A method for synthesizing polystyrene-based single-ion conductor copolymers with controllable side chain structures

Abstract

This invention relates to the field of polymer materials technology, and particularly to a method for synthesizing a polystyrene-based single-ion conductor copolymer with a controllable side chain structure. The process steps include: (1) Synthesis of PEG macromonomer: First, through DCC / DMAP-catalyzed esterification, mPEG with terminal hydroxyl groups is reacted with 4-vinylbenzoic acid to prepare a polymerizable PEG macromonomer mPEG-4-vinylbenzoate; (2) Synthesis of anionic monomer: STFSIK monomer with polymerizable vinyl groups and strongly delocalized negatively charged anions is prepared; (3) Copolymerization reaction: A comb-like copolymer with both PEG side chains and potassium imine salt side chains is formed; (4) Ion exchange: The potassium-containing copolymer is reacted with lithium perchlorate to obtain the final target product. The synthesis route of this invention is clear. Through four well-defined chemical reactions, a complex single-ion conductor is synthesized. It is highly controllable and reproducible, and its performance is adjustable.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, and in particular to a method for synthesizing a single-ion conductor solid polymer electrolyte for electrochemical energy storage devices (such as lithium batteries). Background Technology

[0002] Traditional lithium-ion batteries generally use organic carbonate liquid electrolytes, whose flammability and leakage characteristics pose major safety risks. Solid polymer electrolytes (SPEs), with their inherent safety, flexibility, and ease of processing, are considered an ideal alternative to liquid electrolytes for achieving high-energy-density lithium metal batteries. Among various SPEs, PEG-based electrolytes have attracted considerable attention due to their excellent lithium salt solubility. However, in traditional PEG-based electrolytes, both anions and cations can move freely, resulting in a low lithium-ion transference number (t⁺) (typically less than 0.2). This can cause significant concentration polarization during battery charging and discharging, limiting the battery's rate performance and inducing lithium dendrite growth.

[0003] To address this issue, single-ion conductor polymer electrolytes have emerged. Their core design involves covalently binding anions to the polymer backbone, thereby restricting their migration and bringing t⁺ close to 1. This design effectively alleviates concentration polarization, improving battery power output and cycle stability. Existing technologies typically employ two strategies: one is to polymerize lithium-containing monomers; the other is to chemically modify existing polymers to introduce anionic groups. However, to achieve excellent overall performance, the electrolyte needs to provide efficient lithium-ion transport channels (such as PEG segments) while simultaneously binding anions. Integrating these two functional groups onto the same polymer chain is an advanced but challenging design. Therefore, developing a novel single-ion conductor with a clear synthetic route, controllable structure, and the ability to synergistically optimize ionic conductivity and mechanical properties has significant research and application value. Summary of the Invention

[0004] The purpose of this invention is to provide a method for synthesizing a novel single-ion conductor copolymer with a well-defined synthetic route and controllable structure. This copolymer integrates fixed anionic groups and flexible PEG solvation segments, aiming to improve lithium-ion transference number and electrochemical performance.

[0005] To address the aforementioned technical problems, this invention provides a method for synthesizing polystyrene-based single-ion conductor copolymers with controllable side chain structures. The technical solution employed is a multi-step synthesis method, with the following process steps: (1) Synthesis of PEG macromonomer: First, through DCC / DMAP catalyzed esterification reaction, mPEG with terminal hydroxyl groups is reacted with 4-vinylbenzoic acid to prepare polymerizable PEG macromonomer (mPEG-4-vinylbenzoate).

[0006] (2) Synthesis of anionic monomers: Using 4-styrenesulfonyl chloride as raw material, react with trifluoromethylsulfonamide, and then neutralize to form potassium salt to prepare a monomer (STFSIK) with polymerizable vinyl groups and a strong delocalized negatively charged anion.

[0007] (3) Copolymerization reaction: The two functional monomers mentioned above are connected to the same polymer backbone in aqueous solution by free radical polymerization reaction to form a comb copolymer with both PEG side chain and imine potassium salt side chain.

[0008] (4) Ion exchange: The potassium-containing copolymer is reacted with lithium perchlorate to exchange potassium ions for lithium ions, thus obtaining the final target product.

[0009] The core advantage of this invention lies in its high designability. By selecting mPEG raw materials with different molecular weights and precisely controlling the feed ratio of the two monomers, the length of the PEG chain and the density of anionic groups in the final polymer can be easily adjusted, thereby controlling the EO:Li molar ratio within the optimal range and optimizing the ionic conductivity.

