Search Results (113)

Three-dimensional trench electrode silicon detectors play an important role in particle physics research, nuclear radiation detection, and other fields. A novel polysilicon-fill-strengthened etch-through 3D trench electrode detector is proposed to address the shortcomings of traditional 3D trench electrode silicon detectors; for example, the distribution of non-uniform electric fields, asymmetric electric potential, and dead zone. The physical properties of the detector have been extensively and systematically studied. This study simulated the electric field, potential, electron concentration distribution, complete depletion voltage, leakage current, capacitance, transient current induced by incident particles, and weighting field distribution of the detector. It also systematically studied and analyzed the electrical characteristics of the detector. Compared to traditional 3D trench electrode silicon detectors, this new detector adopts a manufacturing process of double-side etching technology and double-side filling technology, which results in a more sensitive detector volume and higher electric field uniformity. In addition, the size of the detector unit is 120 µm × 120 µm × 340 µm; the structure has a small fully depleted voltage, reaching a fully depleted state at around 1.4 V, with a saturation leakage current of approximately $4.8\times {10}^{-10}\mathrm{A}$, and a geometric capacitance of about 99 fF. Full article

Lithium-ion batteries (LIBs) with high power, high capacity, and support for fast charging are increasingly favored by consumers. As a commercial electrode material for power batteries, LiFePO₄ was limited from further wide application due to its low conductivity and lithium-ion diffusion rate. The development of advanced architectures integrating rational conductive networks with optimized ion transport pathways represents a critical frontier in optimizing the performance of cathode materials. In this paper, a novel self-supporting cathode material (designated as LFP@LVP-CES) was synthesized through an integrated coaxial electrospinning and controlled pyrolysis strategy. This methodology directly converts LiFePO₄, Li₃V₂(PO₄)₃, and polyacrylonitrile (PAN)) into flexible, binder-free cathodes with a hierarchical structural organization. The 3D carbon nanofiber (CNF) matrix synergistically integrates LiFePO₄ (Li/Fe/PO_x) and Li₃V₂(PO₄)₃ (Li/V/PO_x) nanoparticles, where CNFs act as a conductive scaffold to enhance electron transport, while the PO_x polyanionic frameworks stabilize Li⁺ diffusion pathways. Morphological characterizations (SEM and TEM) revealed a 3D cross-connected carbon nanofiber matrix (diameter: 250 ± 50 nm) uniformly embedded with active material particles. Electrochemical evaluations demonstrated that the LFP@LVP-CES cathode delivers an initial specific capacity of 165 mAh·g⁻¹ at 0.1 C, maintaining 80 mAh·g⁻¹ at 5 C. Notably, the material exhibited exceptional rate capability and cycling stability, demonstrating a 96% capacity recovery after high-rate cycling upon returning to 0.1 C, along with 97% capacity retention over 200 cycles at 1 C. Detailed kinetic analysis through EIS revealed significantly reduced R_ct and increased Li⁺ diffusion. This superior electrochemical performance can be attributed to the synergistic effects between the 3D conductive network architecture and dual active materials. Compared with traditional coating processes and high-temperature calcination, the preparation of controllable electrospinning and low-temperature pyrolysis to some extent avoid the introduction of harmful substances and reduce raw material consumption and carbon emissions. This original integration strategy establishes a paradigm for designing freestanding electrode architectures through 3D structural design combined with a bimodal active material, providing critical insights for next-generation energy storage systems. Full article

With the growing demand for electric vehicles and consumer electronics, lithium-ion batteries with a high energy density are urgently needed. Lithium-rich manganese-based materials (LRMs) are known for their high theoretical specific capacity, rapid electron/ion transfer, and high output voltage. Constructing electrodes with a substantial amount of active materials is a viable method for enhancing the energy density of batteries. In this study, we prepare thick LRM electrodes through a dry process method of binder fibrillation. A point-to-line-to-surface three-dimensional conductive network is designed by carbon agents with various morphologies. This structural design improves conductivity and facilitates efficient ion and electron transport due to close particle contact and tight packing. A high-loading cathode (35 mg cm⁻²) is fabricated, achieving an impressive areal capacity of up to 7.9 mAh cm⁻². Moreover, the pouch cell paired with a lithium metal anode exhibits a remarkable energy density of 949 Wh kg⁻¹. Compared with the cathodes prepared by the wet process, the dry process optimizes the pathways for e⁻/Li⁺ transport, leading to reduced resistance, superior coulombic efficiency, retention over cycling, and minimized side reaction. Therefore, the novel structural adoption of the dry process represents a promising avenue for driving innovation and pushing the boundaries for enhanced energy density for batteries. Full article

