Electrolyte solution and lithium ion battery comprising same

Abstract

The invention relates to the technical field of lithium ion batteries, in particularly to an electrolyte solution and a lithium ion battery comprising the electrolyte solution. The electrolyte solution provided by the invention comprises a lithium salt, an organic solvent and an additive, wherein the additive comprises cyclotrisilazane as shown in formula (1) and a dinitrile compound, with an ether bond, as shown in formula (2). The electrolyte solution can improve the cycle performance, rate performance and high-temperature storage performance of the lithium ion battery under high voltage, and also improves the safety performance of the lithium ion battery. One or more in an ether compound, a nitrile compound, a cyclic ester compound containing a sulfur bond and an oxygen bond, a cyclic carbonate compound containing a carbon-carbon unsaturated bond and a compound containing a carbon-nitrogen double bond can further be contained in the electrolyte solution, so that the cycle performance and rate performance of the lithium ion battery under high voltage and the storage performance of the lithium ion battery under high temperature can further be improved.

Description

technical field [0001] The present application relates to the technical field of lithium-ion batteries, in particular to an electrolyte and a lithium-ion battery including the electrolyte. Background technique [0002] In recent years, with the rapid development of electronic products, higher requirements have been placed on the endurance of lithium-ion batteries. The main factor determining the endurance of lithium-ion batteries is battery capacity. Higher requirements have also been put forward. In order to improve the energy density of lithium-ion batteries, the development of high-voltage lithium-ion batteries is one of the effective methods. However, as the voltage increases, the reaction between the water in the electrolyte and other components in the electrolyte will be accelerated, and hydrofluoric acid (HF) will be generated, which will reduce the cycle performance of the lithium-ion battery and seriously affect the lithium-ion battery. performance. [0003] In ad...

AI Technical Summary

Problems solved by technology

Although these chain silazanes can improve the storage stability and thermal stability of lithium-ion batteries to a certain extent, because these chain silazanes will participate in the solid electrolyte interface (SEI) film on the surface of the anode Formation makes the formed SEI film unstable, which in turn causes a decrease in the performance of the lithium-ion battery such as the rate, and further causes a decrease in the cycle performance of the lithium-ion battery

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