Solid electrolyte material with low interface impedance and preparation method of solid electrolyte material

Abstract

The invention discloses a solid electrolyte material with low interface impedance and a preparation method of the solid electrolyte material. The material comprises a major structure with a chemical formula Li1+x+yAlx(Ti,Ge)2-xSiyP3-yO12, and lithium iodide dispersed in the major structure, wherein the major structure of the material is an NASICON fast ion conductor; x is greater than 0 and less than or equal to 0.4; y is greater than 0 and less than or equal to 0.1; and the mass percentage a of lithium iodide in the material is greater than 0 and less than or equal to 10%. The preparation method of the material comprises the following steps of (1) synthesizing the major structure: selecting raw materials according to a stoichiometric equation of the solid electrolyte material and performing planet ball milling, cold pressing and a solid-phase reaction to obtain the major structure of the dense flaky solid electrolyte material, and (2) performing modification treatment: soaking a sample obtained in Step (1) in a lithium iodide aqueous solution, performing heating for some time, taking the sample out, cleaning the sample and performing vacuum drying treatment. According to the solid electrolyte material and the preparation method, a lithium iodide material with lithium ion conduction property is added to a solid electrolyte layer, so that the interface impedance is reduced, a three-dimensional ion conduction network is formed, and the ion conductivity is improved.

Description

technical field [0001] The invention relates to a solid electrolyte material with low interface impedance and a preparation method thereof, and belongs to the field of preparation of lithium ion conductive solid electrolytes. Background technique [0002] At present, the electrolyte used in lithium-ion batteries is usually a flammable liquid organic electrolyte, which brings about safety issues that need to be solved urgently for the large-scale application of lithium-ion batteries. The commonly used polymer electrolytes can alleviate the safety problems of lithium-ion batteries to a certain extent, but their low lithium-ion transport performance and low-temperature performance make it difficult to completely replace liquid electrolytes. All-solid-state lithium-ion batteries made of inorganic solid-state electrolyte materials can completely avoid battery safety problems caused by electrolyte leakage and battery abuse. Therefore, research on all-solid-state lithium-ion batter...

AI Technical Summary

Problems solved by technology

Using LiI as the post-treatment material of the NASICON electrolyte material can reduce the interfacial impedance of the electrolyte material while participating in the transport of lithium ions. In theory, it can have a better modification effect on the electrolyte material than LiCl. It is easily oxidized to form iodine in the air, and the interfacial impedance of LiI on NASICON electrolytes has not received much attention from researchers.

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