Polymer electrolyte for lithium-ion cell and preparation method

Abstract

The invention refers to a polymer electrolyte used in lithium cell as well as the making method, including polymer base material (A) and (B) and liquid electrolyte solution (C) which contains a lithium salt and proton inert solvent. A is poly(methyl methacrylate-acylic nitrile-methacrylate lithium) (P(MMA-AN-MALi), PMAML, the molar composition of the components: 40%<AN<90%, 10%<MMAM<40%, and 0%<MALi<20%. B is the polyvinylidene (PVDF) or the poly (polyvinylidene-hexafluoro propylene), P(VDF-HFP). Its film can be one-step obtained by volatilizing agent, the conductivity at room temperature high (3.2X10 to the power -3 S.cm-1).

Description

technical field [0001] The invention relates to an electrolyte for a lithium ion battery and a preparation method thereof, more particularly to a polymer electrolyte for a lithium ion battery and a preparation method thereof. Background technique [0002] Polymer lithium-ion batteries have the characteristics of high energy density, no electrolyte leakage, good safety performance, flexible design, and easy mass production. With the continuous miniaturization of electronic devices, secondary batteries should also develop in the direction of light weight and ultra-thin. Lithium-ion batteries with polymer materials as electrolytes can meet this requirement. [0003] Among the existing polymer electrolytes, the conductivity of pure solid polymer electrolytes (without plasticizer) at room temperature is too low to meet the requirements of practical production. Although many methods have been reported attempting to prepare solid polymer electrolytes with...

AI Technical Summary

Problems solved by technology

At present, the main problem of polymer electrolytes is the contradiction between mechanical properties and electrical conductivity.

In order to improve the room temperature conductivity of the gel polymer electrolyte, a large amount of organic plasticizer needs to be cured in the polymer matrix, which will greatly reduce its mechanical strength.

Second, the interface stability between the electrolyte and the electrode is poor

As the number of charge-discharge cycles or storage time increases, the interface impedance between the polymer electrolyte and the electrode will also increase, which will affect the charge-discharge performance of the battery.

Third, the preparation process is complex

Whether it is the method of extracting pore-forming agents or the phase inversion method, there are many inconveniences in large-scale production, and the production process is complicated.

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