Volume Expansion Research Articles

Preparing Carbon-Coated Copper Foil with a Low-Cost and Environmentally Friendly Carbon Slurry to Stabilize Silicon Anode for Lithium-Ion Battery.

Introducing a conductive carbon layer between the copper foil current collector and silicon active material effectively mitigates electrode damage and battery capacity loss caused by uneven silicon expansion. In this study, a low-cost, environmentally friendly carbon-coated copper foil (CCF) is designed using zeolitic imidazolate framework 8-derived carbon (ZPC) as the carbon source, polyethylenepyrrolidone (PVP) as the binder, and deionized water as the solvent. The large surface area and porosity of ZPC effectively accommodate the volume expansion of silicon, thereby enhancing the overall performance of the battery. The bare copper foil electrode experiences rapid decay, with a failure occurring after just 75 cycles at 0.5 C. In contrast, the CCF electrode maintains a reversible capacity of 576.8 mAh/g even after 200 cycles. The CCF electrode demonstrates superior specific capacity and cycle stability in both the rate and cycling test. According to the relaxation time distribution (DRT) analysis, the porous carbon layer on the CCF surface ensures excellent electrical contact between silicon and the Cu foil during cycling, facilitates uniform lithium insertion into silicon, prevents uncontrolled growth of the SEI layer, and guarantees stable battery operation. This CCF preparation process provides a promising solution to mitigate the degradation of battery performance caused by silicon expansion.

Slurry Additive Approach Enables a Mechanically Robust Binder for Silicon-Carbon Anodes in Lithium-Ion Batteries.

Silicon-carbon (Si/C) composites hold great promise as substitutes for conventional graphite anodes in high-specific-energy lithium-ion batteries (LIBs). However, their performance is hindered by silicon's substantial volume expansion during cycling, which can lead to electrode degradation. Traditional poly(acrylic acid) (PAA) binders often struggle to maintain electrode integrity under these conditions. To address this challenge, polyether modified polyurethane acrylic (PUMA) is used as physicochemical cocrosslinking polymer. PUMA offers superior mechanical properties, elasticity, and interfacial stability, enabling it to effectively accommodate silicon's volume changes and prevent electrode fracture. Through a simple preparation process, we used PUMA as a slurry additive in combination with PAA to form a functional composite binder, facilitating the construction of a stable and robust SEI film. This is conducive to alleviating the volume expansion of silicon and ensuring the cycling stability of the electrode. In Si/C450 half-cells, electrodes enhanced by our binder show a remarkable longevity, maintaining 97.26% of their capacity post 200 cycles at 0.5 C. The full cells Si/C450||NCM811 display a notable performance, achieving a capacity retention of 82.10% after 100 cycles at 0.2 C. These findings underscore the potential of our innovative binder design in enhancing the efficacy of silicon-based anodes in high-energy LIBs.

Facial Aging in Thyroid Eye Disease: Quantification by Artificial Intelligence.

This study aims to elucidate the effect of thyroid eye disease on perceived facial aging. In this cross-sectional cohort study, an artificial intelligence (AI) model (previously trained to infer patient age from facial photographs) was used to analyze facial aging changes in 2 groups: (1) TED patients and (2) age-matched controls. Standardized photos were analyzed from initial and final visits of patients with more than 5 years of clinic follow-up. The performance of the AI model was compared to that of an expert group composed of oculoplastic surgeons. Chronological, AI-inferred, and expert-estimated ages were compared. AI initially estimated TED subjects to be 4.3 years older than their actual age, compared to 0.63 years older in control subjects (P=0.005). At the final timepoint, TED patients were estimated to be 5.0 years younger than their actual age, compared to 1.4 years younger in controls (P=0.004). The mean difference between actual and AI-inferred change in age was 9.3 years for TED patients and 2.0 years for controls (P<0.001). Human experts tended to underestimate age across all groups and time points. The AI model was significantly more accurate than human experts in estimating the age of controls at the final time point. AI estimated that TED patients were older than their chronological age initially and younger than their chronological age at the final follow-up. This may be due to initial pathologic soft tissue volume expansion in TED, which may compensate for age-related soft tissue deflation.

