CN-122011015-A - Electrolyte additive for flame retardance and application thereof

Abstract

The invention belongs to the technical field of electrolyte additives and discloses an electrolyte additive for flame retardance and application thereof, wherein the preparation method of the electrolyte additive for flame retardance comprises the steps of mixing an organic phosphorus source compound, a fluorine-containing alcohol compound and a composite catalyst to obtain a mixture, carrying out esterification reaction on the mixture, adding a silane coupling agent into an esterification reaction product, then carrying out condensation reaction, and sequentially carrying out reduced pressure distillation, molecular sieve adsorption and supercritical carbon dioxide extraction purification on the condensation reaction product to obtain the electrolyte additive for flame retardance.

Inventors

• Dai Benqian
• DONG SHUXIN
• ZHAO JUNRUI
• CUI WENXI
• WANG ZHIPENG
• LIU XIANGLIANG
• BAI JINQUAN
• CHEN HAO
• ZHAO KUN
• ZHANG LISONG
• WU PENGYUE
• WANG XIAOHUI
• CHEN SI
• Lou Fangxi
• XUE LEI
• Bian Shengjun
• XIN FUQIANG

Assignees

• 西安热工研究院有限公司
• 华能伊敏煤电有限责任公司

Dates

Publication Date

20260512

Application Date

20260120

Claims (10)

1. 1. The preparation method of the electrolyte additive for flame retardance is characterized by comprising the following steps of: mixing an organic phosphorus source compound, a fluorine-containing alcohol compound and a composite catalyst to obtain a mixture; carrying out esterification reaction on the mixture; Adding a silane coupling agent into the esterification reaction product, and then carrying out condensation reaction; And (3) sequentially carrying out reduced pressure distillation, molecular sieve adsorption and supercritical carbon dioxide extraction and purification on the condensation reaction product to obtain the electrolyte additive for flame retardance.
2. 2. The method for preparing the electrolyte additive for flame retardance according to claim 1, wherein the molar ratio of the organic phosphorus source compound to the fluorine-containing alcohol compound is 1 (1.5-3.0); the composite catalyst accounts for 0.5% -5.0% of the total mass of the organophosphorus source compound and the fluorine-containing alcohol compound.
3. 3. The method for preparing a flame retardant electrolyte additive according to claim 1, wherein the organic phosphorus source compound comprises at least one of trimethyl phosphate, triethyl phosphate, and dimethyl methylphosphonate; The fluorine-containing alcohol compound comprises one of trifluoroethanol, pentafluoropropanol and hexafluoroisopropanol; the composite catalyst is a mixture of tetraisopropyl titanate and p-toluenesulfonic acid in a mass ratio of (3-1): 1.
4. 4. The method for preparing the electrolyte additive for flame retardance according to claim 1, wherein the temperature of the esterification reaction is 40-80 ℃, the pressure of the esterification reaction is 0.1-0.5 Mpa, and the time of the esterification reaction is 2-6 h.
5. 5. The method for preparing the electrolyte additive for flame retardance according to claim 1, wherein the molar ratio of the silane coupling agent to the organophosphorus source compound is 1 (0.2-0.8); the temperature of the condensation reaction is 60-100 ℃, and the time of the condensation reaction is 4-10 hours.
6. 6. The method for preparing a flame retardant electrolyte additive according to claim 1, wherein the silane coupling agent is a silane coupling agent containing an amino group or an epoxy group.
7. 7. The method for preparing the flame-retardant electrolyte additive according to claim 1, wherein the temperature of reduced pressure distillation is 50-70 ℃, the pressure of reduced pressure distillation is-0.07 to-0.09 MPa, and the time of reduced pressure distillation is 1-3 hours; And the pore diameter of the molecular sieve is 3-10A.
8. 8. The method for preparing the flame-retardant electrolyte additive according to claim 1, wherein the pressure of supercritical carbon dioxide extraction and purification is 8-15 MPa, the temperature of supercritical carbon dioxide extraction and purification is 35-50 ℃, and the time of supercritical carbon dioxide extraction and purification is 1-6 h.
9. 9. Electrolyte additive for flame retardance, characterized in that it is obtained based on a method for preparing an electrolyte additive for flame retardance according to any one of claims 1 to 8.
10. 10. Use of an electrolyte additive for flame retardance according to claim 9 in a supercapacitor.

