WO2023098189A1

WO2023098189A1 - Preparation process for fluoroethylene carbonate and lithium battery applying fluoroethylene carbonate

Info

Publication number: WO2023098189A1
Application number: PCT/CN2022/116186
Authority: WO
Inventors: 王振一; 王小龙; 周龙; 管晓东; 周洋
Original assignee: 苏州华一新能源科技股份有限公司
Priority date: 2021-11-30
Filing date: 2022-08-31
Publication date: 2023-06-08
Also published as: KR20230084093A; CN114163412A; CN114163412B

Abstract

The present invention relates to the technical field of lithium battery additives. Disclosed are a preparation process for fluoroethylene carbonate and a lithium battery applying fluoroethylene carbonate. The preparation process comprises: mixing raw materials to obtain a reaction solution; according to a height interval, dividing the interval where the reaction solution is located into at least two position areas from bottom to top, performing a thermal insulation reaction on the reaction solution, respectively suctioning away the reaction solution in each position area, and then mixing same to obtain a circulating liquid, performing gradient cooling on the circulating liquid, mixing the circulating liquid with the reaction solution, and sequentially stopping suctioning away the reaction solution in each position area from bottom to top to obtain a crystal-containing fluid; and performing solid-liquid separation and distillation purification on the crystal-containing fluid to obtain fluoroethylene carbonate. The preparation process in the present application is beneficial to continuing crystallization of ungrown small crystals, so that the yield of fluoroethylene carbonate is improved, and fluoroethylene carbonate prepared in the present application is used for the lithium battery, so that the high and low temperature performance of an electrolyte in the lithium battery can be improved.

Description

Preparation process of fluoroethylene carbonate and lithium battery using fluoroethylene carbonate

technical field

The invention relates to the technical field of lithium battery additives, in particular to a preparation process of fluoroethylene carbonate and a lithium battery using fluoroethylene carbonate.

Background technique

Fluoroethylene carbonate is an additive that can be used in lithium batteries. Fluoroethylene carbonate helps to form a denser SEI film, which can prevent the decomposition of the electrolyte and improve the high and low temperature performance of the lithium battery electrolyte. Fluorinated ethylene carbonate is generally prepared by using fluorinating agent, phase transfer catalyst, chloroethylene carbonate and organic solvent as raw materials, and is prepared by stirring and crystallizing.

In the related art, a kind of preparation method of fluoroethylene carbonate is disclosed, comprising the following steps: in the presence of protective gas, alkali metal fluoride, quaternary phosphonium salt and organic solvent are added to the reaction vessel and mixed, and the temperature is raised to 45- 100°C, then drop chloroethylene carbonate into the reaction vessel, and carry out stirring and crystallization to produce fluoroethylene carbonate; wherein the alkali metal hydrofluoride is anhydrous potassium bifluoride and/or anhydrous sodium bifluoride.

In view of the related technologies mentioned above, the inventor believes that the production of fluoroethylene carbonate by stirring and crystallization has the problem of low yield.

Contents of the invention

In order to improve the problem of low yield of fluoroethylene carbonate produced by stirring crystallization, the application provides a preparation process of fluoroethylene carbonate and a lithium battery using fluoroethylene carbonate.

First aspect, the application provides a kind of preparation technology of fluoroethylene carbonate, adopts following technical scheme:

A kind of preparation technology of fluoroethylene carbonate, comprises the steps,

Mixing: Mix the fluorinating agent, phase transfer catalyst and organic solvent evenly to obtain a mixed solution;

Dynamic crystallization: Add chloroethylene carbonate dropwise to the mixed solution at 50-130°C to obtain a reaction solution. The reaction solution is subjected to a heat preservation reaction, and the reaction solution is divided according to the height interval from bottom to top. There are at least two position zones. During the heat preservation reaction, the reaction solution in each position zone is sucked out and then mixed to obtain a circulating fluid. The circulating fluid is subjected to gradient cooling and then mixed with the reaction solution. After the reaction solution in the unit area, the heat preservation reaction ends, and the liquid containing crystals is obtained;

Filtration: solid-liquid separation of crystal-containing liquid to obtain crude crystals and mother liquor;

Purification: Purify the crude crystals by rectification to obtain fluoroethylene carbonate.

