifically, we delve into the development of carbon-based current collectors with various dimensions and structures and the application of interface engineering techniques to tackle the challenges of unstable SEI, volume changes, and dendrite growth. Furthermore, we explore advanced characterization techniques that provide deeper insights into the reaction mechanisms and behavior of these enhancement strategies. Finally, we discuss the current limitations and future research directions in protecting alkali metal anodes, aiming to provide valuable insights into the study of dendrite growth and the development of effective protection strategies for alkali metal anodes.

Cost effective selective separation of indium and germanium from zinc processing waste leach liquor using D2EHPA-YW100 synergistic system and selective stripping with HCl and NH4F

Indium and germanium are rare elements and contribute to supporting materials for contemporary high technology new materials. Research and development of efficient separation and extraction of indium and germanium have important practical significance. A new process of “one step extraction and stepwise stripping” is proposed in this work to coextract indium and germanium with D2EHPA-YW100 synergistic system of Di(2-ethylhexyl) phosphoric acid (D2EHPA) and C7–9 hydroxamic acid (YW100) denoted by D2EHPA-YW100. In the coextraction process, 98.9 % of indium and 99.9 % germanium were extracted utilizing an organic phase consisting of YW100 (1.4 %), D2EHPA (15 %) and sulfonated kerosene (83.6 %). During the two-step stripping process, 99.9 % of indium was selectively stripped from the loaded organic phase in step-1 using 4 M HCl. In step-2, 99.5 % of germanium was stripped using a 1 M NH4F solution. This separation resulted the enrichment of germanium concentration by 6–7 fold and indium concentration by 19 fold. This method has four advantages: (i) simplifies the separation process, (ii) reduces equipment investment by nearly 50 %, (iii) minimizes extraction agent loss, and (iv) reduces management and labor costs.

Life cycle assessment (LCA) of the industrial production of structural glued laminated bamboo

Bamboo is a promising bio-based construction material for achieving China’s carbon neutrality goal. This study developed methodological approaches for life cycle assessment (cradle to gate) of structural glued laminated bamboo (SGLB) produced from moso bamboo (Phyllostachys edulis), including measuring and calculating biogenic carbon storage and emissions during the manufacturing process. Primary data was collected through experiments and field investigation resulting in development of world’s first life cycle inventory (LCI) of SGLB; background data from Ecoinvent 3.10 was used, and the analysis was performed using OpenLCA 2.1: IPCC 2021 method AR6. Uncertainty analysis was conducted using Monte Carlo Simulation. The results illustrate that SGLB can store 1140 kgCO2e/m3, which is more than twice biogenic CO2 emitted (467 ± 9.1 kgCO2e/m3) during its production. Electricity, adhesive, and transportation are the top three emission sources, among which electricity contributed to 71% of the final emission and was mainly consumed at the fine-planed bamboo strip processing factories. The production process generates around 60% of bamboo co-products, which can be effectively used for heat and power co-generation that can drastically reduce the carbon emissions to 156 kgCO2e/m3. In addition, maximal use of sea transportation between factory gate and consumer can further mitigate carbon emission. Further research on the end-of-life scenarios of SGLB in structures, and research on SGLB produced from other bamboo species in Africa, Latin America, and Southeastern Asia need to be undertaken.

Fiber motion in rotor spinning unit airflow: Numerical simulation and experimental validation

Airflow-assisted manufacturing holds significant promise across various applications, including rotor spinning, where airflow is crucial for fiber transfer and ultimately affects yarn performance. This study introduces a three-dimensional model of flexible fiber motion within the flow field of a rotor spinning unit. The fiber is modeled as cylindrical segments connected by rigid joints, with the segments experiencing fluid torques and the joints subjected to fluid forces. The model accounts for the fiber bending and torsional deformation. Fiber motion is determined by solving the translational and rotational equations, alongside the fiber–wall interactions. Emphasis is placed on the fiber stripping process from the opening roller. Supported by the numerical methods validated through visualization experiments and further corroborated by spinning examinations, we advance the understanding of the motion behavior of fibers released from different initial positions in the rotor spinning unit, and specifically, delve into the impact of airflow patterns on fiber movement. The developed numerical methodology and findings are vital for optimizing rotor spinning unit design and effectively harnessing airflow technology in processing.