CoNiSe2 Nanoparticles Embedded in Pod‐Like N‐Doped Carbon Nanofibers for High‐Performance Sodium‐Ion Batteries

Sluggish kinetics and severe volume expansion critically limit the electrochemical performance of sodium‐ion batteries (SIBs). Herein, a novel material combining CoNiSe2 nanoparticles with pod‐like N‐doped carbon nanofibers (CoNiSe2/PCNFs) is designed and fabricated. The bimetallic selenide of CoNiSe2 combines the redox characteristics of Co and Ni, which offers more redox active sites for Na+ adsorption. The nanocubes show large surface areas, which contribute to faster Na+ diffusion kinetics. Unique pod‐like N‐doped carbon nanofibers not only serve as reinforcing frameworks to inhibit volume change but also improve the conductivity of CoNiSe2/PCNFs. Herein, the CoNiSe2/PCNFs electrode achieves a high capacity of 395.8 mAh g−1 at a current density of 0.1 A g−1 after 100 cycles and exhibits excellent cycling stability for 1000 cycles at a current density of 1.0 A g−1 with a capacity of 284.3 mAh g−1. The novel structure and high electrochemical properties of CoNiSe2/PCNFs shed new light on developing high‐performance bimetallic selenides as SIB anodes.

Micro-Nano Conductive Network Structured Aramid Paper-Based Self-Supporting Cathode Enhances Cycling Stability in Lithium-Sulfur Battery.

Lithium-sulfur batteries (LSBs) continue to encounter significant challenges in practical applications, primarily attributed to the low electrical conductivity of the cathode active material sulfur, volume expansion during cycling and the uncontrolled shuttle effect of lithium polysulfides (LiPSs). In this work, flexible meta-aramid fibrids (AFs) were innovatively introduced, and polydopamine (PDA) was employed to effectively adhere highly conductive multiwalled carbon nanotubes (MWCNTs) to the AFs surface, thereby forming nanoscale conductive pathways. A wet-laid process analogous to aramid paper-making was utilized to enhance interfacial bonding between AFs and rigid carbon fibers (CFs), resulting in a self-supporting paper-based cathode material with a uniform, dense three-dimensional micronano-scale conductive network and stable structure. The porous structure between the fibers effectively alleviates sulfur's volume expansion. The polar PDA coating layer offers numerous chemical adsorption sites, which chemically anchor LiPSs and thereby more effectively suppresses the shuttle effect. The research results demonstrate that the AF@PDA-MWCNT/CF/S cathode delivers an impressive initial discharge specific capacity of 1140 mAh g-1 at a sulfur loading of 2.3 mg cm-2 and a current density of 0.2 C. After 400 cycles at a higher current density of 1 C, the single-cycle capacity fade rate is as low as 0.005%. Even at a high sulfur loading of 3.1 mg cm-2, the material still exhibits an initial discharge specific capacity of 890 mAh g-1. The AF@PDA-MWCNT/CF/S composite cathode developed in this study exhibits significant application potential and offers an approach for constructing self-supporting, paper-based cathode materials.

A Particle Rearrangement Approach for Optimizing Planar and Surface Particle Distributions in Meshless Particle Methods

Particle-based meshless methods are commonly used in fluid dynamics and solid mechanics involving finite deformations, owing to their ability to break through the limitations imposed by mesh topology. Particle distribution usually plays a crucial role in determining the accuracy of simulation results for them. In this study, an error estimation was first conducted to ascertain the requirements for particle distribution necessary for accurate simulations. It was revealed that the sawtooth and chaotic particle distributions can significantly reduce numerical accuracy and even cause numerical instability in simulations. To address this issue, we propose a particle rearrangement approach including a pseudo hydrostatic pressure treatment to achieve body-fitted particles and a geometric smoothing method based on the metric of a point cloud unit to optimize chaotic particle distributions for improved regularity. The particles are iteratively moved according to their proximity to neighboring particles. Notably, the number of particles remains constant throughout the smoothing procedure, neither particles inserted or removed, nor particles overflow or volume expansion. This new approach facilitates the generation of body-fitted and relatively regular planar and surface particle distributions, meeting the requirements for arbitrarily complex shape particle distributions. The effectiveness of this method has been demonstrated through two-dimensional SPH simulations for problems of the flow around a cylinder, dam break, and Taylor–Green vortex.

