Low-temperature electrolyte and application thereof

Abstract

The invention discloses a low-temperature electrolyte and application thereof, the low-temperature electrolyte comprises a lithium salt, a solvent and an additive, and the solvent is a mixed solvent. The mixed solvent is composed of 40-90% by volume of a cyclic ether solvent and 10-35% by volume of a carbonic ester solvent, the concentration of the lithium salt is 0.5-5.0 mol / L, and the additive accounts for 1-3 wt% of the electrolyte. Compared with traditional electrolyte, the electrolyte disclosed by the invention has good low-temperature conductivity and low-temperature performance, and can stably work at an extremely low temperature of-70 DEG C.

Description

technical field [0001] The invention belongs to the technical field of low-temperature lithium-ion batteries, and in particular relates to a low-temperature electrolyte and its application. Background technique [0002] With the continuous utilization of traditional fossil energy by human beings, the environmental problem of global warming has become more and more acute. Reducing dependence on fossil energy has become a new challenge for human beings. Among many new energy sources, lithium-ion batteries have attracted much attention due to their high voltage, high capacity, low self-discharge rate, and good cycle performance. They are widely used in energy storage, civil equipment, and power batteries. [0003] In areas where low temperature conditions exist, such as aerospace, polar scientific research, and electric vehicles, the application of lithium-ion batteries has attracted much attention. However, at low temperatures, lithium-ion batteries have problems such as soli...

AI Technical Summary

Problems solved by technology

[0004] Ether solvents have the advantages of low melting point, low viscosity and strong solubility, but because of the unsatisfactory charge and discharge performance and poor cycle performance of ether electrolyte batteries at room temperature, ether solvents cannot be used in large quantities as electrolytic electrolytes in traditional electrolytes. liquid main solvent

[0005] In order to design a suitable battery, people have carried out various researches, and concluded that the factors affecting the low-temperature performance of the battery are as follows: 1. The viscosity increases, resulting in a decrease in conductivity; 2. The compatibility between the electrolyte and the negative electrode and the diaphragm changes. Poor; 3. The solvation effect of lithium ions; 4. The charge transfer resistance (Rct) increases significantly, etc.

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