All-solid-state polymer electrolyte with semi-interpenetrating network structure, and preparation method of electrolyte

Abstract

The invention discloses an all-solid-state polymer electrolyte with a semi-interpenetrating network structure, and a preparation method of the electrolyte. The all-solid-state polymer electrolyte is mainly prepared from the following raw materials in parts by weight: 50-95 parts of a modified block copolymer, 5-50 parts of a polyether acrylate oligomer monomer, a proper amount of a solvent, 0.1-1part of an initiator, 10-60 parts of lithium salt and 0-50 parts of an assistant. The all-solid-state polymer electrolyte is a polyether electrolyte with the semi-interpenetrating network structure; the modified block copolymer is used as a matrix; and the acrylate oligomer monomer containing multi-alkenyl functional groups is introduced to generate a cross-linking polymerization reaction so as toform two polyether semi-interpenetrating network structures. Compared with an existing polymer electrolyte, other inorganic fillers or toughening agents do not need to be doped; the obtained polymerelectrolyte has good mechanical properties; the ionic conductivity at the room temperature is greatly improved; and an electrochemical window is wider, so that the matching of high-voltage electrode materials is facilitated, and a lithium battery with higher energy density is obtained.

Description

Technical field [0001] The invention relates to the technical field of lithium ion batteries, in particular to an all-solid polymer electrolyte with a semi-interpenetrating network structure and a preparation method thereof. Background technique [0002] Lithium-ion batteries, as an efficient secondary energy storage electrochemical device, have been widely used in consumer electronics, new energy vehicles, stationary energy storage equipment and other fields. Its structure is mainly composed of positive electrode, negative electrode, separator, and electrolyte. At present, most of the commonly commercialized lithium-ion battery electrolytes are liquid and contain a variety of organic solvents. There are potential safety hazards such as leakage and flammability, which reduces their safety performance. As an ideal electrolyte form, the solid electrolyte is recognized as one of the most likely ways to solve the safety problems of lithium batteries. The solid electrolyte includes po...

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Problems solved by technology

[0007] The Chinese invention patent of CN103500845B discloses a polymer modification method, that is, introducing crosslinking sites by modifying polyethylene oxide, and forming a film by initiating a crosslinking reaction, but the obtained electrolyte still has low room temperature ionic conductivity , The problem of low voltage window

[0008] The Chinese invention patent application of CN109037770A discloses a preparation method of a solid polymer electrolyte by crosslinking polyether monomers and alkene acid monomers, which improves the conductivity and voltage window of the polymer electrolyte to a certain extent, but the preparation process The components involved are complex, and a certain amount of organic additives or (and) inorganic fillers are added, which will affect the long-term stability of the electrolyte membrane

However, the inventors have found in practice that the obtained solid polymer electrolyte still has the problems of low room temperature ionic conductivity and low voltage window.

[0010] It can be seen that although people have conducted extensive research on polymer electrolytes and tried various methods to improve the overall performance of polymer electrolytes, the existing polymer electrolytes still have low electrochemical windows, poor room temperature ionic conductivity, and poor mechanical properties. Poor, poor stability and other problems, so that there is no material that can meet the long-term durability requirements and industrial applications of lithium-ion batteries, and the performance of polymer electrolytes needs to be further improved

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