Electrolyte for lithium secondary battery as well as preparation method and application of electrolyte

Abstract

The invention discloses an electrolyte for a lithium secondary battery as well as a preparation method and application of the electrolyte. The electrolyte for the lithium secondary battery comprises the following preparation raw materials: a solvent, which comprises dimethyl carbonate and fluorobenzene; an additive, wherein the additive comprises dioctyl phosphate; and a lithium salt. According to the electrolyte for the lithium secondary battery provided by the invention, the performance reduction of the secondary battery caused by dissolution of positive electrode material metal can be remarkably inhibited through the matching of the preparation raw materials.

Description

technical field [0001] The invention belongs to the technical field of secondary batteries, and in particular relates to an electrolyte solution for a lithium secondary battery and a preparation method and application thereof. Background technique [0002] In recent years, lithium secondary batteries have developed rapidly, and their types are becoming more and more diverse. Specifically, according to the type of negative electrode materials, they can be divided into lithium-ion batteries and lithium metal batteries; according to the types of positive electrode materials, they can be divided into lithium-sulfur batteries and lithium metal oxides. Batteries, etc.; according to the type of electrolyte, it can be divided into aqueous lithium-ion batteries, organic lithium-ion batteries, solid-state lithium-ion batteries, and gel lithium-ion batteries. Although there are more and more types of lithium secondary batteries, the most widely used and mature ones on the market are st...

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Problems solved by technology

[0003] In the process of improving the performance of organic lithium-ion batteries, there are some insurmountable technical difficulties, including: the side reaction of the electrolyte on the surface of the positive and negative electrodes, the short circuit and safety problems caused by the growth of lithium dendrites in the negative electrode, and the metal material of the positive electrode. Dissolution leads to failure of the electrolyte and its impact on the performance of the negative electrode

[0004] At present, the method to solve the metal dissolution of the positive electrode material is to densely wrap the positive electrode active material or the positive electrode sheet (usually inert coating). Although this method has a certain effect, it also reduces the ionic conductivity of the positive electrode. Even the electronic conductivity will lose the cycle, rate and other properties of the obtained secondary battery to a certain extent.

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