A method and device for preparing a lithium battery electrolyte additive

Abstract

The present invention relates to the technical field of lithium batteries, and specifically to a method and device for preparing a lithium battery electrolyte additive. The method and device comprise a reactor chamber, a feeding pipe, a nitrogen inlet pipe, a stirring hollow shaft, a tube wall dynamic hole, a lifting inner pipe, a shaft end gear disk, an airtight cannula, a tetrachloroethylene inlet pipe, and an air exhaust pipe. The upper portion of the reactor chamber is connected and provided with a feeding pipe and a nitrogen inlet pipe. A stirring hollow shaft is provided inside the reactor chamber for vertical rotation. The stirring hollow shaft is in the shape of a cylindrical tube with upper and lower openings. The surface of the stirring hollow shaft is penetrated by the tube wall dynamic hole. The preparation device of the present invention is suitable for the preparation of lithium battery electrolyte additives. The stirring hollow shaft, the tube wall dynamic hole, the lifting inner pipe and other structures cooperate with each other, so that during the nitrogen replacement process, the air in the reactor chamber can be efficiently discharged, so that the oxygen content inside the reactor chamber is quickly reduced and the nitrogen loss is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium batteries, and in particular to a method and device for preparing a lithium battery electrolyte additive. Background Art

[0002] The lithium battery electrolyte formula is an important component of the lithium battery, which directly affects the performance and life of the lithium battery. The lithium battery electrolyte is composed of solvents, salts and additives. Different formulas will affect the performance and safety of the lithium battery. The additives in the lithium battery electrolyte are mainly stabilizers, inhibitors, flame retardants, etc. These additives can improve the stability, safety and durability of the lithium battery electrolyte, and enhance the performance and life of the lithium battery. In the existing technology, during the preparation of lithium battery electrolyte additives, nitrogen and tetrachloroethylene are lost significantly, resulting in low economic benefits. Summary of the Invention

[0003] The object of the present invention is to provide a method and apparatus for preparing a lithium battery electrolyte additive to solve the problems raised in the above background technology.

[0004] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a lithium battery electrolyte additive preparation device, comprising a reactor chamber, a feeding pipe, a nitrogen inlet pipe, a stirring hollow shaft, a tube wall dynamic hole, a lifting inner tube, a shaft end gear plate, an airtight cannula, a tetrachloroethylene inlet pipe and an air exhaust pipe, the upper part of the reactor chamber is connected to the feeding pipe and the nitrogen inlet pipe, the interior of the reactor chamber is vertically rotated with a stirring hollow shaft, the stirring hollow shaft is cylindrical and tubular, with upper and lower openings, and the surface of the stirring hollow shaft is penetrated by an opening. A dynamic hole is provided in the tube wall, and a lifting inner tube is provided inside the stirring hollow shaft. The lifting inner tube is in sealing contact with the inner wall surface of the stirring hollow shaft. A height control mechanism with a relative rotation function is provided below the lifting inner tube. The upper end of the stirring hollow shaft is located outside the reactor bin and is fixed with a shaft end gear disk. The internal seal of the shaft end gear disk is inserted with an airtight cannula, and the airtight cannula is connected to the upper part of the stirring hollow shaft. The upper part of the airtight cannula is connected with a tetrachloroethylene input pipe and an air exhaust pipe.

[0005] A gas temporary storage mechanism with a clutch control function is provided on the outside of the mixing hollow shaft, and the gas temporary storage mechanism can collect and temporarily store the gas inside the reactor chamber and release it at a fixed time.

