Abstract
Experimental data are presented on the evolution of a helium atmospheric pressure plasma jet driven by a tailored voltage waveform generated as bunches of voltage pulses consisting of a ...superposition of
$$\approx 43$$
≈
43
kHz bipolar square pulses and
$$\approx 300$$
≈
300
kHz oscillations. The characteristics of directed ionization waves (guided streamers) are compared for bunches with different first pulse polarities and different bunch duty cycles. The longest and brightest streamers are achieved at the voltage bunch with the first negative pulse and a minimum duty cycle. The dynamics of streamers at the voltage bunch with the first positive pulse are characterized by the shortest length and a lower brightness. The plasma jet length can be smoothly changed by varying the number of pulses in the bunch and the polarity of the first pulse. It is thus possible to precisely localize the region of a strong field in space by combining the parameters of the applied voltage (the duty cycle and polarity of the first pulse of a bunch) with a stepwise propagation mode of a guided streamer.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Abstract Pursuing of straightforward and cost‐effective methods for synthesizing high‐performance anode materials for lithium‐ion batteries is a topic of significant interest. This study elucidates a ...one‐step synthesis approach for a conversion composite using glow discharge in a nickel formate solution, yielding a composite precursor comprising metallic nickel, nickel hydroxide, and basic nickel salts. Subsequent annealing of the precursor facilitated the formation of the Ni@NiO composite, exhibiting exceptional electrochemical properties as anode material in Li‐ion batteries: a capacity of approximately 1000 mAh g −1 , cyclic stability exceeding 100 cycles, and favorable rate performance (200 mAh g −1 at 10 A g <M−.1 ). Comparative analysis across various methods for synthesizing NiO‐based materials underscored the superiority of the Ni@NiO composite. Furthermore, an assessment of resource costs demonstrated the cost‐effectiveness and scalability of the approach in terms of resource consumption per Ah. Lastly, the integration of a Ni@NiO anode with an NMC532 cathode in a full battery highlights Ni@NiO's potential for conversion anodes, achieving a practical gravimetric energy density of 92 Wh kg −1 .
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
A coaxial electrode configuration with surface dielectric barrier discharge was designed to generate a cold plasma jet flowing out into the ambient air. A technique for determining the plasma region ...extension based on measuring average current and applied voltage has been proposed. The capacitance of the system was calculated from measured current and voltage. Using photographic images of the discharge region, the specific capacitance of the discharge system was determined depending on the electric parameters. The obtained values were compared with the calculated capacitance of the given electrode system geometry.