High Load Research Articles

3D Printed Carbon Nanotube/Phenolic Composites for Thermal Dissipation and Electromagnetic Interference Shielding.

Here we demonstrate direct ink write (DIW) additive manufacturing of carbon nanotube (CNT)/phenolic composites with heat dissipation and excellent electromagnetic interference (EMI) shielding capabilities without curing-induced deformation. Such polymer composites are valuable for protecting electronic devices from overheating and electromagnetic interference. CNTs were used as a multifunctional nanofiller to improve electrical and thermal conductivity, printability, stability during curing, and EMI shielding performance of CNT/phenolic composites. Different CNT loadings, curing conditions, substrate types, and sample sizes were explored to minimize the negative effects of the byproducts released from the cross-linking reactions of phenolic on the printed shape integrity. At a CNT loading of 10 wt %, a slow curing cycle enables us to cure printed thin-walled CNT/phenolic composites with highly dense structures; such structures are impossible without a filler. Moreover, the electrical conductivity of the printed 10 wt % CNT/phenolic composites increased by orders of magnitude due to CNT percolation, while an improvement of 92% in thermal conductivity was achieved over the neat phenolic. EMI shielding effectiveness of the printed CNT/phenolic composites reaches 41.6 dB at the same CNT loading, offering a shielding efficiency of 99.99%. The results indicate that high CNT loading, a slow curing cycle, flexible substrates, and one thin sample dimension are the key factors to produce high-performance 3D-printed CNT/phenolic composites to address the overheating and EMI issues of modern electronic devices.

High dietary acid load predicts severity of autoimmune skin disease: a cross-sectional study

No previous study has examined the association of an acid-base imbalanced diet to autoimmune bullous disease. The present study aimed to investigate the association between dietary acid load (DAL) as either potential renal acid load (PRAL) and net endogenous acid production (NEAP) intake on the odds of high-severity Pemphigus Vulgaris (PV) disease in adult Iranian patients to fill this gap. A cross-sectional study was conducted on 138 patients, aged 18–65 years with confirmed diagnoses of PV in a referral university center for autoimmune bullous diseases. The dietary intakes of all patients during the last year before enrollment in the study were assessed using a 168-item semi-quantitative food frequency questionnaire. Dietary acid load was calculated based on the PRAL and NEAP scores. To assess PV severity, the pemphigus disease area index (PDAI) score was used. Logistic regression was used to evaluate the association between DAL and PDAI. A positive association was observed between PRAL and PDAI score in the crude (adjusted R2 = 0.088, B = 6.88, P < 0.0001) and all other adjusted models, as well as the crude model for NEAP (adjusted R2 = 0.037, B = 4.72, P = 0.013). In terms of adherence to NEAP and PRAL, those in the top tertile of PRAL and NEAP had a higher vulnerability for severe PV in unadjusted (OR = 5.18, 95% (CI) 2.19–12.25) and (OR = 2.48, 95% (CI) 1.08–5.68) respectively. In the present study, we found a significant direct association between DAL and severity of disease in PV patients. Further studies are required to confirm these findings.

Morphological regulation of platinum nanoflowers with high enzyme loading for glucose biosensing and biofuel cells

Glucose enzymatic biosensors and biofuel cells are particularly important in the development of wearable devices, and the performance of both devices is highly dependent on the rational design of enzyme carrier materials as well as the loading of active enzymes. Herein, we designed highly enzyme-loaded flower-like platinum nanoparticle modified electrodes (GOxEPC/Pt NFs/CC) for glucose sensing and biofuel cells, which were modified with platinum nanoflower carriers on flexible carbon cloth substrate by urea-regulated one-step electrodeposition, followed by loading a large amount of glucose oxidase through enzyme precipitation coating. The biosensor exhibits high sensitivity (64.3 μA mM cm−2), ultra-wide linear range (0.01–31.31 mM) and low detection limit (3.3 μM). In addition, the biosensor also shows good selectivity, reproducibility, long-term stability and accuracy of real blood sample detection. The biofuel cell composed of the GOxEPC/Pt NFs/CC electrode and the laccase-modified electrode displays an open circuit voltage of 0.34 V, a high maximum current density of 289 μA cm−2, and a maximum power density of 19.2 μW cm−2. These results show that the proposed enzymatic electrode construction strategy has great application potential in the field of biosensors and biofuel cells.