[0006] A liquid level sensor is vertically provided on the inner wall surface of the reactor bin. The height control mechanism includes a connecting rod, a limit chuck, a rotating block, a telescopic cylinder shaft, a sealing base and a bottom control cylinder. The connecting rod is fixedly provided on the lower end surface of the lifting inner tube. A limit chuck is fixedly provided on the lower part of the connecting rod. A rotating block is rotatably provided on the center position of the limit chuck. The telescopic cylinder shaft is fixedly provided on the lower surface of the rotating block. A sealing base is fixedly provided on the inner lower surface of the reactor bin. The telescopic cylinder shaft seal is inserted through the sealing base. The bottom control cylinder is provided on the lower part of the telescopic cylinder shaft.

[0007] The gas temporary storage mechanism includes a supporting outer ring, a gear push spring, a shaft-moving tooth, a limiting vertical ridge and an engaging push plate. The supporting outer ring is fixedly arranged on the outer surface of the mixing hollow shaft. The outside of the mixing hollow shaft is located above the supporting outer ring and is sleeved with a gear push spring. The outside of the mixing hollow shaft is located above the gear push spring and is sleeved with a shaft-moving tooth. The outer surface of the mixing hollow shaft is fixedly provided with a limiting vertical ridge. The limiting vertical ridge is limitedly matched with the shaft-moving tooth, and an engaging push plate is provided above the shaft-moving tooth.

[0008] An engaging drive cylinder is fixedly provided on the inner upper surface of the reactor bin, and the engaging drive cylinder drives the engaging push plate to move up and down. A driven large tooth is rotatably provided on one side of the shaft-driven tooth near the lower position. When the shaft-driven tooth moves downward, it can engage with the driven large tooth. An intermittent disc is fixedly provided on the upper surface of the driven large tooth, and a straight single tooth is fixedly provided on the side surface of the intermittent disc.

[0009] A linear top shaft is provided on the outside of the intermittent disc, and top shaft teeth are provided on the surface of the linear top shaft. The linear single tooth can engage with the top shaft teeth. A top shaft seat is fixedly provided on the inner upper surface of the reactor chamber, and the linear top shaft passes through the top shaft seat.

[0010] A piston outer cavity is provided inside the reactor chamber, and a piston disk is airtightly provided inside the piston outer cavity. The end of the linear top shaft is fixedly installed on the piston disk. A piston one-way valve is embedded through the surface of the piston disk. An inner spacer is fixedly provided inside the piston outer cavity. The piston one-way valve allows gas to flow in one direction from the outside of the piston outer cavity to the inside of the piston outer cavity.

[0011] A return spring is provided between the inner partition plate and the piston plate, a partition plate one-way valve is embedded through the surface of the inner partition plate, a compressed gas cylinder is fixedly provided on the inner upper surface of the reactor chamber, the outer cavity of the piston is connected to the compressed gas cylinder through the partition plate one-way valve, the partition plate one-way valve allows gas to flow in one direction from the inside of the outer cavity of the piston to the inside of the compressed gas cylinder, and an electrically controlled air release valve is provided at the bottom of the compressed gas cylinder.

[0012] A heating ring is provided inside the reactor bin, a discharge pipe is provided at the bottom of the reactor bin, a pressure sensor is provided on the upper surface of the reactor bin, a gear drive mechanism is provided on the upper surface of the reactor bin, and the gear drive mechanism drives the gear at the end of the shaft to rotate. Electromagnetic valves are respectively provided inside the discharge pipe, the feeding pipe, the nitrogen input pipe, the tetrachloroethylene input pipe and the air exhaust pipe, and a stirring blade is fixedly provided on the surface of the hollow stirring shaft.