Planning for heat beyond the big city: comparing smaller cities’ heat activities, opportunities, and constraints in California

ABSTRACT Addressing extreme heat has emerged as a key frontier of urban climate adaptation planning. However, most studies have focused on large cities, whereas most of the existing urban population lives and urban growth occurs in small- to medium-sized municipalities within metropolitan areas in the U.S. and globally. We hypothesise based on structuration theory that these smaller municipalities face fundamentally different constraints and opportunities to enhance their heat planning capabilities than large cities. Accordingly, in this study we analyze heat planning capacity, current activities, and expansion opportunities in small- to medium-sized cities across two neighbouring but distinct regions in California: northern Los Angeles County (n = 20) and the southern San Joaquin Valley (n = 38). Using data from these 58 cities, we first comprehensively reviewed heat-related activities in their key planning documents. We then conducted 17 semi-structured interviews with local government planners, planning consultants, and utilities’ staff to more holistically analyze how heat planning and implementation occurs on the ground. The planning document analysis shows that a narrow majority of cities identified heat as a general issue of concern. The most common long-term adaptation and resilience strategies were enhancing urban tree canopy, green infrastructure, and shade structures, but both prevalence and strategy type vary by heat exposure level, population size, and the socioeconomic status of cities. However, in interviews, we generally found that while local officials had high levels of heat awareness, they had low levels of focused capacity and deployed heat interventions compared with other climate adaptation efforts.

Agroforestry as land-based carbon dioxide removal in central Europe: tensions between institutions, interests, and ideas hindering scaling up

ABSTRACT Agroforestry systems (AFS) present significant potential for carbon dioxide removal (CDR), climate adaptation, and the provision of environmental and social co-benefits. However, their current rate of expansion remains insufficient to meet the European Union's climate neutrality objectives. This study critically examines the political dynamics influencing AFS adoption in the trinational Upper Rhine region (Germany, Switzerland, and France) using the analytical framework of institutions, interests, and ideas (3I). While there is broad conceptual support for expanding AFS, conflicting perceptions and restrictive institutional frameworks reveal deeper structural resistance – particularly in Germany, where AFS are frequently perceived as economically nonviable and incompatible with modern agricultural practices. Conversely, the stronger cultural and economic valuation of trees and hedgerows in Switzerland and, increasingly, in France highlights alternative pathways for scaling up AFS. Effective policy interventions must prioritize climate adaptation, enhance farmer engagement, and create enabling conditions for experimentation. This necessitates the development of more robust compensation mechanisms and supportive legal frameworks to facilitate the broader implementation of agroforestry systems.

Spatial patterns of individual morphological deformation in schizophrenia: Putative cortical compensatory of unaffected sibling.

Spatial patterns of individual morphological deformation in schizophrenia: Putative cortical compensatory of unaffected sibling.

Investigation on the physical–mechanical response characteristics and failure mechanisms of shale under the laser thermal field

The mainstream method for extracting shale gas involves hydraulic fracturing to create fracture networks. However, as extraction depth increases, notable issues such as rapid production decline, low recovery rates, high water consumption, and resource waste become apparent. Identifying new and efficient auxiliary rock-breaking technologies is crucial for overcoming these challenges. The laser, successfully utilized in industrial production, medical treatment, and technological research, offers unique features such as good directionality, coherence, and high energy density, providing novel possibilities for addressing the limitations of existing deep reservoir transformation. This research focuses on a novel laser-assisted rock-breaking technology, with shale featuring different bedding angles as the subject of investigation. The investigation methodically explored how shale responded to thermal fracture at high temperatures when exposed to laser irradiation with different spot diameter. It investigates the spatiotemporal evolution characteristics of the shale temperature field under laser irradiation, the propagation features of cracks on shale surface, and the physicochemical fracture mechanisms. The research yields the following results: (1) The region of thermal influence of the irradiation surface can be divided into three regions based on the change of rise curve of temperature in the shale surface. (2) Based on the scanning electron microscopy (SEM) testing, combined with the macroscopic and microscopic morphological characteristics of shale fracture surfaces, it reveals significantly distinct zoning characteristics in the roughness of the rock sample’s fracture surfaces after laser irradiation. (3) The thermal fracturing process of shale under laser irradiation involves chemical reactions of constituent minerals and stress generated by the thermal expansion of shale oil in the reservoir. (4) The damage and fracture of shale under the irradiation of laser show significant bedding effect, and there are three modes of rock sample failure: Pattern T (thermal failure), Pattern T-B (thermal and bedding synergistic failure), and Pattern B (bedding failure). The research findings presented in this article serve as a foundation and reference for the theory and technology of laser-assisted shale gas extraction.

