Lithium-sulfur (Li-S) batteries are a promising candidate of next generation energy storage systems owing to its high theoretical capacity and energy density. However, to date, its commercial application was hindered by the inherent problems of sulfur cathode. Additionally, with the rapid decline of non-renewable resources and active appeal of green chemistry, the intensive research of new electrode materials was conducted worldwide. We have obtained a sheet-like carbon material (shaddock peel carbon sheets SPCS) from organic waste shaddock peel, which can be used as the conductive carbon matrix for sulfur-based cathodes. Furthermore, the raw materials are low-cost, truly green and recyclable. As a result, the sulfur cathode made with SPCS (SPCS-S), can deliver a high reversible capacity of 722.5 mAh g−1 at 0.2 C after 100 cycles with capacity recuperability of ~90%, demonstrating that the SPCS-S hybrid is of great potential as the cathode for rechargeable Li-S batteries. The high electrochemical performance of SPCS-S hybrid could be attributed to the sheet-like carbon network with large surface area and high conductivity of the SPCS, in which the carbon sheets enable the uniform distribution of sulfur, better ability to trap the soluble polysulfides and accommodate volume expansion/shrinkage of sulfur during repeated charge/discharge cycles.
This work reports on the systematic comparison of the crystalline structural, morphological and hydrophobic properties of ZnO and Al-doped ZnO (AZO) thin films fabricated by atomic layer deposition and the hydrothermal method. It was revealed that the surface wettability can be largely modified by Al doping in the zinc oxide film growth process. With Al doping, the morphology of the AZO films became more complex and rough. The water contact angle of a flower-like hierarchical ZnO film (123 AE 4 ) was improved by about 40 via Al doping to 160 AE 4 . We attributed the variation in surface hydrophobicity with Al doping to changes in the bond angle and distance between ZnO-H 2 O molecule. The computational simulations have been employed to verify the interfacial distinction between two main crystal orientations of AZO. This result suggests that Al doping can be considered a critical factor in changing the surface morphology of AZO as well as the hydrophobic properties. It is believed that the present route holds promise in the design and application of practical superhydrophobic materials.
With the advancements of materials science and technology, organic materials found significant applications in aerospace industry. But under the orbital thermal and vacuum environment, organic materials can outgas and the outgassed products and induced environment often degraded performances of spacecraft or its subsystem. In this article, the typical impacts of outgassing environment on spacecraft are explained briefly. Then the outgassing theory, test method, identification of compounds and control measures were reviewed in detail. The need for transient and long-term outgassing model is discussed. The standard test methods of E595 and E1559 are compared. The promising new techniques such as infrared spectrometry and/or mass-spectrometry with thermogravimetric analysis is proposed for the identification of outgassed compounds. The vacuum bakeout and molecular absorber for outgassing control are reviewed and for the last more research work is needed.
In this paper, we investigate the effect of thermal annealing on the degree of crystallinity, the fraction of electro-active phase (β-phase) and the dielectric properties, such as dielectric constant and loss tangent. Through control the thermal annealing conditions, dramatic improvements have been achieved. The degree of crystallinity is greatly enhanced up to 45.2%. The relative content of electro-active phase increases remarkably by 61% and the dielectric constant is improved greatly by 17.8% and reaches its maximum value of 9.9 meanwhile the dielectric loss being as low as 0.026.
The ghost dust clouds in the vicinity of Earth-Moon triangular libration points are known as the “Kordylewski clouds” (KDCs). Objects in the KDCs may give hints to the physical, chemical, and dynamical properties of the solar system. As a result, in situ exploration of the KDCs can help us understand the evolution of our solar system. This paper first summarizes the observation history of the KDCs. Based on the properties of the KDCs, a ground- and space-based observation concept is proposed, using the CAST 100 platform developed by DFH and ground stations. Some details of the concept are exploited.
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