[0010] Preferably, the synthesis steps of the polystyrene-based single-ion conductor copolymer with a controllable side chain structure of the present invention include: Step (1): Synthesis of mPEG-4-vinylbenzoate mPEG, 4-vinylbenzoic acid, DCC, and DMAP were placed in a four-necked flask, the flask was purged, and then filled with nitrogen. Dichloromethane was added to dissolve the mixture, and the mixture was stirred at room temperature. After filtration, the filtrate was concentrated by rotary evaporation. The resulting concentrate was reprecipitated with pre-cooled diethyl ether, filtered, and the solid was dried under vacuum to obtain a white solid product, mPEG-4-vinylbenzoic acid ester. Step (2): Synthesis of STFSIK Oxaloyl chloride and DMF were added to anhydrous acetonitrile and stirred to promote the formation of a complex. When the solution turned yellow, sodium 4-styrenesulfonate was slowly added to the solution under a nitrogen atmosphere and at room temperature. The mixture was stirred to obtain a 4-styrenesulfonyl chloride solution for later use. Triethylamine, trifluoromethylsulfonamide, and DMAP were added to anhydrous acetonitrile in sequence and stirred until completely dissolved. The pre-prepared 4-styrenesulfonyl chloride solution was cooled, and the above mixture was added dropwise with stirring, followed by a reaction at room temperature. After the reaction was completed, the solvent was removed by vacuum distillation, and the resulting brown solid was dissolved in dichloromethane. The organic phase was washed successively with aqueous NaHCO3 and aqueous HCl solutions. After separation, the acidic monomer was neutralized with excess aqueous K2CO3 solution. The organic phase was stirred, separated, and dried, and rotary evaporated to obtain the crude product. The crude product was recrystallized in water to obtain pure STFSIK. Step (3): Synthesis of potassium-containing copolymer electrolyte mPEG-4-vinylbenzoate, STFSIK, and deionized water were added to a three-necked flask and deoxygenated by bubbling with nitrogen. Ammonium persulfate initiator was added, and the resulting solution was heated under a nitrogen stream. After the reaction was completed, the solution was cooled, and most of the water was removed by vacuum evaporation to obtain a glassy polymer. To remove unreacted monomers and impurities, the polymer was dissolved in DMSO and then reprecipitated in THF. This dissolution-precipitation process was repeated three times, and finally, the polymer was dried under vacuum to obtain a pure potassium-containing copolymer. Step (4): Synthesis of lithium-containing copolymer electrolyte The dried potassium-containing copolymer electrolyte obtained in step (3) was placed in ethanol, and then an excess of LiClO4 was added. The solution was added and stirred continuously. During the reaction, a white precipitate of potassium perchlorate was precipitated and removed by filtration. The filtrate was passed through a multifunctional rotary evaporator to remove the solvent and obtain a pale yellow solid. For further purification, the solid was dissolved in DMSO and then precipitated in THF. The purification steps were repeated three times, and finally vacuum dried to obtain the target product, namely the lithium-containing single-ion conductor copolymer electrolyte.

[0011] As a preferred embodiment, the method for synthesizing polystyrene-based single-ion conductor copolymers with controllable side chain structures specifically includes: Step (1): Synthesis of mPEG-4-vinylbenzoate 10-40 g mPEG, 1.78 g 4-vinylbenzoic acid, 24.8 g DCC and 1.2 g DMAP were placed in a flask, the flask was purged, and then filled with nitrogen. Dichloromethane was added to dissolve the mixture, and the mixture was stirred at room temperature. After filtration, the filtrate was concentrated by rotary evaporation. The resulting concentrate was reprecipitated with pre-cooled diethyl ether, filtered, and the solid was dried under vacuum to obtain a white solid product, mPEG-4-vinylbenzoic acid ester. Step (2): Synthesis of STFSIK 2.0 mL of oxalyl chloride and 0.087 g of DMF were added to 40 mL of anhydrous acetonitrile and stirred for 5 hours to promote complex formation. When the solution turned yellow, 4 g of sodium 4-styrenesulfonate was slowly added to the solution under a nitrogen atmosphere and at room temperature. The mixture was stirred for one day to obtain a 4-styrenesulfonyl chloride solution for later use. 8.1 mL of triethylamine, 2.89 g of trifluoromethylsulfonamide, and 9% molar amount of DMAP were added sequentially to 30 mL of anhydrous acetonitrile and stirred for 1 hour until completely dissolved. The pre-prepared 4-styrenesulfonyl chloride solution was cooled to 0°C, and the above mixture was slowly added dropwise under vigorous stirring, followed by a reaction at room temperature for 16 hours. After the reaction was completed, the solvent was removed by vacuum distillation, and the resulting brown solid was dissolved in 50 mL of dichloromethane. The organic phase was washed sequentially with 4% NaHCO3 aqueous solution and 1 M HCl aqueous solution. After separation, the acid monomer was neutralized with excess K2CO3 aqueous solution. After stirring for 1 hour, the organic phase was separated and dried, and rotary evaporated to obtain 4.2 g of sodium 4-styrenesulfonate. g crude product; recrystallization of the crude product in water yielded 3.63 g pure STFSIK, which was a light yellow powder; Step (3): Synthesis of potassium-containing copolymer electrolyte 1.13-4.13 g of mPEG-4-vinylbenzoate, 0.35 g of STFSIK, and 20 mL of deionized water were added to a three-necked flask and deoxygenated by bubbling under nitrogen for 30 minutes. 20 mg of ammonium persulfate initiator was added, and the resulting solution was heated to 80 °C under a nitrogen stream for one day. After the reaction, the solution was cooled, and most of the water was removed by vacuum evaporation to obtain a glassy polymer. To remove unreacted monomers and impurities, the polymer was dissolved in a small amount of DMSO and then reprecipitated in a large amount of THF. This dissolution-precipitation process was repeated three times, and finally, 0.82 g of pure potassium-containing copolymer was obtained by vacuum drying. Step (4): Synthesis of lithium-containing copolymer electrolyte 0.80 g of the dried potassium-containing copolymer electrolyte obtained in step (3) was placed in 50 mL of ethanol, followed by the addition of 0.53 g of excess LiClO4. The solution was heated to 45°C and stirred continuously for 12 hours. During the reaction, a white precipitate of potassium perchlorate was formed, which was removed by filtration. The filtrate was then passed through a multi-functional rotary evaporator to remove the solvent, yielding a pale yellow solid. For further purification, the solid was dissolved in a small amount of DMSO and then reprecipitated in a large amount of THF. The purification steps were repeated three times, and finally, the product was dried under vacuum to obtain the target product—a lithium-containing single-ion conductor copolymer electrolyte, 0.65 g of pale yellow solid.

