Volume Expansion Research Articles

High-performance lithium metal anode enhanced by multifunctional film of PAN@AgNWs with antimicrobial activity

Lithium metal is expected to be the perfect anode material for the next generation of rechargeable batteries owing to its ultra-high theoretical specific capacity, low density and the lowest redox potential. However, the practical application of lithium metal batteries faces serious challenges, including uneven lithium deposition, negative electrode volume expansion, and short circuits brought by dendritic protrusions. Although the 3D structure of silver nanowires is effective in inhibiting lithium dendrite growth and lithium metal volume expansion, it still suffers from lithium inhomogeneity caused by uneven distribution of silver nanowires and complicated preparation. Therefore, PAN@AgNWs collector was prepared by a simple suction filtration method, and uniform dispersion of silver nanowires and uniform deposition of lithium were achieved. Lithium nucleation overpotential and lithium dendrite formation can be effectively reduced by PAN@AgNWs hosts due to the reduction of local current density by 3D collectors and the improved lithiophilicity of silver nanowires. With low voltage hysteresis, the symmetric battery constructed with its composite anode may cycle steadily for 4500 hours at 1 mA cm−2 and 1 mAh cm−2. At the same time, the Li-PAN@AgNWs||LFP full cell still possesses a reversible of 144.18 mAh g−1 after 500 cycles at 1C. Moreover, due to large specific surface area and high surface energy of 3D silver nanowires, it exhibits excellent antimicrobial properties, with an inactivation efficiency of 96.3% after contacting with E. coli for 2.5 h. This work shows the possibility of using PAN@AgNWs in a large scale for LMBs, and paves the way for development of high-performance antimicrobial materials.

Zero thermal expansion high-strength metallic glass-based composites

Zero thermal expansion high-strength metallic glass-based composites

Porous PbBr2 films modulation by indium tribromide additive for the fabrication of SnO2-based CsPbBr3 perovskite solar cells

The achievement of complete conversion of PbBr2 films presents a significant challenge in the development of CsPbBr3 films with consistent growth, comprehensive coverage, and controllable components. To address this challenge, introducing a porous structure in the planar PbBr2 film is advantageous for facilitating the immersion of CsBr precursor, thereby reducing impurity phase formation and mitigating strain caused by the film volume expansion. In order to accomplish this, indium tribromide (InBr3) was employed as an additive and the InBr3(DMF)3 adduct was utilized to expedite the release of organic molecules in PbBr2(DMF), resulting in the transformation of planar PbBr2 film into porous structures. The growth orientation of PbBr2 crystals was altered by this transformation, effectively suppressing the generation of metallic Pb impurities in the film. Additionally, it not only optimizes the morphology of CsPbBr3 film but also reduces impurity phase. As a result, the InBr3:CsPbBr3 perovskite solar cell achieved an efficiency of 7.28 %. The majority of In3+ ions were concentrated near the buried interface between SnO2 and InBr3:CsPbBr3, leading to significant improvements in both non-radiative recombination defect states within the perovskite film and electron injection and collection capabilities within the device.

Effects of inspiratory muscle training on thoracoabdominal volume regulation in older adults: a randomised controlled trial

ObjectivesWe investigated the effect of inspiratory muscle training (IMT) on inspiratory muscle strength, functional capacity and respiratory muscle kinematics during exercise in healthy older adults. Methods24 adults were randomised into an IMT or SHAM-IMT group. Both groups performed 30 breaths, twice daily, for 8 weeks, at intensities of ~50% maximal inspiratory pressure (PImax; IMT) or <15% PImax (SHAM-IMT). Measurements of PImax, breathing discomfort during a bout of IMT, six-minute walk distance, physical activity levels, and balance were assessed pre- and post-intervention. Respiratory muscle kinematics were assessed via optoelectronic plethysmography (OEP) during constant work rate cycling. ResultsPImax was significantly improved (by 20.0±11.9 cmH2O; p=0.001) in the IMT group only. Breathing discomfort ratings during IMT significantly decreased (from 3.5±0.9 to 1.7±0.8). Daily sedentary time was decreased (by 28.0±39.8min; p=0.042), and reactive balance significantly improved (by 1.2±0.8; p<0.001) in the IMT group only. OEP measures showed a significantly greater contribution of the pulmonary and abdominal rib cage compartments to total tidal volume expansion post-IMT. ConclusionsIMT significantly improves inspiratory muscle strength and breathing discomfort in this population. IMT induces greater rib cage expansion and diaphragm descent during exercise, thereby suggesting a less restrictive effect on thoracic expansion and increased diaphragmatic power generation.