Оценка технологии полосовой обработки почвы и внесения минеральных гранулированных удобрений на урожайность и качество продукции кукурузы

The evaluation of the developed strip tillage sowing tool with simultaneous application of mineral granular fertilizers on the yield and quality of corn products in field conditions on the basis of LLC Bashkir-Agroinvest Tavros Group was carried out. The infestation of corn plants with diseases, pests, yield of green mass, grain and quality in terms of starch and crude protein content was determined depending on the depth of strip processing (18, 22, 25 cm) and the dose of mineral fertilizer (100, 150, 200, 250 kg/ha). The maximum yield of the green mass of corn (56.8 t/ha), grain (10.63 t/ha) was formed at a depth of 22 cm of tillage and the application of mineral fertilizers at a dose of 200 kg/ha. The content of crude protein in corn grain varied from 9.3 to 13.8%, the starch content from 52.2 to 64.4%. Keywords: STRIP TILLAGE, SOWING, GREEN MASS YIELD, QUALITY, PROTEIN, STARCH

Complexion-induced Cu2+ coordinated phase separation PBI membrane for lithium metal batteries

The uncontrolled dendritic lithium production issues and the highly reactive behavior of lithium with electrolytes has limited use of lithium metal batteries. Herein, we utilized a straightforward method of the Complexion-Induced Phase Separation (CIPS) to fabricate a Cu2+ coordinated polybenzimidazole (PBI) membrane for a lithium metal battery. CIPS offer improved control over the structure and composition of the membrane, potentially leading to improved selectivity in ion transport, enhancing the safety and longevity of the battery. The formation mechanism and influencing elements of PBI-Cu are analyzed through experimental analysis and density functional theory calculations (DFT). The PBI-Cu membrane is effective in facilitating reversible lithium stripping and plating processes, suppressing dendrite formation, and promoting stable long-term cycling. Notably, the PBI-Cu cell demonstrated stable cycling conditions for over 200 h at a very high current density of 4 mA cm−2. The impressive rate performance was also confirmed during Li//LiFePO4 full cell operation, where it maintained a stable capacity of 120 mAh g−1 for more than 300 cycles. This research provides an in-depth insight into membrane design and paves the way for its application in various other energy-related technologies.

Sustainable separation of molybdenum from mixed mineral acids generated as semiconductor industry waste streams using tributyl phosphate (TBP) by effects of hybrid machine learning models

This study explores the separation and optimization of molybdenum (Mo) from mixed mineral acids derived from semiconductor industry waste streams with tributyl phosphate (TBP) by implementing machine learning (ML) models. Considerable experimental tests were performed to evaluate the impact of various operational variables on the effectiveness of Mo extraction and stripping. The support vector regression (SVR) paired with harmony search algorithm (HSA), genetic algorithm (GA), and shuffled frog leaping algorithm (SFLA) were employed for enhancement in the separation process and structural optimization. The SVR-SFLA model yielded the most meticulous predictions, identifying optimal extraction conditions with a TBP concentration, mixing time, temperature, and O/A ratio of 50%, 30 min, 25 °C, and 1, respectively, achieving 77.8% efficiency. The derived results from the SVR-SFLA model, in tandem with the McCabe-Theil diagram, indicated a four-stage counter-current extraction process required to achieve a yield exceeding 99%. For the stripping process, the hybrid model indicated optimal conditions with 3 M NH4OH and an A/O ratio of 0.5 at 50 °C for 20 min, requiring two counter-current stages for nearly complete stripping. Feature importance analysis using a random forest algorithm (RFA) highlighted the NH4OH concentration and phase ratio as the most significant factors, contributing 40.3% and 29.1%, respectively, to the stripping from the loaded TBP phase. The final product, obtained after crystallization and thermal decomposition of the strip solutions, was characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS), revealing 99.74% purity for molybdenum trioxide.

