Metal sulfide and preparation method and application thereof

Abstract

The invention provides a metal sulfide as well as a preparation method and application thereof. The preparation method comprises the following steps: (1) heating and preserving heat of a molybdenum-based precursor in a nitrogen atmosphere, and conducting cooling to obtain a pretreated molybdenum-based precursor; and (2) adding a sulfur source into the pretreated molybdenum-based precursor, conducting heating and preserving heat in a nitrogen atmosphere, and conducting cooling to obtain the metal sulfide. According to the preparation method of the metal sulfide, molybdenum trioxide can be reduced into low-valence molybdenum dioxide through first-time high-temperature annealing, so that subsequent vulcanization is more complete; and Mo-MOF with a smooth surface and a large number of nanoscale holes can be obtained through secondary annealing, the morphology of an MOF structure after two times of annealing is kept, the specific surface area of an original MOF material is reserved, and a large amount of spaces can be provided for embedding and removing ions when the Mo-MOF material serves as an electrode material.

Description

technical field [0001] The invention belongs to the technical field of battery materials, and in particular relates to a metal sulfide and its preparation method and application. Background technique [0002] As the most commonly used energy storage device in daily life, batteries are used in various fields. Lithium-ion batteries are used in portable electronic devices and even large workstations such as space satellites. 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 become a hot spot. 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 anode materials that have been actually used in lithium-ion batteries are basically carbon materials, and their specific capacity reaches more than 300mAh / g, which is close to that...

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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