Investigation of corrosion-induced cracks using corrosion products quantified by an X-ray technique and FE analysis of single- and multiple-rebar beams

The effects of corrosion methods, galvanostatic (GS) vs. artificial climate environment (ACE), on the relationships between corrosion products and corrosion cracks of corroded reinforced concrete beams are investigated. The experimental results show that the GS method induces smaller corrosion crack width. A novel quantitative detection method of corrosion product thickness using X-ray and digital image processing techniques is proposed for investigating the continuous development of corrosion products. As the corrosion level increases, a smaller steel-to-rust volume expansion ratio caused by continuous leakage and a lower oxidation degree of corrosion products for the GS specimens are the major reasons for the smaller corrosion cracks. Regarding the effect of rebar arrangement on the development of corrosion-induced cracks, the expansion stress from corner-located rebars restrained the growth of corrosion products and further limited the propagation of corrosion-induced cracks of the center rebar. Estimated corrosion crack width via FE analysis using measured corrosion products as input show good agreement with experimental results.

Improved Cycling Stability of LFP by W-Ti Co-Doping Strategy for Li-Ion Batteries

Olivine-type lithium iron phosphate (LFP) is used widely as a cathode material with excellent cycling stability, thermal stability, and low cost for lithium-ion batteries in power vehicles and energy storage. However, it has inherent drawbacks that limit its further development, such as low electronic conductivity and lithium ion diffusion rate. Here, secondary spherical particles LFP-W/Ti@C were synthesized using a simple sanding and spray drying method. The pyrolysis of glucose forms a uniform and dense amorphous carbon on the surface of LFP, and the constructed three-dimensional conductive network accelerates the transfer of electrons and ions while mitigating the volume expansion during the lithiation-delithiation process. In addition, the synergistic co-doping of W/Ti achieves nanosizing of primary particles with more active sites providing locations for lithium ions storage, while reducing polarization and internal resistance and enhancing the diffusion kinetics of lithium ion. The LFP-W/Ti@C obtained after optimization still has a discharge capacity of 107.7 mAh g−1 (with a cycle retention rate of up to 100%) after 500 cycles at 5 C. This simple W/Ti co-doping strategy provides excellent rate performance and shows great potential for fast charging in electric vehicles.

Coupling 3D Vertical graphene skeleton with lithophilic ZnO Interface to enable highly stable lithium metal anode

Lithium metal has been considered as the most promising anode material for high energy density batteries owing to its high theoretical capacity and low reduction potential. Unfortunately, the uncontrollable growth of lithium dendrites and unrestrained volume expansion seriously hinder its practical applications. Designing 3D skeletons with high electronic conductivity, and high lithophilicity to control the lithium plating/stripping process has been proven to be an effective strategy to alleviate these two issues. In this study, ZnO-decorated 3D vertical graphene skeleton (ZnO@VG) was developed as the host material to regulate lithium nucleation and dendrite growth. Attributing to the unique cavity arrangement, enlarged specific surface area, and numerous lithiophilic sites of ZnO@VG, a remarkable coulombic efficiency of 99.12% after 350 cycles is achieved. Furthermore, symmetric cells based on ZnO@VG/Li electrodes demonstrate lower voltage polarization and enhanced cycling stability (over 1800 h) at 0.5 mA cm−2 and 1 mA h cm−2. Notably, when coupled with a LiFePO4 cathode, the full cell exhibits a discharge specific capacity of 100.33 mA h cm−2 at 5 C and maintains a high capacity retention of 89.1% after 740 cycles at 1 C.