[0013] A method for preparing a lithium battery electrolyte additive, using a lithium battery electrolyte additive preparation device, comprises the following steps:

[0014] Step 1: Add potassium hydroxide to trifluoroethanol and dissolve it completely to obtain a potassium alcoholate mixed solution;

[0015] Step 2: The potassium alcoholate mixed solution and deionized water are transported to a lithium battery electrolyte additive preparation device. At room temperature, the gas in the lithium battery electrolyte additive preparation device is replaced with nitrogen, and the oxygen concentration is made ≤30ppm; then tetrafluoroethylene is introduced to increase the pressure inside the lithium battery electrolyte additive preparation device to 0.8-0.85MPa;

[0016] Step 3: Heat while stirring and maintain the reaction at 70°C. When the internal pressure of the lithium battery electrolyte additive preparation device drops to 0.6MPa, add tetrafluoroethylene and continue the reaction until there is no more pressure drop;

[0017] Step 4: After the reaction is completed, cool to room temperature, drain the unreacted tetrafluoroethylene and discharge the material, collect the reaction liquid, and purify it by water washing, liquid separation, and distillation to obtain the target product, and dehydrate it using 4A molecular sieve to obtain the electrolyte additive.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The preparation device of the present invention is suitable for preparing lithium battery electrolyte additives. The hollow stirring shaft, dynamic holes in the tube wall, and the lifting inner tube cooperate with each other, so that during the nitrogen replacement process, the air in the reactor chamber can be efficiently discharged, so that the oxygen content inside the reactor chamber is quickly reduced and nitrogen loss is reduced; because the density of nitrogen is lower than that of air, the above-mentioned structures can adapt to the liquid level in the reactor chamber, so that the air discharge port is adaptively located at the bottom close to the liquid surface. Therefore, when nitrogen is filled from the top, the air can be efficiently squeezed out from the bottom, reducing nitrogen loss; and during the tetrachloroethylene input process, the dynamic holes in the tube wall can be converted to an outward jetting state, and in combination with the rotation and stirring of the hollow stirring shaft, the ejected tetrachloroethylene gas can be fully mixed with the reaction liquid, thereby improving the reaction efficiency.

[0020] By setting up a gas temporary storage mechanism, the tetrafluoroethylene mixed gas can be automatically recovered and stored during the process of emptying the incompletely reacted tetrafluoroethylene, so that the internal pressure of the reactor chamber is converted to normal pressure, thereby facilitating discharge; and in the next reaction, the recovered tetrafluoroethylene mixed gas can be fed back to the reactor chamber, reducing the loss of tetrafluoroethylene and improving economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0022] Figure 2 It is a front view of the overall structure of the present invention.

[0023] Figure 3 It is a schematic cross-sectional view of the reactor chamber of the present invention.

[0024] Figure 4 for Figure 3 Enlarged schematic diagram of area A in the middle.

[0025] Figure 5 This is a schematic diagram of the reactor chamber of the present invention cut away from another angle.

[0026] Figure 6 It is a three-dimensional half-section schematic diagram of the overall structure of the present invention.

[0027] Figure 7 for Figure 6 Enlarged schematic diagram of area B in the middle.

[0028] Figure 8 for Figure 6 Enlarged schematic diagram of area C in the middle.

[0029] Figure 9 It is a three-dimensional half-section schematic diagram of the outer cavity of the piston of the present invention.

[0030] Figure 10 for Figure 9 Enlarged schematic diagram of area D in the middle.

[0031] Figure: 1, reactor chamber; 2, feed pipe; 3, nitrogen inlet pipe; 4, mixing hollow shaft; 5, dynamic hole in tube wall; 6, lifting inner tube; 7, shaft end gear plate; 8, airtight cannula; 9, tetrachloroethylene inlet pipe; 10, air exhaust pipe; 601, liquid level sensor; 602, connecting rod; 603, limit chuck; 604, rotating block; 605, telescopic cylinder shaft; 606, sealing base; 607, bottom control cylinder; 401, support outer ring; 402, gear push spring; 403, shaft moving tooth; 404, limit vertical edge; 405, meshing push plate; 406. Meshing drive cylinder; 407. Driven large tooth; 408. Intermittent disc; 409. Linear single tooth; 410. Linear top shaft; 411. Top shaft teeth; 412. Top shaft seat; 413. Piston outer cavity; 414. Piston disc; 415. Piston one-way valve; 416. Inner spacer; 417. Return spring; 418. Spacer one-way valve; 419. Compressed gas cylinder; 420. Electric control air release valve; 101. Heating ring; 102. Discharge pipe; 103. Pressure sensor; 104. Tooth disc drive mechanism; 105. Solenoid valve; 421. Stirring blade. DETAILED DESCRIPTION