[0012] Preferably, the multifunctional rotary evaporator used in step (4) includes a top frame and a rotary evaporator fixing mechanism. The rotary evaporator fixing mechanism includes gear B, a sleeve, a rotary evaporator flask, a suction tube, a pressure valve, and a sealing ring. Gear B is rotatably connected to the top of the top frame, the sleeve is rotatably connected to the inside of the top frame, gear B is fixedly sleeved on the outer surface of the sleeve, the rotary evaporator flask is threadedly sleeved on the outer surface of the sleeve, the suction tube is slidably connected to the inner wall of the sleeve, the pressure valve is fixedly connected to the top of the suction tube, and the sealing ring is fixedly sleeved on the outer surface of the sleeve, with the sealing ring in contact with the rotary evaporator flask.

[0013] Preferably, a support rod is fixedly connected to the surface of the top frame of the device, a device base is fixedly connected to the bottom of the support rod, a plurality of electric push rods are fixedly connected to the top of the device base, and a heating bath base is fixedly connected to the top of the electric push rods.

[0014] Preferably, the top of the heating bath base has a groove that matches the bottom of the rotary evaporator, and the groove contains a heating medium.

[0015] Preferably, a motor is fixedly connected to the bottom of the device top frame, and the output end of the motor extends to the top of the device top frame and is fixedly connected to a gear A, which meshes with a gear B.

[0016] Preferably, a support is fixedly connected to the top of the device's top frame, the filtration tube is slidably connected to the support, a connecting pipe is fixedly connected to the surface of the filtration tube, and a control valve is provided on the surface of the connecting pipe.

[0017] Preferably, a filtrate collection bottle is fixedly connected to the top of the device base, and a funnel is movably connected to the top of the filtrate collection bottle, with a connecting tube extending into the inside of the funnel.

[0018] Preferably, the rotary evaporator is provided with an anti-boiling bead inside, and the bottom of the suction tube extends into the interior of the rotary evaporator.

[0019] The step (1) further includes the following: The synthesis of mPEG-4-vinylbenzoate includes placing 10 mmol mPEG, 12 mmol 4-vinylbenzoic acid, 120 mmol DCC and 10 mmol DMAP in a flask, purging the flask, and filling it with nitrogen; then adding dichloromethane to dissolve it, and stirring the mixture at room temperature; after filtration, the filtrate is concentrated by rotary evaporation; the resulting concentrate is reprecipitated with pre-cooled diethyl ether, filtered to obtain a solid, and vacuum dried to obtain a white solid product mPEG-4-vinylbenzoate.

[0020] In summary, the present invention has the following beneficial effects: (1) Clear synthetic route: This method starts from commercially available raw materials and synthesizes complex single-ion conductors through four well-defined chemical reactions, with strong controllability and repeatability.

[0021] (2) Structural integration: The PEG chain that solubilizes lithium ions and the anionic group that provides lithium ions are integrated on the same polymer backbone, which avoids the phase separation problem that may be caused by polymer blending and is conducive to the formation of a stable and efficient ion transport network.

[0022] (3) Performance is adjustable: By precisely controlling the monomer structure (mPEG molecular weight) and copolymer composition (monomer ratio), the EO:Li ratio of the material can be systematically adjusted, providing an effective way to optimize and customize the electrolyte performance for specific application scenarios.

[0023] (4) The multifunctional rotary evaporator of the present invention has a rotary evaporation fixing mechanism that connects the rotary evaporation flask and the sleeve through a threaded connection. This allows for precise control of the fixing force, ensuring that the evaporation flask remains stable during rotation and preventing it from shifting or falling off. The fixing operation can be completed quickly without repeated adjustments, simplifying the operation process and improving experimental efficiency. At the same time, the fixed connection structure of the gear and the sleeve provides stable transmission support for the rotation of the evaporation flask. In conjunction with the sealing ring, it enhances the sealing effect and further assists in fixing the evaporation flask, reducing the influence of external factors on the fixing stability and improving the experimental accuracy and yield of the present invention. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the main body of the multifunctional rotary evaporator of the present invention; Figure 2 This is a schematic diagram of the internal structure of the multifunctional rotary evaporator of the present invention; Figure 3 This is a schematic diagram showing the disassembled multifunctional rotary evaporator of the present invention; Figure 4 This is a schematic diagram of the working state of the multifunctional rotary evaporator of the present invention.

[0025] Reference numerals in the attached diagram: 1. Top frame of the device; 2. Support rod; 3. Base of the device; 4. Electric push rod; 5. Base of the heating bath; 6. Controller; 7. Motor; 8. Gear A; 9. Gear B; 10. Sleeve; 11. Rotary evaporation flask; 12. Anti-bumping inner bead; 13. Vacuum filtration tube; 14. Pressure valve; 15. Connecting pipe; 16. Control valve; 17. Funnel; 18. Filtrate collection bottle; 19. Sealing ring; 20. Support. Detailed Implementation

[0026] The invention will now be described in detail with reference to examples.

[0027] Example 1

[0028] Synthesis of polystyrene-based single-ion conductor copolymers with controllable side chain structures, number-average molecular weight of mPEG ( M n (The concentration is 1000 g / mol, the molar ratio of PEG-4-vinylbenzoate to STFSIK monomer is 1:1, and EO:Li = 22.5) Step (1): Synthesis of mPEG-4-vinylbenzoate 10 g (10 mmol) of mPEG, 1.78 g (12 mmol) of 4-vinylbenzoic acid, 24.8 g (120 mmol) of DCC, and 1.2 g (10 mmol) of DMAP were placed in a 150 mL four-necked flask, the flask was purged, and then filled with nitrogen. 100 mL of dichloromethane was added to dissolve the mixture, and the mixture was stirred at room temperature for 48 h. After filtration, the filtrate was concentrated by rotary evaporation. The resulting concentrate was reprecipitated with pre-cooled diethyl ether, filtered, and dried under vacuum to give 9.1 g of a white solid product, mPEG-4-vinylbenzoate, in 81% yield.

