Lithium ion battery gel polymer electrolyte and preparation method thereof

Abstract

The invention provides a lithium ion battery gel polymer electrolyte and a preparation method thereof. The lithium ion battery electrolyte is composed of a macromolecular polymer, an ionic liquid, an organic solvent, a lithium salt and a film-forming additive. Through preparation of the gel polymer electrolyte, the disadvantages of leakage, easy corrosion of electrode materials and the like can be eliminated. The high temperature performance of the electrolyte can be improved by using an ionic liquid. By adding the organic solvent, the viscosity of the ionic liquid is reduced and the conductivity is enhanced. And by adding the film-forming additive, the problem of poor compatibility between the ionic liquid and graphite or a lithium electrode material can be solved. Experiments prove that the lithium ion battery gel polymer electrolyte provided by the invention is an elastic self-supporting electrolyte membrane, which has ionic conductivity up to the 10<-3>S/cm magnitude order, good high temperature stability and safety, and has good compatibility with a lithium cathode or a graphite cathode material. Lithium ions can undergo effective lithium insertion and removal circulation, and can achieve high capacity when applied to lithium ion battery charge-discharge cycle.

Description

technical field [0001] The invention belongs to the field of preparation of polymer electrolytes for lithium ion batteries, and in particular relates to a gel polymer electrolyte for lithium ion batteries and a preparation method thereof. Background technique [0002] Due to the advantages of high power density, low self-discharge rate, no memory effect and stable discharge voltage, lithium-ion batteries have gradually replaced traditional lead-acid batteries and nickel-cadmium batteries and become the main choice of power batteries. [0003] At present, the operating temperature range of lithium-ion batteries is -20°C to 60°C, and the high-power output performance of power batteries poses a major challenge to the maximum operating temperature and working safety of lithium-ion batteries. The use of a safe electrolyte system is the most direct way to solve the safety problem of lithium-ion batteries. Therefore, it is a new requirement for power lithium batteries to research ...

AI Technical Summary

Problems solved by technology

[0007] The technical purpose of the present invention is to provide a gel polymer electrolyte for lithium-ion batteries in view of the shortcomings of the above-mentioned gel polymer electrolyte. The lithium-ion battery using this electrolyte not only has good electrical conductivity, but also greatly improves its high-temperature safety. At the same time, it also solves the problem that lithium ions in ionic liquids cannot perform effective intercalation and delithiation cycles.

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