- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Binder- and conductive additive-free laser-induced graphene/LiNi1/3Mn1/3Co1/3O2 for advanced hybrid supercapacitors
摘要： Hybrid supercapacitors have recently emerged as next-generation energy storage devices that bridge the gap between supercapacitors and lithium-ion batteries. However, developing high energy cathodes that maintain long-term cycle stability and a high rate capability for real applications remains a significantly challenging issue. Herein, we report a facile synthesis method for a laser-scribed graphene/LiNi1/3Mn1/3Co1/3O2 (LSG/NMC) composite for high energy cathode materials for use in hybrid supercapacitors. LSG/NMC composites exhibit not only a high capacitance of up to 141.5 F/g but also an excellent capacitance retention of 98.1% after 1000 cycles at a high current density of 5.0 A/g. The introduction of an NMC spacer between the LSG layers provides an enlarged interspace that can act as an efficient channel for additional storage sites and rapid access. In addition, we further confirmed that hybrid supercapacitors using LSG/NMC cathodes and H2Ti2O25 anodes with an AlPO4/carbon hybrid coating layer (H-HTO) deliver a remarkable energy density of ~123.5 Wh/kg, power density of ~14074.8 W/kg, and a long-term cycle stability of 94.6% after 20,000 cycles. This work demonstrates that our proposed material can be considered a strong cathode candidate for next-generation hybrid supercapacitors.
关键词： laser-scribed graphene,high energy density,hybrid supercapacitors,LiNi1/3Mn1/3Co1/3O2,long-term cycle stability
更新于2025-09-19 17:13:59
-
Thermal stability analysis of buffered layer P3HT/P3HT:PCBM organic solar cells
摘要： The manual creation of complex 3D structures for use in engineering analysis is a major obstacle to analyzing physically realistic structures. A bias is invariably imposed when a mixture is manually composed, and the structure is rarely representative of the process by which composites are fabricated. Properties such as packing density and anisotropies that seem to easily occur in nature are very difficult to obtain with manual arrangements. This paper addresses the creation of complex 3D mixtures, comprising crystals embedded in a matrix, for subsequent electromagnetic (EM) analysis. The physically realistic arrangement of the crystals is facilitated by the use of physics engine software, specifically the Bullet physics library, which renders the realistic effects in advanced computer games. A composite mixture of crystals is created by pouring a series of random crystals into a box with the crystals bouncing against each other and aligning just as they do in the real world. Higher packing densities are obtained than can be reasonably obtained with manual construction. The arrangement of the obtained crystals reflects the real world alignment of asymmetric crystals. A composite is created here and used with EM simulation software to investigate energy localization in materials.
关键词： Automated crystal modeling,gaming software,relative permittivity,electric energy density,transient simulation,electromagnetic analysis,mixtures
更新于2025-09-19 17:13:59
-
[IEEE 2019 IEEE Asia-Pacific Microwave Conference (APMC) - Singapore, Singapore (2019.12.10-2019.12.13)] 2019 IEEE Asia-Pacific Microwave Conference (APMC) - Overcome the Limitations of Performance Parameters of On-Chip Antennas Based on Metasurface and Coupled Feeding Approaches for Applications in System-on-Chip for THz Integrated-Circuits
摘要： The manual creation of complex 3D structures for use in engineering analysis is a major obstacle to analyzing physically realistic structures. A bias is invariably imposed when a mixture is manually composed, and the structure is rarely representative of the process by which composites are fabricated. Properties such as packing density and anisotropies that seem to easily occur in nature are very difficult to obtain with manual arrangements. This paper addresses the creation of complex 3D mixtures, comprising crystals embedded in a matrix, for subsequent electromagnetic (EM) analysis. The physically realistic arrangement of the crystals is facilitated by the use of physics engine software, specifically the Bullet physics library, which renders the realistic effects in advanced computer games. A composite mixture of crystals is created by pouring a series of random crystals into a box with the crystals bouncing against each other and aligning just as they do in the real world. Higher packing densities are obtained than can be reasonably obtained with manual construction. The arrangement of the obtained crystals reflects the real world alignment of asymmetric crystals. A composite is created here and used with EM simulation software to investigate energy localization in materials.
