RESUMEN
Lithium sulfur battery is a novel kind of secondary battery which has high energy density, however its application is greatly affected by the shuttle effect of polysulfides generated in the redox reaction of cathode electrode. Metal active sites are supposed as effective catalysts which can absorb and accelerate the conversion efficiency of lithium polysulfides, thus the shuttle effect will be alleviated. In this work, we conducted a simple way to prepare a metal Fe doped ketjen black to serve as the sulfur host of lithium sulfur battery. Ketjen black has a large specific surface area and rich porous structure, while Fe nanodot is an excellent catalyst for lithium polysulfides. Because of these advantages, the Fe/KB host can effectively confine a large amount of active material and accelerate its, therefore the Fe/KB-S cathode electrode show an excellent electrochemical performance.
RESUMEN
Strategy selection is critical for constellation deployment missions, both in terms of energy consumption and time cost. The different effects of impulse thrust and continuous thrust on orbit elements lead to a different choice of strategy. With impulse thrust, constellation types are differentiated according to high and medium-low inclinations. Constellations with high inclination are deployed using a strategy that controls the inclination. Constellations with medium-low inclination are deployed using a strategy that controls the semi-long axis. With continuous thrust, constellations are classified according to high, medium, and low inclination. High inclination constellations are deployed with a strategy of controlling inclination. Medium inclination constellations are deployed with a strategy that controls the semi-long axis. Low inclination constellations are deployed with a strategy of directly applying continuous thrust.
RESUMEN
The shuttle effect of soluble lithium polysulfide (LiPS) is a major obstacle to the practical application of lithium-sulfur (Li-S) batteries. In order to reduce the negative impact of the shuttle effect, Nd-MOF was combined with carbon nanofibers (CNFs) so that Nd-MOF was embedded in the CNFs and the Nd2O3-C/CNF composite was realized as a separation modification material. This embedded structure made the combination between Nd2O3-C and CNFs tighter, and it exhibited better synergistic effects to inhibit the shuttle effect of polysulfides while also enhancing the tensile strength of the separator and improving the safety performance of the battery. Based on these advantages, a lithium-sulfur coin cell with the Nd2O3-C/CNF-modified separator exhibited excellent electrochemical performance.