Magnetic Field-Driven Ion Selectivity Boosts LiF-Rich SEI Formation for Enhanced Lithium Metal Battery Performance Across Temperatures.

Lithium metal anodes are considered highly promising electrode materials due to their exceptional theoretical capacity and low reduction potential. However, their path to large-scale commercialization has been obstructed by significant challenges such as uncontrolled volume expansion, severe side reactions, and dendrite formation. To tackle these issues, our study introduces a covalent modification of separators using tannic acid (TA) and Co2+, coupled with the application of an external magnetic field. This innovative approach promotes the adsorption of CO32- ions while inhibiting the uptake of F- ions on the TA-Co/PP separators, leading to the formation of a LiF-rich solid electrolyte interface on the anode surface. Such modifications significantly enhance the electrochemical performance of lithium metal batteries. Remarkably, with the aid of the magnetic field, batteries featuring these modified separators maintained a Coulombic efficiency of 90% over 650 cycles at 1 mA cm-2. Additionally, under challenging conditions at 60 °C and 4 mA cm-2, the polarization voltage of Li symmetric cells utilizing TA-Co/PP separators is maintained at just 20 mV. This successful demonstration underlines the potential of our method to catalyze the broader adoption and commercialization of lithium metal batteries across varied temperature spectra.

A High-Modulus Dual-Cross-Linked Shell Promoting Phosphorus-Carbon Composites for Stable and High-Rate Lithium Ion Storage.

Phosphorus is considered an ideal anode material for lithium ion storage by virtue of its high theoretical capacity and moderate lithiation potential. However, issues such as large volume expansion of phosphorus leading to an electrical loss of contact and instability of the solid electrolyte interface hinder its practical performance. Improvement strategies that can effectively suppress volume expansion and provide stable electrical contacts are urgently needed. Herein, by introduction of a carbon nanotube cross-linked microstructure into the polyimide coating layer, a high-modulus coating layer is effectively constructed to suppress volume expansion and provide a stable and fast conductive network. The prepared dual-cross-linked phosphorus-carbon composites exhibit excellent cycling stability and high-rate performance. After cycling 500 cycles at a current density of 1 A g-1, it can still provide a specific capacity of 1467.68 mAh g-1, with a capacity retention rate of 87.28%. And even at a high current of 10 A g-1, it can still provide a high specific capacity of 1450.72 mAh g-1.

SODIUM.

Sodium is the major cation of extracellular fluid (ECF) and, due to its osmotic action, is involved in the regulation of extracellular fluid volume and blood pressure (BP). The ingested sodium is almost completely absorbed by the intestine. Circulating sodium is filtered by the glomeruli and its renal tubular handling is responsible for the maintenance of sodium and water balance. Sodium deficiency is rare and occurs just in some medical condition. High dietary sodium intake is associated with ECF volume expansion and is a leading risk factor for hypertension and cardiovascular diseases; it also adds to the risk of gastric cancer, nephrolithiasis, reduced bone mineral density and osteoporosis. Salt added while cooking and eating, the amount added during food transformation and that occurring naturally in foods contribute to the dietary sodium intake. Additional small amounts of sodium may be occasionally acquired through oral or parenteral medications. The National Academy of Science, Engineering and Medicine (NASEM) set an Adequate Intake (AI) of 1.5 g and a Chronic Disease Risk Reduction intake (CDRR) of 2.3 g of sodium per day for the adult population. The European Food Safety Authority (EFSA) and the World Health Organization (WHO) set a Standard Dietary Target (SDT) for sodium of 2 g/day (5 g of salt). Recent studies highlighted the relevance of salt intake reduction for all-cause mortality risk and, in particular, for stroke. Sodium also appears to affect the activity of the immune system by influencing the gut microbiota composition and the macrophage and lymphocyte differentiation.

Antimony Telluride as Bifunctional Host Material for Dendrite-Free Sodium Metal Batteries.

