Lithium sheet with double-phase surface protection layer, and production method and application thereof

Abstract

The invention discloses a lithium sheet with a double-phase surface protection layer, and a production method and an application thereof. The production process of the lithium sheet with the double-phase surface protection layer comprises the following steps: (1) dissolving a metal halide in an organic solvent to obtain a solution with the concentration of 10 mM-50 mM, dropwise adding the solutionto the surface of the lithium sheet covered with a glass fiber diaphragm, and standing for 20 min-40 min; (2) removing the glass fiber diaphragm, and sequentially washing the lithium sheet with an organic solvent; and (3) drying the cleaned lithium sheet at a room temperature to obtain the lithium sheet. When the lithium sheet is applied to a symmetric battery, the lithium sheet has a very good inhibition effect on the growth of lithium metal dendrites; and when the lithium sheet is applied to a lithium-sulfur battery, the double-phase surface protection layer reacts with polysulfide to generate a metal sulfur bond, electron-rich polysulfide is repelled while the reaction of polysulfide and lithium gold is blocked, and the lithium sheet has a very good inhibition effect on the growth of dendrites.

Description

technical field [0001] The invention belongs to the technical field of lithium metal batteries, in particular to a lithium sheet with a dual-phase surface protection layer, its preparation method and application. Background technique [0002] With the development and utilization of fossil energy to a large extent, environmental pollution is intensifying, so the development of new energy has become the focus of current research. However, the energy density of lithium-ion batteries with traditional graphite negative electrodes is close to the theoretical value, and lithium metal is used instead of traditional graphite negative electrodes, S or O 2 High specific energy lithium-sulfur and lithium-oxygen secondary metal batteries that replace traditional cathodes have become a hot research topic today. However, during the charging and discharging process of the battery, side reaction factors such as soluble polysulfides will continuously react with the metal lithium negative ele...

AI Technical Summary

Problems solved by technology

However, during the charging and discharging process of the battery, side reaction factors such as soluble polysulfides will continuously react with the metal lithium negative electrode, resulting in the continuous consumption of active materials (lithium, sulfur), and the unstable solid electrolyte interface film will cause lithium dendrites. Crystal growth and other characteristics hinder the commercialization of lithium-sulfur batteries with high energy density

[0003] In view of the above-mentioned problems existing in metal lithium anodes and lithium-sulfur batteries, the main strategies currently adopted are as follows: In terms of lithium anodes, 1) solid / quasi-solid electrolytes inhibit the growth of dendrites, and solid / quasi-solid electrolytes can be used in a certain To a certain extent, the growth of dendrites can be inhibited or slowed down, but it cannot be inhibited at all, and it brings serious interface impedance problems; 2) The use of 3D current collector framework can greatly reduce the growth of dendrites and the volume change of lithium metal , but the introduction of the 3D framework will greatly increase the mass of the anode, which will greatly reduce the energy density of the battery; 3) Electrolyte optimization or additives to regulate lithium ion deposition, by optimizing the electrolyte composition / or using electrolyte additives and other strategies to improve delithiation / Although lithium intercalation ability is beneficial to improve battery stability to a certain extent, the appropriate electrolyte formula and additives are blank points in current research, and more time is needed to discuss and optimize; 4) interface engineering stabilizes lithium metal anodes, through chemical methods Or physical methods to build a stable interface protective layer on the surface of lithium metal, to achieve high lithium affinity, uniform lithium ion flow, inhibit the growth of dendrites and improve Coulombic efficiency, although this method is highly targeted, simple to operate, and has high The application value, but has not yet found a suitable technical solution that is effective and can be applied on a large scale

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