[0029] Step (2): Synthesis of STFSIK 2.0 mL of oxaloyl chloride (23.3 mmol) and DMF (0.087 g, 1 mmol) were added to 40 mL of anhydrous acetonitrile and stirred for 5 hours to promote complex formation. When the solution turned yellow, 4 g of sodium 4-styrenesulfonate was slowly added to the solution under a nitrogen atmosphere and at room temperature. The mixture was stirred for one day to obtain a 4-styrenesulfonyl chloride solution for later use. 8.1 mL (58.1 mmol) of triethylamine, 2.89 g (19.4 mmol) of trifluoromethylsulfonamide, and 9% molar amount of DMAP were added sequentially to 30 mL of anhydrous acetonitrile and stirred for 1 hour until completely dissolved. The pre-prepared 4-styrenesulfonyl chloride solution was cooled to 0 °C, and the above mixture was slowly added dropwise under vigorous stirring, followed by a reaction at room temperature for 16 hours. After the reaction was complete, the solvent was removed by vacuum distillation, and the resulting brown solid was dissolved in 50 mL of dichloromethane. The organic phase was washed sequentially with 4% NaHCO3 aqueous solution (2 × 20 mL) and 1 M HCl aqueous solution (20 mL). After separation, the acidic monomer (present in the organic phase) was neutralized with excess aqueous K₂CO₃ solution. After stirring for 1 hour, the organic phase was separated and dried, and rotary evaporation yielded 4.2 g of crude product. The crude product was recrystallized in water to give 3.63 g of pure STFSIK as a light yellow powder, with a yield of 53%.

[0030] Step (3): Synthesis of potassium-containing copolymer electrolyte 1.13 g (1 mmol) of mPEG-4-vinylbenzoate, 0.35 g (1 mmol) of STFSIK, and 20 mL of deionized water were added to a three-necked flask, and the mixture was deoxygenated by bubbling under nitrogen for 30 minutes. 20 mg of ammonium persulfate initiator was added, and the resulting solution was heated to 80 °C under a nitrogen stream for one day. After the reaction was complete, the solution was cooled, and most of the water was removed by vacuum evaporation to obtain a glassy polymer. To remove unreacted monomers and impurities, the polymer was dissolved in a small amount of DMSO, followed by reprecipitation in a large amount of THF. This dissolution-precipitation process was repeated three times, and finally, 0.82 g of pure potassium-containing copolymer was obtained by vacuum drying, with a yield of 55%.

[0031] Step (4): Synthesis of lithium-containing copolymer electrolyte (ion exchange) 0.80 g of the dried potassium-containing copolymer electrolyte obtained in step (3) was placed in 50 mL of ethanol, followed by the addition of 0.53 g (5 mmol) of excess LiClO4. The solution was heated to 45°C and stirred continuously for 12 hours. During the reaction, a white precipitate of potassium perchlorate was formed, which was removed by filtration. The filtrate was passed through a multi-functional rotary evaporator to remove the solvent, yielding a pale yellow solid. For further purification, the solid was dissolved in a small amount of DMSO and then reprecipitated in a large amount of THF. The purification steps were repeated three times, and finally dried under vacuum to obtain the target product—a lithium-containing single-ion conductor copolymer electrolyte, 0.65 g of pale yellow solid, with a yield of 81%.

[0032] Please see Figure 1-4 The multifunctional rotary evaporator used in step (4) includes: The top of the device's top frame 1 is rotatably connected to gear B9, internally rotatably connected to sleeve 10, fixedly connected to motor 7 at the bottom, and fixedly connected to support rod 2 and bracket 20 on the surface, providing stable support for each component, ensuring the overall structural stability, and preventing shaking during operation from affecting experimental accuracy.

[0033] The top frame 1 of the device, through its rotational engagement with gear B9 and sleeve 10, and its fixed connection with motor 7, support rod 2, and bracket 20, forms the core support framework of the device, laying the foundation for the coordinated operation of subsequent components.

[0034] The bottom of the support rod 2 is fixedly connected to the base 3 of the device, and the surface is fixedly connected to the controller 6. Through the fixed connection at both ends, the top frame 1 of the device and the base 3 of the device are connected as one unit to form a complete device frame. At the same time, it provides an installation carrier for the controller 6, which is convenient for operation and control.

[0035] The support rod 2 is made of metal and has good load-bearing capacity and stability. Its connection structure can effectively distribute the weight transmitted by the top frame 1 of the device, avoid deformation after long-term use, and ensure the reliability of the overall structure of the device.

[0036] Multiple electric push rods 4 and filtrate collection bottles 18 are fixedly connected to the top of the device base 3. The base is made of heavy metal plate as the main material. The fixed connection provides stable support for the electric push rods 4 and provides a platform for placing the filtrate collection bottles 18 to ensure the stability of the components during the experiment.

[0037] The electric push rod 4 is fixedly connected to the heating bath base 5 at the top. It achieves telescopic movement through electric drive. The position of the heating bath base 5 can be adjusted according to the height requirements of the rotating evaporation flask 11, so that the heating medium can accurately wrap around the bottom of the evaporation flask and improve heating efficiency.

[0038] The electric push rod 4 is fixedly connected to the heating bath base 5 with high-strength bolts to ensure that the heating bath base 5 does not shift during the adjustment process, and the push rod has high extension and retraction accuracy, which can meet the height adjustment requirements under different experimental scenarios.

[0039] The heating bath base 5 has a groove on the top that fits the bottom of the rotary evaporation flask 11. The groove contains the heating medium. By fitting the groove to the bottom of the rotary evaporation flask 11, the heating medium can evenly coat the evaporation flask, achieving uniform heating and avoiding local overheating that could damage the sample.

