A kind of cyclic sulfonate lithium ion battery electrolyte additive, its preparation method and application

Abstract

The invention discloses a cyclic sulfonate lithium-ion battery electrolyte additive, which has the structure shown in formula I: as one of the additives, it can form a non-aqueous electrolytic solution for lithium-ion batteries with non-aqueous solvents and electrolyte lithium salts. The liquid is arranged between the negative electrode and the positive electrode, and can be used to prepare a lithium ion battery. The invention provides a cyclic sulfonic acid ester additive applied to a lithium battery, which can effectively suppress the reduction of battery capacity during high-temperature cycle and high-temperature storage, and can simultaneously suppress the decomposition of electrolyte solution to generate gas.

Description

technical field [0001] The invention relates to the field of lithium batteries, in particular to a cyclic sulfonate lithium-ion battery electrolyte additive, a preparation method and application thereof. Background technique [0002] A lithium-ion battery is mainly composed of a positive electrode, a non-aqueous electrolyte, and a negative electrode. As the negative electrode constituting a lithium ion battery, there are known, for example, metal lithium, metal compounds capable of absorbing and releasing lithium (such as metal monomers, oxides, alloys with lithium, etc.), and carbon materials. Lithium-ion batteries of carbon materials such as artificial graphite and natural graphite that release lithium are widely used. At present, for lithium-ion batteries that use highly crystalline carbon materials such as natural graphite and artificial graphite as negative electrode materials, the non-aqueous solvent in the non-aqueous electrolyte is reduced and decomposed on the surf...

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Problems solved by technology

At present, for lithium-ion batteries that use highly crystalline carbon materials such as natural graphite and artificial graphite as negative electrode materials, the non-aqueous solvent in the non-aqueous electrolyte is reduced and decomposed on the surface of the negative electrode during charging, and the resulting decomposition Substances and gases will hinder the original electrochemical reaction of the battery, thereby reducing the cycle characteristics

[0003] In addition, for lithium ion batteries using lithium metal, its alloys, metal monomers such as silicon and tin, oxides, etc. as negative electrode materials, although the initial capacity is high, the micronization of the negative electrode material is intensified during the cycle, so it is compatible with carbon materials. Compared with the negative electrode of the non-aqueous solvent, the reductive decomposition of the non-aqueous solvent is prone to occur, which leads to a significant decrease in battery performance such as battery capacity and cycle characteristics.

[0004] For the positive electrode, LiCoO is known 2 , LiMn 2 o 4 , LiNiO 2 、LiFePO 4 etc., when the lithium-ion battery using these becomes high temperature in the charged state, the non-aqueous solvent in the non-aqueous electrolyte at the interface between the positive electrode material and the non-aqueous electrolyte will be partially oxidized and decomposed locally, so the resulting decomposition Substances and gases will hinder the original electrochemical reaction of the battery, resulting in a decrease in performance such as battery cycle characteristics.

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