A kind of fluorine-containing polyurethane solid composite electrolyte and preparation method thereof

Abstract

The invention discloses a fluorine-containing polyurethane solid composite electrolyte and a preparation method thereof. The electrolyte is composed of a fluorine-containing polyurethane, an inorganic solid electrolyte and a lithium salt. The preparation method includes: S1: preparation of a fluorine-containing dihydroxy monomer; S2: fluorine-containing Preparation of polyurethane; S3: Preparation of fluorine-containing polyurethane solid-state composite electrolyte. The invention adopts polyether polyurethane as solid electrolyte matrix, and its molecular chain contains a large number of ether groups, which can effectively improve the conductivity of lithium ions at room temperature; at the same time, the fluorine-containing polyurethane is prepared by synthesizing a new type of fluorine-containing dihydroxy monomer as a chain extender, and the introduction of The fluorine structure can effectively improve the electrochemical stability of the polyurethane electrolyte, improve the dissociation degree of lithium salts to a certain extent, and improve the lithium ion conductivity; the fluorine-containing structure can effectively improve the mechanical properties and processing properties of the polyurethane solid electrolyte in the polyurethane; Polyurethane solid electrolyte is prepared by inorganic composite, which can effectively improve the conductivity of lithium ions and improve the thermal stability and mechanical properties of the electrolyte membrane.

Description

technical field [0001] The invention belongs to the technical field of solid lithium ion batteries, and in particular relates to a fluorine-containing polyurethane solid composite electrolyte and a preparation method thereof. Background technique [0002] Lithium-ion batteries have the advantages of high working voltage, high specific energy, long cycle life, low self-discharge rate, and no pollution. They are widely used in 3C products, new energy electric vehicles, electric bicycles, etc. Currently used commercial lithium-ion batteries generally use lithium hexafluorophosphate (LiPF 6 ) organic carbonate liquid electrolyte. However, this type of battery contains volatile and flammable liquid organic substances, so there are safety hazards such as leakage, fire, and explosion. When the battery is subjected to thermal shock, overcharge, overdischarge, short circuit, etc., safety hazards are more likely to occur. . [0003] In view of this, enterprises and universities are...

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Problems solved by technology

[0004] In view of the problems existing in the prior art, the object of the present invention is to provide a fluorine-containing polyurethane solid composite electrolyte and a preparation method thereof, aiming at preparing a fluorine-containing polyurethane solid composite electrolyte, which can improve the room temperature lithium ion conductivity of the solid electrolyte, mechanical Performance and thermal stability, while solving the safety problem of lithium-ion batteries

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