By adopting the above technical solution, during the heat preservation reaction, the reaction solution crystallizes and generates crystals, the grown crystal particles are concentrated in the lower-height area, and the ungrown small crystals are concentrated in the higher-height area. In the preparation process of the present application, the reaction solutions in different height ranges are sucked out and mixed separately, and then the temperature is gradually lowered to help the formation of crystals; the suction of the reaction solutions in each position area is stopped sequentially from bottom to top, so that the grown crystal particles Gradient cooling is no longer carried out, and at the same time, the unfinished small crystals continue to carry out gradient cooling, which helps the unfinished small crystals to continue to crystallize, thereby helping to improve the yield of fluoroethylene carbonate, and the prepared Crystal particles are more uniform. Therefore, the preparation process of the present application helps to improve the problem of low yield of fluoroethylene carbonate caused by stirring crystallization.

Preferably, the height of the at least two position areas is 200-650mm.

By adopting the above technical scheme, when the height of the position area is controlled within the above range, the particle size of the crystals in each position area is relatively uniform, and when the reaction liquid in each position area is sucked out, it can reduce the Disturbance of the reaction solution.

Preferably, in the dynamic crystallization stage, the range of the gradient temperature drop is 35-40°C.

By adopting the above technical scheme, controlling the temperature within the above range helps to reduce the dissolution of fluoroethylene carbonate crystals and facilitates the improvement of the yield of fluoroethylene carbonate.

Preferably, the mixing stage and the dynamic crystallization stage are carried out in an anti-blocking dynamic crystallization device, the anti-blocking dynamic crystallization device includes a reactor, a circulation pipe, an output pipe, a circulation pump and a gradient cooling unit, and the reactor There are at least two circulation pipes, and the circulation pipes are arranged sequentially from bottom to top. The circulation pipes are connected with the reaction kettle, and all the circulation pipes are far away from the reaction kettle. One end of each is connected with the output pipe, and the said output pipe is connected with the reaction kettle, and said gradient cooling element and circulation pump are installed on the output pipe, and all said circulation pipes are equipped with liquid control valves, said The discharge pipe is provided with an anti-blocking component for stirring the flow of the crystal liquid.

By adopting the above technical scheme, the raw materials are mixed in the reactor, and the circulation pipe, the output pipe and the circulation pump cooperate to help suck the reaction liquid out of the reactor, and the gradient cooling part is used for gradient cooling of the circulating liquid. And liquid containing crystals are relatively viscous, and crystals are easy to adhere to the pipe wall of the discharge pipe when discharging, thereby causing the discharge pipe to be blocked, and also reducing the productive rate of fluoroethylene carbonate. Therefore, the present application arranges the anti-blocking assembly in the discharge pipe, which can reduce crystal adhesion on the pipe wall of the discharge pipe, help to improve the productive rate of fluoroethylene carbonate, and can also improve the flow of crystals when the crystal-containing liquid is blocked. The problem of the material pipe makes the discharge smoother.

Preferably, the anti-blocking assembly includes a screw feeding column, a support rod, a gear ring and a driving member for driving the gear ring to rotate, the gear ring is rotatably connected to the discharge pipe, and the gear ring is provided with a The feed hole, the feed hole communicates with the discharge pipe, the support rod is fixedly connected to the hole wall of the feed hole, the spiral feeding column is installed in the feed hole, and the spiral feeding column is connected to the discharge pipe. The support rod is fixedly connected, the driving part is installed on the discharge pipe, and the driving part is connected with the gear ring.

By adopting the above technical scheme, the driving part drives the gear ring to rotate, and the gear ring can drive the support rod and the screw feeding column to rotate synchronously, and the screw feeding column can stir the crystal-containing liquid, so that the crystal-containing liquid can accelerate the flow under external disturbance , and reduce crystal adhesion on the pipe wall of the discharge pipe, which helps to improve the yield of fluoroethylene carbonate and reduce the blockage of the discharge pipe.

Preferably, the driving member includes a driving motor, a driving gear and a rotating shaft, the driving motor is fixedly connected to the discharge pipe, the driving gear is fixedly connected to the motor shaft of the driving motor, and the driving gear meshes with the gear ring , the rotating shaft is rotatably connected to the discharge pipe, and the rotating shaft is fixedly connected to the driving gear.

By adopting the above technical solution, the cooperation between the driving motor and the driving gear helps to drive the gear ring to rotate, and the rotating shaft helps to support the driving gear, so that the driving gear rotates more stably.

