Lithium-free salt modified graphene composite solid electrolyte material, electrolyte membrane and preparation method thereof

Abstract

The invention discloses a lithium-free salt modified graphene composite solid electrolyte material, an electrolyte membrane and a preparation method thereof. On the basis of a lithium ion conductor inorganic material and a polymer matrix material, a modified graphene material is added to prepare the composite solid electrolyte material according to an improved preparation method, and the modifiedgraphene composite solid electrolyte material is free of adding of lithium salts. Compared with the prior art, the lithium-free salt modified graphene composite solid electrolyte material, the electrolyte membrane and the preparation method thereof have advantages that a preparation process is simple, low material cost and effectiveness in inhibition of lithium dendrite formation and growth are realized, higher room-temperature ion conductivity, electrochemical work window and mechanical performances are achieved as compared with those of composite solid electrolyte materials with the lithiumsalts and without the modified graphene material, and stability in matching with a positive electrode material of a high-voltage system can be realized, so that solid batteries high in energy densitycan be obtained; in addition, low interface impedance in contact with positive and negative electrodes of all-solid-state lithium ion batteries is realized, and high stability in metal lithium negative electrodes is achieved.

Description

technical field [0001] The invention relates to the field of solid electrolytes, in particular to a lithium salt-free modified graphene composite solid electrolyte material, an electrolyte membrane and a preparation method thereof. Background technique [0002] In recent years, with the rapid development of portable electronic devices, electric vehicles, and grid energy storage technologies, the demand for high-energy-density, high-safety batteries and energy storage systems has become increasingly urgent. [0003] The electrolyte material is the carrier of lithium ions in the lithium secondary battery system, and is a key component for the normal operation of the system. At present, the lithium secondary batteries widely used in the market mainly use organic liquid electrolytes, which are flammable, explosive, electrochemical Problems such as low window and small operating temperature range not only bring safety hazards to the use of lithium secondary batteries, but also ca...

AI Technical Summary

Problems solved by technology

[0005] Most of the existing composite solid-state electrolytes are solid-state electrolytes with lithium salts added. The cross-linking or coupling reaction between lithium salts and polymers tends to make the polymers amorphous, thereby reducing the melting point of the polymers, thereby affecting the electrolyte. operating temperature range

[0006] Chinese patent CN107346834A discloses a composite solid electrolyte material without lithium salt addition, electrolyte membrane and its preparation method, including polymer matrix material and fast ion conductor powder material, although it solves a part The above problems, but there are solid-state electrolyte ionic conductivity at room temperature, small electrochemical working window, large contact interface impedance with the positive and negative electrodes of all-solid-state lithium-ion batteries, and poor stability to metal lithium negative electrodes

Images