K-beta ''-Al2O3 solid electrolyte, preparation method thereof and potassium battery

Abstract

The invention provides a preparation method of a K-beta ''-Al2O3 solid electrolyte, which comprises the following steps: according to a target product K1 + 2xAl < 11-x > Li < x > O < 17 >, xlt; 0.5 part; or according to the target product K1 + yAl < 11-y > MgyO17, wherein 0 lt; yt; Yt; the method comprises the following steps: weighing potassium salt, aluminum salt and lithium salt according to a corresponding stoichiometric ratio, and dissolving excessive potassium salt in a solvent; adding a dispersing agent into the solution, uniformly mixing to obtain an emulsion, and evaporating a volatile solvent to obtain uniformly mixed powder; carrying out primary heat treatment on the uniformly mixed powder to obtain K-beta ''-Al2O3 solid electrolyte powder; carrying out ball milling, drying, granulation and cold press molding on the powder and a sintering aid to obtain an unsintered blank; and carrying out final heat treatment on the blank to obtain the K-beta ''-Al2O3 solid electrolyte ceramic block. The prepared K-beta ''-Al2O3 solid electrolyte is compact in microstructure, high in beta'' phase content, high in ionic conductivity and suitable for a solid potassium battery system; the raw materials are easily available, the cost is low, the preparation process is pollution-free, the requirement on production equipment is not high, and the method is suitable for large-scale production.

Description

technical field [0001] The invention belongs to the application field of secondary batteries, in particular to a K-β″-Al 2 o 3 Solid electrolyte, its preparation method and potassium battery. Background technique [0002] In order to realize the ambitious goals of "carbon peak" and "carbon neutrality" as soon as possible, it is the general trend to promote the transformation of energy structure from fossil energy dominance to renewable energy dominance. However, the intermittent and unstable characteristics of renewable energy urgently require large-scale energy storage equipment to achieve "shaving peaks and filling valleys". Lithium-ion batteries, which are widely used in 3C products and new energy vehicles, are not suitable for large-scale energy storage due to the scarcity and high price of the main elements Li and Co. Potassium-ion batteries have gradually entered people's field of vision due to their abundant reserves of main elements, low price and considerable ene...

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Problems solved by technology

So far, its similar K-β″-Al 2 o 3 Solid-state electrolytes have not been extensively studied, regarding K-β″-Al 2 o 3 The reports of solid electrolytes are only based on the synthesis of precursor powders, and most of them do not involve K-β″-Al 2 o 3 Sintering Preparation of Solid Electrolyte Ceramic Blocks

In addition, in K-β″-Al 2 o 3 During the high temperature sintering process, K 2 Severe loss of O, resulting in K-β″-Al 2 o 3 The content of β″ phase in the solid electrolyte ceramic block is reduced, and more β phase is generated, which will adversely affect its ionic conductivity

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