A kind of metal sulfide and its preparation method and application

Abstract

The invention provides a metal sulfide and a preparation method and application thereof. The preparation method includes the following steps: (1) heating and keeping a molybdenum-based precursor in a nitrogen atmosphere, and cooling to obtain a pretreated molybdenum-based precursor; (2) pre-processing The molybdenum-based precursor is treated with a sulfur source, heated and kept in a nitrogen atmosphere, and cooled to obtain metal sulfides. In the preparation method of the metal sulfide of the present invention, the first high-temperature annealing can reduce molybdenum trioxide to low-valence molybdenum dioxide, so that the subsequent vulcanization is more complete; and the second annealing can obtain a smooth surface with a large number of nanometer Mo-MOF with high-grade pores, and the morphology of the MOF structure is maintained after two annealings, retaining the specific surface area of ​​the original MOF material, and as an electrode material, it can provide a lot of space for the insertion and removal of ions.

Description

technical field [0001] The invention belongs to the technical field of battery materials, and in particular relates to a metal sulfide and a preparation method and application thereof. Background technique [0002] As the most commonly used energy storage device in daily life, batteries are widely used in various fields. Portable electronic devices and even large workstations such as aerospace satellites have applications of lithium-ion batteries. However, with the development of the economy and the progress of the times, people have higher requirements for battery performance, especially in recent years, the research on electric vehicles has also become a hot spot, and batteries have become an alternative to traditional fossil energy to achieve large-scale use of clean energy. one of the key technologies. [0003] At present, the negative electrode materials that have been actually used in lithium-ion batteries are basically carbon materials, and their specific capacity re...

AI Technical Summary

Problems solved by technology

However, graphite electrodes also have many problems, such as graphite is sensitive to electrolyte, the first Coulombic efficiency is low, and the cycle performance is poor.

[0006] Despite the high theoretical specific capacity of oxides, the volume change limits the cycle life of such electrodes, especially since the continuous exposure of the surface to the electrolyte leads to electrolyte decomposition and the formation of a solid electrolyte interphase (SEI)

[0007] For general two-dimensional metal sulfides, the continuous aggregation of element particles when the electrode material is delithiated into salt during the charge-discharge cycle during battery operation, which eventually still leads to a rapid decline in capacity

In addition, the electrical conductivity of metal oxides is not as good as that of alloy materials and carbon materials.

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