Method for removing impurities on surface of lithium-lanthanum-zirconium-oxygen electrolyte of solid-state lithium battery

Abstract

The invention relates to the field of oxide solid electrolytes, in particular to a method for removing impurities on the surface of a lithium-lanthanum-zirconium-oxygen electrolyte of a solid-state lithium battery. The method comprises the following steps of: transferring a lithium-lanthanum-zirconium-oxygen sheet containing impurities into an analysis chamber of an X-ray photoelectron spectrometer, and gradually heating in a vacuum environment to remove the impurities on the surface of the lithium-lanthanum-zirconium-oxygen sheet; carrying out in-situ XPS testing on the surface of the lithium-lanthanum-zirconium-oxide sheet in the step-by-step heating process; after impurities on the surface of the lithium-lanthanum-zirconium-oxide sheet are removed, cooling the in-situ heating sample table to the room temperature and then transferring the in-situ heating sample table into a glove box connected with the X-ray photoelectron spectrometer, and taking down the lithium-lanthanum-zirconium-oxide sheet from the in-situ heating sample table to obtain the pure lithium-lanthanum-zirconium-oxide sheet. According to the method, vacuum annealing and in-situ XPS testing are used, removal of the impurity layer on the surface of the lithium-lanthanum-zirconium-oxide sheet is combined with surface component monitoring, and high-precision removal of impurities on the surface of the lithium-lanthanum-zirconium-oxide sheet is achieved.

Description

technical field [0001] The invention belongs to the field of oxide solid electrolytes, and in particular relates to a method for removing impurities on the surface of a lithium-lanthanum-zirconium-oxygen electrolyte for a solid-state lithium battery. Background technique [0002] Solid-state lithium batteries have attracted much attention due to their high safety, high energy density and other advantages. There are many kinds of solid electrolytes used in them, among which the garnet-type solid electrolyte lithium lanthanum zirconium oxide Li 7 La 3 Zr 2 o 12 (LLZO) has attracted much attention due to its high ionic conductivity and stability towards lithium anodes. [1,2] . But the solid electrolyte is unstable in the air, firstly with H 2 O reacts to generate LiOH, which is further combined with CO 2 The reaction produces Li 2 CO 3 [3] . The reaction process is rapid and unavoidable, and the reaction layer is mainly located on the surface of the sample. In additio...

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Problems solved by technology

However, these methods still have limitations: since the annealing process is carried out in air, the lithium lanthanum zirconium oxygen samples treated by this method still inevitably generate Li 2 CO 3 , and the organic adsorption layer cannot be removed [6,7] ;Physical methods such as polishing may destroy the properties of the sample, and it is difficult to achieve a good removal effect [3] ;Chemical methods such as pickling introduce additional ingredients [8]

At present, there is no relevant method that can completely remove the surface impurities of lithium lanthanum zirconium oxide without causing additional effects, which restricts the research and further utilization of the intrinsic properties of lithium lanthanum zirconium oxide

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