Preferably, a ring plate is provided on the end wall of the toothed ring, a ring groove is provided on the pipe wall of the discharge pipe, the ring plate is inserted in the ring groove, and the groove between the ring plate and the ring groove wall abutment.

By adopting the above technical scheme, the ring plate cooperates with the ring groove to realize the rotational connection between the gear ring and the discharge pipe, which helps to reduce the problem that the gear ring is detached from the discharge pipe during the rotation process. Moreover, because the ring plate and the ring groove The abutment of the groove walls helps to reduce the leakage of crystal-containing liquid from the discharge pipe and the gear ring.

Preferably, the discharge pipe includes a feed pipe, a receiving pipe and an airtight box, the feed pipe communicates with the reaction kettle, the feed pipe and the receiving pipe are fixedly connected to the airtight box, and the feed pipe and the receiving pipe are inserted in the airtight box, the anti-blocking assembly is arranged in the airtight box, the feeding pipe and the receiving pipe are connected with the anti-blocking assembly, the feeding pipe and the receiving pipe are connected, and the airtight An air pressure regulator for adjusting the air pressure in the airtight box is installed on the box, and an air pressure sensor for monitoring the air pressure in the airtight box is installed on the airtight box.

By adopting the above technical scheme, since the crystal liquid is affected by the gravity and the air pressure in the reactor, the pressure in the feeding pipe and the receiving pipe is relatively high, and the air pressure in the airtight box can be adjusted to Appropriate size makes the pressure difference between the feeding pipe and the receiving pipe smaller, which helps to reduce the leakage of crystal-containing liquid from the feeding pipe and the receiving pipe.

Preferably, the pressure regulating device includes an air pump, an air delivery pipe and a gas control valve, one end of the air delivery pipe communicates with the airtight box, the other end of the air delivery pipe is connected with the intake end of the air pump, and the gas control valve Installed on the air pipe.

By adopting the above technical scheme, the air pump and the air pipe can be used to fill the airtight box with gas, thereby adjusting the air pressure in the airtight box. The gas control valve helps to reduce the gas leakage in the airtight box, making the air pressure in the airtight box relatively Stablize.

In the second aspect, the application provides a lithium battery using fluoroethylene carbonate, which adopts the following technical scheme:

A lithium battery using fluoroethylene carbonate, the electrolyte of the lithium battery contains the fluoroethylene carbonate obtained by the above preparation process.

By adopting the above technical scheme, the fluoroethylene carbonate obtained by the above preparation process has the characteristics of uniform crystal particle size and high purity, which is helpful to further improve the high and low temperature performance of the lithium battery electrolyte.

In summary, the present application includes at least one of the following beneficial technical effects:

1. The preparation process of the present application sucks out the reaction liquids in different height intervals separately, and stops sucking out the reaction liquids in each position area sequentially from bottom to top, which helps the unfinished small crystals to continue to crystallize, thereby improving the fluorination. The yield of ethylene carbonate;

2. The preparation process of the present application carries out the mixing stage and the dynamic crystallization stage in the anti-blocking type dynamic crystallization device, which helps to improve the productive rate of fluoroethylene carbonate, reduces the crystals in the crystal-containing liquid to block the discharge pipe, and makes the discharge pipe material more smoothly;

3. The lithium battery electrolyte of the present application contains the fluoroethylene carbonate obtained by the above preparation process, which helps to further improve the high and low temperature performance of the lithium battery electrolyte.

Description of drawings

FIG. 1 is a schematic structural view of the anti-blocking dynamic crystallization device in Example 1 of the present application.

Fig. 2 is a cross-sectional view of the discharge pipe of Embodiment 1 of the present application.

Fig. 3 is an enlarged view of A in Fig. 2 .

Fig. 4 is a schematic diagram of the explosion structure of the discharge pipe in Example 1 of the present application.

Fig. 5 is a schematic structural view of the anti-blocking dynamic crystallization device in Example 1 of the present application.

Fig. 6 is a schematic structural view of the anti-blocking dynamic crystallization device in Example 1 of the present application.