Sensitive and rapid detection of bisphenol A using signal amplification nanoparticles loaded with anti-bisphenol A monoclonal antibody

Bisphenol A has been reported to be a ubiquitous contaminant, and exposure to this compound can lead to adverse effects in human health. In the study, monoclonal antibody against BPA (anti-BPA mAb) with high affinity (3.74 × 109 L/mol) secreted by cell line 2E3 was successfully screened. Inspired by the signal amplification of nanoparticles, anti-BPA mAbs were labeled with nano-materials including colloidal gold (AuNP) and gold nanoflowers (AuNF) for preparation of immunoprobes and AuNP-/AuNF-based test strips. The developed AuNP- and AuNF-based test strips achieved the rapid and sensitive detection of BPA within 10 min, with the limit of detection (LOD) of 25 μg/mL and 3.125 μg/mL, respectively. The detection result in BPA spiked samples measured by the proposed methods was consistent with that detected by LC-MS method. The preparation process of as-prepared test strip is time-saving and considered as ideal candidates method for rapid screening BPA in real samples.

Formation Mechanism and Prevention of Cu Undercut Defects in the Photoresist Stripping Process of MoNb/Cu Stacked Electrodes

The Cu undercut is a recently discovered new defect generated in the wet stripping process of MoNb/Cu gate stacked electrodes for thin-film transistors (TFTs). The formation mechanism and preventive strategy of this defect were identified and investigated in this paper. The impact of stripper concentration and stripping times on the morphology and the corrosion potential (Ecorr) of Cu and MoNb were studied. It is observed that the undercut is Cu tip-deficient, not the theoretical MoNb indentation, and the undercut becomes severer with the increase in stripping times. The in-depth mechanism analysis revealed that the abnormal Cu undercut was not ascribed to the galvanic corrosion between MoNb and Cu but to the local crevice corrosion caused by the corrosive medium intruding along the MoNb/Cu interface. Based on this newly found knowledge, three possible prevention schemes (MoNiTi (abbreviated as Mo technology development (MTD) layer/Cu), MoNb/Cu/MTD, and MoNb/Cu/MoNb) were proposed. The experimental validation shows that the Cu undercut can only be completely eliminated in the MoNb/Cu/MTD triple-stacked structure with the top MTD layer as a sacrificial anode. This work provides an effective and economical method to avoid the Cu undercut defect. The obtained results can help ensure TFT yield and improve the performance of TFT devices.

Construction of composite lithium with high adhesion work and fast ionic conductivity by black phosphorus for solid-state lithium batteries

Li6.4La3Zr1.4Ta0.6O12 (LLZTO) based solid-state lithium metal batteries (SSLMBs) have a broad application prospect because of the nonflammable nature as well as the high energy density. However, the loose contact and the contact degradation of Li/LLZTO in the stripping process result in the serious lithium dendrites growth. Herein, these issues are addressed by a composite lithium anode (CLA), which is prepared through the reaction between black phosphorus and molten lithium. In comparison to pure lithium, a higher adhesion work (722.67 mJ m−2) and Li+ diffusion coefficient (2.45×10−12 cm2 s−1) are achieved for CLA, thus assuring the intimate interfacial contact of CLA/LLZTO interface during the lithium stripping process. As a result, a small interfacial resistance of 3.7 Ω cm2, a high critical current density of 1.5 mA cm−2, and extra-long cycle life of 8200 h at 0.3 mA cm−2 are achieved for CLA symmetric cell at 25 ºC. More importantly, the full cell coupled with high mass loading LiFePO4 cathode (10.6 mg cm−2) still shows a large discharge capacity of 156.3 mAh g−1 and cycles stably at 25 ºC. This work provides an alternative approach to develop the long lifespan and high capacity of SSLMBs.

