Interface wetting agent and preparation method and application thereof

Abstract

The invention discloses an interface wetting agent and a preparation method and application thereof. The interface wetting agent comprises a plastic crystal compound, inorganic lithium salt, a first additive and a second additive, wherein the first additive comprises at least one of ethyl carbonate/propylene ester, dimethyl carbonate/ethyl carbonate, ethyl methyl carbonate, trifluoropropenyl esterand lithium difluorophosphate; the second additive comprises at least one from lithium carbonate, trifluoromethyl phosphorous acid, methyl chloroformate, bromo-butyrolactone, fluoroacetate ethane, fluoroethylene carbonate, vinylene carbonate, vinylethylene carbonate, vinyl acetate, styrene carbonate, ethyl aminocarbonate, methyl aminocarbonate, 1, 3-dioxolane, 1, 4-dioxane, 1, 2-bis (cyanoethoxy)ethane, ethylene sulfate and dimethyl sulfite. The interface wetting agent has the advantages of high lithium ion conductivity and better electrochemical stability, the interface resistance of the solid-state battery can be effectively reduced, and the multiplying power and the cycle performance of the solid-state battery are improved.

Description

technical field [0001] The invention belongs to the field of materials, and in particular relates to an interface wetting agent and its preparation method and application. Background technique [0002] As people's requirements for the safety and energy density of lithium-ion batteries are getting higher and higher, the current commercialized liquid batteries have safety problems such as leakage, fire, and explosion due to the use of flammable liquid electrolytes, which seriously hinder the development of lithium-ion batteries. Further development of ion batteries. The solid-state battery that replaces the organic electrolyte with a solid electrolyte has the characteristics of high specific energy and good safety performance, and is considered to be the development direction of lithium-ion batteries in the future. [0003] In recent years, the research on solid-state electrolyte materials has made great progress: the ionic conductivity of polymer-based composite electrolytes...

AI Technical Summary

Problems solved by technology

Although this method can improve the interface contact impedance between the positive and negative electrodes of the solid-state battery and the electrolyte membrane, it cannot improve the interface reaction impedance, and the electrochemical stability of the interface is still very poor, which is not conducive to the cycle performance of the solid-state battery; The method of spraying, brushing or injecting liquid, and then vacuuming will make more ester solvents remain in the solid-state battery, which is not conducive to the safety of the solid-state battery

Patent CN 110190335A proposes to coat a layer of oxide nanowires with a cross-linked network structure on the surface of the inorganic solid electrolyte by electrospinning and then drying and calcining, so as to suppress the space charge layer and increase the contact between the electrode and the electrolyte Although this method solves the problem of interface reaction, the solid oxide nanowires at the interface have a limited effect on alleviating the interface contact resistance, and it cannot conduct lithium ions, but will increase the interface impedance

[0004] Therefore, the interface resistance between the solid electrolyte and the positive and negative electrodes in the existing solid-state batteries needs to be improved.

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