[0032] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0033] See also Figures 1 to 10 The present invention provides a technical solution: a lithium battery electrolyte additive preparation device, comprising a reactor chamber 1, a feeding pipe 2, a nitrogen input pipe 3, a stirring hollow shaft 4, a tube wall dynamic hole 5, a lifting inner tube 6, a shaft end gear plate 7, an airtight cannula 8, a tetrachloroethylene input pipe 9 and an air exhaust pipe 10, the upper part of the reactor chamber 1 is connected with the feeding pipe 2 and the nitrogen input pipe 3, the interior of the reactor chamber 1 is vertically rotated with a stirring hollow shaft 4, the stirring hollow shaft 4 is cylindrical, with upper and lower openings, and the surface of the stirring hollow shaft 4 is penetrated A dynamic hole 5 is penetrated through the tube wall, and a lifting inner tube 6 is provided inside the stirring hollow shaft 4. The lifting inner tube 6 is in sealing contact with the inner wall surface of the stirring hollow shaft 4. A height control mechanism with a relative rotation function is provided below the lifting inner tube 6. The upper end of the stirring hollow shaft 4 is located outside the reactor bin 1 and is fixed with a shaft end gear disk 7. The internal seal of the shaft end gear disk 7 is inserted with an airtight cannula 8, which is connected to the upper part of the stirring hollow shaft 4. The upper part of the airtight cannula 8 is connected with a tetrachloroethylene input pipe 9 and an air exhaust pipe 10.

[0034] A gas temporary storage mechanism with a clutch control function is provided on the outside of the stirring hollow shaft 4 , and the gas temporary storage mechanism can collect and temporarily store the gas inside the reactor chamber 1 and release it at a fixed time.

[0035] A liquid level sensor 601 is vertically provided on the inner wall surface of the reactor bin 1. The height control mechanism includes a connecting rod 602, a limit chuck 603, a rotating block 604, a telescopic cylinder shaft 605, a sealing base 606 and a bottom control cylinder 607. The connecting rod 602 is fixedly provided on the lower end surface of the lifting inner tube 6. The limit chuck 603 is fixedly provided at the lower part of the connecting rod 602. The rotating block 604 is rotatably provided at the center position of the limit chuck 603. The telescopic cylinder shaft 605 is fixedly provided on the lower surface of the rotating block 604. A sealing base 606 is fixedly provided on the inner lower surface of the reactor bin 1. The telescopic cylinder shaft 605 is sealed and inserted through the sealing base 606. The bottom control cylinder 607 is provided at the lower part of the telescopic cylinder shaft 605.

[0036] The gas temporary storage mechanism includes a supporting outer ring 401, a gear push spring 402, an axially moving tooth 403, a limiting vertical ridge 404 and an engaging push plate 405. The supporting outer ring 401 is fixedly arranged on the outer surface of the mixing hollow shaft 4. The outside of the mixing hollow shaft 4 is located above the supporting outer ring 401 and is sleeved with a gear push spring 402. The outside of the mixing hollow shaft 4 is located above the gear push spring 402 and is sleeved with an axially moving tooth 403. The outer surface of the mixing hollow shaft 4 is fixedly provided with a limiting vertical ridge 404. The limiting vertical ridge 404 is limited by the axially moving tooth 403, and an engaging push plate 405 is provided above the axially moving tooth 403.