Dendrite Growth and Dead Lithium Formation in Lithium Metal Batteries and Mitigation Using a Protective Layer: A Phase-Field Study.

Lithium metal batteries (LMBs) are considered one of the most promising next-generation rechargeable batteries due to their high specific capacity. However, severe dendrite growth and subsequent formation of dead lithium (Li) during the battery cycling process impede its practical application. Although extensive experimental studies have been conducted to investigate the cycling process, and several theoretical models were developed to simulate the Li dendrite growth, there are limited theoretical studies on the dead Li formation, as well as the entire cycling process. Herein, we developed a phase-field model to simulate both electroplating and stripping process in a bare Li anode and Li anode covered with a protective layer. A step function is introduced in the stripping model to capture the dynamics of dead Li. Our simulation clearly shows the growth of dendrites from a bare Li anode during charging. These dendrites detach from the bulk anode during discharging, forming dead Li. Dendrite growth becomes more severe in subsequent cycles due to enhanced surface roughness of the Li anode, resulting in an increasing amount of dead Li. In addition, it is revealed that dendrites with smaller base diameters detach faster at the base and produce more dead lithium. Meanwhile, the Li anode covered with a protective layer cycles smoothly without forming Li dendrite and dead Li. However, if the protective layer is fractured, Li metal preferentially grows into the crack due to enhanced Li-ion (Li+) flux and forms a dendrite structure after penetration through the protective layer, which accelerates the dead Li formation in the subsequent stripping process. Our work thus provides a fundamental understanding of the mechanism of dead Li formation during the charging/discharging process and sheds light on the importance of the protective layer in the prevention of dead Li in LMBs.

Determination of silver ions in distilled water by stripping voltammetry at a Nafion-coated gold electrode in combination with quartz crystal microbalance and electrochemical impedance spectroscopy

Here, we propose a stripping voltammetric method for Ag+ ion determination in distilled water utilizing screen-printed Au electrodes coated with Nafion (Nafion/Au screen-printed electrodes). The concentration of Ag+ in pure water was determined by linear sweep voltammetry (LSV) after silver deposition on the Nafion/Au electrode. The anodic stripping peak current increased linearly with the concentration of Ag+ ion in the range from 1 ppm to 22 ppm. The LSV oxidative peak current was increased by extending the silver deposition time from 300 s to 500 s. Repetitive LSV measurements revealed satisfactory reproducibility of the Nafion/Au screen-printed electrodes. The detection mechanism was elucidated by recording mass changes of the Nafion/Au electrode with a quartz crystal microbalance (QCM), and by determining changes in the low-frequency capacitance of the Nafion/Au electrode by electrochemical impedance spectroscopy (EIS). The observed changes in mass and capacitance confirmed Ag+ accumulation and release processes at the Nafion/Au electrodes, in good agreement with stripping voltammetry. The combination of stripping voltammetry, QCM and EIS allowed a detailed characterization of the ion transfer, deposition and stripping processes at the Nafion/Au electrodes in presence of Ag+ ions. The Nafion/Au screen-printed electrode enabled voltammetric determination of low Ag+ concentrations in distilled water, without any sample pretreatment nor addition of supporting electrolyte.

Effect of Pouring Techniques and Funnel Structures on Crucible Metallurgy: Physical and Numerical Simulations

