Sulfur Abundance Research Articles

Modification and Functionalization of Separators for High Performance Lithium-Sulfur Batteries.

Lithium-sulfur batteries (LSB) have been recognized as a prominent potential next-generation energy storage system, owing to their substantial theoretical specific capacity (1675 mAh g-1) and high energy density (2600 Wh kg-1). In addition, sulfur's abundance, low cost, and environmental friendliness make commercializing LSB feasible. However, challenges such as poor cycling stability and reduced capacity, stemming from the formation and diffusion of lithium polysulfides (LiPSs), hinder LSB's practical application. Introducing functional separators represents an effective strategy to surmount these obstacles and enhance the electrochemical performance of LSBs. Here, we have conducted a comprehensive review of recent advancements in functional separators for LSBs about various (i) carbon and metal compound materials, (ii) polymer materials, and (iii) novel separators in recent years. The detailed preparation process, morphology and performance characterization, and advantages and disadvantages are summarized, aiming to fundamentally understand the mechanisms of improving battery performance. Additionally, the development potential and future prospects of advanced separators are also discussed.

Sustainable Sulfur-Carbon Hybrids for Efficient Sulfur Redox Conversions in Nanoconfined Spaces.

Nanoconfinement is a promising strategy in chemistry enabling increased reaction rates, enhanced selectivity, and stabilized reactive species. Sulfur's abundance and highly reversible two-electron transfer mechanism have fueled research on sulfur-based electrochemical energy storage. However, the formation of soluble polysulfides, poor reaction kinetics, and low sulfur utilization are current bottlenecks for broader practical application. Herein, a novel strategy is proposed to confine sulfur species in a nanostructured hybrid sulfur-carbon material. A microporous sulfur-rich carbon is produced from sustainable natural precursors via inverse vulcanization and condensation. The material exhibits a unique structure with sulfur anchored to the conductive carbon matrix and physically confined in ultra-micropores. The structure promotes Na+ ion transport through micropores and electron transport through the carbon matrix, while effectively immobilizing sulfur species in the nanoconfined environment, fostering a quasi-solid-state redox reaction with sodium. This translates to ≈99% utilization of the 2e- reduction of sulfur and the highest reported capacity for a room temperature Na-S electrochemical system, with high rate capability, coulombic efficiency, and long-term stability. This study offers an innovative approach toward understanding the key physicochemical properties of sulfurcarbon nanohybrid materials, enabling the development of high-performance cathode materials for room-temperature Na-S batteries with efficient sulfur utilization.

Volatile composition of the HD 169142 disk and its embedded planet

Abstract The composition of a planet’s atmosphere is intricately linked to the chemical makeup of the protoplanetary disk in which it formed. Determining the elemental abundances from key volatiles within disks is therefore essential for establishing connections between the composition of disks and planets. The disk around the Herbig Ae star HD 169142 is a compelling target for such a study due to its molecule-rich nature and the presence of a newly-forming planet between two prominent dust rings. In this work, we probe the chemistry of the HD 169142 disk at small spatial scales, drawing links between the composition of the disk and the planet-accreted gas. Using thermochemical models and archival data, we constrain the elemental abundances of volatile carbon, oxygen, and sulfur. Carbon and oxygen are only moderately depleted from the gas phase relative to their interstellar abundances, with the inner ~60 au appearing enriched in volatile oxygen. The C/O ratio is approximately solar within the inner disk (~0.5) and rises above this in the outer disk (>0.5), as expected across the H2O snowline. The gas-phase sulfur abundance is depleted by a factor of ~1000, consistent with a number of other protoplanetary disks. Interestingly, the observed SiS emission near the HD 169142 b protoplanet vastly exceeds chemical model predictions, supporting previous hypotheses suggesting its origin in shocked gas or a localised outflow. We contextualise our findings in terms of the potential atmospheric composition of the embedded planet, and highlight the utility of sulfur-bearing molecules as probes of protoplanetary disk chemistry.

Evidence for a hydrogen sulfide-sensing E3 ligase in yeast.

