A method for preparing a polysulfone-polyether double-layer solid-state electrolyte
By preparing a polysulfone-polyether bilayer solid electrolyte, the problems of narrow electrochemical window and high interfacial impedance of polymer electrolytes were solved, achieving high oxidation stability and reduction stability, and improving the energy density and cycle performance of lithium metal solid batteries.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- BEIJING UNIV OF CHEM TECH
- Filing Date
- 2025-06-18
- Publication Date
- 2026-07-31
AI Technical Summary
Existing polymer solid electrolytes have narrow electrochemical windows, making it difficult to simultaneously match highly reducing lithium metal anodes and high-voltage layered transition metal cathodes. Furthermore, polysulfone electrolytes are difficult to form and have poor film-forming properties, resulting in excessively high interfacial impedance in solid-state batteries.
A polysulfone-polyether bilayer solid electrolyte was prepared by reacting and extracting the electrolyte in a three-necked flask, followed by vacuum drying, dissolving it in LiPF6 and LiFSI, and then curing it with an ultraviolet light source to form an asymmetric polysulfone-polyether bilayer polymer electrolyte.
It broadens the electrochemical window of the electrolyte, combining high oxidation stability and high reduction stability, reduces interfacial impedance, and improves the energy density and cycle stability of lithium metal solid-state batteries.
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Figure CN120809946B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of alkali metal solid-state battery technology, and in particular to a method for preparing a polysulfone-polyether bilayer solid electrolyte. Background Technology
[0002] Environmental pollution and energy crises caused by traditional fossil fuels have led to a growing preference for clean energy sources. Lithium-ion batteries, as excellent energy storage materials, play a crucial role in this process. With the rapid development of electronic devices, especially portable devices, higher performance requirements have been placed on energy storage equipment. To achieve higher energy density, lithium metal batteries have gained increasing attention. Replacing traditional graphite anodes with lithium metal anodes can increase the current battery energy density from 200Wh / kg to over 500Wh / kg. However, the instability of lithium metal anodes and the resulting safety concerns have hindered the commercialization of lithium metal batteries. Replacing flammable electrolytes with solid electrolytes to create solid-state lithium metal batteries significantly improves safety and is currently a key trend.
[0003] Currently, commercially available polymer electrolytes are mainly polyethers, which have the characteristics of high ionic conductivity, good reduction stability and excellent mechanical properties. However, ethers have poor oxidation stability, which leads to the phenomenon of continuous electrolyte decomposition and failure when matched with high-voltage cathode materials. This contradicts the goal of high energy density in solid-state lithium metal batteries.
[0004] Unlike electron-rich ether electrolytes, sulfone compounds have strong electron-withdrawing groups, which gives them high oxidation stability, but at the same time their reduction stability is correspondingly weakened. Therefore, introducing sulfones into polymer solid electrolyte systems is expected to solve the key technical problems of current lithium metal solid batteries. Summary of the Invention
[0005] The present invention aims to provide a method for preparing a polysulfone-polyether bilayer solid electrolyte to solve the problems of existing polymer solid electrolytes having a narrow electrochemical window, making it difficult to simultaneously match a highly reducing lithium metal anode and a high-voltage layered transition metal cathode, as well as the problems of polysulfone electrolytes being difficult to form, having poor film-forming performance, and having excessively high interfacial impedance in solid batteries.
[0006] To achieve the above objectives, the present invention provides the following technical solution: a method for preparing a polysulfone-polyether bilayer solid electrolyte, comprising the following steps:
[0007] Step 1: Add hydroxyethyl sulfone, acryloyl chloride and triethylamine to a three-necked flask in a ratio of 1:1.05:1.2, and dissolve them in 100 mL of dichloromethane. React for 12 h under ice bath conditions. After the reaction is complete, filter to remove the solid and obtain the filtrate.
[0008] Step 2: Place the filtrate into a separatory funnel, add an equal volume of 0.1 mol / L hydrochloric acid solution and extract for 3 min. After extraction, collect the oil phase. Then, place the filtrate into a separatory funnel and add an equal volume of saturated sodium bicarbonate solution and extract for 3 min. After extraction, collect the oil phase.
[0009] Step 3: Remove the solvent from the collected oil phase by rotary evaporation to obtain a yellow transparent oil. Then, vacuum dry the oil at 60°C. Add calcium hydride to the dried oil and let it stand for 48 hours. Filter to obtain a transparent oil, which is denoted as ethyl methyl sulfone acrylate (MSEA).
[0010] Step 4: Add 0.5 mol / L LiPF6 and LiFSI to MSEA and dissolve them at 40℃. After no obvious solid is found, add 0.5% benzoin dimethyl ether (DMPA) and dissolve to obtain a transparent solution, which is denoted as polysulfone prepolymer solution.
[0011] Step 5: Add 0.5 mol / L LiNO3 and LiFSI to polyethylene glycol monomethyl ether acrylate (PEGDA) and dissolve it at 40°C. After no obvious solid is found, add 0.5% benzoin dimethyl ether (DMPA) and dissolve to obtain a transparent solution, which is denoted as the polyether prepolymer solution.
