A method for synthesizing tris(2,2,2-trifluoroethyl) borate
By using boron anhydride, trifluoroethanol and sulfuric acid as reaction raw materials and catalysts, the reaction conditions were controlled, and the yield, yield and purity of tri(2,2,2-trifluoroethyl) borate was successfully improved, and the problem of low yield and purity in the prior art was solved, and the demand for high-performance lithium-ion batteries was met.
Patent Information
- Application Number
- CN202310067798.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-02-06
- Publication Date
- 2025-04-01
- Estimated Expiration
- 2043-02-06
AI Technical Summary
In the prior art, the synthesis method of tri(2,2,2-trifluoroethyl) borate uses trifluoroethanol and boron trichloride as reaction raw materials, resulting in low yield, yield and purity, making it difficult to meet the needs of high-performance lithium-ion power and energy storage batteries.
Boron anhydride and trifluoroethanol are used as the reaction raw materials, sulfuric acid is added as a catalyst and dehydrating agent, the reaction temperature and time are controlled, and tris(2,2,2-trifluoroethyl) borate product is obtained after decompression distillation and rectification.
This method significantly improves the yield, yield and purity of tris(2,2,2-trifluoroethyl) borate, reaching 99.40% purity and 83.5% yield, meeting the needs of high-performance lithium-ion batteries.
Smart Images
Figure CN116003457B_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the field of battery electrolyte additives, and in particular to a method for synthesizing tris(2,2,2-trifluoroethyl) borate. Background Art
[0002] Electrolyte additives refer to small amounts of additives added to the electrolyte to improve the electrochemical properties of the electrolyte and the quality of cathode deposition. Electrolyte additives are some natural or synthetic organic or inorganic compounds that generally do not participate in the electrode reaction of the electrolysis process, but can change the electrochemical properties of the electrolyte system, affect the discharge conditions of ions, and put the electrolysis process in a better state.
[0003] As an additive, TTFEB significantly improves the cycle efficiency and coulombic efficiency, especially at high temperature, 0.5wt% TTFEB can reduce the content of lithium-containing inorganic components in the positive electrode-electrolyte interface film, inhibiting the reduction of tetravalent manganese on the positive electrode surface. With the continuous promotion of new energy vehicles in my country and the rapid growth of energy storage batteries, this product is of great significance for the development of key material electrolytes for high-performance lithium-ion power and energy storage batteries. The current synthesis method of tri(2,2,2-trifluoroethyl) borate on the market uses trifluoroethanol and boron trichloride as reaction raw materials, and the output, yield and purity of tri(2,2,2-trifluoroethyl) borate are relatively low. Therefore, it is necessary to establish a synthesis method of tri(2,2,2-trifluoroethyl) borate. Summary of the invention
[0004] The invention aims to solve the problem of low production and yield of p-hydroxybenzenesulfonyl chloride in the prior art, and proposes a method for synthesizing tris(2,2,2-trifluoroethyl) borate.
[0005] In order to achieve the above object, the present invention adopts the following technical solutions:
[0006] A method for synthesizing tri(2,2,2-trifluoroethyl) borate, comprising taking boric anhydride and trifluoroethanol as reaction raw materials, adding sulfuric acid, controlling the reaction temperature and reaction time, and performing reduced pressure distillation and rectification after the reaction to obtain a tri(2,2,2-trifluoroethyl) borate product.
[0007] As an improved technical solution, the boric anhydride and the trifluoroethanol are added in a molar ratio of 1:5-7.
[0008] As a preferred technical solution, the boric anhydride and the trifluoroethanol are added in a molar ratio of 1:6.
[0009] As an improved technical solution, the mass concentration of the sulfuric acid is 98%, and the mass ratio of the sulfuric acid to the trifluoroethanol is 10%.
[0010] As an improved technical solution, the reaction temperature is controlled at 65-85°C and the reaction time is controlled at 15-20h.
[0011] As a preferred technical solution, the reaction temperature is controlled at 80°C and the reaction time is controlled at 18 hours.
[0012] As an improved technical solution, the temperature of the tower top is controlled at 40°C during distillation.
[0013] The reaction equation involved in the synthesis method of the present invention is:
[0014]
[0015] Compared with the prior art, the present invention has the following beneficial effects:
[0016] The invention uses trifluoroethanol and boric anhydride as reaction raw materials, sulfuric acid as a catalyst and a dehydrating agent, controls the reaction temperature and reaction time, and obtains a tri(2,2,2-trifluoroethyl) borate product by distillation after the reaction is completed. The method greatly improves the yield, yield and purity of the target product. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 is the GC-MS spectrum of tris(2,2,2-trifluoroethyl) borate of the present invention; DETAILED DESCRIPTION
[0018] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments.
[0019] Example 1
[0020] To the reaction apparatus, 69.6 g of boric anhydride, 500 g of trifluoroethanol and 50 g of 98 wt % sulfuric acid were added in sequence, stirring was started, the reaction temperature was controlled at 65 ° C, the reaction was carried out for 15 h, and after the reaction was completed, it was subjected to reduced pressure distillation, and the collected crude product was further distilled (the temperature at the top of the tower was controlled at 40 ° C) to obtain 257.10 g of tris (2,2,2-trifluoroethyl) borate product, with a yield of 83.5% and a purity of 99.40%.