In yeast, control of sulfur amino acid metabolism relies upon Met4, a transcription factor that activates the expression of a network of enzymes responsible for the biosynthesis of cysteine and methionine. In times of sulfur abundance, the activity of Met4 is repressed via ubiquitination by the SCFMet30 E3 ubiquitin ligase, but the mechanism by which the F-box protein Met30 senses sulfur status to tune its E3 ligase activity remains unresolved. Herein, we show that Met30 responds to flux through the trans-sulfuration pathway to regulate the MET gene transcriptional program. In particular, Met30 is responsive to the biological gas hydrogen sulfide, which is sufficient to induce ubiquitination of Met4 in vivo. Additionally, we identify important cysteine residues in Met30's WD-40 repeat region that sense the availability of sulfur in the cell. Our findings reveal how SCFMet30 dynamically senses the flow of sulfur metabolites through the trans-sulfuration pathway to regulate the synthesis of these special amino acids.

Planetary Waves Drive Horizontal Variations in Trace Species in the Venus Deep Atmosphere

Abstract The deep atmosphere of Venus remains mysterious because of the planet’s high, optically thick cloud decks. While phenomena such as the observed decadal fluctuations in sulfur dioxide abundance above the clouds could shed light on conditions below, poor understanding of vertical and horizontal transport limits such an approach. Nightside spectral windows permit observation of trace gas species in the lower atmosphere, but incomplete understanding of the circulation makes the distribution of these species challenging to interpret. We performed two simulations with the Venus Planetary Climate Model including an age of air calculation to investigate tracer transport (a) between the surface and the stagnant lower haze layer and (b) between the cloud deck and the observable upper atmosphere. We find a timescale on the order of many decades for surface-to-lower haze layer transport and ∼1.4 yr from the lowest cloud deck to 101 km. The extreme slowness of transport from the surface to the clouds makes it unlikely that compositional variability at the surface could affect the upper atmosphere sulfur dioxide abundance on observed timescales. Planetary-scale Rossby waves with a zonal wavenumber of 1 in both hemispheres are found to circumnavigate the planet in the deep atmosphere in 36 Earth days. These waves are associated with gyres that collect tracers and areas of upwelling that transport them to higher altitudes, leading to significantly younger air at polar latitudes in the altitude range of 25–45 km. The existence of chemically enhanced traveling Rossby gyres could explain the observed deep atmosphere carbon monoxide variability.

Challenges and Approaches to Designing High‐Energy Density Lithium‐Sulfur Pouch Cells

Lithium‐sulfur (Li‐S) batteries are of great interest as next‐generation energy storage devices in a wide variety of applications, due to their high specific capacity and the environmental abundance of sulfur. However, liquid electrolyte Li‐S technology faces several challenges such as polysulfide shuttling, anode corrosion and sluggish cathode kinetics. Practical deployment of Li‐S batteries requires evaluation in large‐format, high energy density pouch cells. Stringent operating conditions such as high sulfur loading and operating current, low electrolyte amount, and limited anode quantity are required for high energy density pouch cells, which further curtails the electrochemical performance and cycle life. This review aims to provide an understanding of the different failure mechanisms of large‐format Li‐S pouch cells and formulate key design parameters of Li‐S pouch cells that have high capacity, coulombic efficiency and long cycle life. Recent developments in Li‐S pouch cells are then discussed, focusing on cathode and electrolyte design for polysulfide immobilization, accelerated sulfur conversion kinetics, and Li anode protection. A review of advanced characterization techniques suitable for Li‐S pouch cell studies is also provided. Finally, viewpoints are offered on the remaining challenges and prospects to guide future research in scaling up Li‐S technology for real‐world applications.

Exploring the Rhizospheric Microbial Communities under Long-Term Precipitation Regime in Norway Spruce Seed Orchard.

