Lithium-sulfur battery positive host material as well as preparation method and application thereof

Abstract

The invention provides a lithium-sulfur battery positive host material as well as a preparation method and application thereof. The lithium-sulfur battery positive electrode host material is of a core-shell structure, a core of the core-shell structure is a cobalt metal organic framework, and a shell of the core-shell structure is organic ligand doped bimetal hydroxide; the double-metal hydroxideis cobalt-nickel hydroxide and / or cobalt-zinc hydroxide. The core of the core-shell structure is not only beneficial to uniform distribution of elemental sulfur, but also high in graphitization degreeand high in conductivity; the shell of the core-shell structure provides a large adsorption surface area, and a large number of fine double hydroxides embedded into the sheet layer of the shell structure also provide a large number of polar adsorption sites, so that lithium polysulfide can be effectively adsorbed, the shuttle effect of a charge-discharge intermediate product polysulfide is inhibited, and the cycling stability of the lithium-sulfur battery is effectively improved.

Description

technical field [0001] The invention belongs to the technical field of energy materials, and in particular relates to a lithium-sulfur battery cathode host material and a preparation method and application thereof. Background technique [0002] Among many currently researched batteries, sulfur-containing cathode materials have become the most promising one among all cathode materials due to their high discharge specific capacity. Based on the high specific energy and low price of elemental sulfur, elemental sulfur has irreplaceable advantages as a cathode material for lithium-sulfur batteries compared with other cathode materials. However, the low electronic conductivity of elemental sulfur and the high solubility of polysulfide ions cause faster decay and lower utilization of active materials, prompting people to look for suitable sulfur-loading hosts to improve this problem. Hierarchical porous graphitized carbonaceous materials loaded with polar metal-based compounds are...

AI Technical Summary

Problems solved by technology

Although lithium-sulfur batteries have many advantages, there are still some problems: first, the active material sulfur and its discharge product lithium sulfide have poor conductivity; "Corrosion" to the lithium negative electrode; the third is that the volume of sulfur changes greatly during charging and discharging

However, the 3D-NiO / Co obtained by this preparation method 3 o 4 The degree of graphitization on the surface of / CNT / S composite materials is low, and the energy density is generally low, and this method often has the disadvantages of complex process, time-consuming energy consumption, and disadvantages for large-scale production.

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