Search Results (52)

Silicon anodes for lithium-ion batteries (LIBs) offer exceptional theoretical capacity (~4200 mAh/g) but face critical challenges due to significant volume expansion (>300%) during lithiation, leading to mechanical degradation and rapid capacity fading. This review highlights recent advancements in mitigating these issues, including structural designs such as core–shell architectures, porous composites, and multidimensional encapsulation techniques that buffer mechanical stress and stabilize the solid electrolyte interphase (SEI). Binder innovations and hybrid material systems further enhance electrode integrity and cycling stability. While substantial progress has been made, challenges remain in scaling these solutions for commercial applications. This paper provides insights into current strategies and future directions for enabling silicon-based anodes in next-generation LIBs. Full article

Lithium-ion batteries (LIBs) have become the dominant energy storage technology due to their versatility and superior performance across diverse applications. Silicon (Si) stands out as a particularly promising high-capacity anode material for next-generation LIBs, offering a theoretical capacity nearly ten times greater than conventional graphite anodes. However, its practical implementation faces a critical challenge: the material undergoes a ~300% volume expansion during lithiation/delithiation, which causes severe mechanical stress, electrode pulverization, and rapid capacity decay. In addressing these limitations, advanced polymer binders serve as essential components for preserving the structural integrity of Si-based anodes. Notably, self-healing polymeric binders have emerged as a groundbreaking solution, capable of autonomously repairing cycle-induced damage and significantly enhancing electrode durability. The evaluation of self-healing performance is generally based on mechanical characterization methods while morphological observations by scanning electron microscopy provide direct evidence of crack closure; for electrochemically active materials, electrochemical techniques including GCD, EIS, and CV are employed to monitor recovery of functionality. In this study, a novel self-healing copolymer (PHX-23) was synthesized for Si anodes using a combination of octadecyl acrylate (ODA), methacrylic acid (MA), 2-hydroxyethyl methacrylate (HEMA), and polyethylene glycol methyl ether methacrylate (PEGMA). The copolymer was thoroughly characterized using NMR, FTIR, TGA, SEM, and EDX to confirm its chemical structure, thermal stability, and morphology. Electrochemical evaluation revealed that the PHX-23 binder markedly improves cycling stability, sustaining a reversible capacity of 427 mAh g⁻¹ after 1000 cycles at 1C. During long-term cycling, the Coulombic efficiency of the PHX-23 polymer is 99.7%, and similar functional binders in the literature have shown similar results at lower C-rates. Comparative analysis with conventional binders (e.g., PVDF and CMC/SBR) demonstrated PHX-23’s exceptional performance, exhibiting higher capacity retention and improved rate capability. These results position PHX-23 as a transformative binder for silicon anodes in next-generation lithium-ion batteries. Full article

Prussian blue and its analogs (PBAs), considered potential cathode materials for sodium-ion batteries (SIBs), still confront multiple challenges. For example, many defect vacancies and high crystal water content are generated during the fast crystallization of PBAs, impairing the rate performance. The stress accumulation during Na⁺ insertion/extraction destabilizes the lattice framework and then damages the electrochemical performance. Herein, iron-based Prussian blue with an open-pore skeleton structure (PB-3) is prepared using a facile template method which employs PVP and sodium citrate to control the crystallization rate and adjust the particle morphology. The prepared materials exhibit excellent kinetic properties and are conducive to mitigate the volume changes during ion insertion/extraction processes. PB-3 electrode not only exhibits a superior rate performance (92 mAh g⁻¹ reversible capacity at 2000 mA g⁻¹), but also presents superior cycling performance (capacity retention remained at 90.2% after 600 cycles at a current density of 500 mA g⁻¹). The highly reversible sodium ion insertion/extraction mechanism of PB-3 is investigated by ex situ XRD tests, which proves that the stabilized lattice structure can enhance the long cycling performance. In addition, the considerable capacitance contributes to the rate performance. This study provides valuable insights for the subsequent development of high-performance and stable cathodes for SIBs. Full article

