We recently developed an indium Liquid-Metal-Ion-Source that can emit currents from sub-μA up to several mA. It is based on a porous tungsten crown structure with 28 individual emitters, which is manufactured using Micro-Powder Injection Molding (μPIM) and electrochemical etching. The emitter combines the advantages of internal capillary feeding with excellent emission properties due to micron-size tips. Significant progress was made on the homogeneity of the emission over its current-voltage characteristic as well as on investigating its long-term stability. This LMIS seems very suitable for space propulsion as well as for micro/nano manufacturing applications with greatly increased milling/drilling speeds. This paper summarizes the latest developments on our porous multiemitters with respect to manufacturing, emission properties and long-term testing.
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http://dx.doi.org/10.1016/j.ultramic.2010.11.026 | DOI Listing |
Langmuir
January 2025
College of Materials and Metallurgy, Guizhou University, Guiyang 550025, China.
Lithium-sulfur (Li-S) batteries hold significant promise due to high energy density, cost-effectiveness, and ecological sustainability, but their practical applications are constrained by suboptimal electrochemical performance and the detrimental shuttle effect. Herein, a porous, sandwich-structured composite was developed to function as a freestanding cathode designed for Li-S batteries without aluminum foil. Porous carbon nanofibers (PCNF) were employed as the conductive matrix for sulfur, with tungsten carbide (WC) being incorporated to furnish abundant active sites for polysulfide adsorption.
View Article and Find Full Text PDFRSC Adv
December 2024
Department of Physics, College of Science, University of Bisha P.O. Box 551 Bisha 61922 Saudi Arabia.
Iron-doped tungsten disulfide (Fe-WS) nanoparticles were synthesized a green method using neem leaf extract. X-ray diffraction (XRD) confirmed structural changes, with the formation of a hexagonal structure. The -spacing is increased by Fe doping (6.
View Article and Find Full Text PDFMaterials (Basel)
November 2024
Institute of Mineral Engineering (GHI), RWTH Aachen University, 52074 Aachen, Germany.
The self-passivating tungsten-based alloy W-11.4Cr-0.6Y (in wt.
View Article and Find Full Text PDFNanoscale Adv
January 2025
School of Materials Science and Engineering, Hefei University of Technology Hefei 230009 China
Addressing the sluggish redox kinetics of sulfur electrodes and mitigating the shuttle effect of intermediate lithium polysulfides (LiPS) are crucial for the advancement of high-energy lithium-sulfur batteries. Here, we introduce a pioneering flexible self-supporting composite scaffold that incorporates tungsten oxide nanowire clusters anchored on core-shell porous carbon fibers (WO/PCF) for sulfur accommodation. The core of PCF serves as a robust electrode supporting scaffold, whereas the porous shell of PCF provides a 3D interconnected conductive network to accommodate sulfur, restrain polysulfide diffusion and buffer electrode expansion.
View Article and Find Full Text PDFMaterials (Basel)
November 2024
Institute of Nuclear Physics, Almaty 050032, Kazakhstan.
For the first time, porous tungsten coatings were obtained by vacuum annealing of coatings consisting of both lead solution in β-W and a mixture of Pb solution in β-W and pure lead. Electron microscopic studies of the obtained coatings before and after vacuum annealing at 800 °C for 1 h and 6 h were carried out. The formation of a new phase of tungsten with an octa-lattice and parameter a = 0.
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