| 1. |
- Li, Jianhui, et al.
(författare)
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Novel sulfur-based electrolyte additive for constructing high-quality sulfur-containing electrode-electrolyte interphase films in sodium-ion batteries
- 2024
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Ingår i: Chemical Engineering Journal. - : Elsevier. - 1385-8947 .- 1873-3212. ; 489, s. 151188-151188
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Tidskriftsartikel (refereegranskat)abstract
- Sodium-ion batteries (SIBs) have been considered as the most promising grid-scale energy storage devices following lithium-ion batteries (LIBs). Similar to LIBs, the electrode–electrolyte interphase significantly impacts the cycling performance of the battery, and the presence of high-quality interphase films can greatly enhance the cycling performance of SIBs. In response to the interphase film challenges for SIBs, the investigation proposes the use of the sulfur-based additive 1,3-propanediol cyclic sulfate (PCS) to construct high-quality interphase films for improving electrochemical performance. Density functional theory (DFT) calculations indicate that PCS can preferentially undergo reduction–oxidation (Redox) reactions in conventional ester-based electrolyte systems, thereby forming sulfur-rich high-quality interphase films. The experimental results show that the capacity retention of NaNi1/3Fe1/3Mn1/3O2 (NFM)||hard carbon (HC) pouch cells increase from 33.94 % to 77.56 % after 300 cycles of long-term cycling at a current density of 0.5 C. Although the addition of PCS slightly reduces the ionic conductivity of the electrolyte (7.70 mS cm−1 vs. 8.09 mS cm−1), it lowers the activation energy (1.09 eV vs. 1.20 eV) and increases the Na+ transfer number (0.721 vs. 0.707) of the electrolyte, thereby improving the rate capability of NFM||HC pouch cells. This study demonstrates the potential application of PCS in SIBs and presents a forward-looking approach for exploring the film formation mechanism of sulfur-based additives.
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| 2. |
- Gao, Yun, et al.
(författare)
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Microsecond-response perovskite light-emitting diodes for active-matrix displays
- 2024
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Ingår i: NATURE ELECTRONICS. - : NATURE PORTFOLIO. - 2520-1131. ; 7:6
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Tidskriftsartikel (refereegranskat)abstract
- Perovskite light-emitting diodes (PeLEDs) could be of use in the development of active-matrix displays. However, due to ion migration in crystal structure, PeLEDs have electroluminescence rise times over milliseconds, which is problematic for the development of high-refresh-rate displays. Here, we show that the electroluminescence rise time of PeLEDs can be reduced to microseconds using an individual-particle passivation strategy. The approach is based on BF4 - ions that can passivate every nanocrystal in a perovskite emissive layer during film deposition. It leads to a defect-free film with discrete nanostructure and excellent crystallinity, which inhibits ion migration. Our strategy can be applied in perovskite nanocrystal films with different colours: red (635 nm), green (520 nm) and blue (475 nm). These PeLEDs all demonstrate response times within microseconds and high external quantum efficiencies of 22.7%, 26.2% and 18.1%, respectively. This allows us to create microsecond-response active-matrix PeLEDs that exhibit external quantum efficiencies above 20% at a display brightness of 500-3,000 cd m-2 for green devices with a resolution of 30 pixels per inch. We also develop microsecond-response red, green and blue active-matrix displays with 90 pixels per inch. An individual-particle passivation strategy that reduces ion migration in perovskite nanocrystal film can be used to make high-refresh-rate active-matrix displays with microsecond response times reduced by three orders of magnitude compared with typical perovskite light-emitting diodes.
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| 3. |
- Miao, Yanfeng, et al.
(författare)
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Stable and bright formamidinium-based perovskite light-emitting diodes with high energy conversion efficiency
- 2019
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Ingår i: Nature Communications. - : NATURE PUBLISHING GROUP. - 2041-1723. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- Solution-processable perovskites show highly emissive and good charge transport, making them attractive for low-cost light-emitting diodes (LEDs) with high energy conversion efficiencies. Despite recent advances in device efficiency, the stability of perovskite LEDs is still a major obstacle. Here, we demonstrate stable and bright perovskite LEDs with high energy conversion efficiencies by optimizing formamidinium lead iodide films. Our LEDs show an energy conversion efficiency of 10.7%, and an external quantum efficiency of 14.2% without outcoupling enhancement through controlling the concentration of the precursor solutions. The device shows low efficiency droop, i.e. 8.3% energy conversion efficiency and 14.0% external quantum efficiency at a current density of 300 mA cm(-2), making the device more efficient than state-of-the-art organic and quantum-dot LEDs at high current densities. Furthermore, the half-lifetime of device with benzylamine treatment is 23.7 hr under a current density of 100 mA cm(-2), comparable to the lifetime of near-infrared organic LEDs.
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| 4. |
- Zhu, Jie, et al.
(författare)
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An effective trajectory planning heuristics for UAV-assisted vessel monitoring system
- 2024
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Ingår i: Peer-to-Peer Networking and Applications. - : Springer. - 1936-6442 .- 1936-6450. ; 17:4, s. 2491-2506
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Tidskriftsartikel (refereegranskat)abstract
- Due to the high mobility of Unmanned Aerial Vehicle (UAV), it can be an effective method for pollution detection of vessels on the sea. How to optimize the flight path of the UAV so that the visited energy consumption is minimized is a problem that remains to be solved. In this paper, the Lin-Kernighan-Helsgaun-based trajectory planning method (LKH-TPM) is used to solve the UAV scheduling problem to minimize the UAV visit path length and compare it with the ant colony (ACO) algorithm, simulated annealing (SA) algorithm and tabu search (TS) algorithm. The experiments are carried out under different ship numbers, different sea areas, and different base station numbers, and it is verified that LKH-TPM is a more effective solution for the problem under study.
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