关键词： electromagnetic analysis,relative permittivity,Automated crystal modeling,transient simulation,mixtures,electric energy density,gaming software
更新于2025-09-19 17:13:59
-
Maximizing magnetic field generation in high power laser–solid interactions
摘要： In order to understand the transport of fast electrons within solid density targets driven by an optical high power laser, we have numerically investigated the dynamics and structure of strong self-generated magnetic fields in such experiments. Here we present a systematic study of the bulk magnetic field generation due to the ponderomotive current, Weibel-like instability and resistivity gradient between two solid layers. Using particle-in-cell simulations, we observe the effect of varying the laser and target parameters, including laser intensity, focal size, incident angle, preplasma scale length, target thickness and material and experimental geometry. The simulation results suggest that the strongest magnetic field is generated with laser incident angles and preplasma scale lengths that maximize laser absorption efficiency. The recent commissioning of experimental platforms equipped with both optical high power laser and X-ray free electron laser (XFEL), such as European XFEL-HED, LCLS-MEC and SACLA beamlines, provides unprecedented opportunities to probe the self-generated bulk magnetic field by X-ray polarimetry via Faraday rotation with simultaneous high spatial and temporal resolution. We expect that this systematic numerical investigation will pave the way to design and optimize near future experimental setups to probe the magnetic fields in such experimental platforms.
关键词： laser–plasmas interaction,X-ray free electron laser probing,high energy density physics
更新于2025-09-19 17:13:59
-
Mesoscopic-scale simulation of pore evolution during laser powder bed fusion process
摘要： Laser powder bed fusion (LPBF) is an advanced manufacturing technology that uses data-driven, layer-by-layer accumulation of materials to form metal components and has been widely applied in aerospace and other fields. Effectively controlling pore defects is a key scientific problem and technical difficulty in LPBF industrial production. Based on the open-source discrete element method code Yade, the particle distribution of the powder bed was obtained. Based on the open-source computational fluid dynamics code OpenFOAM, the pore evolution during the LPBF formation process at the mesoscopic scale was predicted. The thermal–force factors affecting the molten pool included the surface tension, Marangoni effect, gasification recoil force, and mushy drag force. The laser energy model used a body heat source based on interface tracking. First, dimensionless analysis of the molten pool evolution in the case of LPBF single-track formation was carried out. The molten pool evolution was mainly influenced by the gasification recoil force, Marangoni effect and surface tension, and the main influencing factors on different zones of the molten pool were different. To examine the influences of the laser power, scanning speed, powder bed thickness, and hatch space on the pore defect in the LPBF formation process, simulations were carried out and compared with experimental results. When the volumetric energy density was too small, pore defects occurred due to insufficient fusion of metal particles, and when the volumetric energy density was too large to cause the “keyhole” effect, pore defects occurred because the entrained gas could not escape in time. This paper is expected to provide theoretical guidance for the scientific regulation of pore defects in LPBF production.
关键词： OpenFOAM,Volumetric energy density,Dimensionless analysis,Pore defect,Laser powder bed fusion,Numerical simulation
更新于2025-09-19 17:13:59
-
Glass (Selected Properties and Crystallization) || 9. Crystallization of Undercooled Liquids: Results of Molecular Dynamics Simulations
摘要： The present contribution is devoted to molecular dynamics (MD) simulations modeling of the kinetics of spontaneous crystal nucleation in under-cooled one-component Lennard-Jones liquids and detailed comparison with the basic assumptions and results of classical nucleation theory (CNT). In the MD-computations the following spectrum of properties of the respective nucleating systems under consideration is determined: nucleation rate, J, diffusion coefficient of the crystal clusters in cluster size space, D, non-equilibrium Zeldovich factor, Z, size of the critical crystal nucleus, n?, pressure inside the critical crystal nucleus, p?. Based on these data, the interfacial energy density of the critical crystal nucleus is determined. Simultaneously, the interfacial energy density is computed by molecular dynamics methods for the planar interface liquid-crystal. It is found that for typical sizes of the critical nuclei in the range of 0.7–1.0 nm the value of the effective specific interfacial energy differs from that of the planar interface by less than 15 %. A comparison of the molecular dynamics results with the classical nucleation theory shows that for the considered case of crystallization of one-component liquids MD simulation results are in good agreement with the classical nucleation theory not only with respect to the final result, the nucleation frequency, but also with respect to the parameters D, Z, n?. Consequently, the results of molecular dynamics simulations of crystallization in one-component liquids demonstrate the validity of the basic assumptions and the final results of CNT for this particular case of phase formation.
关键词： molecular dynamics simulations,nucleation rate,critical crystal nucleus,Lennard-Jones liquids,classical nucleation theory,interfacial energy density,crystallization,undercooled liquids
更新于2025-09-16 10:30:52
-
Laser energy density dependence of performance in additive/subtractive hybrid manufacturing of 316L stainless steel
摘要： An enormous amount of research effort goes into the manufacturing process for additive manufacturing (AM) or subtractive manufacturing (SM) process for property microstructure. Moreover, additive/subtractive hybrid manufacturing (ASHM), which combines additive and subtractive processes in a single machine, has provided an important opportunity to increase the high percentage of stock utilization and produce complex functional components. However, the system comprehensive investigation and the study of ASHM-manufactured parts by various process parameters have rarely been reported. The present paper depicted the effect of laser energy density (ψ) on the phase change, density, microstructure, Vickers hardness, and tensile testing within the ASHM specimens. It was observed that the highest Vickers microhardness, the largest tensile strength, and the attendant ductility were gained at ψ =222 J/mm3, the most excellent value, which was put down to the high density and relatively fine grains. The results of this study have a better knowledge of the ASHM method to produce a high surface state and mechanical behavior 316L SS component by governing laser energy density (ψ).
