Dry preparation process of solid electrolyte

Abstract

The invention relates to a lithium battery electrolyte, and especially relates to a dry preparation process of a solid electrolyte. The dry preparation process comprises the following steps: mixing lanthanum oxide, zirconium oxide, a lithium source and a doping raw material, and uniformly grinding to obtain a mixture; presintering the mixture, and cooling to room temperature; carrying out secondary grinding on the pre-sintered mixture to obtain mother powder; tabletting the mother powder to obtain a biscuit; and carrying out secondary sintering on the biscuit to obtain the solid electrolyte. Compared with the prior art, the process has the advantages that the magnesium oxide crucible is adopted for secondary sintering, and short-time sintering is carried out at high temperature, so that the volatilization of lithium in the high-temperature process can be effectively reduced, and the formation of secondary phases such as lanthanum zirconate and the like is avoided. The LLZO prepared by the process has the characteristics of higher density, almost no grain boundary and the like, and almost no lithium oxide is enriched at the grain boundary, so that the LLZO prepared by the process has higher air stability.

Description

technical field [0001] The invention relates to a lithium battery electrolyte, in particular to a dry preparation process of a solid electrolyte. Background technique [0002] Commercial lithium-ion batteries have potential safety hazards due to the use of liquid electrolytes containing flammable organic solvents. The development of all-solid-state lithium batteries is one of the feasible technical approaches to improve battery safety. Among various solid electrolyte materials, garnet-type solid electrolytes are preferred due to their advantages of non-flammability, high safety, good chemical and electrochemical stability, lithium ion migration number close to 1, and high room temperature conductivity. attention. [0003] Since 2003, Thangadurai et al. synthesized lithium-containing garnet (hereinafter referred to as LLZO) for the first time using solid-state sintering method, and many scientific researchers began to invest in the research of LLZO. LLZO is a fast conducto...

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Problems solved by technology

However, in this method, wet ball milling is adopted, and secondary sintering is carried out by embedding powder at 950-1150°C for 15-24 hours, which easily leads to volatilization and loss of lithium.

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