Nanocarriers Made of Natural Fatty Acids: Modulation of Their Release Profiles through Photo‐Crosslinking

AbstractNatural fatty acids are attractive carrier materials for drug delivery, but their rapid dissolution and degradation in vivo calls for new strategies to enhance their stability. Here we report a simple and versatile method capable of photo‐crosslinking carriers made of natural fatty acids for drug delivery under controlled release. By optimizing the crosslinking density, the nanoscale carriers show a high drug loading efficiency, together with a stable network structure for minimal degradation in a body fluid mimic. Fluorescence microscopy analysis also reveals the exceptional intracellular stability of the crosslinked network, resulting in negligible cytotoxicity toward A549 cells up to 24 h when loaded with a potent anticancer drug. We further extend this strategy to microscale carriers fabricated using electrospray. Upon photo‐crosslinking, the carriers show a retarded release of nerve growth factor, resulting in slower neurite outgrowth from dorsal root ganglion. This work holds promise for addressing the efficacy and safety issues critical to nanomedicine and related applications.

Seed-Mediated Synthesis of High Loading PtCo Intermetallic Compounds Enhanced Catalytic Efficacy and Long-Term Stability for Oxygen Reduction Reaction.

Atomically ordered intermetallic Pt-based nanoparticles, recognized as advanced electrocatalysts, exhibit superior activity for the oxygen reduction reaction (ORR) in fuel cell cathodes. Nevertheless, the formation of these ordered structures typically necessitates elevated annealing temperatures, which can accelerate particle growth and diminished reactivity. In this study, we synthesized carbon-supported platinum-cobalt intermetallic compounds (PtCo-IMCs) with sub-4 nm particle sizes and uniform distribution. These catalysts, characterized by high platinum content and exceptional ORR activity, are specifically tailored for heavy-duty vehicle (HDV) applications. The PtCo-IMCs exhibited significantly enhanced catalytic performance and durability compared to conventional Pt-based catalysts, utilizing platinum nanoparticles as nucleation sites to promote growth. This method effectively retained smaller particle sizes while achieving a higher degree of ordering and alloying during high-temperature annealing. Optimization of the annealing temperature resulted in peak activity and stability at 800 °C. The mass activity (MA) of the PtCo-800 catalyst was 2.7-fold and 1.8-fold that of the commercial Pt/C and disordered PtCo catalysts, respectively. Additionally, the single cell employing the PtCo-800 catalyst showed a minimal voltage loss of only 27 mV at a current density of 2 A cm-2 after 30,000 cycles of the accelerated durability test (ADT), underscoring its long-term stability.

Seismic Performance of Shaped Steel Reinforced High‐Strength Concrete Walls: Cyclic Loading Test and Analytical Modeling

ABSTRACTThe thickness of the bottom shear walls in tall and super‐tall structures is often designed too large to meet the limit requirements of axial compression ratios, which increases the weight and cost of the structure. To address this issue, high‐strength concrete (HSC) and shaped steel are combined to form composite shear wall members. This paper focuses on seismic performance and analytical hysteresis model of steel reinforced HSC shear walls (SRHCW) under high axial compressive load. Firstly, the reversed cyclic test was conducted to investigate the influence of concrete strength and the steel ratio on the seismic performance of SRHCWs by comparing the failure mechanism, hysteretic curves, stiffness degradation, ductility, energy dissipation, and steel bar strain variation of each specimen. Then, a hysteresis model for SRHCWs was established, and the model can be used for the nonlinear analysis and seismic performance evaluation of SRHCWs. Finally, the accuracy of the proposed hysteresis model was evaluated by the experimental data. The experimental results show that under high axial compression ratio, the interstory drift ratio capacity of SRHCWs can reach 3.03% showing excellent deformation performance. The wall specimens built with different strength concrete and shaped steel ratios exhibited similar strength, deformation, and initial stiffness, indicating that the steel ratio of the wall can be effectively reduced by upgrading the concrete strength of the wall specimens while ensuring its seismic performance. The analytical model can well predict the hysteresis force–deformation curves of SRHCWs under high axial load ratios.