[0037] An engaging drive cylinder 406 is fixedly provided on the inner upper surface of the reactor chamber 1, and the engaging drive cylinder 406 drives the engaging push plate 405 to move up and down. A driven large tooth 407 is rotated and provided near the lower position on one side of the shaft-driven tooth 403. When the shaft-driven tooth 403 moves downward, it can engage with the driven large tooth 407. An intermittent disc 408 is fixedly provided on the upper surface of the driven large tooth 407, and a straight single tooth 409 is fixedly provided on the side surface of the intermittent disc 408.

[0038] A linear top shaft 410 is provided on the outside of the intermittent disc 408, and a top shaft tooth 411 is provided on the surface of the linear top shaft 410. The linear single tooth 409 can engage with the top shaft tooth 411. A top shaft seat 412 is fixedly provided on the inner upper surface of the reactor chamber 1, and the linear top shaft 410 passes through the top shaft seat 412.

[0039] The reactor chamber 1 is provided with a piston outer chamber 413, and the interior of the piston outer chamber 413 is airtightly provided with a piston disk 414. The end of the linear top shaft 410 is fixedly installed with the piston disk 414. A piston one-way valve 415 is embedded through the surface of the piston disk 414. An inner partition disk 416 is fixedly provided inside the piston outer chamber 413. The piston one-way valve 415 allows gas to flow in one direction from the outside of the piston outer chamber 413 to the inside of the piston outer chamber 413.

[0040] A return spring 417 is provided between the inner partition plate 416 and the piston plate 414. A partition plate one-way valve 418 is embedded through the surface of the inner partition plate 416. A compressed gas cylinder 419 is fixedly provided on the inner upper surface of the reactor chamber 1. The piston outer cavity 413 is connected to the compressed gas cylinder 419 through the partition plate one-way valve 418. The partition plate one-way valve 418 allows the gas to flow in one direction from the inside of the piston outer cavity 413 to the inside of the compressed gas cylinder 419. An electrically controlled air release valve 420 is provided at the bottom of the compressed gas cylinder 419.

[0041] A heating ring 101 is provided inside the reactor bin 1, which is responsible for heating the internal liquid of the reactor bin 1. A discharge pipe 102 is provided at the bottom of the reactor bin 1. A pressure sensor 103 is provided on the upper surface of the interior of the reactor bin 1. The pressure sensor 103 can detect the gas pressure inside the reactor bin 1, thereby facilitating timely replenishment of tetrachloroethylene. A gear drive mechanism 104 is provided on the upper surface of the reactor bin 1. The gear drive mechanism 104 drives the shaft end gear disc 7 to rotate. The gear drive mechanism 104 is composed of a motor and a gear, and is engaged with the shaft end gear disc 7 through the gear to drive the shaft end gear disc 7 to rotate. The discharge pipe 102, the feeding pipe 2, the nitrogen input pipe 3, the tetrachloroethylene input pipe 9 and the air exhaust pipe 10 are respectively provided with an electromagnetic valve 105, and a stirring blade 421 is fixedly provided on the surface of the hollow stirring shaft 4.

[0042] A method for preparing a lithium battery electrolyte additive, using a lithium battery electrolyte additive preparation device, comprises the following steps:

[0043] Step 1: Add potassium hydroxide to trifluoroethanol and dissolve it completely to obtain a potassium alcoholate mixed solution;

[0044] Step 2: The potassium alcoholate mixed solution and deionized water are transported to a lithium battery electrolyte additive preparation device. At room temperature, the gas in the lithium battery electrolyte additive preparation device is replaced with nitrogen, and the oxygen concentration is made ≤30ppm; then tetrafluoroethylene is introduced to increase the pressure inside the lithium battery electrolyte additive preparation device to 0.8-0.85MPa;

[0045] Step 3: Heat while stirring and maintain the reaction at 70°C. When the internal pressure of the lithium battery electrolyte additive preparation device drops to 0.6MPa, add tetrafluoroethylene and continue the reaction until there is no more pressure drop;

[0046] Step 4: After the reaction is completed, cool to room temperature, drain the unreacted tetrafluoroethylene and discharge the material, collect the reaction liquid, and purify it by water washing, liquid separation, and distillation to obtain the target product, and dehydrate it using 4A molecular sieve to obtain the electrolyte additive.

