Metal lithium wire and preparation method thereof

Abstract

The invention relates to a metal lithium wire and a preparation method thereof. The metal lithium wire has a one-dimensional linear structure, and the outer surface of the metal lithium wire is coatedwith a protective layer. The method takes a conductive array template as a deposition matrix, and the metal lithium wire is prepared in an organic electrolyte system through an electrochemical deposition method. The operation procedure at least comprises the following steps: 1) treating a deposition substrate; 2) performing electrochemical deposition of the metal lithium wire; 3) collecting the metal lithium wire; 4) performing high-temperature passivation treatment on the metal lithium wire. The metal lithium wire prepared by the method has a one-dimensional structure, the expansion and shrinkage of the volume of the metal lithium in the charging and discharging process can be buffered, and the surface coating protection layer can inhibit the reaction between the metal lithium and electrolyte or humid air; meanwhile, the preparation method is safe and simple, and the continuous production of preparation and coating of the metal lithium wire can be realized.

Description

technical field [0001] The invention relates to the field of chemical power sources, in particular to a metal lithium wire and a preparation method thereof. Background technique [0002] Energy and environmental issues are important issues faced by all countries in the world. Clean energy vehicles driven by electricity can reduce the demand for energy and reduce environmental problems caused by fuel vehicle emissions. Therefore, electric vehicles have gained high speed worldwide. At the same time, the gradual popularization of electric vehicles has also spawned many emerging fields, driving the development of related industries. As one of the core components of electric vehicles, the performance of power batteries directly affects the promotion and popularization of electric vehicles. The mileage anxiety caused by the low energy density of power batteries has always been a concern of users. The specific energy of the current commercial lithium-ion batteries cannot meet the ...

AI Technical Summary

Problems solved by technology

However, there are still the following problems in the metal lithium negative electrode: 1. The high reactivity of metal lithium causes the occurrence of side reactions in the process of charging and discharging reactions; 2. The generation of metal lithium dendrites causes safety problems such as battery short circuit; 3. The large metal lithium Volume changes lead to electrode and interfacial structural failure

[0004] Although researchers at home and abroad have used different modification methods to modify lithium metal anodes, there is still no effective method that can be used in practical applications.

Recently, there have been reports at home and abroad that a three-dimensional conductive framework is combined with metal lithium to improve the cycle performance of metal lithium, such as the report of a metal lithium anode with a three-dimensional carbon framework as a matrix (J.Am.Chem.Soc.,2017,139(16) ,5916), although the three-dimensional matrix can effectively improve the cycle performance of metal lithium, but the surface density of the three-dimensional matrix is ​​relatively large, which reduces the specific energy of the battery.

Lithium metal powder has a high specific surface area, which can reduce the current density on the surface of the negative electrode during battery charge and discharge, thereby improving the cycle performance of lithium metal. Currently, the main preparation method for lithium metal powder is the melt emulsion method [US20090061321], but this method requires Heating metal lithium to a molten state brings about high energy consumption and safety issues. At the same time, the particle size of metal lithium powder prepared by this method is relatively large, reaching tens of microns, and its chemical activity is low.

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