Impact of Saharan Dust Intrusions on Atmospheric Boundary Layer Height over Madrid

Atmospheric pollution caused by aerosols deteriorates air quality, increasing public health risks. Anthropogenic aerosols are usually located within the atmospheric boundary layer (ABL), which presents a daytime evolution that determines the air pollutants’ vertical mixing of those produced near the surface and, therefore, their ground-level concentration from local sources. Precise and complete characterization of the mixing layer is of crucial importance for numerical weather forecasting and climate models, but traditional methods such as radiosounding present some spatial and temporal limitations. Better resolutions have been obtained using lidar, which provides the aerosol vertical distribution. A particular type of lidar, the ceilometer, has demonstrated continuous measurement capabilities, providing vertical profiles with sub-minute time resolution and several-meter spatial resolution. Advanced methods, such as the recently developed STRATfinder algorithm, are required to estimate the ABL height in the presence of residual layers. More complex situations occur due to the advection of aerosols (e.g., due to long-range transport of desert dust, volcanic eruptions, or pyrocloud convection), producing a lofted layer in the free troposphere that may remain decoupled from the local ABL but can also be mixed. Aerosol-based methods for determination of the ABL height are challenging in those situations. The main objective of this research is the assessment of the impact of Saharan dust intrusions on the ABL using ceilometer signals, over a period of four years, 2020–2023. The ABL height database, obtained from ceilometer measurements every hour, is analyzed based on the most frequent synoptic patterns. A reduction in the ABL height was obtained from high dust load days (1576 ± 876 m) with respect to low dust load days (1857 ± 914 m), although it was still higher than clean days (1423 ± 772 m). This behavior is further studied discriminating by season and synoptic patterns. These results are relevant for health advice during Saharan dust intrusion days.

Simultaneously Enhanced Damping and Stiffness of Amorphous Diaphite.

High-performance damping materials are crucial for numerous applications, yet traditional materials often face a fundamental trade-off between the damping properties and stiffness/strength. Since damping properties of material rely on its inner viscoelastic energy dissipation, it is antagonistic for damping material sustaining high mechanical loads. Recently, an amorphous carbon known as amorphous diaphite (a-DG) was reported, featuring a heterogeneous two-phase composition of nanodiamonds and disordered multilayer graphene (ND/DMG). The a-DG demonstrated diverse microstructure topologies and integrated characteristics, making it a promising candidate for achieving efficient energy dissipation in high-stiffness/strength materials. Herein, we conducted atomistic-based simulations to elucidate the mechanical and damping properties in a-DGs with tunable two-phase structures. Utilizing cyclic loads and Voigt-Reuss-Hill theory, we found that a-DGs exhibit surpassing stiffness and damping capabilities simultaneously, with excellent specific elastic modulus due to lightweight (2.39-3.25 g/cm3). The distinguishing performance is attributed to a balanced combination of flexible DMG and stiff ND grains, which can be tuned through manifesting the hybridization. Specifically, the concentrated shear strains, phase transformation and interfacial hybrid bond conversion significantly enhance internal friction through various relaxation mechanisms, while ND grains ensure high stiffness through blocking the propagation of shear bands. The insights obtained here should provide theoretical support for the design and application of high-performance damping materials, opening up an enticing perspective for investigating other amorphous carbons.

Facile Synthesis of S/Ti3C2Tx Mxene@Se Cathode for High-Sulfur-Loading Lithium–Sulfur Batteries

Lithium–sulfur batteries (LSBs) are gaining much attention because they offer a much higher theoretical energy density compared to traditional lithium-ion batteries. However, the cycling performance of LSBs with high sulfur mass loading is poor due to the shuttle effect, limiting the practical application of LSBs. In this work, a unique porous sulfur/Ti3C2Tx Mxene@selenium (S/Ti3C2Tx@Se) cathode of a LSB is synthesized by a simple hydrothermal method to address these challenges. In this composite, Ti3C2Tx forms a conductive framework and Se is tightly anchored on the framework. The Se inhibits the agglomeration of Ti3C2Tx and prevents the collapse of Ti3C2Tx. The S/Ti3C2Tx@Se composite can adsorb lithium polysulfides (LiPSs) and suppresses the shuttle effect and volume changes during cycling, improving the cycling stability of LSBs with high S loading. A high capacity of 812.2 mAh g−1 at 0.1 C with 5.0 mg cm−2 sulfur mass loading after 100 cycles is obtained. This work could inspire further research into high-performance S host materials for high-S-loading LSBs.