[0047] When the lithium battery electrolyte additive preparation device of the present invention is in use, the potassium alcohol mixed solution is input through the feeding pipe 2, the nitrogen input pipe 3 is connected to the external pressure nitrogen source, the tetrachloroethylene input pipe 9 is connected to the external tetrachloroethylene gas source, and the solenoid valves 105 of each part are in a normally closed state.

[0048] The liquid level sensor 601 detects the liquid level of the potassium alcoholate mixed solution and deionized water mixed solution inside the reactor chamber 1, and then controls the bottom control cylinder 607 to extend and retract so that the limit chuck 603 is flush with the liquid level. At this time, the lower end of the lifting inner tube 6 is at a fixed height from the liquid level, and the electromagnetic valves 105 corresponding to the air exhaust pipe 10 and the nitrogen inlet pipe 3 are opened simultaneously. Nitrogen is input into the upper position inside the reactor chamber 1 through the nitrogen inlet pipe 3. Since the density of nitrogen is lower than that of air, it is in a floating state inside the reactor chamber 1, squeezing the air in the reactor chamber 1 from top to bottom into the dynamic holes 5 in the tube wall, and then discharged from the air exhaust pipe 10 through the lifting inner tube 6, thereby quickly reducing the oxygen concentration inside the reactor chamber 1 to ≤30ppm, reducing the loss of nitrogen escape;

[0049] After the nitrogen replacement is completed, the electromagnetic valves 105 corresponding to the air exhaust pipe 10 and the nitrogen input pipe 3 are closed again, and the electromagnetic valve 105 corresponding to the tetrachloroethylene input pipe 9 is opened. The tetrachloroethylene gas is input through the tetrachloroethylene input pipe 9, passes through the stirring hollow shaft 4 and the lifting inner tube 6, and is ejected from the dynamic holes 5 in the tube wall; during the tetrachloroethylene replenishment process, the stirring hollow shaft 4 rotates and stirs to cooperate with the dynamic holes 5 in the tube wall to eject the tetrachloroethylene gas, which can make the tetrachloroethylene fully react with the waves stirred by the stirring, and under the rotation of the stirring hollow shaft 4, the tetrachloroethylene gas ejected from the dynamic holes 5 in the tube wall can be evenly and quickly filled in the interior of the reactor chamber 1, thereby improving the reaction efficiency.

[0050] When the unreacted tetrafluoroethylene is emptied, the stirring hollow shaft 4 is first maintained to rotate and stir, and then the meshing drive cylinder 406 is extended to drive the meshing push plate 405 to push the shaft-moving tooth 403 downward, so that the shaft-moving tooth 403 is meshed with the driven large tooth 407 for transmission. When the driven large tooth 407 rotates, the intermittent disc 408 intermittently meshes with the top shaft tooth 411 through the linear single tooth 409, thereby causing the linear top shaft 410 to move linearly, and with the cooperation of the return spring 417, the linear top shaft 410 is reciprocated, through The piston disc 414 and the piston one-way valve 415 suck the gas inside the reactor chamber 1 into the piston outer cavity 413, and squeeze it into the compressed gas cylinder 419 under high pressure for storage until the inside of the reactor chamber 1 is at normal pressure, and then the gas is discharged through the discharge pipe 102; before the secondary preparation and filling of tetrachloroethylene gas, the electronically controlled air release valve 420 is first controlled to open to discharge the tetrachloroethylene mixed gas stored in the compressed gas cylinder 419, and then replenish it through the tetrachloroethylene input pipe 9, thereby reducing the loss of tetrachloroethylene and improving economic benefits.

