Lithium-lanthanum-zirconium-oxygen-based solid electrolyte and preparation method and application thereof

Abstract

The invention discloses a lithium lanthanum zirconium oxygen-based solid electrolyte and a preparation method and application thereof, and the preparation method comprises the following steps: adding a lithium source, a lanthanum source and a zirconium source into water, and mixing to obtain a first mixed solution; or, adding the lithium source, the lanthanum source, the zirconium source and the doped metal source into water, and mixing to obtain a first mixed solution; adding a dispersing agent and carbon quantum dots into the first mixed solution, and stirring to obtain a second mixed solution; mixing the second mixed solution with a precipitant, carrying out coprecipitation, and drying to obtain a coprecipitation precursor; and sintering the coprecipitation precursor to obtain the lithium lanthanum zirconium oxygen-based solid electrolyte. The porous sheet-shaped two-dimensional lithium lanthanum zirconium oxygen-based solid electrolyte is prepared by taking carbon quantum dots as nucleation sites and a morphology regulator and adopting a one-step lithium mixing method. According to the preparation method provided by the invention, the lamellar morphology advantage of the lithium-lanthanum-zirconium-oxygen-based solid electrolyte is maintained, meanwhile, a relatively large specific surface area is obtained, and the conductivity of the composite solid electrolyte is effectively improved.

Description

technical field [0001] The invention relates to the field of solid-state lithium batteries, in particular to a lithium lanthanum zirconium oxide solid electrolyte and a preparation method and application thereof. Background technique [0002] Lithium lanthanum zirconium oxide (LLZO) solid electrolyte powders are often used as fillers and polymer electrolytes to prepare composite solid electrolytes (CSEs) materials with good electrochemical and mechanical properties. Common powder preparation methods include solid-phase ball milling, liquid-phase sol-gel method, and co-precipitation method. Among them, the liquid-phase method can achieve element blending at the ionic level, so the activity of the obtained precursor is often higher, and sintering The required temperature is lower, and the obtained particle size is also smaller, but the lithium lanthanum zirconium oxide electrolyte particles prepared by the above methods tend to exhibit spherical morphology (zero dimension). I...

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Problems solved by technology

[0004] In view of the above-mentioned deficiencies in the prior art, the object of the present invention is to provide a lithium lanthanum zirconium-based solid electrolyte and its preparation method and application, aiming at solving the existing problems in the synthesis of two-dimensional fillers with sheet-like morphology for composite solid electrolytes. The methods and researches are relatively scarce, and most of the flakes synthesized by the existing methods have dense and smooth surfaces, the specific surface area is relatively small, and the effect of improving the ion conductivity is not obvious.

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