Low-temperature lithium battery electrolyte

Abstract

The invention belongs to the field of a lithium battery, and discloses a low-temperature lithium battery electrolyte. The low-temperature lithium battery electrolyte comprises an organic solvent, a lithium salt and an additive, wherein the mass ratio of the organic solvent to the lithium salt to the additive is 78-90 to 11.5-15.5 to 1.3-3.7; and the lithium salt of an original low-temperature lithium battery electrolyte only comprises lithium hexafluorophosphate. A small amount of lithium tetrafluoroborate is added to the lithium salt of the low-temperature lithium battery electrolyte provided by the invention; the conductive effect of the lithium tetrafluoroborate is better than that of the lithium hexafluorophosphate, and the addition proportion does not affect the low-temperature performance of the lithium salt; in addition, fluoroethylene carbonate is additionally added to perform a synergistic effect with vinylene carbonate, thereby improving a film-forming effect of the lithium battery, lowering impedance, improving the conduction velocity of electrons and ions at a low temperature, and improving the low-temperature cycle performance of the lithium ion battery; and furthermore, the mass ratios of the components are selected preferably, so that the performance of the electrolyte is more excellent.

Description

technical field [0001] The invention belongs to the field of lithium batteries, in particular to an electrolyte solution for a low-temperature lithium battery. Background technique [0002] Lithium batteries have the characteristics of high nominal voltage, high specific energy, long cycle life, no memory effect, etc., and are environmentally friendly and pollution-free. Therefore, they are widely used in digital products such as mobile phones, notebook computers, and MP3s. At the same time, they are used in electric vehicles, Electric bicycles, national defense equipment and other industries are also widely used. In recent years, lithium batteries have been used more and more widely in various fields. The environment in which batteries are used is complex, and the performance requirements for batteries are also higher. Even at low temperatures, the device can be started quickly. However, the low-temperature performance of lithium-ion batteries is relatively poor at presen...

AI Technical Summary

Problems solved by technology

However, the low-temperature performance of lithium-ion batteries is relatively poor at present, especially in low-temperature environments below -30°C.

[0003] The existing lithium battery electrolyte is mainly composed of organic solvents and lithium salts, which have poor conductivity, especially in low temperature environments, and have relatively high impedance in low temperature environments.

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