A kind of preparation device and method of metal lithium alloy negative electrode

Abstract

The invention discloses a preparation device and method for a metal lithium composite negative electrode. The device includes a heating container, a roll machine and a nitrogen reaction container. A graphite electrode is arranged inside the heating container, and the graphite electrode and the heating container are respectively passed through wires. An external power supply is connected; the heating container is connected with the roll machine through a pipeline, and the nitrogen reaction container is arranged at the end of the roll machine. The cycle performance of the composite metal lithium alloy negative electrode material prepared by the preparation device and method provided by the present invention has been significantly improved, and at the same time, the formation of lithium dendrites has been suppressed, and the safety of the battery has been greatly improved.

Description

technical field [0001] The invention relates to the technical field of lithium metal batteries, in particular to a preparation device and method for a lithium metal alloy negative electrode. Background technique [0002] With the continuous development of science and technology, the demand for high energy density power supply is getting higher and higher. At present, batteries that can theoretically provide high energy density include lithium-air batteries, lithium-sulfur batteries and lithium metal batteries, which are considered to be the most promising next-generation batteries. A generation of high specific energy batteries. Lithium metal anode is considered to be the most potential anode material because of its extremely high theoretical specific capacity (3860mAh·g-1) and extremely negative potential (-3.040Vvs standard hydrogen electrode). However, there are still many problems in the large-scale application of metal lithium anodes: 1. During the charging and dischar...

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Problems solved by technology

However, there are still many problems in the large-scale application of metal lithium anodes: 1. During the charging and discharging process, because of the high activity of metal lithium anodes and the uneven deposition of lithium ions, lithium dendrites are easily grown on the surface, which stimulates The short circuit caused by the penetration of the separator will cause thermal runaway, which will cause serious safety accidents. At the same time, the "dead lithium" formed after dendrite fracture will reduce the Coulombic efficiency. Instability of the structure leads to pulverization of the material, which shortens the service life of the battery

[0005] At present, there are two preparation techniques for composite metal lithium alloy negative electrodes: 1. It is carried out by melting, ingot casting, cooling and rolling, which has the disadvantages of complicated production process and high energy consumption. There is element segregation, which makes the distribution of elements inside the material uneven. When used as a metal lithium battery negative electrode, it will lead to uneven deposition of metal lithium on the surface and inside, resulting in the formation of lithium dendrites, resulting in internal short circuits, thermal runaway, and safety issues.

Although the activity of metal lithium alloy negative electrode is lower than that of pure metal lithium, it will still have side reactions with the electrolyte during charging and discharging, generating "dead lithium", resulting in the loss of lithium, reducing the Coulombic efficiency of the battery, and destroying the battery. 2. Prepare lithium alloys by magnetron sputtering, atomic layer deposition and other methods. These methods have high requirements for equipment and processes and are not suitable for large-scale industrial applications

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