Explanation of reference signs:

1. Reactor; 11. Feed pipe; 12. Discharge pipe; 121. Ring groove; 122. Feed pipe; 123. Acceptor pipe; 124. Airtight box; 1241. Support plate; , air pump; 1252, air pipe; 1253, gas control valve; 126, air pressure sensor; 2, circulation pipe; 21, liquid control valve; 3, output pipe; 4, circulation pump; 5, gradient cooling device; 6, anti Blocking component; 61, screw feeding column; 611, straight column; 612, helical blade; 62, support rod; 63, gear ring; 631, feed hole; 632, ring plate; ; 642, driving gear; 643, rotating shaft.

Detailed ways

The present application will be described in further detail below in conjunction with accompanying drawings 1-4 and embodiments.

Example

Example 1

In this example, a fluoroethylene carbonate was prepared, including the following components by weight: 100 kg of fluorinating agent, 0.5 kg of phase transfer catalyst, 250 L of organic solvent, and 298 kg of chloroethylene carbonate. Wherein, the fluorinating agent is anhydrous sodium hydrogen fluoride, the phase transfer catalyst is tetraphenylphosphine bromide, the organic solvent is ethyl acetate, and the chloroethylene carbonate is monochloroethylene carbonate.

This embodiment discloses an anti-blocking dynamic crystallization device.

Referring to Figure 1 and Figure 2, the anti-blocking dynamic crystallization device includes a reactor 1, a circulation pipe 2, an output pipe 3, a circulation pump 4 and a gradient cooling member 5, the top of the reactor 1 is welded with a feed pipe 11, and the reactor 1 The bottom end of the pipe is welded with a discharge pipe 12, and there are at least two circulation pipes 2. There are three circulation pipes 2 in this embodiment, and the three circulation pipes 2 are arranged sequentially from bottom to top. The bottom circulation pipe 2 and the discharge pipe 12 is welded and communicated with the discharge pipe 12, and the remaining circulation pipes 2 are welded on the peripheral wall of the reactor 1, and the ends of the three circulation pipes 2 away from the reactor 1 are all welded to the output pipe 3, and the circulation pipe 2 is connected to the output pipe 3 Circulation pump 4 and gradient cooling member 5 are all installed on the output pipe 3, the circulation pump 4 is connected with the output pipe 3, the discharge end of the output pipe 3 is welded to the top of the reaction kettle 1, the feed pipe 11, the discharge pipe Both the pipe 12 and the output pipe 3 are in communication with the reactor 1, an anti-blocking assembly 6 is installed on the inner wall of the discharge pipe 12, and a liquid control valve 21 is installed on the feed pipe 11, the discharge pipe 12 and the circulation pipe 2.

The liquid control valve 21 of the present embodiment is a solenoid valve, and the raw material enters the reaction kettle 1 from the feed pipe 11, and the circulation pump 4 sucks out the reaction solution in the reaction kettle 1 through the circulation pipe 2, and the reaction solution is mixed in the output pipe 3. Circulating fluid, the circulating fluid flows into the reactor 1 through the output pipe 3, and the gradient cooling unit 5 cools the circulating fluid in a gradient manner. The gradient cooling unit 5 in this embodiment is a tubular cooler. After the reaction is completed, the crystal-containing liquid is obtained, and the crystal-containing liquid is discharged from the discharge pipe 12, and the anti-blocking component 6 is started at the same time to assist in discharging the crystal-containing liquid.

Referring to FIG. 2 , the discharge pipe 12 includes a discharge pipe 122 , a receiving pipe 123 and an airtight box 124 . The top of the feeding pipe 122 is welded to the bottom of the reactor 1 , and the feeding pipe 122 communicates with the reactor 1 . The top wall of the airtight box 124 is welded to the bottom end of the feeding pipe 122, the bottom end of the feeding pipe 122 is inserted into the airtight box 124, the top of the receiving pipe 123 is welded to the bottom wall of the airtight box 124, and the top of the receiving pipe 123 is inserted into the airtight box. Inside box 124. The axis of the receiving pipe 123 is on the same straight line as the axis of the feeding pipe 122, and one of the liquid control valves 21 is installed on the receiving pipe 123, and the lowermost circulation pipe 2 is welded with the receiving pipe 123 and communicated with the receiving pipe 123.