In the planar flow casting process of amorphous strips, the flow behavior of molten metal and the inclusion content in the crucible are crucial to the morphology and magnetic properties of the material. This study conducts a comparative analysis of the effects of non-immersed and immersed funnels, as well as various funnel structures, on the fluid flow and inclusion removal efficiency in the crucible by integrating numerical and physical models. The findings reveal that for the same pouring flow rate, the diameter of the liquid column in non-immersed pouring conditions is smaller than that of the funnel outlet, leading to a faster injection flow velocity. As a result, the melt in the crucible is subjected to severe impacts, accompanied by an increased possibility of slag entrapment. Conversely, immersed pouring substantially reduces the velocity of the molten metal at the funnel outlet, thereby extending the residence time in the crucible and diminishing the volume of the dead zone. Additionally, the molten metal backflows due to the negative pressure formed in the inner chamber of the funnel. The design of a trumpet-shaped funnel increases the effective volume while reducing the height of the backflow fluid, consequently reducing the velocity of the molten metal at the funnel outlet and prolonging the residence time. Compared to the conventional pouring process with the non-immersed funnel, the outlet velocity is reduced from 1.1 m/s to 0.12 m/s by adopting the immersed funnel with an inverted trapezoidal trumpet structure. This reduction results in a stable flow state, a 9.69% reduction in the dead zone volume fraction, and a 22.96% increase in average inclusion removal efficiency. These improvements demonstrate that a crucible funnel with a well-designed structure and the implementation of an immersion process can significantly improve the metallurgical effects in the planar flow casting process.

Study of the stress relaxation resistance and microstructural evolution of a Cu–Ni–Si alloy strip

The stress relaxation resistance of a Cu–Ni–Si alloy strip after 48 h of initial loading stress of 80% σ0.2 at 125 °C was studied. The stress relaxation curve was fitted using a model. By employing EBSD, TEM, and other techniques, this study examined the microstructural characteristics of the Cu–Ni–Si alloy strip before and after stress relaxation. This study investigated the stress relaxation mechanism of the alloy and revealed that the stress relaxation rate of the Cu–Ni–Si alloy strip was 10.82% after 48 h at 125 °C. The stress relaxation process of the alloy strip was divided into two main stages. During the first stage, there was a significant rearrangement and movement of dislocations within the alloy strip, leading to a rapid decline in the remaining stress. In the second stage, the interaction among the Ni2Si phase, twins and dislocations led to a slow decrease in the remaining stress. After the stress relaxation of the alloy strip, the precipitated phase in the microstructure grew from 67 nm to 200 nm, the recrystallization microstructure increased from 57.91% to 62.42%, and the twin boundary content decreased from 22.1% to 18.5%. These observed changes in the microstructure are anticipated to further reduce the stress relaxation resistance of the alloy strip.

High‐frequency (470 kHz) ultrasonics‐assisted room temperature CO2 stripping and fate of Sono exposed solvent

AbstractBACKGROUNDThe conventional CO2 stripping process in solvent‐based postcombustion CO2 capture (PCCC) process uses heating to strip the CO2 (~120 °C). However, the challenges associated with this method are high energy consumption in degassing the CO2 from solvent, solvent loss and degradation resulting from the high –temperatures, resulting in high energy consumption typical of solvent‐based PCCC. The present study demonstrates the use of bath‐type sonication (470 kHz frequency) to remove CO2 from CO2 loaded 30 wt% Monoethanolamine under controlled temperature conditions. Solvent performance was evaluated following exposure to 2 h conventional heating and 75 h sonication.RESULTSIn a batch sono‐assisted process, CO2 stripping became possible at 17.5 °C compared to 102.2 °C using the conventional method. Increasing the sonication time led decreased carbon loading and increased stripping efficiency. The stripping rate was high at the initial stages of treatment. Evaluation of sono‐exposed solvents exhibited decreased pH during CO2 loading and decreased absorption capacity of the conventionally heated sample.CONCLUSIONThe sono‐assisted method consumes 3.57‐foldless energy than conventional heating. Its CO2 stripping rate was found to be higher within 5 min of sonication. Notably, the maximum temperature reached for the 1 h intervening mode of sonication at 470 kHz was 49.49 °C. The reduction in absorption capacity per hour of conventional heating was 24.5%, whereas for sonication it was <0.4% and solvent loss was 19.7% lower than conventional. There was no significant change in the color, pH and density of the sample. A 20.4% higher surface tension than that of the virgin sample was observed. © 2024 Society of Chemical Industry (SCI).