To address the challenge of dynamic monitoring during grouting operations in coal mine fault zones under pressurized mining, this study proposes the Borehole–Tunnel Joint Resistivity Method (BTJRM). By integrating three-dimensional (3D) electrode arrays in both tunnels and boreholes with 3D resistivity inversion technology, this approach enables fully automated underground data acquisition and real-time processing, facilitating comprehensive dynamic monitoring of grout propagation. A case study was conducted on a coal mine fault grouting project, where tunnel and borehole survey lines were deployed to construct a 3D cross-monitoring network, overcoming the limitations of traditional 2D data acquisition. Finite volume method and quasi-Gauss–Newton inversion algorithms were employed to analyze dynamic resistivity variations, enhancing spatial resolution for detailed characterization of grout migration. Key findings include: (1) Grout diffusion reduced resistivity by 10%, aligning with electrical response patterns during fracture-filling stages; (2) 3D inversion reveals that grout propagates along the principal stress axis, forming a “Y”-shaped low-resistivity anomaly zone that penetrates the fault structural block and extends into roadway areas. The maximum planar and vertical displacements of grout reach 100 m and 40 m, respectively. Thirty days post-grouting, resistivity recovers by up to 22%, reflecting the electrical signature of grout consolidation; (3) This method enables 3D reconstruction of grout diffusion pathways, extends the time window for early warning of water-conducting channel development, and enhances pre-warning capabilities for grout migration. It provides a robust framework for real-time sealing control of fault strata, offering a novel dynamic monitoring technology for mine water inrush prevention. The technology can provide reliable grouting evaluation for mine disaster control engineering. Full article

The solid oxide electrolysis cell (SOEC) has potential application value in water electrolysis for hydrogen production. Here, we propose an integrated multi-scale optimization framework for the SOEC, addressing critical challenges in microstructure–property correlation and thermo-mechanical reliability. By establishing quantitative relationships between fuel support layer thickness, air electrode rib coverage, and Ni-YSZ volume ratio, we reveal their nonlinear coupling effects on the hydrogen production rate and thermal stress. The results show that when the fuel support layer thickness increases, the maximum principal stress of the fuel electrode decreases, and the hydrogen production rate and diffusion flux first increase and then decrease. The performance is optimal when the fuel support layer thickness is 5.4 mm. As the rib area decreases, the hydrogen production rate and thermal stress gradually decrease, but the oxygen concentration distribution becomes more uniform when the rib area portion is 42%. When the Ni volume fraction increases, the hydrogen production rate and the maximum principal stress gradually increase, but the uniformity of H₂O flow decreases. When the Ni volume fraction is lower than 50%, the uniformity of H₂O flow drops to 20%. As the volume fraction of nickel (Ni) increases, the fuel utilization gradually increases. When the volume fraction of Ni is between 50% and 60%, the fuel utilization reaches the range of 60–80%. This study indicates that the fuel support layer thickness, rib area, and Ni-YSZ ratio have different effects on the overall performance of the SOEC, providing guidance for the optimization of the flat-tube SOEC structure. Full article

Silicon-based materials provide a new pathway to break through the energy storage limits of battery systems but their industrialization process is still constrained by inherent diffusion hysteresis and unstable electrode structures. In this work, we propose a novel structural design strategy employing a modified spray freeze drying technique to construct multidimensional carbon nanostructures. The continuous morphological transition from carbon nanowires to carbon nanosheets was facilitated by the inducement of ultralow-temperature phase separation and the effect of polymer self-assembly. The unique wrinkled carbon nanosheet encapsulation effectively mitigated the stress concentration induced by the aggregation of silicon nanoparticles, while the open two-dimensional structure buffered the volume changes of silicon. As expected, the SSC-5M composite retained a reversible capacity of 1279 mAh g⁻¹ after 100 cycles at 0.2 C (1 C = 1700 mAh g⁻¹) and exhibited a capacity retention of 677.1 mAh g⁻¹ after 400 cycles at 1 C, demonstrating excellent cycling stability. This study offers a new strategy for the development of silicon-based energy storage devices. Full article