High-temperature dimensional stability and radiation behavior of high-entropy rare earth tungstate ceramics

Materials with high-temperature dimensional stability and resistance to radiation damage are receiving increasing attention in advanced nuclear energy systems. In this research, (Sm0.2Eu0.2Gd0.2Dy0.2A0.2)2W3O12-type (A = Y, Tm ,Ho) high-entropy ceramics is presented. The coefficients of thermal expansion of (Sm0.2Eu0.2Gd0.2Dy0.2Y0.2)2W3O12 (HE-RE2W3O12) is 7.21×10-6K-1 at 300-1100K, which is the lowest among the three synthesized high-entropy ceramics and indicates good dimensional stability at high temperatures. After irradiation with Kr+ fluence of 4.58×1016 ions/cm2 at 400oC, both HE-RE2W3O12 and Gd2W3O12 maintained crystalline, but the lattice volume expansion rate of HE-RE2W3O12 (0.71%) is much lower than that of Gd2W3O12 (1.49%). Additionally, in the post-irradiated HE-RE2W3O12, the Raman spectra vibration peak remained unchanged and no radiation-induced segregation was observed. Nanoindentation tests displayed that the degradation of hardness and elastic modulus in HE-RE2W3O12 is rarely degrade. Overall, these results provide new insights for research on advanced nuclear materials in the future.

Evaluation of renal sodium handling in heart failure with preserved ejection fraction: A pilot study.

The pathophysiology behind sodium retention in heart failure with preserved ejection fraction (HFpEF) remains poorly understood. We hypothesized that patients with HFpEF have impaired natriuresis and diuresis in response to volume expansion and diuretic challenge, which is associated with renal hypo-responsiveness to endogenous natriuretic peptides. Nine HFpEF patients and five controls received saline infusion (0.25 mL/kg/min for 60 min) followed by intravenous furosemide (20 mg or home dose) 2 h after the infusion. Blood and urine samples were collected at baseline, 2 h after saline infusion, and 2 h after furosemide administration; urinary volumes were recorded. The urinary cyclic guanosine monophosphate (ucGMP)/plasma B-type NP (BNP) ratio was calculated as a measure of renal response to endogenous BNP. Wilcoxon rank-sum test was used to compare the groups. Compared to controls, HFpEF patients had reduced urine output (2480 vs.3541 mL; p = 0.028), lower urinary sodium excretion over 2 h after saline infusion (the percentage of infused sodium excreted 12% vs. 47%; p = 0.003), and a lower baseline ucGMP/plasma BNP ratio (0.7 vs. 7.3 (pmol/mL)/(mg/dL)/(pg/mL); p = 0.014). Patients with HFpEF had impaired natriuretic response to intravenous saline and furosemide administration and lower baseline ucGMP/plasma BNP ratios indicating renal hypo-responsiveness to NPs.

Investigation of fracture patterns and effect on capacity in all-solid-state batteries based on peridynamic electro-chemo-mechanical model

The evolution of complex fracture patterns of composite electrodes in all-solid-state batteries (ASSBs) during electrochemical cycles is one of the main phenomena driving capacity degradation. Such fracture patterns in active materials usually involve cracks with various orientations. While conventional wisdom usually treats fracture as ultimate failure of materials in many scenarios, the effect of crack in batteries is worth further investigation. Here, a concurrently coupled electro-chemo-mechanical model based on peridynamics has been developed to study fracture patterns and electrochemical performances of composite anodes during processes of charge and discharge. The framework consists of a classic bond-based peridynamic mechanical model, an electrochemical model, and a coupling technique to reflect the interaction between them in a bidirectional manner. The bond-based peridynamic mechanical model considers the active material’s elastic–plastic deformation and the solid electrolyte’s elastic deformation. The fracture energies of the active material, the solid electrolyte, and the interface are also incorporated into this model. The electrochemical model considers the volume expansion of the active material caused by the intercalation of lithium ions and the Butler-Volmer relation of charge transfer on the interface. Various parametric analyses are performed using this modeling framework to investigate the effects of external pressure, fracture energies of active material and solid electrolyte, and Young’s modulus on fracture patterns and electrochemical performances. It is found that different material parameters result in distinct fracture patterns in the active material with radial cracks or circumferential cracks, thus profoundly affecting the rates of charge and discharge. This work demonstrates the importance of considering the complex fracture patterns in electrode materials of batteries and provides insights for selecting more suitable electrode materials to mitigate capacity degradation.