The main method for large-scaled preparing powder superalloys in the production process is inert gas atomization, particularly vacuum-induced gas atomization (VIGA). A novel technique called electrode-induced gas atomization (EIGA) with a crucible-free electrode was proposed to prepare non-inclusion superalloy powders. In this study, a Ni-based superalloy of FGH4096 powder was prepared using both the VIGA and EIGA methods, while blanks were prepared through direct hot isostatic pressing (as-HIPed) near-net-forming method. The particle size, morphology, microstructure, and mechanical properties of the powders and blanks were compared via a laser particle size analyzer, SEM, TEM, and room-temperature and 650 °C tensile tests. The results indicated that EIGA-prepared powders exhibited a finer particle size and better surface quality than the one prepared via VIGA, which showed reduced satellite powders. However, the as-HIPed blank of EIGA-prepared powders had a lower secondary γ’ ratio and slightly reduced strength compared to the as-HIPed blank of VIGA-prepared powders due to its slightly lower secondary γ’ phase ratio and less effective inhibition of dislocation movement. Furthermore, the overall performance of the two samples did not differ significantly due to the similar microstructural characteristics of the powders. However, the variation in particle size affects heat conduction during the HIP process, resulting in slight differences in blanks’ properties. Full article

This paper presents a novel microfluidic device that integrates dielectrophoresis (DEP) forces with a membrane filter to concentrate and trap microparticles in a narrow region for enhanced optical analysis. The device combines the broad particle capture capability of a membrane filter with the precision of DEP to focus particles in regions optimized for optical measurements. The device features transparent indium tin oxide (ITO) top electrodes on a glass substrate and gold (Au) bottom electrodes patterned on a small area of the membrane filter, with spacers to control the gaps between the electrodes. This configuration enables precise particle concentration at a specific location and facilitates real-time optical detection. Experiments using 0.8 μm fluorescent polystyrene (PS) beads and Escherichia coli (E. coli) bacteria demonstrated effective particle trapping and concentration, with fluorescence intensity increasing proportionally to particle concentration. The application of DEP forces in a small region of the membrane filter resulted in a significant enhancement of fluorescence intensity, showcasing the effectiveness of the DEP-enhanced design for improving particle concentration and optical measurement sensitivity. The device also showed promising potential for bacterial detection, particularly with E. coli, by achieving a linear increase in fluorescence intensity with increasing bacterial concentration. These results highlight the device’s potential for precise and efficient microparticle concentration and detection. Full article

Engineers, geomorphologists, and ecologists acknowledge the need for temporally and spatially resolved measurements of sediment clogging (also known as colmation) in permeable gravel-bed rivers due to its adverse impacts on water and habitat quality. In this paper, we present a novel method for non-destructive, real-time measurements of pore-scale sediment deposition and monitoring of clogging by using wire-mesh sensors (WMSs) embedded in spheres, forming a smart gravel bed (GravelSens). The measuring principle is based on one-by-one voltage excitation of transmitter electrodes, followed by simultaneous measurements of the resulting current by receiver electrodes at each crossing measuring pores. The currents are then linked to the conductive component of fluid impedance. The measurement performance of the developed sensor is validated by applying the Maxwell Garnett and parallel models to sensor data and comparing the results to data obtained by gamma ray computed tomography (CT). GravelSens is tested and validated under varying filling conditions of different particle sizes ranging from sand to fine gravel. The close agreement between GravelSens and CT measurements indicates the technology’s applicability in sediment–water research while also suggesting its potential for other solid–liquid two-phase flows. This pore-scale measurement and visualization system offers the capability to monitor clogging and de-clogging dynamics within pore spaces up to 10,000 Hz, making it the first laboratory equipment capable of performing such in situ measurements without radiation. Thus, GravelSens is a major improvement over existing methods and holds promise for advancing the understanding of flow–sediment–ecology interactions. Full article

