Lithium metal negative electrode and preparation method and application thereof

Abstract

The invention discloses a lithium metal negative electrode and a preparation method and application thereof. Pretreated lithium metal and a precursor are placed at the heating temperature of 50-200 DEG C to react for 0.5-24 h, after the precursor volatilizes at the heating temperature and reacts with the lithium metal, and a protective layer with the thickness of 1 nm-100 microns is generated on the surface of the lithium metal in situ, so the stable and effective protection can be provided for lithium metal. According to the invention, the preparation process can be quickly completed only through a thermal driving mode, and is easy to implement in industry, so that the production cost and the preparation time are greatly reduced, and the practical process of the lithium metal negative electrode battery is promoted. The prepared lithium metal negative electrode can realize uniform deposition and stripping processes, and also can effectively inhibit the generation of lithium dendrites, so that the cycling stability and the safety performance of the battery are obviously improved.

Description

technical field [0001] The invention belongs to the field of electrochemistry, and in particular relates to a lithium metal negative electrode and a preparation method and application thereof. Background technique [0002] Lithium-ion batteries are widely used in electric vehicles, smart grids, and portable electronic devices due to their advantages such as high specific energy, small self-discharge, and no memory effect. However, with the rapid development of today's energy technology, higher requirements are placed on the energy density and power density of lithium-ion batteries. Traditional lithium-ion batteries use graphite as the negative electrode material, but the theoretical specific capacity of the graphite negative electrode is low (372mAh / g), and its energy density is difficult to break through the limit value of 300Wh kg-1, which seriously limits its further development. Therefore, the development of anode materials with higher specific capacity is particularly ...

AI Technical Summary

Problems solved by technology

However, there are some problems in the use of lithium metal anodes, which seriously restrict its further development.

Including the following points: first, the solid electrolyte interfacial film (SEI) formed on the surface of lithium metal is uneven, causing uneven deposition and stripping of lithium metal; second, there is a large volume expansion of lithium metal during the deposition and stripping process, which further leads to The instability of SEI; the third is the high reactivity of lithium metal and electrolyte, which leads to the continuous consumption of lithium metal and electrolyte

[0004] In response to the above problems, researchers have proposed a variety of improvement schemes in terms of electrolyte modification and lithium metal surface modification, mainly using strong Lewis acid AlI 3 As an electrolyte additive, the reaction conditions are harsh and the process is complicated; or the strategy of using fluoroethylene carbonate (FEC) to construct an artificial SEI on the surface of lithium metal, the traditional solution immersion method makes it difficult to control the thickness and composition of SEI, and it is difficult to quickly and easily Realization, so it is very limited in terms of industrial application

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