Polyethylene glycol-phospholipid functionalized single-walled carbon nanotubes for enhanced siRNA systemic delivery

Small interfering RNAs (siRNA) technology has emerged as a promising therapeutic tool for human health conditions like cancer due to its ability to regulate gene silencing. Despite FDA-approved, their delivery remains localized and limiting their systemic use. This study used single-walled carbon nanotubes (SWNTs) functionalized with polyethylene glycolated (PEGylated) phospholipids (PL-PEG) derivatives for systemic siRNA delivery. We developed an siRNA systemic delivery vehicle (SWNT-siRNA) by conjugating SWNT functionalized with PL-PEG containing either amine (PA) or maleimide (MA). The functionalized SWNT with a lower molecular weight of PA produced the SWNT-siRNA conjugate system with the highest stability and high siRNA loading quantity. The system delivered siRNA to a panel of tumour cell lines of different organs (i.e. HeLa, H1299 and MCF-7) and a non-cancerous human embryonic kidney 293 cells (HEK293T) with high biocompatibility and low toxicity. The cellular uptake of SWNT-siRNA conjugates by epithelial cells was found to be energy dependent. Importantly, the presence of P-glycoprotein, a marker for drug resistance, did not inhibit SWNT-mediated siRNA delivery. Mouse xenograft model further confirmed the potential of SWNT-siRNA conjugates with a significant gene knock-down without signs of acute toxicity. These findings pave the way for potential gene therapy applications using SWNTs as delivery vehicles.

Stereolithography 3D printing gyroid triply periodic minimal surface vitrified bond diamond grinding wheel

The pores of vitrified bond diamond grinding wheel play a key role in the grinding process. However, uneven pore distribution and low porosity affect the grinding performance of the wheel significantly. Stereolithography based additive manufacturing provides an effective method to fabricate vitrified bond diamond grinding wheels with a uniform distribution and an interconnected pore structure. The key to high-performance grinding wheel via stereolithography 3D printing lies in the preparation of the slurry with high solid loading, low viscosity and uniform stability. In this study, the dispersion and stability of vitrified bond and diamond slurries were investigated systematically. The effects of resin monomers, surface modifiers, and solid loading on the dispersion, rheological behavior and stability of slurries were studied in detail. Finally, an optimal vitrified bond and diamond slurry for stereolithography based additive manufacturing was obtained, and complex-shaped gyroid triply periodic minimal surface grinding wheel were fabricated. By grinding the SiC ceramics, the material removal rate, grinding temperature, and surface roughness were compared to those achieved using a conventional solid structure grinding wheel. The results show that the gyroid porous grinding wheel can achieve better surface roughness and lower the grinding temperature.

A Conductive Cu-Based Metal-Organic Framework Ribbon with High-Density Redox-Active Centers as Cathode for Stable High-Capacity Lithium-Ion Batteries.

