Electrolyte-containing nitrile ethyl amine and lithium secondary battery

Abstract

The invention discloses electrolyte-containing nitrile ethyl amine and a lithium secondary battery. The electrolyte comprises electrolyte lithium salt, nitrile ethyl amine, a non-water organic solvent and an additive, wherein the concentration of the electrolyte lithium salt in electrolyte is 0.5-2mol / L; the nitrile ethyl amine is 0.1%-20% (in percentage by weight) of the electrolyte; the used amount of the additive is 0.1-10.0% of the weight of the organic solvent. The nitrile ethyl molecular structure comprises more than one pair of bisnitrile functional groups and can be complexed with transitional metal ions, is added by a small amount to effectively inhibit irreversible oxidation reaction of the organic solvent on a positive surface, so that the oxidization resistance of the electrolyte is improved; the nitrile ethyl molecular structure contains a Louis alkaline amine radical, and can be used for effectively stabilizing physical and chemical properties of the electrolyte through the complexing between the amine and free trace HF and PF5 in the electrolyte. With the technical characteristics, the nitrile ethyl amine is beneficial to improving the circulating performances of the battery under high voltage, so that a gas inflation rate of the battery under a high-temperature storage environment is reduced, and a capacity recovery rate is increased.

Description

technical field [0001] The invention relates to the field of lithium ion battery preparation, in particular to an electrolyte solution containing nitrile ethylamine and a lithium secondary battery. Background technique [0002] Lithium secondary batteries have the advantages of high working voltage, high specific energy density, long cycle life, low self-discharge rate, no memory effect, and low environmental pollution. Ideal power source for power tools. In the technical field, increasing the working voltage or platform voltage of lithium secondary batteries can effectively increase the energy density of lithium ion batteries. [0003] On the one hand, the application of high-voltage cathode materials can significantly increase the specific energy of a single lithium-ion battery, but it also brings other technical drawbacks, such as the interface stability between the cathode / electrolyte. Carbonate solvents widely used at present tend to gradually oxidize on the surface o...

AI Technical Summary

Problems solved by technology

Carbonate solvents widely used at present tend to gradually oxidize on the surface of the electrode when the charging voltage is higher than 4.5V, causing the electrolyte to dry up and the internal resistance of the battery to increase. surge

These factors make the service life of the battery seriously shortened, and even bring serious safety hazards

In addition, LiPF is widely used in the electrolyte system 6 As a conductive lithium salt, LiPF 6 Its own thermal stability is relatively poor, it is sensitive to water, and it is easy to produce harmful substances such as hydrogen fluoride and phosphorus pentafluoride, which seriously damages the high temperature performance and cycle performance of the battery

Images