[0051] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A device for preparing a lithium battery electrolyte additive, comprising a reactor chamber (1), a feeding pipe (2), a nitrogen inlet pipe (3), a stirring hollow shaft (4), a dynamic hole in the tube wall (5), a lifting inner tube (6), a shaft end gear plate (7), an airtight cannula (8), a tetrachloroethylene inlet pipe (9) and an air exhaust pipe (10), characterized in that: The upper part of the reactor chamber (1) is connected to a feeding pipe (2) and a nitrogen inlet pipe (3), and a stirring hollow shaft (4) is vertically rotated inside the reactor chamber (1). The stirring hollow shaft (4) is in a cylindrical tubular shape with upper and lower openings. The surface of the stirring hollow shaft (4) is penetrated by a tube wall dynamic hole (5). The interior of the stirring hollow shaft (4) is provided with a lifting inner tube (6), and the lifting inner tube (6) is in sealing contact with the inner wall surface of the stirring hollow shaft (4). A height control mechanism with a relative rotation function is provided below the lifting inner tube (6). The upper end of the stirring hollow shaft (4) is located outside the reactor chamber (1) and is fixedly provided with a shaft end toothed disk (7). The interior of the shaft end toothed disk (7) is sealed and inserted with an airtight cannula (8). The airtight cannula (8) is connected to the upper part of the stirring hollow shaft (4), and the upper part of the airtight cannula (8) is connected to a tetrachloroethylene inlet pipe (9) and an air exhaust pipe (10); A liquid level sensor (601) is vertically provided on the inner wall surface of the reactor chamber (1). The height control mechanism comprises a connecting rod (602), a limiting chuck (603), a rotating block (604), a telescopic cylinder shaft (605), a sealing base (606) and a bottom control cylinder (607). The connecting rod (602) is fixedly provided on the lower end surface of the lifting inner tube (6). The limiting chuck (603) is fixedly provided on the lower portion of the connecting rod (602). The rotating block (604) is rotatably provided at the center position of the limiting chuck (603). The telescopic cylinder shaft (605) is fixedly provided on the lower surface of the rotating block (604). The sealing base (606) is fixedly provided on the inner lower surface of the reactor chamber (1). The telescopic cylinder shaft (605) is sealed and inserted through the sealing base (606). The bottom control cylinder (607) is provided on the lower portion of the telescopic cylinder shaft (605).

2. The lithium battery electrolyte additive preparation device according to claim 1, characterized in that: A gas temporary storage mechanism with a clutch control function is provided on the outside of the stirring hollow shaft (4), and the gas temporary storage mechanism can collect and temporarily store the gas inside the reactor chamber (1) and release it at a fixed time.

3. The lithium battery electrolyte additive preparation device according to claim 2, characterized in that: The gas temporary storage mechanism comprises a supporting outer ring (401), a gear push spring (402), a shaft-moving tooth (403), a limiting vertical ridge (404) and an engaging push plate (405); the supporting outer ring (401) is fixedly arranged on the outer surface of the mixing hollow shaft (4); the gear push spring (402) is sleeved and installed on the outside of the mixing hollow shaft (4) above the supporting outer ring (401); the shaft-moving tooth (403) is sleeved and installed on the outside of the mixing hollow shaft (4) above the gear push spring (402); the outer surface of the mixing hollow shaft (4) is fixedly provided with a limiting vertical ridge (404); the limiting vertical ridge (404) is limitedly engaged with the shaft-moving tooth (403); and an engaging push plate (405) is arranged above the shaft-moving tooth (403).

4. The lithium battery electrolyte additive preparation device according to claim 3, characterized in that: An engaging drive cylinder (406) is fixedly provided on the inner upper surface of the reactor chamber (1), and the engaging drive cylinder (406) drives the engaging push plate (405) to move up and down. A driven large tooth (407) is rotatably provided on one side of the shaft-moving tooth (403) near the lower position. When the shaft-moving tooth (403) moves downward, it can engage with the driven large tooth (407). An intermittent disc (408) is fixedly provided on the upper surface of the driven large tooth (407), and a straight single tooth (409) is fixedly provided on the side surface of the intermittent disc (408).

