High-purity fluorine-containing organophosphorus flame retardant and preparation method thereof

Abstract

The invention relates to a high-purity fluorine-containing organophosphorus flame retardant and a preparation method thereof. The preparation method comprises the following steps: (1) preparation of trifluoroethyl phosphate, namely adopting phosphorus oxychloride and trifluoroethanol of which the total molar weight ratio is (1:3)-(1:6), adding a catalyst which accounts for 2%-10% of total weight of reactants, carrying out catalytic reaction at the temperature of 10-90 DEG C for 2-16 hours, carrying out reduced pressure distillation for 1-5 hours to remove insufficiently reacted phosphorus oxychloride and trifluoroethanol after the catalytic reaction is completed, and then carrying out suction filtration to obtain the catalyst capable of being recycled and a crude trifluoroethyl phosphate product; (2) purification and refining of the trifluoroethyl phosphate, namely refining phosphate by adopting a continuous rectification process, adding a drying agent to the crude trifluoroethyl phosphate product so as to remove moisture contained in a to-be-purified substance, rectifying by introducing into a low-boiling removing rectifying column, condensing high-purity trifluoroethyl phosphate rectified through multi-times column chromatography into liquid, namely the high-purity trifluoroethyl phosphate flame retardant contained in the electrolyte of a lithium ion secondary battery, by virtue of a condenser, wherein the purity is more than or equal to 99.9%, and the yield is more than or equal to 92%.

Description

technical field [0001] The invention relates to a high-purity fluorine-containing organic phosphate as a flame retardant for lithium battery electrolyte, in particular to a preparation method for a high-purity fluorine-containing organic phosphorus flame retardant. Background technique [0002] Lithium-ion secondary batteries will emit a lot of heat under the condition of over charge and discharge, short circuit and high current for a long time, which becomes a safety hazard of flammable electrolyte, which may cause thermal breakdown or even battery explosion. A small amount of flame retardant will not change the performance of the battery and can make the flammable organic electrolyte flammable or non-flammable, thereby preventing the battery from burning or exploding under overheating conditions. [0003] Composite flame retardants have the characteristics of multiple flame retardants, and the synergistic effect between the flame retardant elements can reduce the amount of...

AI Technical Summary

Problems solved by technology

[0006] The purpose of the present invention is to solve the problem that the existing lithium-ion secondary battery will emit a lot of heat when it is overcharged and discharged, short-circuited and operated for a long time with a large current. It may cause thermal breakdown or even battery explosion. A high-purity fluorine-containing organophosphorus flame retardant is provided. A small amount of high-purity tris (fluoroethoxy) phosphate is used as a flame retardant in the electrolyte, neither It will change the performance of the battery and make the flammable organic electrolyte flammable or non-flammable, so as to prevent the battery from burning or exploding under overheating conditions

[0007] Another purpose of the present invention is exactly to overcome existing tri (fluoroethoxy) phosphoric acid ester preparation technology process and exist and fail to effectively absorb and handle escape product HCl and To solve the problem of consuming a relatively large amount of catalyst, a method for preparing a high-purity fluorine-containing organophosphorus flame retardant is provided, which can reduce serious pollution to the environment, ensure safe production, and can recover and recycle the catalyst to effectively reduce production costs.

Images