Advanced Anode Materials for Aqueous Potassium‐Ion Batteries

AbstractAqueous electrolytes are praised for their inherent safety, cost‐effectiveness, and minimal environmental impact, making aqueous potassium‐ion batteries (APIBs) a viable alternative for sustainable and eco‐friendly energy solutions. Researchers have endeavored to anode materials that align with the unique requirements of aqueous electrolytes, and some proud achievements are made. The research about APIBs anode has focused on organic materials and polyanionic compounds, both exhibiting desirable hydrated potassium storage performance, and in recent years, on the development of metal compounds and alloy‐based materials with high theoretical capacities. However, the anode of APIBs faces a narrow electrochemical stability window (ESW) caused by aqueous electrolytes and volume expansion problems due to the large radius of potassium ions, which prevents them from exhibiting appreciable capacity with satisfactory cycling stability. This review meticulously delineates the latest advancements and representative materials for the anode of APIBs and introduces several common aqueous electrolytes and effective improvement strategies for them. The focus is on the advantages and bottlenecks faced by different types of anode materials, culminating in a proposed methodology to enhance APIBs anode efficacy. This review endeavors to furnish novel perspectives on the development and pragmatic deployment of APIBs anodes.

Nano-silicon embedded in mildly-exfoliated graphite for lithium-ion battery anode materials

Silicon-based materials have a high theoretical specific capacity and a low discharge potential, whereas the significant capacity fading owing to weak conductivity and volume exfoliation effect. The co-utilization of silicon and graphite has become a feasible method for realizing high-performance lithium-ion batteries (LIBs). Herein, the C@p-Si/ESG composite anode material with “sandwich” structure was obtained by electrostatic assembly of mildly-exfoliated graphite and electrostatic modified nano silicon, and subsequent coated with amorphous carbon on the surface of the material. The carbon coating and the mildly-exfoliated graphite form a buffer space, which alleviates the volume expansion effect of silicon in the process of lithium alloying. In addition, the SEI film is generated outside the carbon layer, reducing the consumption of the electrolyte and the occurrence of side reactions. C@p-Si/ESG exhibits a high charge–discharge rate and an excellent long-term cycle stability.

Distortions of the Hubble diagram: Line-of-sight signatures of local galaxy clusters

The Universe expansion rate is modulated around local inhomogeneities due to their gravitational potential. Velocity waves are then observed around galaxy clusters in the Hubble diagram. This paper studies them in a sim 738 Mpc-wide, 2048$^3$-particle cosmological simulation of our cosmic environment (a.k.a. CLONE: Constrained LOcal Nesting Environment Simulation). For the first time, the simulation shows that velocity waves that arise in the lines of sight of the most massive dark matter halos agree with those observed in local galaxy velocity catalogs in the lines of sight of Coma and several other local (Abell) clusters. For the best-constrained clusters such as Virgo and Centaurus -- that is, those closest to us -- secondary waves caused by galaxy groups, further into the non-linear regime, also stand out. This match was not utterly expected given that before being evolved into a fully non-linear z=0 state, assuming Lambda CDM, CLONE initial conditions are constrained solely with linear theory, the power spectrum, and highly uncertain and sparse local peculiar velocities. Additionally, Gaussian fits to velocity wave envelopes show that wave properties are tightly tangled with cluster masses. This link is complex, though, and involves the environment and formation history of the clusters. A proposed metric, measuring the distance between the observed and several re-centred simulated lines of sight, waves included, is shown to be capable of providing a tight mass range estimate for massive local clusters. Using machine learning techniques to grasp more thoroughly the complex wave-mass relation, velocity waves could in the near future be used to provide additional and independent mass estimates from galaxy dynamics within large cluster radii.

