Preparation method of bimetallic sulfide for sodium-sulfur secondary battery

Abstract

The invention discloses a preparation method of a bimetal sulfide for a sodium-sulfur secondary battery. A porous hollow structure is beneficial to storage of sulfur, and the storage rate of sulfur reaches 70% or above; besides, through the synergistic effect of double metals, Co3S4 has high adsorption performance on sodium polysulfide, more sodium polysulfide can be limited in the porous structure, Ni3S4 on the outer layer has good catalytic performance, and the kinetic performance of catalytic conversion of sodium polysulfide is greatly improved; and finally, through detection, 1000 circlesof circulation can be stably carried out, the coulombic efficiency is always 98% or above, and the rate capability is excellent. The preparation method disclosed by the invention is simple, convenient, feasible, safe and low in manufacturing cost, and the preparation of the bimetallic sulfide with the core-shell structure is realized by a relatively simple method. The sodium-sulfur battery prepared by adopting the preparation method is relatively high in specific capacity and excellent in cycling stability and rate capability.

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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