[0040] The heating bath base 5 is made of high-temperature resistant material and can withstand the heating temperature required for the experiment. Its groove has high dimensional accuracy and can fit tightly against the rotary evaporation flask 11, reducing heat loss and improving energy utilization.

[0041] The controller 6 is electrically connected to the heating bath base 5, and signal transmission and power supply are achieved through wires. It can accurately set the heating temperature of the heating bath base 5, and at the same time control the start, stop and speed of the motor 7, so as to realize centralized control of the device's operating parameters.

[0042] The output end of motor 7 extends to the top of the device top frame 1 and is fixedly connected to gear A8. Through the fixed connection between the output end and gear A8, the power of motor 7 is transmitted to gear A8, providing a power source for gear transmission and ensuring that the rotating parts can operate stably.

[0043] Gear A8 and gear B9 mesh together. Through precise meshing of the tooth surfaces, the power transmitted by motor 7 is converted into the rotational motion of gear B9, achieving smooth power transmission. The meshing clearance is small, reducing noise and energy loss during transmission.

[0044] Gear B9 is fixedly sleeved on the outer surface of sleeve 10, and the fixed connection is achieved through interference fit. When gear B9 rotates, it can directly drive sleeve 10 to rotate synchronously. The transmission process is without delay, ensuring that sleeve 10 can follow gear B9 to maintain a stable speed.

[0045] The fixed connection structure between gear B9 and sleeve 10 eliminates the need for additional connecting parts, simplifying the assembly process. At the same time, the tightness of the interference fit prevents relative slippage between gear B9 and sleeve 10, ensuring transmission accuracy.

[0046] The outer surface of the sleeve 10 is threaded to the rotary evaporator 11, the inner wall is slidably connected to the suction tube 13, and the outer surface is fixedly fitted with a sealing ring 19. The threaded connection enables quick loading and unloading of the rotary evaporator 11, the sliding connection facilitates the adjustment of the position of the suction tube 13, and the sealing ring enhances the sealing effect.

[0047] The rotary evaporation flask 11 is equipped with anti-bumping inner beads 12. By rolling the anti-bumping inner beads 12 in the liquid, the bubbles generated when the liquid boils are broken, preventing the liquid from splashing out and ensuring experimental safety. At the same time, the rotary evaporation flask 11 is made of high temperature resistant glass material with high transparency, which makes it easy to observe the state of the sample inside.

[0048] The rotary evaporator 11 and the sleeve 10 are connected by a threaded seal ring 19, which can achieve a good sealing effect and prevent solvent evaporation and leakage. The bottle body design meets the requirements of rotational dynamics, and the liquid can be evenly attached to the bottle wall when rotating, increasing the evaporation area.

[0049] The size of the anti-boiling inner bead 12 is matched with the volume of the rotary evaporation flask 11, and the number is appropriate. It can effectively suppress the boiling phenomenon without affecting the liquid flow, and avoid sample loss or experimental interruption due to boiling.

[0050] The top of the suction tube 13 is fixedly connected to the pressure valve 14, the surface is fixedly connected to the connecting tube 15, the bottom extends into the interior of the rotary evaporator 11, and is slidably connected to the support 20. The depth of the suction tube 13 into the evaporator can be adjusted by the sliding connection, while the fixed connection ensures that the pressure valve 14 and the connecting tube 15 are in stable position.

[0051] The pressure valve 14 is fixedly connected to the filtration tube 13, which can adjust the pressure in the filtration tube 13 according to the experimental requirements, ensuring that the system pressure is stable within a suitable range, preventing excessive pressure from damaging components or excessive pressure from affecting filtration efficiency. The valve has high adjustment accuracy and is easy to operate.

[0052] A control valve 16 is provided on the surface of the connecting tube 15. One end is fixedly connected to the suction tube 13, and the other end extends into the inside of the funnel 17. The fixed connection enables the suction tube 13 to communicate with the funnel 17. The control valve 16 can adjust the flow rate of liquid or gas to meet the needs of different experimental stages.

[0053] The connecting pipe 15 is made of transparent flexible tubing, which makes it easy to observe the internal fluid flow. It is flexible and can adapt to the position layout of various components of the device. The connection with the suction pipe 13 and the funnel 17 is fixed with clamps, which are tight and leak-proof.

[0054] The control valve 16, in conjunction with the connecting pipe 15, can quickly open or close the fluid passage. It is easy to operate during adjustment, and when the valve is closed, it has good sealing performance, which can effectively block the flow of fluid, prevent the backflow of filtrate or the leakage of solvent, and ensure the smooth progress of the experiment.

[0055] The funnel 17 is movably connected to the top of the filtrate collection bottle 18. Through the cooperation between the funnel opening and the connecting tube 15, it receives the liquid delivered from the connecting tube 15. The filtration structure of the funnel can separate impurities in the liquid, allowing pure liquid to flow into the filtrate collection bottle 18. The movable connection facilitates subsequent disassembly and cleaning of impurities inside the funnel.

[0056] The filtrate collection bottle 18 is fixedly connected to the top of the device base 3. The fixed connection ensures the stability of the collection bottle and prevents it from tipping over when the liquid overflows. The collection bottle is made of transparent material, which makes it easy to observe the amount of liquid collected inside. Its volume can be selected according to experimental needs to meet the collection needs of different sample amounts.

[0057] The filtrate collection bottle 18 fits tightly with the funnel 17, effectively receiving the filtered liquid. The scale markings on the bottle body allow for precise reading of the collected volume, facilitating experimental data recording. Furthermore, the bottle body material is resistant to chemical corrosion and can be adapted to the collection of various filtrates.

