Method for preparing flexible three-dimensional solid electrolyte membrane

Abstract

The invention belongs to the technical field of lithium ion batteries and relates to a method for preparing a flexible three-dimensional solid electrolyte membrane. The method comprises the followingsteps: adding nano fibers into a solvent to prepare nano fiber suspension; adding lithium-ion conductive ceramic particles into the nano fiber suspension, stirring at high speed, and performing freezedrying so as to obtain a ceramic particle / nano fiber three-dimensional porous composite scaffold; adding lithium salt into an acetonitrile solution of polyethylene oxide, and stirring at high speed so as to obtain a lithium salt-polyethylene oxide mixed solution; soaking the ceramic particle / nano fiber three-dimensional porous composite scaffold into the lithium salt-polyethylene oxide mixed solution, drying and performing hot-pressing treatment, thereby obtaining the flexible three-dimensional solid electrolyte membrane. According to the method disclosed by the invention, the lithium-ion conductive ceramic particles are uniformly attached onto the nano fibers to form the three-dimensional porous scaffold, so that the transmission path of lithium ions in a polymer matrix is lengthened, and the solid composite electrolyte membrane has high ionic conductivity, excellent electrochemical stability and flexibility at room temperature.

Description

technical field [0001] The invention belongs to the technical field of lithium ion batteries, and in particular relates to a preparation method of a flexible three-dimensional solid electrolyte diaphragm. Background technique [0002] With the development of flexible electronic devices, flexible energy storage systems have been developed towards high capacity, high safety and long life. All-solid-state lithium-ion batteries have high safety performance and become a research hotspot. Compared with traditional liquid electrolyte lithium-ion batteries, all-solid-state lithium-ion batteries have obvious advantages: 1) higher specific energy and energy density (>300 Wh / kg); 2) wider temperature range; 3) self- Small discharge rate; 4) Good safety performance, no hidden danger of electrolyte leakage; 4) No side reactions occur during the cycle, with longer cycle life; 5) Electrochemical window > 5 V, which can match high-voltage cathode materials ; 6) The electrolyte has h...

AI Technical Summary

Problems solved by technology

However, nanofillers are easy to aggregate and agglomerate in the polymer matrix, making the ion-conducting particles form island distribution in the polymer matrix, which cannot effectively improve the ionic conductivity of the polymer electrolyte.

The use of nano-conductive fillers with a fibrous structure can improve the above problems, but the brittle nature of the inorganic material itself makes the polymer electrolyte not have good flexibility.

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