The outer wall of the airtight box 124 is provided with a pressure regulating device 125 , and the pressure regulating device 125 includes an air pump 1251 , an air delivery pipe 1252 and a gas control valve 1253 . The air delivery pipe 1252 is welded on the side wall of the airtight box 124, the air delivery pipe 1252 communicates with the airtight box 124, and the end of the air delivery pipe 1252 away from the airtight box 124 is fixedly connected with the air outlet of the air pump 1251. The gas control valve 1253 is installed on the gas delivery pipe 1252 . An air pressure sensing element 126 is fixedly connected to the outer wall of the airtight box 124 , and the air pressure sensing element 126 is inserted into the airtight box 124 . The air pressure sensing element 126 in this embodiment is an air pressure sensor.

Referring to Fig. 2, the anti-blocking assembly 6 is located in the airtight box 124. The anti-blocking assembly 6 includes a screw feeding column 61, a support rod 62, a toothed ring 63 and a driving member 64. The middle part of the toothed ring 63 is provided with a feed hole 631, and the spiral The feeding column 61 is inserted in the feeding hole 631 . The spiral blanking column 61 includes a straight column 611 and a spiral blade 612, the spiral blade 612 is welded on the peripheral wall of the straight column 611, the spiral blade 612 spirally extends from top to bottom, and the axis of the straight column 611 is at the same axis as the through hole 631. in a straight line. The support rod 62 is located in the feed hole 631 , one end of the support rod 62 is welded to the wall of the feed hole 631 , and the other end of the support rod 62 is welded to the peripheral wall of the straight post 611 .

Referring to Fig. 3 and Fig. 4, the gear ring 63 is located between the feeding pipe 122 and the receiving pipe 123, the end walls at both ends of the gear ring 63 are welded with ring plates 632, the end wall at the bottom of the feeding pipe 122 and the top of the receiving pipe 123 Ring grooves 121 are provided on the end walls, and the ring plate 632 is inserted into the ring groove 121, and the ring plate 632 abuts against the groove wall of the ring groove 121; in a straight line.

The driving member 64 includes a driving motor 641, a driving gear 642 and a rotating shaft 643. Two vertically opposite supporting plates 1241 are welded on the inner wall of the airtight box 124, and the driving motor 641 is riveted on the supporting plate 1241 above. The driving gear 642 is welded on the motor shaft of the driving motor 641, the driving gear 642 and the rotating shaft 643 are located between the two support plates 1241, the rotating shaft 643 is welded on the driving gear 642, and the driving gear 642 is located between the driving motor 641 and the rotating shaft 643 . The axes of the rotating shaft 643 , the driving gear 642 and the motor shaft are all on the same straight line, and the end of the rotating shaft 643 away from the driving gear 642 is rotationally connected with the support plate 1241 located below, and the driving gear 642 meshes with the outer ring wall of the gear ring 63 .

The crystal-containing liquid flows out of the reaction kettle 1 from the feeding pipe 122, the driving motor 641 drives the driving gear 642 and the gear ring 63 to rotate, the support rod 62, the straight column 611 and the helical blade 612 all follow the gear ring 63 to rotate synchronously, and the helical blade 612 disturbs the containing Crystalloids, fluids containing crystalloids accelerate flow.

The preparation technology of the fluoroethylene carbonate of present embodiment, comprises the steps:

Mixing: firstly put the fluorinating agent, the phase transfer catalyst and the organic solvent into the reactor 1 from the feed pipe 11, and mix well to obtain a mixed solution.

Dynamic crystallization: raise the temperature of the reactor 1 to 90°C, operate the liquid control valve 21 on the feed pipe 11, and add chloroethylene carbonate from the feed pipe 11 to the reactor 1 dropwise, and keep the speed during the dropping process After 1 hour, all the chloroethylene carbonate was added dropwise into Reactor 1 to obtain a reaction liquid. Keep the temperature of the reaction kettle 1 at 90° C., and carry out the heat preservation reaction. According to the height interval, the interval where the reaction solution is located is divided into at least two position areas from bottom to top. This embodiment is divided into three position areas, and the height of each position area is 420mm. The pipe 2 is opposite, and the three bit areas are called the lower area, the middle area and the upper area from bottom to top.