[0058] The sealing ring 19 is fixedly fitted onto the outer surface of the sleeve 10 and contacts the rotary evaporation flask 11. Through the elastic deformation of the sealing ring, the gap between the sleeve 10 and the rotary evaporation flask 11 is filled, enhancing the sealing performance of the connection between the two and preventing solvent from evaporating and leaking from the gap.

[0059] The sealing ring 19 is made of high-temperature resistant and chemically resistant rubber material, which has good elasticity and sealing performance. It is not easy to age when in contact with solvents for a long time and can maintain the sealing effect continuously. Its size is precisely matched to the connection part of the sleeve 10 and the rotary evaporator 11 to ensure a tight fit.

[0060] The bracket 20 is fixedly connected to the top of the device top frame 1 and slidably connected to the suction tube 13. The fixed connection provides support for the suction tube 13 and prevents the suction tube 13 from sagging due to its own weight. The sliding connection allows the suction tube 13 to be adjusted in position according to experimental needs, improving operational flexibility.

[0061] Working principle: During the experiment, a small amount of sample mixed with lutein is first poured into the rotary evaporation flask 11. Then, the temperature of the heating bath base 5 is set by the controller 6 to heat the internal heating medium, thereby heating the mixture in the rotary evaporation flask 11. The rotary evaporation flask 11 is rotated and fixed on the outer surface of the sleeve 10. The sealing ring 19 can enhance the sealing and fixation. The drive motor 7 drives the gears A8 and B9 to rotate, thereby rotating the sleeve 10 and the rotary evaporation flask 11. This causes the mixture to form a thin film on the inner wall of the flask, increasing the heating area and accelerating the volatilization of the dichloromethane emulsifier. The anti-boiling inner bead 12 rolls continuously with the liquid flow, impacting the bubbles that are forming in the flask, breaking the surface tension of the bubbles, and preventing them from agglomerating into large bubbles that can cause boiling. It uses its own weight to transfer heat, making the temperature distribution inside the flask more uniform and reducing sudden boiling caused by local overheating. When vacuum filtration is required, the negative pressure is created by controlling valve 16 to draw the liquid in the rotary evaporator 11 into the funnel 17. The liquid is then filtered through the funnel 17, and impurities remain in the funnel 17. The filtered liquid enters the filtrate collection bottle 18. During this process, pressure valve 14 adjusts the pressure in the system as needed. After the rotary evaporation is completed, the rotary evaporator 11 is stopped from rotating, and the heating and pressure control are turned off. At this time, a dark red powdery solid will remain in the rotary evaporator 11.

[0062] Example 2

[0063] Synthesis of polystyrene-based single-ion conductor copolymers with controllable side chain structures, mPEG M n (The molar ratio of PEG-4-vinylbenzoate to STFSIK monomer is 1:2, and the EO:Li ratio is 22.5, with a concentration of 2000 g / mol.) Step (1): Synthesis of mPEG-4-vinylbenzoate 20 g (10 mmol) of mPEG, 1.78 g (12 mmol) of 4-vinylbenzoic acid, 24.8 g (120 mmol) of DCC, and 1.2 g (10 mmol) of DMAP were placed in a 150 mL four-necked flask, the flask was purged, and then filled with nitrogen. Subsequent steps were the same as in Example 1, yielding 18.6 g of a white solid product, mPEG-4-vinylbenzoate, in 87% yield.

[0064] Step (2): The synthesis of STFSIK is the same as in Example 1. Step (3): Synthesis of potassium-containing copolymer electrolyte 2.13 g (1 mmol) of mPEG-4-vinylbenzoate, 0.35 g of STFSIK, and 20 mL of deionized water were added to a three-necked flask, and the mixture was deoxygenated by bubbling with nitrogen for 30 minutes. Subsequent steps were the same as in Example 1, yielding 1.44 g of pure potassium-containing copolymer, with a yield of 58%.

[0065] Step (4): The synthesis of the lithium-containing copolymer electrolyte is the same as in Example 1, yielding a pale yellow solid with a yield of 79%.

[0066] Example 3

[0067] Synthesis of polystyrene-based single-ion conductor copolymers with controllable side chain structures, mPEG M n (The molar ratio of PEG-4-vinylbenzoate to STFSIK monomer is 1:4, and the EO:Li ratio is 22.5, with a concentration of 4000 g / mol.) Step (1): Synthesis of mPEG-4-vinylbenzoate 40 g (10 mmol) of mPEG, 1.78 g (12 mmol) of 4-vinylbenzoic acid, 24.8 g (120 mmol) of dicyclohexylcarbodiimide (DCC), and 1.2 g (10 mmol) of 4-dimethylaminopyridine (DMAP) were placed in a 150 mL four-necked flask, the flask was purged, and then filled with nitrogen. Subsequent steps were the same as in Example 1, yielding 36.9 g of a white solid product, mPEG-4-vinylbenzoate, in 88.3% yield.

[0068] Step (2): The synthesis of STFSIK is the same as in Example 1. Step (3): Synthesis of potassium-containing copolymer electrolyte 4.13 g (1 mmol) of mPEG-4-vinylbenzoate, 0.35 g of STFSIK, and 20 mL of deionized water were added to a three-necked flask, and the mixture was deoxygenated by bubbling with nitrogen for 30 minutes. Subsequent steps were the same as in Example 1, yielding 2.64 g of pure potassium-containing copolymer, with a yield of 59%.

[0069] Step (4): The synthesis of the lithium-containing copolymer electrolyte is the same as in Example 1, yielding a pale yellow solid with a yield of 77%.

[0070] This specific embodiment is merely an explanation of the present invention and is not intended to limit the invention. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they are within the scope of the claims of the present invention.

