Preparation method of electrolyte containing ZIF-67 nanoparticles

Abstract

The invention provides a preparation method of an electrolyte containing ZIF-67 nanoparticles, which belongs to the field of lithium metal batteries. The ZIF-67 nanoparticles are synthesized first, then vacuum activation is performed at 80-100 DEG C for 12-24 hours, the ZIF-67 nanoparticles subjected to vacuum activation are dispersed into the electrolyte of a lithium-sulfur battery, and the electrolyte with the concentration of the ZIF-67 nanoparticles being 0.4-0.6 g/L is obtained after uniform stirring. Unsaturated metal cobalt ions in the ZIF-67 metal organic framework have Lewis acidity and can adsorb and anchor anions in the electrolyte, and diffusion migration of the anions and cations is regulated and controlled; the porous structure of ZIF-67 is beneficial to transmission of Li ions, uniform deposition of lithium is realized, dendritic crystal growth is inhibited, and meanwhile, the shuttle effect is effectively inhibited; the high-load lithium-sulfur battery using the electrolyte has the advantages of no dendrite growth lithium symmetric battery cycle stability, high load and high initial capacity.

Description

technical field [0001] The invention relates to the field of lithium metal batteries, in particular to a method for preparing an electrolyte containing ZIF-67 nanoparticles. Background technique [0002] Lithium (Li) metal anode has a very high theoretical capacity (about 3860mAh g -1 ) has been extensively studied in recent years, matching lithium-sulfur batteries (Li-S) with sulfur cathodes due to their high energy density (approximately 2600Wh kg -1 ) has received attention. However, when a high-load lithium-sulfur battery is close to practical applications, under the condition of applying a large current, the short-circuit of the battery caused by the piercing of lithium dendrites and the capacity fading caused by the shuttle effect are important factors hindering its development. [0003] To this end, a variety of methods and strategies to inhibit the growth of lithium dendrites and the shuttling effect have emerged. Among them, electrolyte modification has great pot...

AI Technical Summary

Problems solved by technology

In lithium-sulfur batteries, the more uniform the distribution of Li ions after migrating to the surface of the Li negative electrode, the smaller the local charge and the more uniform the Li deposition. Therefore, many researchers have improved Li deposition from the perspective of directly adjusting the distribution of Li ions, but There is little research on improving Li deposition by regulating the distribution of Li ions by restricting the movement of anions.

[0004] In addition, the shuttle effect of high-load lithium-sulfur batteries is also very serious, and the problem of capacity fading is prominent. In addition to the sulfur cathode modification that has been studied more, it is also an excellent method to change the transport path of polysulfides in the solution through electrolyte additives, thereby inhibiting the shuttle. strategy

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