The development of the sodium metal anode is hampered by uncontrolled Na dendrite growth and unstable solid electrolyte interface (SEI). Herein, Sb2Te3 nanosheets are anchored into the fibers of carbon cloth (CC) to construct Sb2Te3@CC material as Na metal host for sodium metal batteries (SMBs). The alloying product of Na3Sb with strong sodiophilicity serves as a nucleation seed to induce homogeneous Na deposition and boost the formation of a dendrite-free Na metal anode. Meanwhile, the conversion product of Na2Te covers the surface of Na metal to form a robust SEI film. Low current density, uniform Na ionic flux, and suppressed volume expansion can be guaranteed by three-dimensional carbon fibers. Therefore, a Na@Sb2Te3@CC electrode contributes ultrastable cyclic performance for over 1600 h with a low overpotential of 30.5 mV. The assembled Na metal full batteries deliver a high initial energy density of 307.3 Wh kg-1 and superior cycling stability with an ultralong lifespan of over 2000 cycles.

Dynamic Humidity Modulation of Quasi‐Bound States in the Continuum by Symmetry Breaking in Geometry and Permittivity

Hybrid metal‐dielectric metasurfaces, exhibiting bound states in the continuum (BICs), support high‐quality factor resonances and electric field confinement due to their ability to restrain radiation loss. However, the dynamic transformation between quasi‐BICs and BICs in hybrid nanostructures by symmetry breaking in a multiplicity of ways remains a significant challenge. Herein, a novel humidity‐modulated strategy is demonstrated, which regulates the dynamic transition from quasi‐BICs to BICs based on the symmetry‐breaking in geometry and permittivity for the hybrid photonic‐plasmonic asymmetric gratings (HPAG), which consists of two alternating dielectric gratings deposited on an aluminum oxide and gold film. The regulatory mechanism involves the humidity‐sensitive polyvinyl alcohol, which undergoes volume expansion and refractive index reduction as the relative humidity (RH) increases. Its Q‐factor of a quasi‐BIC in HPAG reached up to 873, primarily due to the breaking of out‐of‐plane symmetry. The HPAG can be used for humidity sensing with a sensitivity of up to 2.63/RH. Moreover, the humidity‐modulated strategy is proven to be suitable for similar nanostructures (e.g., cylinder dimers, tetrameric cubes, and loop antennae). The results indicate that the humidity‐modulated strategy is a promising approach for regulating optical characteristics and is applied in micro/nanophotonic devices, such as humidity sensors, and active components.

Tailoring Self‐Catalytic N─Co Bonds into Heterostructure Architectures: Deciphering Polytellurides Conversion Mechanism Toward Ultralong‐Lifespan Potassium Ion Storage

AbstractTransition metal tellurides (TMTes) are promising anodes for potassium‐ion batteries (PIBs) due to their high theoretical specific capacity and impressive electronic conductivity. Nevertheless, TMTes suffer from persistent capacity degradation due to the large volume expansion, high ion‐diffusion energy barriers, and the dissolution/shuttle of potassium polytellurides (KxTey). Herein, a heterostructured CoTe2 composite equipped with a self‐catalytic center (N‐CoTe2/LTTC) is developed, exploiting its low‐tortuosity tunneling, chemical tunability, and self‐catalytic properties to elevate cycling stability to new heights. Systematic experiments have verified that the elaborate N‐CoTe2/LTTC provides a short‐range and efficient electron/ion transport path, accelerates K+ diffusion kinetics, and suppresses huge volume distortion. Notably, the N─Co bonds self‐catalytic center can promote the adsorption capabilities and accelerate the conversion kinetics for KxTey under the synergistic effect of heterojunction. Consequently, the optimized N‐CoTe2/LTTC electrode delivers an ultralong‑lifespan cyclability (over 25 000 cycles at 2.0 A g−1, only 0.0019% capacity decay rate per cycle), outperforming those of reported Te‐based anodes. Finally, the N‐CoTe2/LTTC//PTCDA@450 full cell manifests impressive stability (over 4300 cycles at 2.0 A g−1). This work uncovers the impact of catalytic centers on the conversion of KxTey and provides valuable insights for rationally designing ultralong‐lifespan TMTes anodes for PIBs.