Claims

1. A method for synthesizing a polystyrene-based single-ion conductor copolymer with a controllable side chain structure, characterized in that... The process steps are as follows: (1) Synthesis of PEG macromonomer: First, mPEG with terminal hydroxyl groups is reacted with 4-vinylbenzoic acid through DCC / DMAP catalytic esterification reaction to prepare polymerizable PEG macromonomer mPEG-4-vinylbenzoate. (2) Synthesis of anionic monomers: Using 4-styrenesulfonyl chloride as raw material, react with trifluoromethylsulfonamide, and then neutralize to form potassium salt, prepare the monomer STFSIK with polymerizable vinyl groups and strongly delocalized negatively charged anions; (3) Copolymerization reaction: The two functional monomers mentioned above are connected to the same polymer backbone in aqueous solution by free radical polymerization reaction to form a comb copolymer with both PEG side chain and imine potassium salt side chain; (4) Ion exchange: The potassium-containing copolymer is reacted with lithium perchlorate to exchange potassium ions for lithium ions, thus obtaining the final target product.

2. The method for synthesizing a polystyrene-based single-ion conductor copolymer with a controllable side chain structure according to claim 1, characterized in that... include: Step (1): Synthesis of mPEG-4-vinylbenzoate mPEG, 4-vinylbenzoic acid, DCC, and DMAP were placed in a four-necked flask, the flask was purged, and then filled with nitrogen. Dichloromethane was added to dissolve the mixture, and the mixture was stirred at room temperature. After filtration, the filtrate was concentrated by rotary evaporation. The resulting concentrate was reprecipitated with pre-cooled diethyl ether, filtered, and the solid was dried under vacuum to obtain a white solid product, mPEG-4-vinylbenzoic acid ester. Step (2): Synthesis of STFSIK Oxaloyl chloride and DMF were added to anhydrous acetonitrile and stirred to promote the formation of a complex. When the solution turned yellow, sodium 4-styrenesulfonate was slowly added to the solution under a nitrogen atmosphere and at room temperature. The mixture was stirred to obtain a 4-styrenesulfonyl chloride solution for later use. Triethylamine, trifluoromethylsulfonamide, and DMAP were added to anhydrous acetonitrile in sequence and stirred until completely dissolved. The pre-prepared 4-styrenesulfonyl chloride solution was cooled, and the above mixture was added dropwise with stirring, followed by a reaction at room temperature. After the reaction was completed, the solvent was removed by vacuum distillation, and the resulting brown solid was dissolved in dichloromethane. The organic phase was washed successively with aqueous NaHCO3 and aqueous HCl solutions. After separation, the acidic monomer was neutralized with excess aqueous K2CO3 solution. The organic phase was stirred, separated, and dried, and rotary evaporated to obtain the crude product. The crude product was recrystallized in water to obtain pure STFSIK. Step (3): Synthesis of potassium-containing copolymer electrolyte mPEG-4-vinylbenzoate, STFSIK, and deionized water were added to a three-necked flask and deoxygenated by bubbling with nitrogen. Ammonium persulfate initiator was added, and the resulting solution was heated under a nitrogen stream. After the reaction was completed, the solution was cooled, and most of the water was removed by vacuum evaporation to obtain a glassy polymer. To remove unreacted monomers and impurities, the polymer was dissolved in DMSO and then reprecipitated in THF. This dissolution-precipitation process was repeated three times, and finally, the polymer was dried under vacuum to obtain a pure potassium-containing copolymer. Step (4): Synthesis of lithium-containing copolymer electrolyte The dried potassium-containing copolymer electrolyte obtained in step (3) was placed in ethanol, and then an excess of LiClO4 was added; the solution was added and stirred continuously; during the reaction, a white precipitate of potassium perchlorate was precipitated, which was removed by filtration; The solvent was removed from the filtrate using a multi-functional rotary evaporator to obtain a pale yellow solid. For further purification, the solid was dissolved in DMSO and then reprecipitated in THF. The purification steps were repeated three times, and finally vacuum dried to obtain the target product, namely the lithium-containing single-ion conductor copolymer electrolyte.