5. The lithium battery electrolyte additive preparation device according to claim 4, characterized in that: A linear top shaft (410) is provided on the outside of the intermittent disc (408), and top shaft teeth (411) are provided on the surface of the linear top shaft (410). The linear single tooth (409) can engage with the top shaft teeth (411). A top shaft seat (412) is fixedly provided on the inner upper surface of the reactor chamber (1), and the linear top shaft (410) passes through the top shaft seat (412).

6. The lithium battery electrolyte additive preparation device according to claim 5, characterized in that: The reactor chamber (1) is provided with a piston outer chamber (413), the interior of the piston outer chamber (413) is provided with a piston disc (414) in an airtight manner, the end of the linear top shaft (410) is fixedly mounted on the piston disc (414), a piston one-way valve (415) is embedded through the surface of the piston disc (414), and an inner spacer (416) is fixedly provided inside the piston outer chamber (413), and the piston one-way valve (415) allows gas to flow in one direction from the outside of the piston outer chamber (413) to the inside of the piston outer chamber (413).

7. The lithium battery electrolyte additive preparation device according to claim 6, characterized in that: A return spring (417) is provided between the inner spacer (416) and the piston disk (414); a spacer one-way valve (418) is embedded in the surface of the inner spacer (416); a compressed gas cylinder (419) is fixedly provided on the inner upper surface of the reactor chamber (1); the piston outer cavity (413) is connected to the compressed gas cylinder (419) through the spacer one-way valve (418); the spacer one-way valve (418) allows gas to flow in one direction from the inside of the piston outer cavity (413) to the inside of the compressed gas cylinder (419); and an electrically controlled air release valve (420) is provided at the bottom of the compressed gas cylinder (419).

8. The lithium battery electrolyte additive preparation device according to claim 1, characterized in that: A heating ring (101) is provided inside the reactor chamber (1), a discharge pipe (102) is provided at the bottom of the reactor chamber (1), a pressure sensor (103) is provided on the upper surface of the reactor chamber (1), a toothed disc drive mechanism (104) is provided on the upper surface of the reactor chamber (1), and the toothed disc drive mechanism (104) drives the shaft end toothed disc (7) to rotate. Solenoid valves (105) are provided inside the discharge pipe (102), the feeding pipe (2), the nitrogen inlet pipe (3), the tetrachloroethylene inlet pipe (9), and the air exhaust pipe (10), respectively. A stirring blade (421) is fixedly provided on the surface of the stirring hollow shaft (4).

9. A method for preparing a lithium battery electrolyte additive, characterized in that: The lithium battery electrolyte additive preparation device according to any one of claims 1 to 8 comprises the following steps: Step 1: Add potassium hydroxide to trifluoroethanol and dissolve it completely to obtain a potassium alcoholate mixed solution; Step 2: The potassium alcoholate mixed solution and deionized water are transported to a lithium battery electrolyte additive preparation device. At room temperature, the gas in the lithium battery electrolyte additive preparation device is replaced with nitrogen, and the oxygen concentration is made ≤30ppm; then tetrafluoroethylene is introduced to increase the pressure inside the lithium battery electrolyte additive preparation device to 0.8-0.85MPa; Step 3: Heat while stirring and maintain the reaction at 70°C. When the internal pressure of the lithium battery electrolyte additive preparation device drops to 0.6MPa, add tetrafluoroethylene and continue the reaction until there is no more pressure drop; Step 4: After the reaction is completed, cool to room temperature, drain the unreacted tetrafluoroethylene and discharge the material, collect the reaction liquid, and purify it by water washing, liquid separation, and distillation to obtain the target product, and dehydrate it using 4A molecular sieve to obtain the electrolyte additive.

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