High-temperature high-voltage non-aqueous electrolyte and lithium ion battery containing non-aqueous electrolyte

Abstract

The invention relates to the technical field of lithium ion batteries, in particular to a high-temperature high-voltage non-aqueous electrolyte and a lithium ion battery containing the non-aqueous electrolyte. The high-temperature high-voltage non-aqueous electrolyte comprises a lithium salt, a non-aqueous solvent and an additive, wherein the additive comprises a first borate additive, a second nitrogen-containing lithium salt additive, a third silicon-nitrogen-based additive and a fourth sulfonate and sulfate mixed additive. According to the present invention, after the various additives areproperly proportioned, the advantages of the additives can be provided, the disadvantages of the additives can be mutually inhibited, the high-temperature storage performance of the battery is improved through the synergistic effect of the additives, the high-temperature cycle performance of the battery is improved, and the application prospect is good under the conditions of high temperature andhigh voltage.

Description

technical field [0001] The invention relates to the technical field of lithium ion batteries, in particular to a high-temperature, high-voltage non-aqueous electrolytic solution and a lithium-ion battery containing the non-aqueous electrolytic solution. Background technique [0002] In lithium-ion batteries, high-voltage ternary cathode materials are widely used in portable electronic devices such as mobile phones, notebook computers, electric vehicles, and large energy storage devices due to their high energy density, environmental friendliness, and long cycle life. The energy density requirements of batteries are getting higher and higher, making it difficult for commercial ternary cathode material lithium-ion batteries (working voltage 4.2V) to meet the requirements. [0003] At present, studies have shown that one of the effective ways to increase the energy density of ternary electrode materials is to increase the working voltage of the battery, which is the trend of ba...

AI Technical Summary

Problems solved by technology

However, after the working voltage of the ternary power battery is increased, the performance of the battery such as charge and discharge cycles is reduced.

The reason may be: on the one hand, the positive electrode material is not stable enough under high voltage, on the other hand, the matching between the electrolyte and the material is not good, and the ordinary electrolyte will be oxidized and decomposed under high voltage conditions, resulting in high-temperature storage of the battery. Poor performance, poor high temperature cycle performance, poor low temperature discharge performance and poor safety

[0004] Chinese invention patent application (publication number CN103579676A) proposes to use fluorinated solvents (FEC, TFPC, etc.) On the graphite negative electrode, the thickness of the SEI film will increase, which will affect the charge and discharge performance. At the same time, the moisture brought in during the test will also make the LiPF 6 Decompose to generate HF, so that the thickness of SEI film increases continuously, and gas production occurs

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