Negative electrode of lithium metal battery, preparation method of negative electrode, lithium metal battery and electric equipment

Abstract

The invention provides a lithium metal battery negative electrode and a preparation method thereof, a lithium metal battery and electric equipment. The lithium metal battery negative electrode is made of an aluminum-lithium alloy, and the mass of aluminum in the aluminum-lithium alloy accounts for 0.15%-5% of the total mass of the aluminum-lithium alloy. The preparation method of the lithium metal battery negative electrode comprises the following steps: carrying out extrusion molding on the aluminum-lithium alloy to obtain an aluminum-lithium alloy strip, and carrying out post-treatment to obtain the lithium metal battery negative electrode. The lithium metal battery comprises the negative electrode of the lithium metal battery. The electric equipment comprises the lithium metal battery. According to the lithium metal battery negative electrode provided by the invention, the content of the aluminum metal in the aluminum-lithium alloy is increased, so that the aluminum metal wraps the lithium metal in a three-dimensional net shape, the three-dimensional net-shaped aluminum metal can play a conductive role and can also be linked with fragmented lithium metal, and the phenomenon that a lithium strip is fractured at the end of battery discharge is prevented.

Description

technical field [0001] The present application relates to the field of lithium metal batteries, in particular to a lithium metal battery negative electrode and a preparation method thereof, a lithium metal battery and electrical equipment. Background technique [0002] Lithium metal battery is a high-energy chemical primary battery, commonly known as lithium primary battery. Metal lithium is used as the negative electrode, solid salts or salts dissolved in organic solvents are used as the electrolyte, and metal oxides or other solid and liquid oxidants are used as the positive active material. Lithium primary battery is a general term for this type of chemical power supply series using metallic lithium as the negative electrode material. Lithium metal battery is a new type of high-energy lithium battery, which has the characteristics of light weight, high energy, low temperature resistance, strong high current discharge capacity, extremely low annual self-discharge rate, lo...

AI Technical Summary

Problems solved by technology

[0003] At present, the common problem in the industry is: when using the battery made of winding structure (rate type), the negative electrode is made of extruded thin sheet of lithium metal, but since the lithium metal discharges with the battery, the positive and negative electrodes participate in the reaction , lithium metal loses electrons and converts to lithium ions to produce corresponding compounds through the separator and the positive electrode material, so the lithium metal in the negative electrode gradually decreases; and due to the production process of lithium strips, the closing process, the battery welding tab glue process, the battery winding process, etc. It will cause slight deformation of the lithium sheet; at the same time, the surface of the positive electrode is not smooth, which leads to uneven reaction on the contact surface of the positive and negative electrodes of the battery. The phenomenon of battery energy density reduction

[0004] In the prior art, the following methods are usually used to solve this problem: 1. By inhibiting the surface of the positive electrode or the surface of the negative electrode or the surface of the separator, that is, preventing or weakening the chemical reaction in some areas of the positive and negative electrodes, so that part of the lithium negative electrode remains more, thereby playing a role The role of current collection and conduction; the disadvantages of this method: 1.1. By inhibiting the chemical reaction in some areas of the positive and negative electrodes, the usual method is to brush the pole piece to inhibit the glue, or to pull the glued paper on the surface of the pole piece to isolate some area reactions; the added inhibition Objects will occupy the volume and weight, so the energy density of the battery will be reduced

Disadvantages of this method: 2.1. At present, there are composite current collectors on the market, such as the copper-based lithium strip produced by Tianjin Zhongneng. The disadvantages are: the reaction on both sides of the copper-based lithium strip is uneven, and the battery system with a large expansion coefficient Under the statistics, the copper current collector is easy to break; and the cost is very high

2.2. The composite steel mesh current collector lithium belt represented by Japan's Panasonic has the main disadvantages: the composite steel mesh needs to be light and thin to resist stretching, and the composite negative electrode is not easy to cut and manufacture, and the final price is very expensive

[0005] How to simply and effectively solve the problem that "at the end of the discharge, the negative electrode of the lithium sheet is prone to breakage, causing part of the lithium metal to not fully participate in the reaction, resulting in a decrease in the energy density of the battery" has become a research hotspot.

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