In this study, a novel multiscale carbon architecture was developed by integrating mesocarbon microbeads (MCMBs), graphitic nanofibers (GNFs), and mesoporous carbon, aimed at enhancing the performance of symmetric supercapacitors. The unique combination of spherical MCMB particles, conductive GNF nanofibers, and mesoporous carbon sheets resulted in a highly effective electrode material, offering improved conductivity, increased active sites for charge storage, and enhanced structural stability. The fabricated MCMB/GNF/MC architecture demonstrated a remarkable specific capacitance of 393 F g⁻¹ at 1 A g⁻¹ in a three-electrode system, significantly surpassing the performance of individual MCMBs and MCMB/GNF electrodes. Furthermore, the architecture was incorporated into a symmetric supercapacitor (SSC) device, where it achieved a capacitance of 86 F g⁻¹ at 1 A g⁻¹. The device exhibited excellent cycling stability, retaining 92% of its initial capacitance after 10,000 charge–discharge cycles, with an outstanding coulombic efficiency of 99%. At optimal operating conditions, the SSC device delivered an energy density of 11 Wh kg⁻¹ at a power density of 500 W kg⁻¹, making it a promising candidate for high-performance energy-storage applications. This multiscale carbon architecture represents a significant advancement in the design of electrode materials for symmetric supercapacitors, offering a balance of high energy and power density, long-term stability, and excellent scalability for practical applications. This work not only contributes to the development of high-performance electrode materials but also paves the way for scalable, long-lasting supercapacitors for future energy-storage technologies. Full article

The supported RuO₂ catalysts are known for their synergistic and interfacial effects, which significantly enhance both catalytic activity and stability. However, polymer-supported RuO₂ catalysts have received limited attention due to challenges associated with poor conductivity. In this study, we successfully synthesized the RuO₂-polytetrafluoroethylene (PTFE) catalyst via a facile annealing process. The optimized nucleation and growth strategies enable the formation of RuO₂ particles (~13.4 nm) encapsulating PTFE, establishing a conductive network that effectively addresses the conductivity issue. Additionally, PTFE induces the generation of oxygen vacancies and the formation of stable RuO₂/PTFE interfaces, which further enhance the acidic OER activity and the stability of RuO₂. As a result, the RuO₂-PTFE catalyst exhibits a low overpotential of 219 mV at 10 mA cm⁻² in the three-electrode system, and the voltage of the RuO₂-PTFE||commercial Pt/C system can keep 1.50 V for 800 h at 10 mA cm⁻². This work underscores the versatility of PTFE as a substrate for fine-tuning the catalyst morphology, the crystal defect, and the stable interface outerwear. This work not only broadens the application scope of PTFE in catalyst synthesis but also provides a novel approach to the design of high-performance metallic oxide catalysts with tailored oxygen vacancy concentration and stable polymer outerwear. Full article

A magnetically assembled electrode (MAE) is a modular electrode format in electrochemical oxidation wastewater treatment. MAE utilizes magnetic forces to attract the magnetic catalytic auxiliary electrodes (AEs) on the main electrode (ME), which has the advantages of high efficiency and flexible adjustability. However, the issue of the insufficient polarization of the AEs leaves the potential of this electrode underutilized. In this study, natural tourmaline (Tml) particles with pyroelectric and piezoelectric properties were utilized to solve the above issue by harvesting and converting the waste energy (i.e., the joule heating energy and the bubble striking mechanical energy) from the electrolysis environment into additional electrical energy applied on the AEs. Different contents of Tml particles were composited with Fe₃O₄/Sb-SnO₂ particles as novel AEs, and the structure–activity relationship of the novel MAE was investigated by various electrochemical measurements and orthogonal tests of dye wastewater treatment. The results showed that Tml could effectively enhance all electrochemical properties of the electrode. The optimal dye removal rate was obtained by loading the AEs with 0.2 g·cm⁻² when the Tml content was 4.5 wt%. The interaction of current density and Tml content had a significant effect on the COD removal rate, and the mineralization capacity of the electrode was significantly enhanced. The findings of this study have unveiled the potential application of minerals and energy conversion materials in the realm of electrochemical oxidation wastewater treatment. Full article