Latest Evolution of the X-Ray Remnant of SN 1987A: Beyond the Inner Ring

Based on our Chandra imaging-spectroscopic observations, we present the latest evolution of the X-ray remnant of SN 1987A. Recent changes in the electron temperatures and volume emission measures suggest that the blast wave in SN 1987A is moving out of the dense inner ring structure, also called the equatorial ring (ER). The 0.5–2.0 keV X-ray light curve shows a linearly declining trend (by ∼4.5% yr−1) between 2016 and 2020 as the blast wave heats the hitherto unknown circumstellar medium (CSM) outside the ER. While the peak X-ray emission in the latest 0.3–8.0 keV image is still within the ER, the radial expansion rate in the 3.0–8.0 keV images suggests an increasing contribution of the X-ray emission from less dense CSM since 2012, at least partly from beyond the ER. It is remarkable that, since 2020, the declining soft X-ray flux has stabilized around ∼7 × 10−12 erg s−1 cm−2, which may signal a contribution from the reverse-shocked outer layers of ejecta as predicted by the three-dimensional magnetohydrodynamic models. In the latest ACIS spectrum of supernova remnant 1987A in 2022 we report a significant detection of the Fe K line at ∼6.7 keV, which may be due to changing thermal conditions of the X-ray emitting CSM and/or the onset of reverse shock interactions with the Fe ejecta.

Instantaneous thermal fracture behaviors of a bimaterial with a penny-shaped interface crack via generalized fractional heat transfer

In the high-temperature environment, a larger thermal expansion mismatch of a bimaterial leads to marked thermal stresses and interface crack growth. In this paper, a generalized fractional heat conduction model is used to determine the instantaneous thermal fracture behaviors of a bimaterial interface crack. An axisymmetric thermoelastic problem is solved with the aid of Goodier's thermoelastic displacement potential and Love's potential functions. A mixed initial-boundary value problem is then converted to a singular integral equation of second kind by using the Hankel and Laplace integral transforms. Numerical results of the intensity factors of heat flux and thermal stresses are evaluated using Stehfest's Laplace inversion scheme. The influence of fractional kernel functions with power and exponential law are analyzed, respectively, for aluminum-steel and steel-epoxy, respectively. The thermal stress intensity factors exhibit more wave-like behaviors based on Riemann-Liouville and Atangana-Baleanu models which is different from Caputo-Fabrizio and the complete diffusion model.

Combining techno-economic modeling and spatial analysis for heat planning in rural regions: A case study of the Holbæk municipality in Denmark

This study examines the opportunities and challenges related to heat decarbonization in rural municipalities by applying a spatial analysis in combination with techno-economic modeling using TIMES. While the transition to low-carbon heating technologies is progressing in urban areas, this shift is happening more slowly in rural areas, reflecting a difference in decarbonization rate between the urban and rural contexts. This study takes the Holbæk Municipality in Denmark as a case to investigate the potential for rural heating systems considering local fuels, excess heat, and investments in different energy infrastructures. The technology options investigated include both individual heating technologies, such as domestic boilers and heat pumps, and district heating. The modeling results demonstrate that use of excess heat from the municipal wastewater treatment plant and the neighboring industrial site for district heating competes with individual heating systems that have heat pumps and biogas-fueled boilers, where the mix depends on the conditions assumed for each technology and the heat demand density. The extent of district heating expansion differs between districts in the municipality, ranging from 14% to 100% depending on the heat demand density and proximity to the current district heating network. The different possibilities for the transition of the heating sector revealed in this work indicate that a successful transition will require both a clear policy for the heating sector and an explicit decarbonization strategy for the industries that can provide excess heat for district heating.

Co3O4/RGO Nanoparticles Fabricated by Facile Solvothermal Method as an Anode Material for High‐Performance Lithium‐Ion Batteries

AbstractA potential anode material for lithium‐ion batteries (LIBs), Co3O4 has been widely considered by many scholars because of its excellent properties in terms of electrochemical characteristics and theoretical specific capacity. However, according to the existing research results, we found that the improvement of the electrochemical performance of Co3O4 has encountered a bottleneck because its intrinsic conductivity is not high enough, and more importantly, the volume expansion is too significant during the charge and discharge process, which leads to the material structure breaking. Therefore, this paper proposes a simple and scalable solvothermal and subsequent calcination method to prepare Co3O4 and reduced graphene oxide (RGO) composite nanoparticles with superior microstructures, and their morphological and electrochemical properties were investigated at different calcination temperatures. As a high‐performance anode material for lithium‐ion batteries, the Co3O4/RGO nanoparticles obtained at 550 °C exhibited terrific initial discharge capacity of 1714.2 mAh g−1, the reversible specific capacity of 1191.9 mAh g−1 with quality coulombic efficiency 98.17 % at 0.5 A g−1 after 100 cycles and extraordinary rate performance (907.6 mAh g−1 with a coulombic efficiency of 99.2 % at 2 A g−1). The facile synthesis method and excellent findings have led to better application prospects for Co3O4/RGO nanoparticles.

