Composite gel solid electrolyte, preparation method and all-solid-state lithium ion battery

Abstract

The invention relates to a composite gel solid electrolyte for a lithium ion battery and a preparation method thereof. The composite gel solid electrolyte for the lithium ion battery is prepared by compounding a lithium bis (trifluoromethylsulfonyl) imide composite polyimide gel precursor and a lithium-based gel precursor, wherein the lithium bis (trifluoromethanesulfonyl) imide composite polyimide gel precursor is prepared from the following components: 2, 2 '-dimethyl benzidine, 3, 3', 4, 4 '-biphenyl tetracarboxylic dianhydride, N-methyl-2 pyrrolidone, 3-aminopropyltrihexyloxysilane, lithium bis (trifluoromethanesulfonyl) imide and acetic anhydride; the lithium-based gel precursor is prepared from the following components: lithium perchlorate, glycerol, deionized water, polyacrylic acidand formamide. According to the composite gel solid electrolyte for the lithium ion battery, the longitudinal thermal shrinkage and the transverse thermal shrinkage can be reduced while the mechanical property and the puncture strength are maintained; the initial shrinkage temperature, the deformation temperature and the rupture temperature are effectively increased; meanwhile, the ionic conductivity and the lithium ion transference number are improved.

Description

technical field [0001] The invention belongs to the field of lithium batteries, and in particular relates to a composite gel solid electrolyte for lithium ion batteries, a preparation method and a corresponding all-solid lithium ion battery. Background technique [0002] With the continuous consumption of traditional energy and increasingly prominent environmental problems, the importance of renewable energy acquisition and application is self-evident. Energy storage technology is the key to the effective application of renewable energy. Especially in recent years, mobile communication, new energy rail transit and aerospace technology have developed rapidly. The application side has put forward higher and higher requirements for energy storage products and technologies. Energy density, light weight, fast charging and discharging, long life, environmental friendliness and safety performance are the core evaluation indicators. [0003] In recent years, lithium-ion batteries h...

AI Technical Summary

Problems solved by technology

Organic polymer solid electrolytes are easy to shape and have high processability, but they mainly have the following disadvantages: 1) The interface compatibility between organic polymer solid electrolytes and electrodes is poor, and the interface resistance is large; 2) Organic polymer solid electrolytes are easy to crystallize , the applicable temperature range is narrow; 3) The mechanical properties of the organic polymer solid electrolyte are not ideal; the above deficiencies will lead to a change in the morphology of the organic polymer electrolyte due to local temperature rise and interface chemical reactions during actual use, resulting in open circuit; At the same time, its mechanical properties are further reduced at high temperature, causing a short circuit inside the battery.

Inorganic solid electrolytes are suitable for high temperature and corrosive application environments, and have higher capacity storage performance, but they mainly have the following shortcomings: 1) high rigidity, which is not conducive to molding, especially micro molding; 2) complex manufacturing process and high cost ; 3) The thermodynamic stability is not high, it is easy to react with metal lithium, and it is easy to cause oxidation of high-voltage cathode materials; 4) The volume is affected by temperature changes, causing poor contact between the electrolyte and the metal electrode, and there is a high interface impedance

[0005] In order to improve the deficiencies of existing materials, researchers in the field began to study the application of organic composite materials, inorganic composite materials or organic-inorganic composite materials in the field of solid electrolytes. The research on new materials and composite materials can effectively improve a certain level of solid electrolytes. performance indicators, but it is not yet possible to prepare products with excellent comprehensive performance

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