The aging of lithium-ion cells critically affects their lifetime, safety, and performance, particularly due to electrode and electrolyte degradation. This study introduced a novel combined-measurement cell-integrating operando dilatometry and operando mass spectrometry to observe real-time physical and chemical changes during electrochemical cycling. Operando dilatometry measures thickness changes in the working electrode, while operando mass spectrometry analyzes gas emissions to provide insights into the underlying degradation processes. The results indicated significant correlations between electrochemical behavior, thickness changes, and gas evolution, revealing both the reversible and irreversible growth of constituents on particles and the electrode surface. The formation of the solid electrolyte interphase due to the degradation of electrolyte components, such as solvents or conductive salts, is identified as a key factor contributing to irreversible changes. The operando gas analysis highlighted the presence of decomposition intermediates and products, which are all linked to electrolyte degradation. Additionally, post-mortem gas chromatography coupled with mass spectrometry identified several compounds, confirming the presence of different decomposition pathways. This integrated and holistic approach deepened the understanding of the aging mechanisms at the electrode level. Full article

Triboelectric separation has recently been investigated as a novel process for dry enrichment and separation of protein of various crops like wheat flour. The triboelectric effect allows for the separation of starch and protein particles in an electric field based on their different charging behavior despite having a similar density and size distribution. Particles are triboelectrically charged in a charging section before being separated in an electric field based on their polarity. While the charging section is crucial, the influence of process parameters remains largely unexplored. Thus, the influence of the charging sections’ dimensions and the particle concentration as process key parameters was investigated experimentally. Varying the length (0, 105, and 210 mm) showed that the protein shift increases with the length (max. 0.53%) during separation. Varying the diameter (6, 8, and 10 mm) influenced the charging behavior, resulting in an increase in protein accumulation on the negative electrode as the diameter decreased. Varying the mass flow of flour (40, 80, 160, and 320 g·h⁻¹) also affected the separability, leading to a maximum protein shift of 0.61%. Based on the observed results, it is hypothesized that the electrostatic agglomeration behavior of oppositely charged particles is directly affected by alterations in machine parameters. These agglomerates have a charge-to-mass ratio that is too low for separation in the electric field. Full article

To realize highly sensitive SAW devices, novel Al–Cu thin films were developed using a combinatorial sputtering system. The Al–Cu sample library exhibited a wide range of chemical compositions and electrical resistivities, providing valuable insights for selecting optimal materials for SAW devices. Considering the significant influence of electrode resistivity and density on acoustic wave propagation, an Al–Cu film with 65 at% Al was selected as the IDT electrode material. The selected Al–Cu film demonstrated a resistivity of 6.0 × 10⁻⁵ Ω-cm and a density of 4.4 g/cm³, making it suitable for SAW-based microfluidic actuator applications. XRD analysis revealed that the Al–Cu film consisted of a physical mixture of Al and Cu without the formation of Al–Cu alloy phases. The film exhibited a fine-grained microstructure with an average crystallite size of 7.5 nm and surface roughness of approximately 6 nm. The SAW device fabricated with Al–Cu IDT electrodes exhibited excellent acoustic performance, resonating at 143 MHz without frequency shift and achieving an insertion loss of −13.68 dB and a FWHM of 0.41 dB. In contrast, the Au electrode-based SAW device showed significantly degraded acoustic characteristics. Moreover, the SAW-based microfluidic module equipped with optimized Al–Cu IDT electrodes successfully separated 5 μm polystyrene (PS) particles even at high flow rates, outperforming devices with Au IDT electrodes. This enhanced performance can be attributed to the improved resonance characteristics of the SAW device, which resulted in a stronger acoustic radiation force exerted on the PS particles. Full article