关键词： Additive/subtractive hybrid manufacturing,Laser energy density,Microstructure,Densification,Vickers microhardness,Tensile properties
更新于2025-09-16 10:30:52
-
Research on epoxy-based nanocomposites with high energy density and charge-discharge efficiency filled with Ti0 <sub/>2</sub> nanofibers
摘要： Capacitor films with high energy density are critical to energy storage. However, the energy density of state-of-the-art commercial capacitor films are limited by their low dielectric permittivity. In this study, epoxy-based nanocomposite films are prepared by filling with TiO2 nanofibers. Results show that nanocomposite films have larger discharge energy density because of the significant increase in dielectric permittivity, which caused by the additional interface polarization and space charge polarization. And a superior charge-discharge efficiency is achieved in the composite films at the same time due to the low dielectric loss. In addition, the composites also keep a high breakdown strength because of the dispersion of the nanofibers. The discharge energy density of 5.19 J/cm3 with the efficiency of 80% is achieved at 470 MV/m in the nanocomposites containing 2wt% nanofibers. The excellent energy density and charge-discharge efficiency of epoxy-based nanocomposites offer a promising opportunity for future researches and industrial application.
关键词： dielectric permittivity,energy density,epoxy-based nanocomposites,charge-discharge efficiency,TiO2 nanofibers
更新于2025-09-16 10:30:52
-
Coarse Grained Simulation and Turbulent Mixing || Laser Driven Turbulence in High Energy Density Physics and Inertial Confinement Fusion Experiments
摘要： The mixing of initially separate materials in a turbulent ?ow by the small scales of turbulent motion is a critical and often poorly understood element of many research programs, such as inertial con?nement fusion (ICF), supernova implosions and explosions, and combustion, as well as many other applications in engineering, geophysics, and astrophysics. In typical contexts of interest, we are interested in achieving detailed understanding of interpenetration, hydrodynamical instabilities, and mixing arising from perturbations at the material interfaces, that is, driven by Rayleigh–Taylor (RT), Richtmyer–Meshkov (RM), and Kelvin–Helmholtz (KH) instabilities (buoyancy, shock, and shear induced instabilities, respectively). Laboratory observations typically provide only limited integrated measures of complex nonlinear three-dimensional physical processes, leaving many details and mechanisms unresolved. Carefully controlled computational experiments based on the numerical simulations play a crucial complementary role, providing insight into the underlying dynamics. Collaborative laboratory/computational studies are used to establish predictability of the models in conjunction with the development of frameworks for analysis, metrics for veri?cation and validation, and uncertainty quanti?cation.
关键词： Richtmyer–Meshkov instability,Rayleigh–Taylor instability,inertial con?nement fusion,turbulent mixing,high energy density physics,Kelvin–Helmholtz instability
更新于2025-09-12 10:27:22
-
High-Energy-Density Physics and Laser Technologies
摘要： This paper is devoted to the jubilee of I.M. Khalatnikov, the founder and the first director of the Landau Institute for Theoretical Physics of the Russian Academy of Sciences. I.M. Khalatnikov organized a first-class institute the studies at which cover a broad spectrum of research directions. The plasma and lasers department of the Institute conducts research on plasma physics problems, laser–matter interaction, questions pertaining to laser applications, and hydrodynamics problems. Much attention is given to solid-state physics with an emphasis on the behavior of matter in extreme conditions under intense laser irradiation. A number of new results are presented: the behavior of metals in two-temperature states (when the temperature of the electron subsystem of a metal is much greater than the temperature of the ion subsystem due to ultrafast laser heating); determining the boundaries of existence of a single-wave propagation mode of elastoplastic shock waves in ductile metal crystals; the formation of a laser torch from target materials and liquids under metal laser ablation of a metal into the surrounding liquid; the physical–mechanical consequences (melting, capillarity, recrystallization) of nonuniform (along the irradiated surface) energy dissipation caused by the interference of plasmon–polariton and laser electromagnetic fields.
关键词： laser–matter interaction,plasma physics,laser ablation,hydrodynamics,two-temperature states,plasmon–polariton,solid-state physics,high-energy-density physics,laser technologies,elastoplastic shock waves
更新于2025-09-12 10:27:22