Conductive Cu-based metal-organic framework (Cu-MOF) materials hold significant potential as cathodes for lithium-ion batteries (LIBs) due to their flexible structural design, high electronic conductivity, and independence from costly resources. However, their practical application is often limited by their capacity and cyclability. In this study, we report a one-dimensional Cu-MOF (DDA-Cu, DDA=1, 5-Diamino-4, 8-dihydroxy-9, 10-anthraceneedione) featuring extended π-d conjugated coordination ribbon and high-density redox-active centers, making it a stable, high-capacity cathode for LIBs. The π-d conjugated Cu-O3N motifs embedded within the ribbon not only serve as redox-active centers for enhanced lithium-ion storage capacity but also contribute to structural robustness, enabling resistance against electrode solubility in organic electrolytes, thus ensuring superior cyclability. Furthermore, these π-d conjugated Cu-O3N units promote efficient charge transfer, leading to high electronic conductivity at room temperature. These advantageous properties allow the Cu-MOF cathode to deliver a remarkable capacity (353 mAh g-1 at 0.05 A g-1) and exceptional cyclability, achieving capacity retention of 78 % after 1000 cycles, surpassing state-of-the-art MOF electrodes. Additionally, this DDA-Cu demonstrates considerable wettability with the electrolyte, achieving outstanding performance even when tested in a lean electrolyte environment (2 μL mg-1) with a high mass loading of the MOF (6.8 mg cm-2).

Low-valence platinum single atoms in sulfur-containing covalent organic frameworks for photocatalytic hydrogen evolution

This study focuses on optimizing catalytic activity in photocatalytic hydrogen evolution reaction by precisely designing and modulating the electronic structure of metal single atoms. The catalyst, denoted as PtSA@S-TFPT, integrates low-valence platinum single atoms into sulfur-containing covalent organic frameworks. The robust asymmetric four-coordination between sulfur and platinum within the framework enables a high platinum loading of 12.1 wt%, resulting in efficient photocatalytic hydrogen production activity of 11.4 mmol g−1 h−1 and stable performance under visible light. These outcomes are attributed to a reduced hydrogen desorption barrier and enhanced photogenerated charge separation, as indicated by density functional theory calculations and dynamic carrier analysis. This work challenges traditional notions and opens an avenue for developing low-valence metal single atom-loaded covalent organic framework catalysts to advance photocatalytic hydrogen evolution.

Enhanced fischer-tropsch synthesis performance on Co@SiO2 catalyst with core-shell structure

Energy is of great importance for the development of modern society, which is mostly dependent on crude oil. Due to the severe pollution caused by using crude oil and the diminishing of crude oil reserves, it is urgent to look for clean oil from alternative resource other than crude oil. Currently, Coal-to-Liquid (CTL) or Biomass-to-Liquid (BTL) technology is an important way to produce clean liquid fuels through Fischer-Tropsch Synthesis (FTS) of syngas. For FTS process, catalyst is a main factor for affecting on syngas conversion and product distribution. For traditional oxides-supported catalysts, the mutual constraint between active metal loading and dispersion at high metal loading is hard to overcome, which will hinder the synthesis of high-performance FTS catalysts. In this paper, a new type of Co@SiO2-T (CS-T) and Co@SiO2-X (CS-X) catalysts with core-shell structure were prepared by using polyvinyl pyrrolidone (PVP) as the structural stabilizer, hexadecyl trimethyl ammonium Bromide (CTAB) as the templating agent and tetraethyl orthosilicate (TEOS) as the silica source. The effects of hydrothermal temperature and pyrolysis temperature on the catalyst physical-chemical properties and FTS performance were investigated. The results showed that increasing the hydrothermal temperature favored the formation of the core-shell structure of the catalysts. With the increase of pyrolysis temperature, the catalyst particle size decreased from 0.54 μm to 0.23 μm. The FTS activities of the catalysts showed a volcano trend with hydrothermal and pyrolysis temperatures.

A Conductive Cu‐Based Metal‐Organic Framework Ribbon with High‐Density Redox‐Active Centers as Cathode for Stable High‐Capacity Lithium‐Ion Batteries