Semiconductor detectors for high-energy sensing ($X/\gamma$-rays) play a critical role in fields such as astronomy, particle physics, spectroscopy, medical imaging, and homeland security. The increasing need for precise detector characterization highlights the importance of developing advanced digital twins, which help optimize the design and performance of imaging systems. Current simulation frameworks primarily focus on modeling electron–hole pair dynamics within the semiconductor bulk after the photon absorption, leading to the current signals at the nearby electrodes. However, most simulations neglect charge diffusion and Coulomb repulsion, which spatially expand the charge cloud during propagation due to the high complexity they add to the physical models. Although these effects are relatively weak, their inclusion is essential for achieving a high-fidelity replication of real detector behavior. There are some existing methods that successfully incorporate these two phenomena with minimal computational cost, including those developed by Gatti in 1987 and by Benoit and Hamel in 2009. The present work evaluates these two approaches and proposes a novel Monte Carlo technique that offers higher accuracy in exchange for increased computational time. Our new method enables more realistic performance predictions while remaining within practical computational limits. Full article

Lithium-ion batteries offer the highest energy density of any currently available portable energy storage technology. By using different anode materials, these batteries could have an even greater energy density. One material, tin, has a theoretical lithium capacity (994 mAh/g) over three-times higher than commercial carbon anode materials. Unfortunately, to achieve this high capacity, bulk tin undergoes a large volume expansion, and the material pulverizes during cycling, giving a rapid capacity fade. To mitigate this issue, tin must be scaled down to the nano-level to take advantage of unique micromechanics at the nanoscale. Synthesis techniques for Sn nanoparticle anodes are costly and overly complicated for commercial production. A novel one-step process for producing carbon-coated Sn nanoparticles via spark plasma erosion (SPE) shows great promise as a simple, inexpensive production method. The SPE method, characterization of the resulting particles, and their high-capacity reversible electrochemical performance as anodes are described. With only a 10% addition of these novel SPE carbon-coated Sn particles, one anode composition demonstrated a reversible capacity of ~460 mAh/g, achieving the theoretical capacity of that particular electrode formulation. These SPE carbon-coated Sn nanoparticles are drop-in ready for present commercial lithium-ion anode processing and would provide a ~10% increase in the total capacity of current commercial lithium-ion cells. Full article

Herein, we report the preparation of nanocomposites using activated biochar derived from rice husk (RHBC) by doping with a metal–organic framework, namely the zeolitic imidazolate framework (ZIF-8). The morphological and structural characterization of the prepared nanocomposite was performed using SEM, BET, XRD, FTIR, TGA, and UV–Vis spectroscopy. The average particle sizes as observed from SEM micrographs for ZIF-8 and ZIF-8@RHBC were 67 nm and 78 nm, respectively. The BET surface analysis of the ZIF-8@RHBC composite showed a value of 308 m²/g and a pore diameter of about 42.56 A°. The inclusion of RHBC in ZIF-8 resulted in a 4% increase in the optical band gap and a 5% increase in the optical conductivity. The electrochemical properties of this nanocomposite were investigated through cyclic voltammetry, and it was observed that ZIF-8@RHBC showed improved CV curves in comparison to bare ZIF-8. The specific capacitance of ZIF-8@RHBC was significantly enhanced from 348 F/g to 452 F/g at a 1 A/g current density after incorporating ZIF-8 into the RHBC matrix. The formation of a mesoporous structure in the ZIF-8@RHBC composite contributed to the improved diffusion rate at the electrode surface, resulting in excellent electrochemical features in the composite. Furthermore, the EIS studies confirmed the reduced charge transfer resistance and increased conduction at the electrode surface in the case of the ZIF-8@RHBC composite. Owing to the ease of its green synthesis and its excellent structural and morphological features and optical and electrochemical properties, this ZIF@RHBC nanocomposite could represent a novel multifunctional material to be used in optoelectronics and energy storage applications. Full article