The rhizosphere is the hotspot for microbial enzyme activities and contributes to carbon cycling. Precipitation is an important component of global climate change that can profoundly alter belowground microbial communities. However, the impact of precipitation on conifer rhizospheric microbial populations has not been investigated in detail. In the present study, using high-throughput amplicon sequencing, we investigated the impact of precipitation on the rhizospheric soil microbial communities in two Norway Spruce clonal seed orchards, Lipová Lhota (L-site) and Prenet (P-site). P-site has received nearly double the precipitation than L-site for the last three decades. P-site documented higher soil water content with a significantly higher abundance of Aluminium (Al), Iron (Fe), Phosphorous (P), and Sulphur (S) than L-site. Rhizospheric soil metabolite profiling revealed an increased abundance of acids, carbohydrates, fatty acids, and alcohols in P-site. There was variance in the relative abundance of distinct microbiomes between the sites. A higher abundance of Proteobacteria, Acidobacteriota, Ascomycota, and Mortiellomycota was observed in P-site receiving high precipitation, while Bacteroidota, Actinobacteria, Chloroflexi, Firmicutes, Gemmatimonadota, and Basidiomycota were prevalent in L-site. The higher clustering coefficient of the microbial network in P-site suggested that the microbial community structure is highly interconnected and tends to cluster closely. The current study unveils the impact of precipitation variations on the spruce rhizospheric microbial association and opens new avenues for understanding the impact of global change on conifer rizospheric microbial associations.

Addition of a Polar, Porous Phase-Inversion-PVDF Membrane to Lithium–Sulfur Cells (LSBs) Already with a Microporous Polypropylene Separator Enhances the Battery Performance

Lithium–sulfur batteries (LSBs) are widely studied as an alternative to lithium-ion batteries, this emphasis being due to their high theoretical energy density and low cost, and to the high natural abundance of sulfur. Lithium polysulfide shuttling and lithium dendrite growth have limited their commercialization. Porous polyvinylidene fluoride (PVDF) separators have shown improved performance (relative to hydrocarbon separators) in lithium-ion batteries due to faster lithium-ion migration and higher Li+ transference number. A thin polar PVDF membrane has now been fabricated via phase inversion (an immersion-precipitation method) yielding a β (polar) phase concentration of 72%. Preparation from commercial PVDF used dimethylformamide (DMF) solvent at the optimized crystallizing temperature of 70 °C, and pores in the membrane were generated by exchange of DMF with deionized water as non-solvent. The polar PVDF film produced has the advantages of being ultrathin (15 µm), lightweight (1.15 mg cm−2), of high porosity (75%) and high wettability (84%), and it shows enhanced thermal stability relative to polypropylene (PP). The porous, polar PVDF membrane was combined with a commercially available PP membrane to give a hybrid, two-layer, separator combination for LSBs. A synergy was created in the two-layer separator, providing high sulfur utilization and curbing polysulfide shuttling. The electrochemical performance with the hybrid separator (PP–β-PVDF) was evaluated in LSB cells and showed good cyclability and rate capability: those LSB cells showed a stable capacity of 750 mA h g−1 after 100 cycles at 0.1 C, much higher than that for otherwise-identical cells using a commercial PP-only separator (480 mA h g−1).

Screening Conductive Mxenes for Polysulfide Adsorption in Li-S Batteries

Lithium-sulfur batteries (LSBs) show promise as next-generation batteries due to their high charge density and natural abundance of sulfur. Nevertheless, their commercialization faces challenges due to the polysulfide shuttle effect and the insulating nature of sulfur and discharge products. MXenes have recently emerged as a solution by providing conducting pathways and polar sites to trap lithium polysulfides (LiPSs). While previous studies have explored the potential of MXenes in various passive components, a quantitative investigation of polysulfides adsorbed on MXenes, a crucial factor in enhancing LSB performance, remains lacking. In this study, we systematically investigate LiPSs adsorbed on seven MXenes: Ti2CT x , Ti3C2T x , Ti3CN x , Mo2TiC2T x , V2CT x , Nb2CT x , and Nb4C3T x . We explore the influence of soaking time, polysulfide concentration, and MXene composition on polysulfide adsorbed. Our spectroscopic findings reveal the formation of thiosulfate and polythionate species upon polysulfide adsorption for all MXene compositions. Furthermore, our study reveals the specific preferences of sulfur and lithium adsorbed on the MXene surface, dependent on MXene chemistry, adding a new level of understanding to the field. We expect our work can serve as a general guiding principle for the rational selection of MXenes for various passive components in the development of high-performance LSBs.

