Preparation method of composite polymer electrolyte membrane and lithium ion battery

Abstract

The invention discloses a preparation method of a composite polymer electrolyte membrane and a lithium ion battery. The preparation method of the electrolyte membrane comprises the following steps: mixing a carbonate functionalized vinyl monomer and a polyether structural monomer with a solvent under stirring in an inert gas atmosphere, then adding an initiator, reacting in the inert gas atmosphere, and drying and purifying to obtain a carbonate functionalized vinyl copolymer; adding the obtained carbonate functionalized vinyl copolymer and inorganic filler into the solvent, and mixing under stirring to obtain a uniform mixed solution; and uniformly coating the mixed solution on a mold, and performing vacuum drying and evaporation on the solvent to obtain a composite polymer electrolyte membrane. The electrolyte membrane disclosed by the invention has higher liquid retention rate, higher lithium ion conductivity, more superior mechanical property, high machining performance, higher electrochemical stability and better application prospect.

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 composite polymer electrolyte membrane of a polymer lithium ion battery and a lithium ion battery using the polymer electrolyte membrane. Background technique [0002] Lithium-ion batteries have the advantages of high power density, high energy density and no memory effect. They have been widely used in consumer electronics, medical electronics and other fields, and are gradually being used in emerging fields such as electric vehicles and energy storage. Due to the use of liquid electrolytes in lithium-ion batteries, although people have made many attempts to select and modify positive and negative electrode materials, use functional electrolytes, and reduce the internal resistance of lithium-ion batteries using liquid electrolytes, it is still difficult Avoid safety problems such as battery leakage, overheating, thermal runaway...

AI Technical Summary

Problems solved by technology

At present, the semi-solid electrolytes used in lithium-ion batteries are mainly polyether-based, polymethylmethacrylate-based, polyacrylonitrile-based and polyvinylidene fluoride-based polymers, but polymer gel electrolytes have poor mechanical strength. , Poor electrochemical stability and low liquid retention rate

[0004] In order to improve the low liquid absorption and liquid retention rate, low room temperature conductivity and poor mechanical properties of polymer gel electrolytes such as polyether series, polymethyl methacrylate series, polyacrylonitrile series and polyvinylidene fluoride series. Disadvantages, different solutions have been proposed

For example, the Chinese Invention Patent No. 201210276094.6 discloses a method for preparing a multi-component polymer gel electrolyte. The composite gel polymer electrolyte includes at least polyether, polymethyl methacrylate, and polyacrylonitrile Polyvinylidene fluoride and at least one related structural polymer have high electrical conductivity, but poor electrochemical stability and cumbersome preparation process

The Chinese invention patent application with the publication number CN106654365A discloses a multilayer composite gel electrolyte prepared from polymer materials such as polyethylene oxide, polypropylene oxide, polyarylether, polyester, etc., the polymer is introduced into different The polymer material structure can combine the advantages of various materials to a certain extent, but it still has the disadvantages of low liquid absorption rate and low electrical conductivity, which leads to poor electrochemical performance of lithium-ion batteries assembled with it.

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