Soil salinity is among the crucial factors influencing agricultural productivity of crops, including oat. The respiratory metabolic pathways are of great significance for plants to adapt to salt stress, but current research is limited and there are few reports on salt-tolerant crops such as oat, which is necessary to conduct in-depth research. In this study, we conducted a pot experiment to determine the effects of salt stress on oat root growth and respiratory metabolism. Three salt stress levels—control (CK), moderate, and severe—were applied to compare the salt tolerance of the salt-tolerant cultivar Bai2 and the salt-sensitive cultivar Bai5. We selected oat roots at the seedling stage as the research focus and analyzed fresh root samples using an Oxytherm liquid-phase oxygen electrode, a digital scanner, and proteomics. The results showed that with an increased concentration of salt stress, the dry and fresh weight, root–shoot ratio, total root length, root surface area, root volume, and average diameter of the two oat cultivars showed a decreasing trend. Compared with CK, the total root respiration rate of Bai2 under moderate and severe stress decreased by 15.6% and 28%, respectively, and that of Bai5 decreased by 70.4% and 79.0%, respectively. After quantitative analysis of 18 oat root samples from the 2 cultivars using the label-free method, 7174 differential proteins were identified and 63 differential proteins were obtained, which involved 7 functional categories. In total, 111 differential proteins were specifically expressed in the root of the salt-tolerant cultivar Bai2, involving 12 functional categories. Through interaction network analysis, the proteins differentially expressed between the salt treatment and CK groups of the salt-tolerant cultivar Bai2 were analyzed. In total, five types of differentially expressed proteins interacting with each other were detected; these mainly involved antioxidant enzymes, pyruvate metabolism, glycolysis, tricarboxylic acid cycle, and energy metabolism pathways. Salt stress promoted the respiration rate of oat root glycolysis. The respiration rate of the tricarboxylic acid pathway decreased with increased salt stress concentration, while the respiration rate of the pentose phosphate pathway increased. Compared with CK, following moderate and severe salt stress treatment, alcohol dehydrogenase activity in Bai2 increased by 384% and 145%, respectively, while that of Bai5 increased by 434% and 157%, respectively. At increased salt stress concentrations, Bai2 mainly used pyruvate–ethanol fermentation for anaerobic respiration, while Bai5 mainly used pyruvate–lactic acid fermentation for anaerobic respiration. This significant discovery revealed for the first time from the perspective of respiratory metabolism that different salt-tolerant oat cultivars adapt to salt stress in different ways to maintain normal growth and development. The experimental results provide new insights into plant adaptation to salt stress from the perspective of respiratory metabolism. Full article

Diffusion stress in the anode of an automotive lithium-ion battery could cause volume changes, particle rupture, and detachment of the electrode, which may lead to the failure of anode materials. In order to investigate the mechanism of diffusion stress in the anode of the battery, this paper proposes an electrochemical–mechanical coupling model to simulate the stress and strain changes in the anode. And, SEM and X-ray diffraction are also carried out to examine the mechanism between diffusion stress and the damage to the anode microstructure. The results show that as the discharge C-rate increases, the intercalation and deintercalation of lithium ions in the anode become more active, leading to greater diffusion stress. This results in noticeable cracking in the anode material, with significant particle fragmentation, ultimately causing an increase in internal resistance. Full article

Silicon (Si) has attracted worldwide attention for its ultrahigh theoretical storage capacity (4200 mA h g⁻¹), low mass density (2.33 g cm⁻³), low operating potential (0.4 V vs. Li/Li⁺), abundant reserves, environmentally benign nature, and low cost. It is a promising high-energy-density anode material for next-generation lithium-ion batteries (LIBs), offering a replacement for graphite anodes owing to the escalating energy demands in booming automobile and energy storage applications. Unfortunately, the commercialization of silicon anodes is stringently hindered by large volume expansion during lithiation–delithiation, the unstable and detrimental growth of electrode/electrolyte interface layers, sluggish Li-ion diffusion, poor rate performance, and inherently low ion/electron conductivity. These present major safety challenges lead to quick capacity degradation in LIBs. Herein, we present the synergistic effects of nanostructured silicon and SrTiO₃ (STO) for use as anodes in Li-ion batteries. Si and STO nanoparticles were incorporated into a multiwalled carbon nanotube (CNT) matrix using a planetary ball-milling process. The mechanical stress resulting from the expansion of Si was transferred via the CNT matrix to the STO. We discovered that the introduction of STO can improve the electrochemical performance of Si/CNT nanocomposite anodes. Experimental measurements and electrochemical impedance spectroscopy provide evidence for the enhanced mobility of Li-ions facilitated by STO. Hence, incorporating STO into the Si@CNT anode yields promising results, exhibiting a high initial Coulombic efficiency of approximately 85%, a reversible specific capacity of ~800 mA h g⁻¹ after 100 cycles at 100 mA g⁻¹, and a high-rate capability of 1400 mA g⁻¹ with a capacity of 800 mA h g⁻¹. Interestingly, it exhibits a capacity of 350 mAh g⁻¹ after 1000 lithiation and delithiation cycles at a high rate of 600 mA hg⁻¹. This result unveils and sheds light on the design of a scalable method for manufacturing Si anodes for next-generation LIBs. Full article