Carbon‐Based Cathode Design for Next‐Generation Potassium‐Sulfur Batteries: Status and Perspective

ABSTRACTThe increasing concern for environmental pollution has fastened the development of energy storage devices. Among various devices, lithium‐ion battery (LIB) technology has been leapfrogged owing to its stable performance for various applications ranging from electronic gadgets to electric vehicles (EVs). For ever‐increasing number of EVs has increased the demand for batteries increasing the overall cost. An alternative energy storage device that can replace the dependence on lithium reserves can be another game changer in this area. Potassium‐sulfur batteries (KSBs) have attracted enormous attention owing to the higher abundance of sulfur and potassium. In addition, sulfur bears the highest capacity as a cathodic material (nearly five times higher than the commercial LIBs) and when clubbed with potassium anode can deliver a theoretical energy density of 914 Wh/kg (significantly higher for EVs). However, KSB development is still in the nascent stage owing to the intrinsic challenges including insulating sulfur, volume variation, and shuttle effect of polysulfides. In addition, unstable potassium anode and its dendrite formation is another thorny problem for KSB. The use of carbon matrices for cathode fabrication has been proven to be an excellent choice by initial research on KSB and experience with other metal‐sulfur batteries. This can be related to the higher electronic conductivity of carbon, easy tunability, high specific surface area, and porous morphology. This review is an attempt to show the usage of carbon as a sulfur host for KSBs and its performance. Further, we shed light on flexible and binder‐free carbon electrodes for the development of KSBs, which can be adopted to develop flexible batteries to be used in wearable devices. Finally, we present our perspective for developing a high‐performance carbon‐based cathode material for developing a reliable and long‐cycle life KSB.

Laboratory infrared spectra and fragmentation chemistry of sulfur allotropes

Sulfur is one of six life-essential elements, but its path from interstellar clouds to planets and their atmospheres is not well known. Astronomical observations in dense clouds have so far been able to trace only 1 percent of cosmic sulfur, in the form of gas phase molecules and volatile ices, with the missing sulfur expected to be locked in a currently unidentified form. The high sulfur abundances inferred in icy and rocky solar system bodies indicate that an efficient pathway must exist from volatile atomic sulfur in the diffuse interstellar medium to some form of refractory sulfur. One hypothesis is the formation of sulfur allotropes, particularly of the stable S8. However, experimental information about sulfur allotropes under astrochemically relevant conditions, needed to constrain their abundance, is lacking. Here, we report the laboratory far-infrared spectra of sulfur allotropes and examine their fragmentation pathways. The spectra, including that of cold, isolated S8 with three bands at 53.5, 41.3 and 21.1 µm, form a benchmark for computational modelling, which show a near-perfect match with the experiments. The experimental fragmentation pathways of sulfur allotropes, key information for astrochemical formation/destruction models, evidence a facile fragmentation of S8. These findings suggest the presence of sulfur allotropes distributions in interstellar space or in the atmosphere of planets, dependent on the environmental conditions.

Optimized and cost-effective elemental-sulfur sodium polysulfide/sodium bromide aqueous electrolytes for redox flow batteries

Redox flow batteries (RFBs) can potentially revolutionize large-scale energy-storage technologies for both conventional (fossil fuel) and modern (renewable) electric power systems. This has stimulated the development of new methods for reducing the costs of such batteries by lowering material costs and increasing the energy density. Driven by the abundance and low costs of sulfur and bromine salts, this study investigates the viability of an aqueous flow battery system, in which sodium bromide (NaBr) is used as a catholyte, and a novel electrolyte called elemental added sulfur sodium polysulfide (EASSP) is utilized as an anolyte. The molar ratio of elemental sulfur to sodium (S/Na) in the sodium polysulfide solution is maintained at 1:4. Various concentrations of the EASSP and NaBr electrolytes are examined, and their optimal values corresponding to the minimum overpotential are determined. A bromine–polysulfide redox flow battery (BPRFB) containing a 1.4 M EASSP anolyte and 8 M NaBr catholyte is charged and discharged for 5 min, which results in a capacity of 17 mAh (3.4 mAh cm−2) at a current density of 40 mA cm−2. The cyclic performance of the BPRFB is characterized by a capacity of 17 mAh at 40 mA cm−2, which is retained over 150 cycles with a 98 % coulombic efficiency. The assembled BPRFB cell with the optimized electrolyte composition (1.4 M EASSP: 8 M NaBr) exhibits constant current (without leakage) and potential. The findings of this work demonstrate a high application potential of the developed anolyte for BPRFBs, which is highly soluble in water, inexpensive, and can be scaled up for energy storage applications.