Before the heat preservation reaction starts, open the gas control valve 1253, start the air pump 1251, and the air pump 1251 delivers gas to the airtight box 124, and the air pressure sensor 126 detects the air pressure in the airtight box 124. When the air pressure is the same, close the gas control valve 1253 and the air pump 1251. Then open the liquid control valve 21 on each circulation pipe 2, and start the circulation pump 4 and the driving motor 641 to suck out the reaction liquid in each position area respectively. The driving motor 641 drives the driving gear 642 to rotate, the driving gear 642 drives the gear ring 63 to rotate, the gear ring 63 drives the support rod 62, the straight column 611 and the helical blade 612 to rotate, the helical blade 612 stirs the reaction liquid, and the reaction liquid accelerates to flow.

The reaction solution in each circulation pipe 2 flows into the output pipe 3 and mixes to obtain a circulating liquid. The circulating liquid flows along the output pipe 3, and the temperature of the gradient cooling unit 5 is adjusted to 37.5°C. The circulating fluid flows from the gradient cooling unit 5 After passing through, it flows into the reactor 1 from the top of the reactor 1, and the circulating liquid is mixed with the reaction liquid.

After the heat preservation reaction for 1.2 hours, close the liquid control valve 21 on the bottom circulation pipe 2, stop sucking out the reaction solution in the lower zone, and continue to suck out the reaction solution in the middle zone and the upper zone. After 1.7 hours of heat preservation reaction, close the liquid control valve 21 on the circulation pipe 2 in the middle, stop sucking out the reaction solution in the middle zone, and continue to suck out the reaction solution in the upper zone. After the heat preservation reaction for 2 hours, the liquid control valve 21 and the circulation pump 4 on the uppermost circulation pipe 2 are closed, and the heat preservation reaction is completed to obtain a liquid containing crystals.

Filtration: Start to centrifuge the crystal-containing liquid. After solid-liquid separation, crude crystals and mother liquor are obtained, and the mother liquor is recovered for further use.

Purification: Put the crude crystals into the rectification kettle for rectification and purification, collect the fraction at 77-82°C/3mmHg, then add the fraction to the melting crystallizer, crystallize at 12-19°C, sweat at 20-23°C , to obtain fluoroethylene carbonate.

Example 2

Referring to Fig. 5, the difference between this embodiment and Embodiment 1 is that there are two circulation pipes 2 in this embodiment, and the two circulation pipes 2 are arranged sequentially from bottom to top, and the circulation pipe 2 at the bottom is welded and connected to the receiving pipe 123. It communicates with the receiving pipe 123 , and the upper circulation pipe 2 is welded to the top of the reaction kettle 1 and communicated with the reaction kettle 1 .

In the dynamic crystallization stage, the site area of this embodiment is divided into two from bottom to top, and the height of each site area is 630mm. The two site areas are respectively called the lower site area and the upper site area from bottom to top. After 1.5 hours of heat preservation reaction, close the liquid control valve 21 on the circulation pipe 2 below, stop sucking out the reaction solution in the lower zone, and continue to suck out the reaction solution in the upper zone. After the heat preservation reaction for 2 hours, close the liquid control valve 21 and the circulation pump 4 on the upper circulation pipe 2, and the heat preservation reaction ends, and the liquid containing crystals is obtained.

Example 3

Referring to Figure 6, the difference between this embodiment and Embodiment 1 is that there are six circulation pipes 2 in this embodiment, and the six circulation pipes 2 are arranged sequentially from bottom to top, and the circulation pipe 2 at the bottom is welded to the receiving pipe 123 And communicate with the receiving pipe 123, the circulation pipe 2 at the top is welded to the top of the reactor 1 and communicated with the reactor 1, and the rest of the circulation pipes 2 are welded on the peripheral wall of the reactor 1.

In the dynamic crystallization stage, the site area of this embodiment is divided into six from bottom to top, and the height of each site area is 210 mm. After the heat preservation reaction for 1 hour, close the liquid control valve 21 on the lowermost circulation pipe 2, stop sucking out the reaction solution in the lowermost zone, and continue to suck out the reaction solution in other zones. Then every 0.2 hours, the liquid control valve 21 on the circulation pipe 2 is closed sequentially from bottom to top, and after the heat preservation reaction for 2 hours, the circulation pump 4 is closed, and the heat preservation reaction is completed to obtain a liquid containing crystals.

Example 4

The difference between this embodiment and Embodiment 1 is that in the dynamic crystallization stage, the temperature of gradient cooling is 35°C.

Example 5

The difference between this embodiment and Embodiment 1 is that in the dynamic crystallization stage, the temperature of the gradient cooling is 40°C.