A circular capacitive rainfall sensor can operate from non-touch mode to touch mode; that is, under the action of enough rainwater, its movable electrode plate can form a circular contact area with its fixed electrode plate. Therefore, the weight of rainwater is borne by only its movable electrode plate in non-touch mode operation but by both its movable and fixed electrode plates in touch mode operation, and the total capacitance of its touch mode operation is much larger than that of its non-touch mode operation. Essential to its numerical design and calibration is the ability to predict the deflection shape of its moveable electrode plate to determine its total capacitance. This requires the analytical solution to the fluid–structure interaction problem of its movable electrode plate under rainwater. In our previous work, only the analytical solution for the fluid–structure interaction problem before its movable electrode plate touches its fixed electrode plate was obtained, and how to numerically design and calibrate a circular non-touch mode capacitive rainfall sensor was illustrated. In this paper, the analytical solution for the fluid–structure interaction problem after its movable electrode plate touches its fixed electrode plate is obtained, and how to numerically design and calibrate a circular touch mode capacitive rainfall sensor is illustrated for the first time. The numerical results show that the total capacitance and rainwater volume when the circular capacitive rainfall sensor operates in touch mode is indeed much larger than that when the same circular capacitive rainfall sensor operates in non-touch mode, and that the average increase in the maximum membrane stress per unit rainwater volume when the circular capacitive rainfall sensor operates in touch mode can be about 20 times smaller than that when the same circular capacitive rainfall sensor operates in non-touch mode. This is where the circular touch mode capacitive rainfall sensor excels. Full article

SiN_x:H film deposition via plasma-enhanced chemical vapor deposition has been widely used in semiconductor devices. However, the relationship between the chemical bonds and the physical and chemical properties has rarely been studied for films deposited using tools in terms of the actual volume production. In this study, we investigated the effects of the deposition conditions on the H-related chemical bonding, physical and chemical properties, yield, and quality of SiN_x:H films used as passivation layers at the 28 nm technology node. The radiofrequency (RF) power, electrode plate spacing, temperature, chamber pressure, and SiH₄:NH₃ gas flow ratio were selected as the deposition parameters. The results show a clear relationship between the H-related chemical bonds and the examined film properties. The difference in the refractive index (RI) and breakdown field (E_B) of the SiN_x:H films is mainly attributed to the change in the Si–H:N–H ratio. As the Si–H:N–H ratio increased, the RI and E_B showed linear growth and exponential downward trends, respectively. In addition, compared with the Si–H:N–H ratio, the total Si–H and N–H contents had a greater impact on the wet etching rates of the SiN_x:H films, but the stress was not entirely dependent on the total Si–H and N–H contents. Notably, excessive electrode plate spacing can lead to a significant undesired increase in the non-uniformity and surface roughness of SiN_x:H films. This study provides industry-level processing guidance for the development of advanced silicon nitride film deposition technology. Full article