Sulfur Dioxide and Other Molecular Species in the Atmosphere of the Sub-Neptune GJ 3470 b

We report observations of the atmospheric transmission spectrum of the sub-Neptune exoplanet GJ 3470 b taken using the Near-Infrared Camera on JWST. Combined with two archival Hubble Space Telescope/Wide-Field Camera 3 transit observations and 15 archival Spitzer transit observations, we detect water, methane, sulfur dioxide, and carbon dioxide in the atmosphere of GJ 3470 b, each with a significance of >3σ. GJ 3470 b is the lowest-mass—and coldest—exoplanet known to show a substantial sulfur dioxide feature in its spectrum, at M p = 11.2 M ⊕ and T eq = 600 K. This indicates that disequilibrium photochemistry drives sulfur dioxide production in exoplanet atmospheres over a wider range of masses and temperatures than has been reported or expected. The water, carbon dioxide, and sulfur dioxide abundances we measure indicate an atmospheric metallicity of approximately 100× solar. We see further evidence for disequilibrium chemistry in our inferred methane abundance, which is significantly lower than expected from equilibrium models consistent with our measured water and carbon dioxide abundances.

PDRs4All

Context. One of the main problems in astrochemistry is determining the amount of sulfur in volatiles and refractories in the interstellar medium. The detection of the main sulfur reservoirs (icy H2S and atomic gas) has been challenging, and estimates are based on the reliability of models to account for the abundances of species containing less than 1% of the total sulfur. The high sensitivity of the James Webb Space Telescope provides an unprecedented opportunity to estimate the sulfur abundance through the observation of the [S I] 25.249 µm line. Aims. Our aim is to determine the amount of sulfur in the ionized and warm molecular phases toward the Orion Bar as a template to investigate sulfur depletion in the transition between the ionized gas and the molecular cloud in HII regions. Methods. We used the [S III] 18.7 µm, [S IV] 10.5 µm, and [S l] 25.249 µm lines to estimate the amount of sulfur in the ionized and molecular gas along the Orion Bar. For the theoretical part, we used an upgraded version of the Meudon photodissociation region (PDR) code to model the observations. New inelastic collision rates of neutral atomic sulfur with ortho-and para- molecular hydrogen were calculated to predict the line intensities. Results. The [S III] 18.7 µm and [S IV] 10.5 µm lines are detected over the imaged region with a shallow increase (by a factor of 4) toward the HII region. This suggests that their emissions are partially coming from the Orion Veil. We estimate a moderate sulfur depletion, by a factor of ~2, in the ionized gas. The corrugated interface between the molecular and atomic phases gives rise to several edge-on dissociation fronts we refer to as DF1, DF2, and DF3. The [S l] 25.249 µm line is only detected toward DF2 and DF3, the dissociation fronts located farthest from the HII region. This is the first ever detection of the [S l] 25.249 µm line in a PDR. The detailed modeling of DF3 using the Meudon PDR code shows that the emission of the [S l] 25.249 µm line is coming from warm (>40 K) molecular gas located at AV ~1–5 mag from the ionization front. Moreover, the intensity of the [S l] 25.249 µm line is only accounted for if we assume the presence of undepleted sulfur. Conclusions. Our data show that sulfur remains undepleted along the ionic, atomic, and molecular gas in the Orion Bar. This is consistent with recent findings that suggest that sulfur depletion is low in massive star-forming regions because of the interaction of the UV photons coming from the newly formed stars with the interstellar matter.

