Preparation method of solid electrolyte membrane

Abstract

The invention discloses a preparation method of a solid electrolyte membrane. The method comprises the following steps: carrying out dip coating on a polymer solution by a nonwoven fabric; then dryingand carrying out hot rolling; finally, preparing the solid electrolyte membrane with compact texture and flat surface. The solid-solid interface formed by bonding the solid electrolyte membrane withan electrode material is small and ionic conductivity is low. Besides, the nonwoven fabric plays a role of a framework in the solid electrolyte membrane, therefore, the solid electrolyte membrane hasgood mechanical property, and particularly tensile strength and toughness are greatly improved; by use of the effect, the breaking rate in the assembling process can be reduced and further the production cost is reduced. The product prepared by the preparation method disclosed by the invention is in a strip shape; centralized winding and discharging operation are facilitated in the production process; the preparation method is especially suitable for batch production and support.

Description

technical field [0001] The invention belongs to the technical field of chemical power sources. Specifically, the invention relates to a solid electrolyte membrane, especially a method for preparing the solid electrolyte membrane. Background technique [0002] If the battery is distinguished by the physical state of the built-in electrolyte, there are currently two types of liquid battery and solid-state battery. Liquid battery is a traditional product, and solid-state battery is a new technology product. Compared with liquid batteries, solid-state batteries have performance advantages such as high safety and high energy density, so the application prospects of solid-state batteries are very broad. However, the performance of solid-state batteries in the research and development stage is still not perfect, and there are three main problems to be improved from a technical perspective. The first type of problem to be improved is the large internal resistance: the built-in elec...

AI Technical Summary

Problems solved by technology

However, the performance of solid-state batteries in the research and development stage is still not perfect. From a technical perspective, there are three main problems to be improved.

The first type of problem to be improved is the large internal resistance: the built-in electrolyte and electrode materials of the lithium-ion battery system in the prior art form a solid-liquid interface, while the built-in solid electrolyte and electrode materials of a solid-state battery form a solid-solid interface, and the solid-solid interface and There is an essential difference in the type of solid-liquid interface. In practical applications, the main difference is that the internal resistance value is different. The reason is that there is no wettability between the solid-solid interface, and there must be a large contact resistance on the joint surface. Insufficient contact of the interface not only affects the diffusion efficiency and reaction speed of the components, but also forms a space charge layer phenomenon between the solid-solid interface, which is the main reason for the increase in the internal resistance of the battery

The second problem to be improved is that the ionic conductivity of the solid-state electrolyte membrane is generally low: due to the large contact resistance between the solid-solid interface, the ionic conductivity of the solid-state electrolyte membrane is generally low, thereby reducing the rate performance and delaying the charging speed of the solid-state battery

The third problem to be improved is that the preparation method is unscientific: in the prior art, the coating method is used to realize the compounding of the polymer solution and the carrier. Insufficient density, poor surface flatness and poor mechanical strength

However, the coated composite adhesive layer is not easy to embed into the porous support material, and too many micro-voids inside will naturally hinder the normal transmission of lithium ions.