[0021] Example 2
[0022] To the reaction apparatus, 69.6 g of boric anhydride, 600 g of trifluoroethanol and 60 g of 98 wt % sulfuric acid were added in sequence, stirring was started, the reaction temperature was controlled at 70 ° C, the reaction was carried out for 16 hours, and after the reaction was completed, it was subjected to reduced pressure distillation, and the collected crude product was further distilled (the temperature at the top of the tower was controlled at 40 ° C) to obtain 262.34 g of tris (2,2,2-trifluoroethyl) borate product, with a yield of 85.2% and a purity of 99.45%.
[0023] Example 3
[0024] To the reaction apparatus, 69.6 g of boric anhydride, 650 g of trifluoroethanol and 65 g of 98 wt % sulfuric acid were added in sequence, stirring was started, the reaction temperature was controlled at 80 ° C, the reaction was carried out for 18 hours, and after the reaction was completed, it was subjected to reduced pressure distillation, and the collected crude product was further distilled (the temperature at the top of the tower was controlled at 40 ° C) to obtain 270.34 g of tris (2,2,2-trifluoroethyl) borate product, with a yield of 87.8% and a purity of 99.65%.
[0025] Example 4
[0026] To the reaction apparatus, 69.6 g of boric anhydride, 700 g of trifluoroethanol and 70 g of 98 wt % sulfuric acid were added in sequence, stirring was started, the reaction temperature was controlled at 85 ° C, the reaction was carried out for 20 h, and after the reaction was completed, it was subjected to reduced pressure distillation, and the collected crude product was further distilled (the temperature at the top of the tower was controlled at 40 ° C) to obtain 260.49 g of tris (2,2,2-trifluoroethyl) borate product, with a yield of 84.6% and a purity of 99.53%.
[0027] In order to better prove that the synthesis method of the present invention can improve the yield, purity and output of tris(2,2,2-trifluoroethyl) borate, three comparative examples are given with reference to Example 3.
[0028] Comparative Example 1
[0029] The difference from Example 3 is that SOCl2 is used instead of sulfuric acid. The other operations are the same to obtain 218.3 g of tri(2,2,2-trifluoroethyl) borate product with a yield of 70.9% and a purity of 98.64%.
[0030] Comparative Example 2
[0031] The difference from Example 3 is that P2O5 is used as a dehydrating agent. The other operations are the same to obtain 162.27 g of tris(2,2,2-trifluoroethyl) borate product with a yield of 52.7% and a purity of 94.31%.
[0032] Application experiment:
[0033] The ternary material NCM (622) lithium is used as the positive electrode material, the negative electrode uses mesophase carbon microspheres, the positive and negative current collectors are distributed as aluminum foil and copper foil, and the diaphragm uses a ceramic diaphragm to form a soft-pack battery. After injecting the electrolyte, it is assembled into a soft-pack battery in a glove box and tested after standing for 8 hours. The battery is activated by charging and discharging at 1 / 10C 3.0V to 4.2V or above at a constant temperature of 25°C to obtain the battery to be tested. The electrolytes tested include basic electrolyte E1 and electrolyte E2, and their compositions are as follows:
[0034] 1. Basic electrolyte E1
[0035] EC: Solution-1: DEC=3:3:4(v:v:v), LiPF6: 1.0M, 0.5% LiFSI,
[0036] 1% VC
[0037] 2. Electrolyte E2
[0038] EC: Solution-1: DEC=3:3:4(v:v:v), LiPF6: 1.0M, 0.5% LiFSI,
[0039] 1% VC, 0.5% tris(2,2,2-trifluoroethyl) borate;
[0040] Test results:
[0041] 1. The test results after 60℃ cycle are as follows:
[0042] Table 2
[0043]
[0044] 2. Place the battery in a low temperature box, control the temperature to -30℃ or -40℃, and place it in a low temperature box for 240 minutes, then measure the battery capacity retention rate.
[0045] Table 3
[0046]
[0047] The above are only preferred specific implementation modes of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solutions and inventive concepts of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.
Claims
1. A method for synthesizing tri(2,2,2-trifluoroethyl) borate, characterized in that: The synthesis method is to use boric anhydride and trifluoroethanol as reaction raw materials, add sulfuric acid, control the reaction temperature and reaction time, and after the reaction is completed, distill and rectify to obtain tri(2,2,2-trifluoroethyl) borate product; The mass concentration of the sulfuric acid is 98%, and the mass ratio of the sulfuric acid to the trifluoroethanol is 10%.
2. The method for synthesizing tris(2,2,2-trifluoroethyl) borate according to claim 1, characterized in that: The boric anhydride and the trifluoroethanol are added in a molar ratio of 1:5-7.
3. The method for synthesizing tris(2,2,2-trifluoroethyl) borate according to claim 2, characterized in that: The boric anhydride and the trifluoroethanol are added in a molar ratio of 1:
6.
4. The method for synthesizing tris(2,2,2-trifluoroethyl) borate according to claim 1, characterized in that: The reaction temperature was controlled at 65-85°C and the reaction time was controlled at 15-20h.
5. The method for synthesizing tris(2,2,2-trifluoroethyl) borate according to claim 1, characterized in that: The reaction temperature was controlled at 80°C and the reaction time was 18 h.
6. The method for synthesizing tris(2,2,2-trifluoroethyl) borate according to claim 1, characterized in that: During distillation, the temperature at the top of the tower was controlled at 40°C.