Oxidized Sulfur Species in Slab Fluids as a Source of Enriched Sulfur Isotope Signatures in Arcs

AbstractRecycling of oxidized sulfur from subducting slabs to the mantle wedge provides simultaneous explanations for the elevated oxygen fugacity (fO2) in subduction zones, their high hydrothermal and magmatic sulfur outputs, and the enriched sulfur isotopic signatures (i.e., δ34S > 0‰) of these outputs. However, a quantitative understanding of the abundance and speciation of sulfur in slab fluids consistent with high pressure experiments is lacking. Here we analyze published experimental data for anhydrite solubility in H2O‐NaCl solutions to calibrate a high‐pressure aqueous speciation model of sulfur within the framework of the deep earth water model. We characterize aqueous complexes, required to account for the high experimental anhydrite solubilities. We then use this framework to predict the speciation and solubility of sulfur in chemically complex fluids in equilibrium with model subducting mafic and ultramafic lithologies, from 2 to 3 GPa and 400 to 800°C at log fO2 from FMQ‐2 to FMQ+4. We show that sulfate complexes of calcium and sodium markedly enhance the stability of sulfate in moderately oxidized fluids in equilibrium with pyrite at fO2 conditions of FMQ+1 to +2, causing large sulfur isotope fractionations up to 10‰ in the fluid relative to the slab. Such fluids could impart oxidized, sulfur‐rich and high δ34S signatures to the mantle wedge that are ultimately transferred to arc magmas, without the need to invoke 34S‐rich subducted lithologies.

Seven white dwarfs with circumstellar gas discs II: tracing the composition of exoplanetary building blocks

ABSTRACT This second paper presents an in-depth analysis of the composition of the planetary material that has been accreted on to seven white dwarfs with circumstellar dust and gas emission discs with abundances reported in Rogers et al. The white dwarfs are accreting planetary bodies with a wide range of oxygen, carbon, and sulphur volatile contents, including one white dwarf that shows the most enhanced sulphur abundance seen to date. Three white dwarfs show tentative evidence (2–3$\sigma$) of accreting oxygen-rich material, potentially from water-rich bodies, whilst two others are accreting dry, rocky material. One white dwarf is accreting a mantle-rich fragment of a larger differentiated body, whilst two white dwarfs show an enhancement in their iron abundance and could be accreting core-rich fragments. Whilst most planetary material accreted by white dwarfs display chondritic or bulk Earth-like compositions, these observations demonstrate that core-mantle differentiation, disruptive collisions, and the accretion of core-mantle differentiated material are important. Less than 1 per cent of polluted white dwarfs host both observable circumstellar gas and dust. It is unknown whether these systems are experiencing an early phase in the disruption and accretion of planetary bodies, or alternatively if they are accreting larger planetary bodies. From this work there is no substantial evidence for significant differences in the accreted refractory abundance ratios for those white dwarfs with or without circumstellar gas, but there is tentative evidence for those with circumstellar gas discs to be accreting more water rich material which may suggest that volatiles accrete earlier in a gas-rich phase.

Iron, cobalt co-embedded in situ graphitized xerogel-derived carbon as sulfur host for ultrahigh rate and high-performance lithium-sulfur batteries

Lithium‑sulfur battery (LSB) is an enticing technology because of its high specific capacity, potential energy density, and natural abundance of sulfur in the earth's crust. However, some notorious issues need to mitigate before commercialization. Here we report a novel and scalable iron, cobalt co-embedded resorcinol formaldehyde derived carbon framework as sulfur host for high-performance LSB. To further increase the specific surface area and porosity of carbon, polyvinyl alcohol (PVA) is used as a sacrificial polymer. One pot synthesis method is used for preparing the Fe, Co co-embedded PVA incorporated RF xerogel-derived carbon (FC-PRFC) framework. The first-principles calculations suggest the advantage of bimetallic doping in enhancing the binding energy and reducing the energy gap of the carbon host for polysulfide anchoring. The porous structure and higher specific area of FC-PRFC enable high sulfur loading in the composite and show excellent rate performance and cyclability, as suggested by detailed electrochemical analysis. Moreover, the FC-PRFC cathode host with a high areal sulfur loading of 4.2 mg cm−2 delivers a high initial discharge capacity of 1283 mAh g−1 at 0.1C. During long-cycling at a high current rate of 4C, it retains a capacity of 372 mAh g−1 after 400 charge-discharge cycles with a capacity retention of 73 %. This scalable, innovative, low-cost fabrication technique has the potential to pave the way for developing an outstanding xerogel-derived carbon framework for high-performance LSBs for commercial applications.

