Fluorine-containing polyurethane solid-state composite electrolyte and preparation method thereof

Abstract

The invention discloses a fluorine-containing polyurethane solid-state composite electrolyte and a preparation method thereof, wherein the electrolyte is composed of fluorine-containing polyurethane,an inorganic solid-state electrolyte and a lithium salt. The preparation method comprises the following steps: S1, preparing a fluorine-containing dihydroxy monomer; S2, preparing fluorine-containingpolyurethane; and S3, preparing a fluorine-containing polyurethane solid-state composite electrolyte. According to the invention, polyether polyurethane is used as a solid-state electrolyte matrix, and the molecular chain of polyether polyurethane contains a large amount of ether groups, so that the conductivity of lithium ions at room temperature can be effectively improved; a synthesized novel fluorine-containing dihydroxy monomer is used as a chain extender to prepare fluorine-containing polyurethane, so that a fluorine structure is introduced to effectively improve the electrochemical stability of polyurethane electrolyte so as to improve the dissociation degree of a lithium salt to a certain extent and improve the conductivity of lithium ions; the fluorine-containing structure effectively improves the mechanical properties and processability of the polyurethane solid-state electrolyte in polyurethane; and the polyurethane solid-state electrolyte is prepared through organic-inorganic compounding, so that the lithium ion conductivity is effectively improved, and the thermal stability and the mechanical property of the electrolyte membrane are improved.

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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