RESUMO
At the Royal Society meeting in 2023, we have mainly presented our lunar orbit array concept called DSL, and also briefly introduced a concept of a lunar surface array, LARAF. As the DSL concept had been presented before, in this article, we introduce the LARAF. We propose to build an array in the far side of the Moon, with a master station which handles the data collection and processing, and 20 stations with maximum baseline of 10 km. Each station consists of 12 membrane antenna units, and the stations are connected to the master station by power line and optical fibre. The array will make interferometric observation in the 0.1-50 MHz band during the lunar night, powered by regenerated fuel cells. The whole array can be carried to the lunar surface with a heavy rocket mission, and deployed with a rover in eight months. Such an array would be an important step in the long-term development of lunar-based ultralong wavelength radio astronomy. It has a sufficiently high sensitivity to observe many radio sources in the sky, though still short of the dark age fluctuations. We discuss the possible options in the power supply, data communication, deployment etc. This article is part of a discussion meeting issue 'Astronomy from the Moon: the next decades (part 2)'.
RESUMO
Aqueous zinc-ion batteries (ZIBs) have attracted more and more attention due to their advantages of low cost, high safety and environmental protection. Unfortunately, the unsatisfactory capacity at high current density and long-term cycling performance of cathode materials hinder the development of ZIBs. Here, a novel Zn0.079V2O5·0.53H2O/graphene (ZVOH@rGO) hybrid aerogel composed of ultrathin Zn0.079V2O5·0.53H2O (ZVOH) nanoribbons and 3D continuous graphene conductive network was successfully prepared and used as cathode of ZIBs. Taking advantage of the synergistic effects associated with ion doping, morphology control and unique aerogel structure, the ZVOH@rGO electrode demonstrated ultrafast charge/discharge capability and remarkable cycling stability: A high reversible capacity of 286.7 mAh g-1 was achieved at a current density as large as 30 A g-1, and an impressive capacity retention ratio of 75.6 % was realized over 9800 ultra-long cycles at 12 A g-1. This work is of great significance for the synthesis modification of vanadium oxides and the development of high performance ultrafast charge-discharge ZIBs.
RESUMO
As a result of the absence of solid-state diffusion limitation, intercalation pseudocapacitance behavior is emerging as an attractive charge-storage mechanism that can greatly facilitate the ion kinetics to boost the rate capability and cycle stability of batteries; however, related research in the field of zinc-ion batteries (ZIBs) is still in the initial stage and only found in limited cathode materials. In this study, a novel V2O5-x@rGO hybrid aerogel consisting of ultrathin V2O5 nanosheets (â¼1.26 nm) with abundant oxygen vacancies (Vö) and a three-dimensional (3D) graphene conductive network was specifically designed and used as a freestanding and binder-free electrode for ZIBs. As expected, the ideal microstructure of both the material and the electrode enable fast electron/ion diffusion kinetics of the electrode, which realize a typical intercalation pseudocapacitance behavior as demonstrated by the simulation calculation of cyclic voltammetry (CV), ex situ X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and first-principles density functional theory (DFT) calculation. Thanks to the elimination of solid-state diffusion limitation, the V2O5-x@rGO electrode delivers a high reversible rate capacity of 153.9 mAh g-1 at 15 A g-1 and 90.6% initial capacity retention at 0.5 A g-1 after 1050 cycles in ZIBs. The intercalation pseudocapacitance behavior is also realized in the assembled soft-pack battery, showing promising practical application prospects.