Synergistic Intercalation and Vacancy Engineering Boosting Superior Rate Performance for High-Performance Potassium Storage

Abstract In this work, a dual-strategy approach of Ti-intercalation and Mo vacancies was utilized to engineer VMo-Ti-MoSe2, aiming to enhance the electrochemical performance of potassium-ion batteries (PIBs). The intercalation strategy reduces the band gap and expands the layer spacing of MoSe2, which alleviates the volume expansion during potassiation/depotassiation processes and accelerates the rapid migration of potassium ions. Furthermore, the engineered Mo vacancies not only facilitate the excitation and conduction of electrons but also significantly accelerate carrier transfer, thereby enhancing the reaction kinetics during the charge/discharge process. Additionally, these vacancies provide abundant active sites that ensure a more stable and superior potassium ion adsorption capability. More importantly, in-situ X-ray diffraction and in-situ Raman spectroscopy, coupled with density functional theory calculations, elucidate the potassification/depotassification behaviors of VMo-Ti-MoSe2 anode during the cycling process. Consequently, VMo-Ti-MoSe2 anode demonstrates an outstanding cycling performance, retaining of 360.1 mAh g-1 after 100 cycles at 2 A g-1. It also delivers a high rate capability of 270.9 mAh g-1 at 5 A g-1. This study shows that vacancy and intercalation strategies significantly enhance the electrochemical performance of PIBs and may be applicable to other battery systems to achieve higher capacity and better cycling stability.

Compressive Strength and Metallurgical Properties of Pellets with Added Oolitic Hematite

The influence of oolitic hematite on the compressive strength and metallurgical properties of oxidized pellets was examined. The experimental results indicate that when the proportion of oolitic hematite does not exceed 8%, the compressive strength of the pellets can reach over 2500 N when roasted at 1250 °C for 15 min. When the proportion is increased to 10%, the compressive strength remains above 2500 N after roasting at 1250 °C for 20 min. As the proportion of oolitic hematite increases, the reduction expansion rate of the pellets decreases; however, the reducibility also diminishes, and the softening and dripping performance deteriorates. Take into account the characteristics of the comprehensive burden structure in blast furnace operations, the proportion of oolitic hematite in pellet production can be increased to 10.0%.

Molecular dynamics simulation of tensile deformation mechanisms in nanocrystalline TWIP steel

We perform tensile deformation studies on nanocrystalline twinning-induced plasticity (TWIP) steels using molecular dynamics (MD) simulations and observe significant volume changes during incremental deformation. The meta-atomic potential function is employed to define atomic interactions in TWIP steels. The nucleation and propagation of dislocations lead to a reduction in tensile stress, which is positively correlated with the average grain size. Tensile tests show that TWIP steels undergo a phase transformation during plastic deformation, primarily from the face-centred cubic (FCC) to the HCP phase. This transformation results in the formation of stacking faults (SFs) and twin boundaries (TBs). The slip of dislocations is intercepted by grain boundaries (GBs) and TBs, leading to stress concentration. When the stress reaches a critical threshold, cracks initiate and propagate at these weak points, causing volume expansion during plastic deformation. This volume change results from the interaction between the material’s complex microstructure and the generation and progression of cracks. In contrast, nanocrystalline Cu exhibits nearly constant volume during the plastic deformation stage, attributed to the insufficient dislocation slip and phase transformations in Cu. Overall, the observed volume increase is specific to TWIP steels and contributes to their high ductility.

Tuning Bi–C 3D architecture of Bi/carbon nanofibres for high power and cycling stability SIBs anodes

Carbon-based materials are frequently employed as anodes for sodium-ion batteries (SIBs) due to their structural stability. This stability enables them to withstand the repeated intercalation and de-intercalation of Na+ during the charge-discharge cycles without significant deformation or performance degradation, thus ensuring the long-term operation of SIBs. However, high energy density and high power density have been the goals of SIBs. Herein, an electrode material combining bismuth (Bi) and carbon nanofibres (CNFs) was prepared. Bi was sputtered on CNFs in the form of nanodots. CNFs-50Bi has a high initial coulombic efficiency of 98.31% at 0.1 A/g and superior rate capability of 186 mAh/g as an anode at 3 A/g. CNFs mitigate volume expansion during alloying and maintain batteries stability. The incorporation of Bi metal into the battery configuration serves to augment the overall capacity and enhance the rate capability. Therefore, the doping of suitable quantities of Bi metal materials may facilitate the development of high-performance carbonaceous materials as anodes for SIBs.