Description

Electrolyte additive for flame retardance and application thereof Technical Field The invention relates to the technical field of electrolyte additives, in particular to an electrolyte additive for flame retardance and application thereof. Background The super capacitor is a novel high-performance energy storage device and is arranged between a traditional capacitor and a battery. Its core advantage is high power density, quick charge and discharge in several seconds, long service life (hundreds of thousands times), and far beyond that of battery. The device stores energy through electrostatic adsorption (electric double layer principle) or rapid oxidation-reduction reaction (pseudo capacitance) on the surface of the electrode, and does not generate chemical reaction in the charge-discharge process, so that the device has high efficiency, small heat generation and good safety. The method is mainly applied to the scenes requiring instant high power, such as start-stop energy recovery of electric automobiles, braking energy storage of rail transit, power compensation of a smart grid, a backup power supply of consumer electronic equipment and the like, and short plates with insufficient battery power and low energy of a traditional capacitor are made up. Currently, with the accelerated popularization of super capacitors in high-power application scenes such as new energy vehicles, rail transit, smart grids and the like, the safety performance of the super capacitors has become a core bottleneck for restricting the development of industries. However, conventional supercapacitors face significant challenges in high reliability application scenarios. Under the abuse conditions of overvoltage, high temperature or internal short circuit, the stability of the internal electrolyte is rapidly reduced, decomposition reaction is extremely easy to occur, the electrolyte decomposition not only damages the electrochemical performance of the supercapacitor, but also is accompanied with gas production, the internal pressure of the supercapacitor is rapidly boosted along with the continuous production of gas, when the pressure exceeds the bearing limit of the shell, the shell is broken to leak internal substances, and meanwhile, the serious consequences of short circuit, combustion and the like are possibly caused, so that the risk of thermal runaway is further generated, the supercapacitor is damaged, and the threat to peripheral equipment and environment is also possible. Therefore, a new material capable of solving the problem of poor safety is needed in the industry. Disclosure of Invention The invention aims to provide an electrolyte additive for flame retardance and application thereof, which are used for overcoming the problems in the prior art, and the electrolyte additive can remarkably improve the flame retardance efficiency, not only can not damage the cycle performance and the multiplying power performance of a battery, but also can remarkably improve the high-temperature safety of the electrolyte, so that the electrolyte additive passes a severe hot box test and meets the safety requirement of a high-energy-density lithium ion battery. In order to achieve the above purpose, the technical scheme adopted by the invention is as follows: in a first aspect, the present invention provides a method for preparing an electrolyte additive for flame retardance, comprising the steps of: Step 1, mixing an organic phosphorus source compound, a fluorine-containing alcohol compound and a composite catalyst to obtain a mixture; step2, carrying out esterification reaction on the mixture; step 3, adding a silane coupling agent into the esterification reaction product, and then carrying out condensation reaction; and step 4, sequentially carrying out reduced pressure distillation, molecular sieve adsorption and supercritical carbon dioxide extraction and purification on the condensation reaction product to obtain the electrolyte additive for flame retardance. In some embodiments, the molar ratio of the organophosphorus source compound to the fluorine-containing alcohol compound is 1 (1.5-3.0); the composite catalyst accounts for 0.5% -5.0% of the total mass of the organophosphorus source compound and the fluorine-containing alcohol compound. In some embodiments, the organophosphorus source compound includes at least one of trimethyl phosphate, triethyl phosphate, dimethyl methylphosphonate; The fluorine-containing alcohol compound comprises one of trifluoroethanol, pentafluoropropanol and hexafluoroisopropanol; the composite catalyst is a mixture of tetraisopropyl titanate and p-toluenesulfonic acid in a mass ratio of (3-1): 1. In some embodiments, the temperature of the esterification reaction is 40-80 ℃, the pressure of the esterification reaction is 0.1-0.5 Mpa, and the time of the esterification reaction is 2-6 h. In some embodiments, the molar ratio of the silane coupling agent to the organophosphorus source compound is 1 (0.2-