Silicon (Si) shows great potential as an anode material for lithium-ion batteries. However, it experiences significant expansion in volume as it undergoes the charging and discharging cycles, presenting challenges for practical implementation. Nanostructured Si has emerged as a viable solution to address these challenges. However, it requires a complex preparation process and high costs. In order to explore the above problems, this study devised an innovative approach to create Si/C composite anodes: micron-porous silicon (p-Si) was synthesized at low cost at a lower silver ion concentration, and then porous silicon-coated carbon (p-Si@C) composites were prepared by compositing nanohollow carbon spheres with porous silicon, which had good electrochemical properties. The initial coulombic efficiency of the composite was 76.51%. After undergoing 250 cycles at a current density of 0.2 A·g⁻¹, the composites exhibited a capacity of 1008.84 mAh·g⁻¹. Even when subjected to a current density of 1 A·g⁻¹, the composites sustained a discharge capacity of 485.93 mAh·g⁻¹ even after completing 1000 cycles. The employment of micron-structured p-Si improves cycling stability, which is primarily due to the porous space it provides. This porous structure helps alleviate the mechanical stress caused by volume expansion and prevents Si particles from detaching from the electrodes. The increased surface area facilitates a longer pathway for lithium-ion transport, thereby encouraging a more even distribution of lithium ions and mitigating the localized expansion of Si particles during cycling. Additionally, when Si particles expand, the hollow carbon nanospheres are capable of absorbing the resulting stress, thus preventing the electrode from cracking. The as-prepared p-Si utilizing metal-assisted chemical etching holds promising prospects as an anode material for lithium-ion batteries. Full article

The mechanical pressure that arises from the external structure of the automotive lithium battery module and its fixed devices can give rise to the concentration and damage of the internal stress inside the battery and increase the risks of battery degradation and failure. Commercial batteries cannot be disassembled, and the diffusion stress distribution at different times during discharge is notoriously difficult to determine. This paper, therefore, establishes the electrochemical force-coupling model based on the electrochemical and diffusion mechanics principles of batteries and studies the internal stress distribution of the battery under the diffusion stress of the electrode-material level and external pressure. Mainly driven by the electrochemical potential of the electrode particle diffusion stress stemming from the lithium-concentration difference inside and outside the particles, rupture is more likely to occur at the surface of the negative-electrode active particle at the end of discharge or the beginning of charging, as shown in simulation analysis. The variation in the volume of electrode material also leads to different stress and strain inside different areas, with the order of strain and stress being negative active material > negative collector fluid > positive active material > positive fluid. Therefore, huge stress and deformation will first cause the negative active particles to deviate from the fluid gradually and squeeze the diaphragm, resulting in mechanical failure accordingly. Full article

This study presents findings on the influence of gap length distance on the lightning impulse breakdown voltage of three dielectric liquids of different chemical origins. The liquids were tested in a model electrode system with a quasi-uniform electric field distribution and a pressboard plate placed on the grounded electrode. The experimental studies were supported using calculations and simulations to show the individual relationships between the lightning impulse breakdown voltage and gap distance, which represent the so-called volume effect of the most stressed liquid. The results of the experiment, which involved four considered gap distances of 2, 4, 6, and 8 mm, show that a dynamic increase in lightning impulse breakdown voltage with an increase in gap distance is associated with mineral oil and bio-based hydrocarbons. However, similar trends were not observed for synthetic ester. Calculations that allowed us to assess the impact of gap length distance on lightning impulse breakdown voltage support the observations from the experimental studies. The curves obtained in this field can be considered in the process of designing insulating systems for transformers. Full article

Silicon is a promising alternative to graphite as an anode material in lithium-ion batteries, thanks to its high theoretical lithium storage capacity. Despite these high expectations, silicon anodes still face significant challenges, such as premature battery failure caused by huge volume changes during charge–discharge processes. To solve this drawback, using amorphous silicon as a thin film offers several advantages: its amorphous nature allows for better stress mitigation and it can be directly grown on current collectors for material savings and improved Li-ion diffusion. Furthermore, its conductivity is easily increased through doping during its growth. In this work, we focused on a comprehensive study of the influence of both electrical and structural properties of intrinsic and doped hydrogenated amorphous silicon (aSi:H) thin-film anodes on the specific capacity and stability of lithium-ion batteries. This study allows us to establish that hydrogen distribution in the aSi:H material plays a pivotal role in enhancing battery capacity and longevity, possibly masking the significance of the conductivity in the case of doped electrodes. Our findings show that we were able to achieve high initial specific capacities (3070 mAhg-1 at the 10th cycle), which can be retained at values higher than those of graphite for a significant number of cycles (>120 cycles), depending on the structural properties of the aSi:H films. To our knowledge, this is the first comprehensive study of the influence of these properties of thin films with different doping levels and hydrogen distributions on their optimization and use as anodes in lithium-ion batteries. Full article