Conductive Cu‐based metal‐organic framework (Cu‐MOF) materials hold significant potential as cathodes for lithium‐ion batteries (LIBs) due to their flexible structural design, high electronic conductivity, and independence from costly resources. However, their practical application is often limited by their capacity and cyclability. In this study, we report a one‐dimensional Cu‐MOF (DDA‐Cu, DDA=1, 5‐Diamino‐4, 8‐dihydroxy‐9, 10‐anthraceneedione) featuring extended π‐d conjugated coordination ribbon and high‐density redox‐active centers, making it a stable, high‐capacity cathode for LIBs. The π‐d conjugated Cu‐O₃N motifs embedded within the ribbon not only serve as redox‐active centers for enhanced lithium‐ion storage capacity but also contribute to structural robustness, enabling resistance against electrode solubility in organic electrolytes, thus ensuring superior cyclability. Furthermore, these π‐d conjugated Cu‐O₃N units promote efficient charge transfer, leading to high electronic conductivity at room temperature. These advantageous properties allow the Cu‐MOF cathode to deliver a remarkable capacity (353 mAh g‐1 at 0.05 A g‐1) and exceptional cyclability, achieving capacity retention of 78% after 1000 cycles, surpassing state‐of‐the‐art MOF electrodes. Additionally, this DDA‐Cu demonstrates considerable wettability with the electrolyte, achieving outstanding performance even when tested in a lean electrolyte environment (2 μL mg‐1) with a high mass loading of the MOF (6.8 mg cm‐2)

Spatiotemporal controls on organic matter sourcing to minerogenic salt marshes

AbstractSalt marshes are important carbon sinks; however, identification of the drivers of carbon burial rates is challenging because estuaries sit at terrestrial and marine interfaces. Here, we address the questions: what are the sources of organic matter sequestered in minerogenic salt marshes, and how do sources change through time? We characterized down‐core sediment biogeochemistry (C : N, δ13C, δ15N) for the last century in seven Oregon USA high marshes and used a mixing model to elucidate differences in organic matter sources across estuaries and through time. Autochthonous biomass production consistently accounted for only half of overall organic matter accumulation, and the remainder was allochthonous, originating from a combination of estuarine and terrestrial sources. Salt marshes with high sediment loads buried more terrestrial organic matter, whereas those with low loads and substantial subtidal habitat buried more estuarine‐derived organic matter. When assessed through depth/time, stable isotope trends indicated that decomposition is not the primary control. Instead, organic matter became increasingly more terrestrial in recent decades, especially in salt marshes with low fluvial loads. We hypothesize that salt marshes with lower loads took longer to regain lost elevation following coseismic subsidence of the 1700 ce Cascadia earthquake. This result magnifies the role of river floods in sediment and carbon accumulation on the marsh surface. Ultimately, the highest carbon burial rates coincided with highest fractions of terrestrially sourced organic matter, though spatiotemporal complexities obscured any potentially significant trends. While the term “blue” typically excludes terrestrial carbon, minerogenic salt marshes still perform the important ecosystem function of burying organic matter.

Biotic agents of tufa formation in сarbon dioxide enriched hard-water springs of Mizhhirya basin and adjacent territories

The main groups of biote and their functional role in the calcareous tufa formation at the hard-water springs enriched by carbon dioxide of the Mizhhirya basin and adjacent territories were investigated. It has been studied that in the formation of calcareous tufa of all surveyed locations, representatives of micro-, bryo and phytobiota play an important role, and therefore, the studied sedimentary rock are mainly biogenic in their origin. Microbiota agents, mainly cyanobacteria of the order Oscillatoriales, play a leading role in the initial acts of calcareous tufa accumulation (stage I). These bacteriogenic initial forms, which can be defined as initial thromboids, are represented by small- or medium-grained, ocher-yellow aggregates of a spherical shape, with a diameter of 0.5-2 mm, which actively accumulate at the springs exits. These congestions (mesoclots) are growing and compacting over time and forming weakly cemented thrombolites, which are a cluster of separate aggregates together with particles of sand, silt, rocks, plant remains, etc. The next post-pioneer stage (II) is marked by the appearance of specialized amphibious Bryophytes vegetation of the Pellion endiviifoliae alliance and pioneer caliciophilic vegetation of the Grimmaldion fragrantis alliance. In the formation of calcareous tufa deposits of the next stage (III), the leading role is played by the Bryophytes vegetation of the Pellion endiviifoliae alliance. Their mineralized turfs are modeling light, fragile and porous bryolithes of an ocher-brown color. Bryolithes usually contain seasonal layers richly encrusted with leaves of trees, which growing near the spring. Base on the specificity and ecological value of the biotic (calcicolous Bryobiota) and abiotic, primarily geological (calcareous iron tufa) component, the hard-water tufagenic springs of Mizhhirya Verkhovyna can be considered significant natural monuments of Transcarpathia region. However, regardless of the nature protection status of most hard-water iron springs (they are hydrological monuments of nature of local importance), they often suffer from human’s improvement, illegal water extraction, high recreational load etc. Thus, they need applicating of conservation measures and nature protection management planning.

