Preparation method of semi-interpenetrating network polymer gel electrolyte membrane

Abstract

The invention provides a preparation method of a semi-interpenetrating network polymer gel electrolyte membrane. The method comprises the following steps: (A) adding a linear polymer and a solvent to a sample bottle, stirring and dissolving the linear polymer and the solvent, adding polyethylene glycol dimethyl acrylic ester, vinylene carbonate and a photoinitiator, and mixing the polyethylene glycol dimethyl acrylic ester, the vinylene carbonate and the photoinitiator evenly to form a solution; (B) coating a glass plate with the solution, covering a layer of glass plate to form a sandwich structure, and curing the sandwich structure to obtain an ultraviolet-cured semi-interpenetrating network polymer membrane; and (C) immersing the ultraviolet-cured semi-interpenetrating network polymer membrane into liquid electrolyte. According to the gel electrolyte provided by the invention, the balance between the ionic conductivity and the mechanical property is relatively well realized; the ionic conductivity at room temperature can be up to 1.49*10<-3>S cm<-1>; the mechanical property is good; the heat stability is good; the electrolyte can be prevented from leaking; the interface stability is good; and a lithium iron phosphate / metal lithium battery assembled by the gel polymer electrolyte membrane has excellent cycle performance and rate performance.

Description

technical field [0001] The invention relates to the field of gel polymer electrolytes, in particular to a preparation method of a semi-interpenetrating network polymer gel electrolyte membrane. Background technique [0002] Polyolefin microporous membranes are commonly used as separators in lithium secondary batteries. However, the separators used do not have good wettability and liquid retention for the electrolyte, which may easily cause electrolyte leakage, and the separators are prone to deformation at high temperatures (above 100°C) , These will bring great safety hazards and affect battery performance. [0003] Gel polymer electrolyte has the advantages of high room temperature ionic conductivity, flexible battery design, low electrolyte leakage and high safety. It is a promising electrolyte system for practical application in high energy density lithium batteries. The current main gel polymer electrolyte matrix materials include: polyethylene oxide (PEO), polymethyl ...

AI Technical Summary

Problems solved by technology

Mechanically supported by the polyolefin microporous membrane, the gel electrolyte separator has excellent mechanical properties, but the interaction between the polymer and the polyolefin microporous membrane is weak after being infiltrated and swollen by the electrolyte, and it is easy to fall off. Moreover, the above The defects of the polyolefin microporous membrane itself still exist, resulting in poor battery performance

Although the chemically cross-linked GPE disclosed by CN102324560A has good thermal stability, dimensional stability and excellent mechanical properties, the cross-linked GPE is very brittle and has poor flexibility, which is difficult to meet the actual use requirements

Although the cross-linked GPE supported by polyolefin microporous membrane exhibits sufficient mechanical properties, the polyolefin separator has low porosity, poor dimensional stability at high temperature, and low ionic conductivity.

Images