Example 6

The difference between this example and Example 1 is that in the dynamic crystallization stage, the temperature of the reactor 1 was raised to 50°C, and the temperature of the reactor 1 was kept at 50°C.

Example 7

The difference between this example and Example 1 is that in the dynamic crystallization stage, the temperature of the reactor 1 was raised to 130°C, and the temperature of the reactor 1 was kept at 130°C.

Application example

Application example 1-7

The application examples 1-7 all provide a lithium battery, and the fluoroethylene carbonate obtained in the examples 1-7 is sequentially added to the electrolyte of the lithium battery in the application examples 1-7.

comparative example

Comparative example 1

The difference between this comparative example and embodiment 1 is that this comparative example has only one circulation pipe 2 , and the circulation pipe 2 is welded to the receiving pipe 123 and communicated with the receiving pipe 123 .

In the dynamic crystallization stage, there is only one position area in this comparative example, and the height of the position area in this comparative example is 1260mm. After the heat preservation reaction for 2 hours, close the liquid control valve 21 and the circulation pump 4 on the circulation pipe 2, and the heat preservation reaction ends, and obtains Contains crystalloids.

Comparative example 2

The difference between this comparative example and Example 1 is that in the dynamic crystallization stage, the temperature of the reactor 1 was raised to 45°C, and the temperature of the reactor 1 was kept at 45°C.

Comparative example 3

The difference between this comparative example and Example 1 is that in the dynamic crystallization stage, the temperature of the reactor 1 was raised to 135°C, and the temperature of the reactor 1 was kept at 135°C.

performance test

Using a GC9800A gas chromatograph, and using ethyl salicylate as an internal standard, the yields of the fluoroethylene carbonates prepared in Examples 1-7 and Comparative Examples 1-3 were calculated by the internal standard standard curve method. The purity of the fluoroethylene carbonate prepared in Examples 1-7 and Comparative Examples 1-3 was calculated by the area normalization method. The test results are shown in Table 1.

Table 1 The test result table of embodiment 1-7 and comparative example 1-3

In conjunction with Example 1-3 and Comparative Example 1 and in conjunction with Table 1, it can be seen that compared to Comparative Example 1, the yield and purity of Example 1-3 are significantly increased, which shows that using the preparation process of the present application, When there are at least two sites, it helps to improve the yield and purity of fluoroethylene carbonate.

In conjunction with Example 1, Examples 6-7 and Comparative Examples 2-3 and in conjunction with Table 1, it can be seen that compared to Example 1, the yield and purity of Comparative Examples 2-3 are smaller, which shows that in this In the dynamic crystallization stage of the preparation process of the application, the reaction temperature is controlled in the range of 50-130° C., which helps to improve the yield of fluoroethylene carbonate.

In conjunction with Example 1 and Example 4-5 and in conjunction with Table 1, it can be seen that the yield and purity of Example 1 and Example 4-5 are all relatively large, which shows that in the dynamic crystallization stage, the temperature of gradient cooling is 35- In the range of 40°C, it helps to increase the yield of fluoroethylene carbonate.

This specific embodiment is only an explanation of this application, and it is not a limitation of this application. Those skilled in the art can make modifications to this embodiment without creative contribution according to needs after reading this specification, but as long as the rights of this application All claims are protected by patent law.

Claims

A kind of preparation technology of fluoroethylene carbonate, is characterized in that, comprises the steps,

Mixing: Mix the fluorinating agent, phase transfer catalyst and organic solvent evenly to obtain a mixed solution;

Dynamic crystallization: Add chloroethylene carbonate dropwise to the mixed solution at 50-130°C to obtain a reaction solution. The reaction solution is subjected to a heat preservation reaction, and the reaction solution is divided according to the height interval from bottom to top. There are at least two position zones. During the heat preservation reaction, the reaction solution in each position zone is sucked out and then mixed to obtain a circulating fluid. The circulating fluid is subjected to gradient cooling and then mixed with the reaction solution. After the reaction solution in the unit area, the heat preservation reaction ends, and the liquid containing crystals is obtained;

Filtration: solid-liquid separation of crystal-containing liquid to obtain crude crystals and mother liquor;

