Fabrication of Niobium Powder for Solid-electrolyte Capacitors

Niobium Powder Synthesized by Calciothermic Reduction of Niobium Hydroxide for Use in Capacitors

Metallic niobium powder was produced for applications in electric capacitors via calciothermic reduction of niobium hydroxide in molten CaCl2. Sub-micrometer spherical metallic particles with coral-like morphologies reflected the particle size of the starting oxide powder. A fine powder was obtained from the mixtures of niobium hydroxide and CaO or Ca(OH)2, respectively. Sintered pellets of the...

Solid Freeform Fabrication Based on Micro-Plasma Powder Deposition

This paper presents a solid freeform fabrication (SFF) technique based on micro-plasma powder deposition (MPPD). The relationship between the geometric features of the deposited layers and the welding parameters is investigated. The arc length is controlled through the monitoring of the arc voltage. The result of building parts with functionally graded components by the MPPD process is shown as...

Fabrication of All-Solid-State Lithium-Ion Cells Using Three-Dimensionally Structured Solid Electrolyte Li7La3Zr2O12 Pellets

All-solid-state lithium-ion batteries using Li+-ion conducting ceramic electrolytes have been focused on as attractive future batteries for electric vehicles and renewable energy conversion systems because high safety can be realized due to non-flammability of ceramic electrolytes. In addition, a higher volumetric energy density than that of current lithium-ion batteries is expected since the a...

Reliability of Solid Tantalum Capacitors

Synthesis and Characterization of a Niobium Nitride Precursor and Niobium Nitride Powder

Anodic dissolution of Nb foil in an electrolyte solution containing liquid NH3 and NH4Br produces an insoluble precursor that can be calcined to yield phase-pure NbN. Infrared spectroscopy is consistent with a precursor having the general formula NbXn(NH2)5-npNH3. By changing the calcination conditions, the phase of the resulting NbN powder can be varied. For example, calcining in pure Ar yield...