Preparation method of lithium cathode of solid-state battery

Abstract

The invention relates to a preparation method of a lithium cathode of a solid-state battery. The preparation method comprises the following steps of (1) mixing lithium salt, an organic solvent, and anelectrolyte additive to prepare an electrolyte, wherein the molar concentration of the lithium salt in the organic solvent is 1mol/L, and the mass concentration of the electrolyte additive is 1.0%; putting the metal lithium into the electrolyte to perform electrochemical pre-circulation, and forming a protective film at the surface of a cathode of the metal lithium; (2) cleaning the cathode of the metal lithium with the electrolyte solvent after circulating in step (1) in a glove box, and volatilizing the solvent, so as to obtain the lithium cathode. Compared with the prior art, the preparation method has the advantages that the preparation method is simple, the operation is easy, and the regulating and controlling are easy; the solid-state battery assembled by the lithium cathode can well avoid the poor reaction between the lithium cathode and the solid-state electrolyte interface, and can obtain excellent cycling property, lower impedance, and good electrochemical property.

Description

technical field [0001] The invention belongs to the technical field of solid-state batteries, and in particular relates to a method for preparing a lithium negative electrode of a solid-state battery. Background technique [0002] In recent years, with the rapid development of electric vehicles and high-end portable electronic devices, the demand for high energy density batteries has become more and more urgent. Metal lithium up to 3860mAhg -1 The ultra-high specific capacity and the lowest electrochemical potential (-3.04V relative to the standard hydrogen electrode) make it the ultimate negative electrode for high energy density lithium batteries. In addition, at this stage, lithium metal batteries represented by lithium-sulfur batteries and lithium-air batteries are considered to be the most promising next-generation energy storage systems. However, metal lithium will generate lithium dendrites during cycling, thus reducing the cycle Coulombic efficiency and lifetime of...

AI Technical Summary

Problems solved by technology

Although these methods provide a method for improving the stability of the lithium anode / solid electrolyte interface, the use of complex thin film preparation systems and high costs limit the practical application of these methods, and some even need to be processed at high temperatures, which is harmful to the interface. + The transfer characteristics adversely affect the

In addition, the protective layer prepared by these methods has a single composition and structure, which cannot fully meet the requirements of high ionic conductivity, low electrical conductivity, and good mechanical properties for the protective layer in solid-state batteries.

Xu's team introduced a PEO-based composite solid electrolyte at the interface of the lithium anode and the solid electrolyte through a coating method. Although the interfacial compatibility was improved, the low lithium ion conductivity of the composite solid electrolyte at room temperature limited the improvement of the rate performance of the solid-state battery ( J.Mater.Chem.A, 2017, 5, 16984)

[0005] In summary, the existing methods to solve the interface compatibility problem of solid electrolyte / lithium anode still have problems such as complex process steps, high cost, and poor interface performance. Therefore, it is necessary to study a simple and feasible method to solve the problem of solid electrolyte / Lithium anode interfacial compatibility issue, which has great significance for the long-term cycle stability of lithium metal solid-state batteries

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