Gel electrolyte for lithium ion secondary battery and preparation method of gel electrolyte

Abstract

The invention discloses a gel electrolyte for a lithium ion secondary battery. The gel electrolyte comprises the following components by mass percent: 70%-90% of an electrolyte substrate (A), 0.1-25% of polymerizable monomers (B,C), 0.1-10% of an initiator (D), and 0.1-15% of a foamer (E), wherein the polymerizable monomers (B,C) comprise a first polymerizable monomer (B) and a second polymerizable monomer (C), and the first polymerizable monomer (B) can be dissolved in the electrolyte substrate (A) but the homopolymer of the first polymerizable monomer (B) can not be dissolved in the electrolyte substrate (A), and the second polymerizable monomer (C) and the homopolymer thereof can be dissolved in the electrolyte substrate (A); the foamer (E) has the chemical formula as shown in the description, wherein X is one of metallic ions including Mn, Mg, Al and the like or ammonium salt materials, and Y is one of alkyl compounds with H atoms and 1-10 carbon atoms or aryl compounds. According to the invention, the chemical safety performance is good, electrical property is superior, and the cycle performance and the rate performance of the battery is preferable, the service life of the battery is prolonged greatly.

Description

technical field [0001] The invention relates to the technical field of lithium-ion secondary batteries, in particular to a lithium-ion secondary battery gel electrolyte and a preparation method thereof. Background technique [0002] Lithium-ion batteries have been widely used as power sources for various mobile devices since their commercialization due to their many advantages such as high operating voltage, high energy density, no memory effect, long cycle life, and no pollution. [0003] Lithium-ion batteries are composed of positive electrodes, negative electrodes, separators, electrolytes, and other auxiliary materials. The electrolyte conducts lithium ions between the positive and negative electrodes of the battery, which has an important impact on the performance of the battery. Electrolyte can be divided into liquid electrolyte and gel electrolyte. The liquid electrolyte is generally composed of high-purity organic solvents, electrolyte lithium salts and additives i...

AI Technical Summary

Problems solved by technology

[0004] Conventional gel electrolyte is as described in CN03158361.X "Lithium-ion battery gel electrolyte and preparation method of the electrolyte" (authorized publication number CN1301565) authorized and disclosed in Chinese patent literature on February 21, 2007. Polymerizable monomers whose polymers are insoluble in liquid electrolyte often require a higher monomer concentration, and after polymerization, due to the closed interface of the electrolyte, ion conduction is difficult, and the interface activity is poor, often resulting in poor electrochemical performance of lithium ions, A series of problems such as low conductivity and easy lithium analysis have seriously affected the application and promotion of gel electrolytes, and currently these technologies are only mastered by a few Japanese battery companies

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