Purification: Purify the crude crystals by rectification to obtain fluoroethylene carbonate.
A preparation process of fluoroethylene carbonate according to claim 1, characterized in that: the height of the at least two positions is 210-630mm.
A preparation process of fluoroethylene carbonate according to claim 1, characterized in that: in the dynamic crystallization stage, the range of gradient cooling is 35-40°C.
The preparation process of a kind of fluoroethylene carbonate according to claim 1, characterized in that: the mixing stage and the dynamic crystallization stage are carried out in an anti-blocking type dynamic crystallization device, and the anti-blocking type dynamic crystallization device includes a reaction Kettle (1), circulation pipe (2), output pipe (3), circulation pump (4) and gradient cooling member (5), described reaction kettle (1) is provided with feed pipe (11) and discharge pipe (12), there are at least two circulating pipes (2), and the circulating pipes (2) are arranged sequentially from bottom to top, and the circulating pipes (2) are communicated with the reactor (1), all of the The end of the circulation pipe (2) away from the reaction kettle (1) is connected with the output pipe (3), and the outlet pipe (3) is connected with the reaction kettle (1), and the gradient cooling member (5) and the circulation pump (4) are all installed on the output pipe (3), all the circulation pipes (2) are equipped with a liquid control valve (21), and the discharge pipe (12) is provided with a Flow anti-blocking assembly (6).
A preparation process of fluoroethylene carbonate according to claim 4, characterized in that: the anti-blocking assembly (6) comprises a screw feeding column (61), a support rod (62), a toothed ring (63) and a drive member (64) for driving the gear ring (63) to rotate, the gear ring (63) is rotatably connected to the discharge pipe (12), and the gear ring (63) is provided with a feed hole (631 ), the feed hole (631) communicates with the discharge pipe (12), the support rod (62) is fixedly connected to the hole wall of the feed hole (631), and the spiral lowering column (61) passes through Set in the feed hole (631), the screw feeding column (61) is fixedly connected with the support rod (62), the driving part (64) is installed on the discharge pipe (12), and the driving part ( 64) link to each other with gear ring (63).
The preparation process of a kind of fluoroethylene carbonate according to claim 5, is characterized in that: described driving member (64) comprises driving motor (641), driving gear (642) and rotating shaft (643), and described driving The motor (641) is fixedly connected to the discharge pipe (12), the drive gear (642) is fixedly connected to the motor shaft of the drive motor (641), and the drive gear (642) meshes with the ring gear (63), The rotating shaft (643) is rotatably connected to the discharge pipe (12), and the rotating shaft (643) is fixedly connected to the driving gear (642).
A kind of preparation technology of fluoroethylene carbonate according to claim 5, is characterized in that: the end wall of described ring gear (63) is provided with ring plate (632), and the discharge pipe (12) A ring groove (121) is provided on the pipe wall, the ring plate (632) is inserted in the ring groove (121), and the ring plate (632) abuts against the groove wall of the ring groove (121).
A kind of preparation technology of fluoroethylene carbonate according to claim 4, is characterized in that: described discharge pipe (12) comprises feed pipe (122), receiving pipe (123) and airtight box (124), The feeding pipe (122) is communicated with the reactor (1), and the feeding pipe (122) and the receiving pipe (123) are all fixedly connected on the airtight box (124), and the feeding pipe (122) and The receiving pipes (123) are all inserted in the airtight box (124), the anti-blocking assembly (6) is arranged in the airtight box (124), and the feeding pipe (122) and the receiving pipe (123) are all connected with the anti-blocking box (124). The blocking assembly (6) is connected, the feeding pipe (122) is communicated with the receiving pipe (123), and the airtight box (124) is equipped with a pressure regulator (125) for adjusting the air pressure in the airtight box (124), An air pressure sensor (126) for monitoring the air pressure in the airtight box (124) is installed on the airtight box (124).
A kind of preparation technology of fluoroethylene carbonate according to claim 8, it is characterized in that: described air regulating device (125) comprises air pump (1251), air delivery pipe (1252) and gas control valve (1253), the said One end of the air delivery pipe (1252) is connected with the airtight box (124), the other end of the air delivery pipe (1252) is connected with the intake end of the air pump (1251), and the gas control valve (1253) is installed in the air delivery pipe (1252) on.
A lithium battery using fluoroethylene carbonate, characterized in that: the electrolyte of the lithium battery contains the fluoroethylene carbonate obtained by the preparation process of any one of claims 1-9.