A fast neural emulator for interstellar chemistry

ABSTRACT Astrochemical models are important tools to interpret observations of molecular and atomic species in different environments. However, these models are time-consuming, precluding a thorough exploration of the parameter space, leading to uncertainties and biased results. Using neural networks to simulate the behaviour of astrochemical models is a way to circumvent this problem, providing fast calculations that are based on real astrochemical models. In this paper, we present a fast neural emulator of the astrochemical code Nautilus based on conditional neural fields. The resulting model produces the abundance of 192 species for arbitrary times between 1 and 107 yr. Uncertainties well below 0.2 dex are found for all species, while the computing time is of the order of 104 smaller than Nautilus. This will open up the possibility of performing much more complex forward models to better understand the physical properties of the interstellar medium. As an example of the power of these models, we ran a feature importance analysis on the electron abundance predicted by Nautilus. We found that the electron density is coupled to the initial sulphur abundance in a low-density gas. Increasing the initial sulphur abundance from a depleted scenario to the cosmic abundance leads to an enhancement of an order of magnitude of the electron density. This enhancement can potentially influence the dynamics of the gas in star formation sites.

NEATH − III. A molecular line survey of a simulated star-forming cloud

ABSTRACT We present synthetic line observations of a simulated molecular cloud, utilizing a self-consistent treatment of the dynamics and time-dependent chemical evolution. We investigate line emission from the three most common CO isotopologues (12CO, 13CO, C18O) and six supposed tracers of dense gas (NH3, HCN, N2H+, HCO+, CS, HNC). Our simulation produces a range of line intensities consistent with that observed in real molecular clouds. The HCN-to-CO intensity ratio is relatively invariant with column density, making HCN (and chemically similar species such as CS) a poor tracer of high-density material in the cloud. The ratio of N2H+ to HCN or CO, on the other hand, is highly selective of regions with densities above $10^{22} \, {\rm cm}^{-2}$, and the N2H+ line is a very good tracer of the dynamics of high volume density ($\gt 10^4 \, {\rm cm}^{-3}$) material. Focusing on cores formed within the simulated cloud, we find good agreement with the line intensities of an observational sample of prestellar cores, including reproducing observed CS line intensities with an undepleted elemental abundance of sulphur. However, agreement between cores formed in the simulation, and models of isolated cores which have otherwise-comparable properties, is poor. The formation from and interaction with the large-scale environment has a significant impact on the line emission properties of the cores, making isolated models unsuitable for interpreting observational data.

One-pot Synthesis of High-capacity Sulfur Cathodes via In-situ Polymerization of a Porous Imine-based Polymer.

Lithium-ion batteries, essential for electronics and electric vehicles, predominantly use cathodes made from critical materials like cobalt. Sulfur-based cathodes, offering a high theoretical capacity of 1675mAhg-1 and environmental advantages due to sulfur's abundance and lower toxicity, present a more sustainable alternative. However, state-of-the-art sulfur-based electrodes do not reach the theoretical capacities, mainly because conventional electrode production relies on mixing of components into weakly coordinated slurries. Consequently, sulfur's mobility leads to battery degradation - an effect known as the "sulfur-shuttle". This study introduces a solution by developing a microporous, covalently-bonded, imine-based polymer network grown in-situ around sulfur particles on the current collector. The polymer network (i) enables selective transport of electrolyte and Li-ions through pores of defined size, and (ii) acts as a robust host to retain the active component of the electrode (sulfur species). The resulting cathode has superior rate performance from 0.1C (1360mAhg-1) to 3C (807mAhg-1). Demonstrating a high-performance, sustainable sulfur cathode produced via a simple one-pot process, our research underlines the potential of microporous polymers in addressing sulfur diffusion issues, paving the way for sulfur electrodes as viable alternatives to traditional metal-based cathodes.