| 1. |
- Shaikh, Gaushiya A., et al.
(författare)
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Assessing the Suitability of a-SiS Nanosheet as an Anode Material for Multivalent Metal-Ion Batteries
- 2023
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Ingår i: Energy & Fuels. - : American Chemical Society (ACS). - 0887-0624 .- 1520-5029. ; 37:19, s. 15116-15126
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Tidskriftsartikel (refereegranskat)abstract
- The search for suitable two-dimensional (2D) anode materials is crucial to drive the progress of multivalent metal-ion batteries capable of delivering exceptional performance, specifically with very fast charging and discharging rates. In this research, we have unveiled novel insights at the density functional theory level, with the workability of 2D puckered silicon monosulfide (a-SiS) as a probable anode material for multivalent metal-ion batteries using Na, Ca, and Al ions. Exploring the stability aspects of both structural and dynamic levels in the a-SiS nanosheet was estimated through the calculation of cohesive energy and non-imaginary phonon frequencies. The a-SiS nanosheet exhibited negative adsorption energies of -1.45, -0.92, and -2.67 eV for Na, Ca, and Al ions, respectively. Additionally, it was observed that the introduction of mono-, di-, and tri-metal atoms to the surface of the a-SiS nanosheet transformed its semiconducting nature into a metallic phase. Minimal activation energies for the active ion migration of Na (0.066 eV), Ca (0.067 eV), and Al (0.18 eV) on the surface of the a-SiS nanosheet suggest high diffusion and optimal charge/discharge functionality. Furthermore, diminished mean operating voltages of 0.44 V (Na), 0.43 V (Ca), and 0.55 V (Al) were attained and improved the theoretical storage performance of 2046.81 mAh/g (Na), 1643.02 mAh/g (Ca), and 2422.76 mAh/g (Al) for the a-SiS nanosheet. The results of this work suggest that the a-SiS nanosheet has the potential to play a crucial role as a hopeful anode material for the creation of budget-friendly, high-functioning metal-ion batteries using Na, Ca, and Al ions.
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| 2. |
- Snelders, M. P., et al.
(författare)
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Detection of ultra-fast radio bursts from FRB 20121102A
- 2023
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Ingår i: Nature Astronomy. - 2397-3366. ; 7:12, s. 1486-1496
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Tidskriftsartikel (refereegranskat)abstract
- Fast radio bursts (FRBs) are extragalactic transient flashes of radio waves with typical durations of milliseconds. FRBs have been shown, however, to present a wide range of timescales: some show sub-microsecond sub-bursts while others last up to a few seconds. Probing FRBs on a range of timescales is crucial for understanding their emission physics, how to detect them effectively and how to maximize their utility as astrophysical probes. FRB 20121102A is the first known repeating FRB source. Here we show that FRB 20121102A produces isolated microsecond-duration bursts with durations less than one-tenth the duration of other currently known FRBs. The polarimetric properties of these microsecond-duration bursts resemble those of the longer-lasting bursts, suggesting a common emission mechanism producing FRBs with durations spanning three orders of magnitude. In detecting and characterizing these microsecond-duration bursts, we show that there exists a population of ultra-fast radio bursts that current wide-field FRB searches are missing due to insufficient time resolution. These results indicate that FRBs occur more frequently and with greater diversity than initially thought. This could also influence our understanding of energy, wait time and burst rate distributions.
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