Illuminating the Incidence of Extraplanar Dust Using Ultraviolet Reflection Nebulae with GALEX

Circumgalactic dust grains trace the circulation of mass and metals between star-forming regions and gaseous galactic halos, giving insight into feedback and tidal stripping processes. We perform a search for ultraviolet (UV) reflection nebulae produced by extraplanar dust around 551 nearby (D < 100 Mpc), edge-on disk galaxies using archival near-ultraviolet and far-ultraviolet images from the Galaxy Evolution Explorer (GALEX), accounting for the point-spread function (FWHM = 4″–5″). We detect extraplanar emission ubiquitously in stacks of galaxies binned by morphology and star formation rate, with scale heights of h h = 1–2.3 kpc and ≈10% of the total (reddened) flux in the galaxy found beyond the B-band isophotal level of μ B = 25 mag arcsec−2. This emission is detected in 7% of the individual galaxies, and an additional one-third have at least 5% of their total flux found beyond μ B = 25 mag arcsec−2 in a disk component. The extraplanar luminosities and colors are consistent with reflection nebulae rather than stellar halos and indicate that, on average, disk galaxies have an extraplanar dust mass of 5%–15% of that in their interstellar medium. This suggests that recycled material composes at least a third of the inner circumgalactic medium (R < 10 kpc) in ∼L* galaxies.

Ethanol removal by stripping with CO2 reduced-size bubbles: Mechanical and thermodynamic entrainments

The efficiency of stripping processes for volatile compounds is governed by mechanical and thermodynamic entrainments, which play crucial roles in ethanol removal during the extractive fermentation process. These mechanisms depend on variables such as bubble diameter, ethanol concentration, liquid volume, pressure, and temperature. However, the quantification of each of them separately and their dependence on bubble diameter have never been addressed. The present study proposes a new methodology to evaluate both mechanical and thermodynamic entrainments, based on experimental data and thermodynamic equilibrium analysis of the bubbles in reactors with working volumes of 10.0 and 50 L, aiming to clarify the role that bubble diameter (microbubbles, fine and coarse bubbles) plays in these mechanisms. The results indicated that thermodynamic equilibrium was reached for any size of bubbles up to 5 mm in diameter, under a wide range of experimental conditions with specific gas flow rates from 0.22 to 10 vvm. Equally important, mechanical entrainment was found to enrich the gas phase in ethanol by a factor of 15, representing a higher concentration factor than for thermodynamic entrainment, which was inconceivable initially. This introduces a new and promising approach to intensify the stripping process of volatile compounds by means of mechanical entrainment.

Facile self-assembled monolayer deposition on copper foil for high-performance lithium-metal batteries

Li metal is widely acknowledged as the optimal negative electrode material for high-energy-density Li rechargeable batteries. However, challenges arise owing to the formation of Li dendrites and poor surface stability, leading to reduced cycle life and energy efficiency, thereby limiting widespread application. In this study, we introduced a novel approach of a molecular single-layer surface modification onto a Cu foil using a self-assembled monolayer with hexamethyldisilane (HMDS) to enhance the performance of Li-metal electrodes. The deposition of a single molecular layer at the Å-level was achieved by a simple combination of precursor casting and heat treatment without greatly affecting the energy and power density. Furthermore, this process was both scalable and cost-effective, making it highly suitable for large-scale battery manufacturing. The molecular deposition of HMDS effectively mitigated electrolyte decomposition and promoted uniform Li deposition by enhancing the surface stability under repeated Li plating–stripping processes. Optical microscopy revealed the homogeneous Li plating even after extended cycling; the first cycle on the modified surface depicted uniform plating without blank spots owing to the reduced gas-phase by-products from electrolyte decomposition. Thus, HMDS modification greatly improved the cycle stability of Li-metal batteries by successfully mitigating polarization due to electrolyte decomposition. Such improvement improved the Coulombic efficiencies and enhanced the energy efficiency, especially over a wide current density range of 1–5 mA cm−2. Furthermore, full cells with LiFePO4 cathodes and HMDS-modified Cu foils exhibited extended cyclability with increased energy efficiencies.