Effect of Carbon Morphology and Slurry Formulation in Sulfur Cathode for Li-S Batteries

The performance of Lithium-Sulfur (Li-S) batteries is significantly influenced by material selection and manufacturing processes, with conductive carbon and slurry formulation playing crucial roles. In this study, the impact of carbon morphology and solvent/solid ratio in slurry preparation on microstructure and electrochemical performance of sulfur cathodes was investigated. Various carbon structures, such as nanotubes, sheets, and particles, were explored, and the solvent volume was adjusted to assess their effects on electrode architecture and electrochemical performance. Our findings demonstrate that the binder dissolution process and consequent electrode architecture and performance are highly influenced by both the carbon structure and slurry solvent volume. Furthermore, it was observed that, contrary to common assumption, advanced carbon structures are not necessary for enhanced capacity and durability of Li-S cathodes. Accordingly, the best cycling durability was achieved by optimizing the slurry with 300 μL/mgPVDF of NMP solvent and using Ketjen black as the conductive carbon, resulting in an initial capacity of 1029 mAh gS −1, with a retention of 830 mAh gS −1 after 500 cycles. These results, obtained at a high areal loading of 4.5 mgS cm−2, demonstrate the commercial potential of the proposed electrode formulation and processing method without reliance on advanced materials or techniques.

Anode interface-stabilizing dry process employing a binary binder system for ultra-thick and durable battery electrode fabrication

Polytetrafluoroethylene (PTFE)-based dry process has gained attention in the battery industry owing to their sustainability, cost-effectiveness, and ability to fabricate high loading electrodes. However, the electrochemical instability of PTFE in anodic environments causes significant capacity loss, hindering the development of high-performance dry-processed anodes. In this study, a binary binder system of PTFE and polyvinylpyrrolidone (PVP) is proposed to prevent direct contact between graphite and PTFE, mitigating unwanted interphase evolution. This strategy improves the mechanical integrity of the electrode. It maintains the binding force between the active materials and PTFE binders. PVP also forms a robust inorganic-rich SEI, enhancing Li-ion kinetics and interfacial stability. Consequently, dry-processed graphite with PVP achieved ultra-high loading anodes (∼10 mAh cm−2) with excellent cycle stability over 200 cycles in full cells coupled with LiNi0.8Co0.1Mn0.1O2 cathodes. This paper presents a cost-effective, high-loading electrode fabrication process and an eco-friendly approach for large-scale electrification.

The tensile behaviour of paper under high loading rates

AbstractThis work deals with the strain-rate dependent characterization of paper under uniaxial tension at high strain-rates. Experiments were performed involving a Split Hopkinson bar for high strain-rate testing, comparing the results with conventional quasi-static tests. Tests were conducted in a strain-rate range between 0.0083 and 212 s−1, which is equivalent to testing velocities between 0.0003 and roughly 13.6 m/s. For the first time the change in tensile behaviour of paper is comprehensively characterized and modelled, using the Cowper-Symonds model for strain-rate hardening. The experimental tests showed that the tensile strength as well as the initial stiffness were gradually increasing with increasing strain-rate. The increase in tensile strength between the lowest and the highest strain-rate was 58% on average whereas the mean increase in stiffness between these two strain-rates was almost 115%. Regarding the fracture strain, it was observed that it significantly decreases with increasing strain-rate. While the average fracture strain of the quasi-static tests was at roughly 6% it was close to 3% for the dynamic tests. In case of the Split Hopkinson bar tests, high-speed videos of the samples were made to determine their elongation via target tracking and digital image correlation (DIC). We found that strain localization, which is a highly relevant mechanism for quasi-static tensile failure, is likely related to short term plastic creep of the material as strain localization nearly entirely disappears at high loading rates of paper.