A kind of preparation method of bimetallic sulfide for sodium-sulfur secondary battery

Abstract

The invention discloses a preparation method of a bimetallic sulfide used in a sodium-sulfur secondary battery. The porous hollow structure is conducive to the storage of sulfur, so that the storage rate of sulfur can reach more than 70%; in addition, the bimetal performs a synergistic effect ,Co 3 S 4 It has strong adsorption performance for sodium polysulfide, which can limit sodium polysulfide more inside the pore structure, and the outer layer of Ni 3 S 4 It has good catalytic performance, which greatly improves the kinetic performance of sodium polysulfide catalytic conversion. Finally, it can be stably cycled for 1000 cycles through detection, the Coulombic efficiency is always above 98%, and the rate performance is excellent. The preparation method of the invention is simple and easy, safe and low in cost, and realizes the preparation of the double metal sulfide with a core-shell structure in a relatively simple method. The sodium-sulfur battery prepared by the invention has high specific capacity, excellent cycle stability and rate performance.

Description

technical field [0001] The invention belongs to the technical field of sodium-sulfur battery preparation, and in particular relates to a preparation method of a bimetallic sulfide used in a sodium-sulfur secondary battery. Background technique [0002] With the rapid development of human society, the demand for electricity is increasing day by day. The shortage of traditional fossil energy and the emission of greenhouse gases are facing severe challenges. The diversification of energy, especially the effective use of renewable energy such as solar energy, wind energy, and ocean energy , has gradually become the focus of attention. However, the instability of renewable energy restricts its large-scale development. Therefore, the development of energy storage technology is a necessary condition to effectively regulate voltage instability and promote the integration of large-scale renewable energy into conventional power grids. Due to its high specific capacitance, up to 2500W...

AI Technical Summary

Problems solved by technology

[0003] Traditional sodium-sulfur positive electrode carrier materials include carbon materials, mainly carbon dots, carbon nanotubes, graphene and other materials. The main characteristics of this type of material are excellent electrical conductivity and relatively high specific surface area. It has a certain effect, but due to the weak polarity of carbon materials, the adsorption performance of sodium polysulfide is weak, and the occurrence of the shuttle effect cannot be effectively suppressed; the other belongs to transition metal compounds, generally metal oxides, nitrogen Compounds, phosphides, sulfides, etc. These materials have strong polarity, and generally suppress the occurrence of the shuttle effect effectively through the adsorption effect of anions on sodium polysulfide. However, because their electrical conductivity is generally not very good, catalytic conversion Insufficient dynamic performance, the final effect is not ideal

Therefore, a single compound cannot effectively improve the problems of sodium-sulfur batteries.

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