In-situ polymerization solid-state battery with multi-layer structure electrolyte and preparation method of in-situ polymerization solid-state battery

Abstract

The invention provides an in-situ polymerization solid-state battery with a multi-layer structure electrolyte. The multi-layer structure electrolyte comprises a positive electrode side in-situ formed oxidation-resistant polymer layer and a negative electrode side in-situ formed reduction-resistant polymer layer. According to the invention, a monomer or an initiator which can form an oxidation-resistant polymer through chemical reaction is preset to a positive pole piece in a mixing process, a monomer or an initiator which can form a reduction-resistant polymer through chemical reaction is preset to a negative pole piece in the mixing process, and then the monomer which reacts with the monomer or the initiator is injected into the battery in a liquid injection manner. And a polymerization reaction is initiated to realize in-situ polymerization in the battery to form a multi-layer structure electrolyte with an oxidation-resistant positive electrode and a reduction-resistant negative electrode, so that the safety and the cycling stability of the in-situ polymerization battery are improved, the interface impedance of the electrolyte and the electrode in the battery is reduced, and the method is simple and easy for expanded production. The invention also provides a preparation method of the in-situ polymerization solid-state battery with the multi-layer structure electrolyte.

Description

technical field [0001] The invention belongs to the technical field of lithium ion batteries, and in particular relates to an in-situ polymerized solid-state battery with a multilayer structure electrolyte and a preparation method thereof. Background technique [0002] At present, large-scale commercialized lithium secondary batteries contain a large amount of flammable and easily leaking organic carbonate small molecule solvents, which have major safety hazards. The use of non-volatile and non-combustible solid electrolytes instead of traditional electrolytes is considered to solve the problem of lithium ion batteries. Effective approach to battery safety concerns. Among them, polymer electrolytes have become a research hotspot in recent years due to their small interface impedance and high safety. However, due to the complexity of the process and the stability of the electrical properties of the polymer itself, it has not quickly entered mass production. [0003] In order...

AI Technical Summary

Problems solved by technology

[0004] The voltage range of lithium-ion batteries is wide, and usually a polymer material cannot take into account both high-voltage and low-voltage stability at the same time. To solve this problem, researchers have developed a composite electrolyte membrane with a multi-layer structure. Oxidation-resistant and reduction-resistant polymer components significantly improve the electrochemical stability window of the electrolyte, such as: CN109565078A provides a multilayer electrolyte, and uses solvent volatilization to prepare polyester and polyether electrolyte films respectively. Esters with strong oxidation resistance and ethers with strong ion conductivity and smaller interface impedance are prepared into a composite film, and the cycle stability of the assembled solid-state battery is significantly improved; CN110048158A is formed by in-situ polymerization on both sides of the porous film by pouring method One side is an ester and the other side is an ether-based double-layer structure electrolyte membrane, which meets the stability needs of the high-voltage positive electrode and the low-voltage negative electrode at the same time; The polymer electrolyte is coated on the contact side, which reduces the oxidation of the electrolyte and improves the safety and cycle stability of the battery. Composite, poor interface contact between electrolyte and electrode, high impedance, which is not conducive to the development of battery capacity

Images