3. The method for synthesizing a polystyrene-based single-ion conductor copolymer with a controllable side chain structure according to claim 2, characterized in that... include: Step (1): Synthesis of mPEG-4-vinylbenzoate 10-40 g mPEG, 1.78 g 4-vinylbenzoic acid, 24.8 g DCC and 1.2 g DMAP were placed in a flask, the flask was purged, and then filled with nitrogen. Dichloromethane was added to dissolve the mixture, and the mixture was stirred at room temperature. After filtration, the filtrate was concentrated by rotary evaporation. The resulting concentrate was reprecipitated with pre-cooled diethyl ether, filtered, and the solid was dried under vacuum to obtain a white solid product, mPEG-4-vinylbenzoic acid ester. Step (2): Synthesis of STFSIK 2.0 mL of oxalyl chloride and 0.087 g of DMF were added to 40 mL of anhydrous acetonitrile and stirred for 5 hours to promote complex formation. When the solution turned yellow, 4 g of sodium 4-styrenesulfonate was slowly added to the solution under a nitrogen atmosphere and at room temperature. The mixture was stirred for one day to obtain a 4-styrenesulfonyl chloride solution for later use. 8.1 mL of triethylamine, 2.89 g of trifluoromethylsulfonamide, and 9% molar amount of DMAP were added sequentially to 30 mL of anhydrous acetonitrile and stirred for 1 hour until completely dissolved. The pre-prepared 4-styrenesulfonyl chloride solution was cooled to 0°C, and the above mixture was slowly added dropwise under vigorous stirring, followed by a reaction at room temperature for 16 hours. After the reaction was completed, the solvent was removed by vacuum distillation, and the resulting brown solid was dissolved in 50 mL of dichloromethane. The organic phase was washed sequentially with 4% NaHCO3 aqueous solution and 1 M HCl aqueous solution. After separation, the acid monomer was neutralized with excess K2CO3 aqueous solution. After stirring for 1 hour, the organic phase was separated and dried, and rotary evaporated to obtain 4.2 g of sodium 4-styrenesulfonate. g crude product; recrystallization of the crude product in water yielded 3.63 g pure STFSIK, which was a light yellow powder; Step (3): Synthesis of potassium-containing copolymer electrolyte 1.13-4.13 g of mPEG-4-vinylbenzoate, 0.35 g of STFSIK, and 20 mL of deionized water were added to a three-necked flask and deoxygenated by bubbling under nitrogen for 30 minutes. 20 mg of ammonium persulfate initiator was added, and the resulting solution was heated to 80 °C under a nitrogen stream for one day. After the reaction, the solution was cooled, and most of the water was removed by vacuum evaporation to obtain a glassy polymer. To remove unreacted monomers and impurities, the polymer was dissolved in a small amount of DMSO and then reprecipitated in a large amount of THF. This dissolution-precipitation process was repeated three times, and finally, 0.82 g of pure potassium-containing copolymer was obtained by vacuum drying. Step (4): Synthesis of lithium-containing copolymer electrolyte Place 0.80 g of the dried potassium-containing copolymer electrolyte obtained in step (3) into 50 mL of ethanol, and then add 0.53 g of excess LiClO4; heat the solution to 45°C and stir continuously for 12 hours; during the reaction, a white precipitate of potassium perchlorate is precipitated, which is removed by filtration; The filtrate was passed through a multi-functional rotary evaporator to remove the solvent, yielding a pale yellow solid. For further purification, the solid was dissolved in a small amount of DMSO and then reprecipitated in a large amount of THF; the purification steps were repeated three times, and finally vacuum dried to obtain the target product—a lithium-containing single-ion conductor copolymer electrolyte, 0.65 g of pale yellow solid.

4. A method for synthesizing a polystyrene-based single-ion conductor copolymer with a controllable side chain structure according to any one of claims 1-3, characterized in that: The multifunctional rotary evaporator used in step (4) includes: a device top frame (1); a rotary evaporator fixing mechanism, which includes a gear B (9), a sleeve (10), a rotary evaporator flask (11), a suction tube (13), a pressure valve (14), and a sealing ring (19). The gear B (9) is rotatably connected to the top of the device top frame (1), the sleeve (10) is rotatably connected to the inside of the device top frame (1), the gear B (9) is fixedly sleeved on the outer surface of the sleeve (10), the rotary evaporator flask (11) is threadedly sleeved on the outer surface of the sleeve (10), the suction tube (13) is slidably connected to the inner wall of the sleeve (10), the pressure valve (14) is fixedly connected to the top of the suction tube (13), and the sealing ring (19) is fixedly sleeved on the outer surface of the sleeve (10) and is in contact with the rotary evaporator flask (11).

5. The method for synthesizing a polystyrene-based single-ion conductor copolymer with a controllable side chain structure according to claim 4, characterized in that: The top frame (1) of the device is fixedly connected to a support rod (2), the bottom of the support rod (2) is fixedly connected to a device base (3), the top of the device base (3) is fixedly connected to multiple electric push rods (4), and the top of the electric push rods (4) is fixedly connected to a heating bath base (5).

6. The method for synthesizing a polystyrene-based single-ion conductor copolymer with a controllable side chain structure according to claim 5, characterized in that: The top of the heating bath base (5) is provided with a groove that fits the bottom of the rotary evaporator (11), and the groove contains a heating medium.

7. The method for synthesizing a polystyrene-based single-ion conductor copolymer with a controllable side chain structure according to claim 6, characterized in that: A motor (7) is fixedly connected to the bottom of the device top frame (1). The output end of the motor (7) extends to the top of the device top frame (1) and is fixedly connected to a gear A (8). Gear A (8) meshes with gear B (9).

8. The method for synthesizing a polystyrene-based single-ion conductor copolymer with a controllable side chain structure according to claim 7, characterized in that: The top of the device top frame (1) is fixedly connected to a bracket (20), the filter tube (13) is slidably connected to the bracket (20), the surface of the filter tube (13) is fixedly connected to a connecting pipe (15), and a control valve (16) is provided on the surface of the connecting pipe (15).

9. The method for synthesizing a polystyrene-based single-ion conductor copolymer with a controllable side chain structure according to claim 8, characterized in that: The top of the device base (3) is fixedly connected to a filtrate collection bottle (18), and the top of the filtrate collection bottle (18) is movably connected to a funnel (17). A connecting tube (15) extends into the inside of the funnel (17). The inside of the rotary evaporator (11) is provided with an anti-boiling bead (12), and the bottom of the suction tube (13) extends into the inside of the rotary evaporator (11).

10. The method for synthesizing a polystyrene-based single-ion conductor copolymer with a controllable side chain structure according to claim 4, characterized in that: The synthesis of mPEG-4-vinylbenzoate in step (1) involves placing 10 mmol mPEG, 12 mmol 4-vinylbenzoic acid, 120 mmol DCC and 10 mmol DMAP in a flask, purging the flask, and filling it with nitrogen; then adding dichloromethane to dissolve the mixture and stirring it at room temperature; after filtration, the filtrate is concentrated by rotary evaporation; the resulting concentrate is reprecipitated with pre-cooled diethyl ether, filtered to obtain a solid, and vacuum dried to obtain a white solid product, mPEG-4-vinylbenzoate.

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