A volume-conservation particle shifting scheme for moving particle method simulating free-surface flow

AbstractIn this study, a novel particle shifting scheme for the moving particle method simulating free surface flow is developed. The overall method is based on the framework of least square moving particle semi-implicit (LSMPS) method, enabling accurate and stable treatment of wall boundary without configuration of dummy or virtual wall particles. To avoid volume expansion, a volume-conservation particle shifting (VCPS) model is developed. An additional term considering the variation of particle numerical density is incorporated into the VCPS model to avoid volume expansion. Several numerical simulations are calculated to validate the effectiveness of the VCPS. It is demonstrated that LSMPS incorporating with VCPS shows satisfactory accuracy and superior capability to conserve volume.

Influence of Stacking Order on the Structural and Optical Properties of Cu2ZnSnS4 Absorber Layer Prepared from DC-Sputtered Oxygenated Precursors

Several studies have attempted to overcome the sudden volume expansion of the precursor during sulfurization by the use of oxygen-containing precursors when growing the CZTS absorber. This work demonstrates the influence of precursor stacking orders on the properties of the CZTS thin film absorber layer from DC-sputtered oxygenated precursors for solar cell applications. CZTS absorber layers were prepared from three types of DC-sputtered stacks, namely, Zn-O/Sn/Cu, Sn/Zn-O/Cu, and Sn/Cu/Zn-O. The precursors were sequentially deposited on a soda lime glass (SLG) using DC-magnetron sputtering and annealed in a sulfur and nitrogen ambient. X-ray diffractometry (XRD) and Raman spectroscopy analyses reveal the formation of crystalline kesterite CZTS structure regardless of the precursor stacking order. Atomic force microscope (AFM) analysis showed that CZTS thin films grown from precursor stacks SLG/Zn-O/Sn/Cu and SLG/Sn/Zn-O/Cu had improved morphological properties with densely packed large grains compared to that with stack SLG/Sn/Cu/Zn-O. SLG/Zn-O/Sn/Cu is the best stack among the studied stacking orders since it exhibits large grains in the absorber layer, which is preferential for high-efficiency thin film solar cells. The use of oxygenated precursor with order Sn/Zn-O/Cu promises improved CZTS absorber properties as it exhibits better morphological properties.

Atomic‐Scale Engineering for New Generation Air Electrode Materials of Solid Oxide Cells: Quintuple Perovskite Sm2Ba3Co2Fe3O15‐δ with Twinned Crystal Structure

AbstractThe catalytic activity and thermomechanical stability of electrode materials are crucial for the efficient operation of reversible solid oxide cell (rSOC). However, these two traits often impose limitations on one another. In this work, a unique quintuple perovskite Sm2Ba3Co2Fe3O15‐δ (SBCF‐5L), comprising of A‐site ordered double perovskite layers and disordered simple perovskite layers, is reported as a high‐performance air electrode material for rSOC. The designed SBCF‐5L material exhibits a highly symmetrical tetragonal structure (pseudo‐cubic) with an isotropic thermal expansion and a limited chemical expansion. The formation barriers for oxygen vacancies are comparable between A‐site ordered layers and disordered simple perovskite layers, resulting in a high concentration of oxygen vacancies and 3D‐like bulk mobility of oxygen ions. Perpendicularly twinned nanodomains are developed in the particles, providing more active sites for surface electrode reaction. When applied in electrolyte‐supported cells, the SBCF‐5L electrode exhibits excellent electrochemical performance with low polarization resistance of 0.017 Ω cm−2, high power density of 1.01 W cm−2 and high electrolysis current density of 1.08 A cm−2 at 1.3 V at 800 °C in fuel cell and electrolysis modes, respectively. This study introduces a new approach of atomic‐scale engineering to rationally design a new generation of air electrodes for rSOC.