[0012] Step 6: Drop the polyether prepolymer solution onto the PE membrane in a glove box until it is completely filled. Irradiate and cure it with a 365nm ultraviolet light source for 3 minutes. After that, drop the polysulfone prepolymer solution onto the membrane and completely cover it. Then cure it with a 365nm ultraviolet light source for 3 minutes to obtain a transparent polysulfone-polyether bilayer polymer solid electrolyte.
[0013] Specifically, the carrier for the ice bath conditions mentioned in step one is a reactor with magnetic stirring function whose temperature is controlled below 0°C.
[0014] Specifically, the PEGDA mentioned in step five refers to PEGDA compounds with 7 or more ethoxy repeating units.
[0015] Specifically, the PE diaphragm mentioned in step six is a diaphragm obtained by wet stretching, with a thickness ranging from 7μm to 20μm.
[0016] The principle and beneficial effects of this technical solution:
[0017] The core principle of the polysulfone-polyether bilayer solid electrolyte of this invention lies in its unique asymmetric structural design. This structure consists of sulfone polymers and ether polymers. The sulfone polymers possess high oxidation stability, effectively matching high-voltage cathode materials, while the ether polymers exhibit good reduction stability, effectively protecting the electrolyte from the reduction of lithium metal. This asymmetric structure not only achieves specific compatibility with both cathode and anode materials but also significantly broadens the electrochemical window of the electrolyte, thus providing a crucial guarantee for the stable operation of high-voltage lithium metal solid-state batteries. Furthermore, the raw materials of this invention are widely available and inexpensive. The main raw materials, such as hydroxyethyl methyl sulfone and acryloyl chloride, are common chemical raw materials that are easily obtained. The preparation process employs photoinitiated polymerization technology, which is simple to operate and operates under mild conditions, requiring no complex equipment or harsh reaction conditions. This facilitates large-scale production and mechanized operation, demonstrating significant potential for industrial application.
[0018] Polysulfone-polyether bilayer solid electrolytes exhibit excellent performance, combining high oxidation stability and high reduction stability, effectively improving the energy density and cycle stability of lithium metal solid-state batteries. Their unique bilayer structure design also reduces interfacial impedance, further optimizing the battery's charge-discharge performance. Attached Figure Description
[0019] Figure 1 This is a schematic diagram of the polysulfone-polyether bilayer electrolyte polymerization reaction;
[0020] Figure 2 The image shows the proton NMR spectrum of MSEA.
[0021] Figure 3 The electrochemical impedance spectroscopy diagram of the polysulfone-polyether bilayer electrolyte at room temperature is shown.
[0022] Figure 4 For the electrochemical window of the polysulfone-polyether bilayer electrolyte;
[0023] Figure 5 The circuit performance diagram shows the high-nickel ternary cathode high-voltage solid-state battery.
[0024] Figure 6 The cycling performance of a lithium-rich manganese-based layered transition metal oxide high-voltage solid-state battery is shown in the figure.
[0025] Figure 7 This is a graph showing the cycle performance of a lithium cobalt oxide high-voltage solid-state battery. Detailed Implementation
[0026] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments:
[0027] Drug purchase source:
[0028] Hydroxyethyl sulfone, acryloyl chloride, polyethylene glycol monomethyl ether acrylate, dimethyl benzoate, and dichloromethane were analytical grade reagents purchased from Saen Chemical Technology (Shanghai) Co., Ltd.; lithium hexafluorophosphate, lithium nitrate, lithium difluorosulfonyl imide, N-methylpyrrolidone, polyvinylidene fluoride, conductive carbon black, high-nickel ternary cathode, lithium cobalt oxide cathode, and lithium-rich manganese base layer transition metal oxides were all purchased from Shenzhen Kejing Co., Ltd.
[0029] Battery performance testing: The battery was connected to the LAND battery testing system and left to stand for 24 hours before a constant current charge-discharge performance test was conducted. The discharge current density was 27.5 mAg-1, and the test voltage range was 3V-4.8V. The data was obtained by directly measuring the coin cell.
[0030] Example 1
[0031] 1) Place 1 mmol hydroxyethyl sulfone, 1.05 mmol acryloyl chloride and 1.2 mmol triethylamine in a three-necked flask, and dissolve them in 100 mL of dichloromethane. React for 12 h in an ice bath at 0 °C. After the reaction is complete, filter to remove the solid and obtain the filtrate.
[0032] 2) Place the obtained filtrate into a separatory funnel and add an equal volume of 0.1 mol / L hydrochloric acid solution for extraction for 3 min. After extraction, collect the oil phase, add it back into the separatory funnel, add an equal volume of saturated sodium bicarbonate solution for extraction for 3 min, and collect the oil phase after extraction.
[0033] 3) The collected oil phase was evaporated to remove the solvent, resulting in a yellow transparent oil. The oil was then vacuum dried at 60°C. Calcium hydride was added to the dried oil and allowed to stand for 48 hours. The oil was then filtered to obtain a transparent oil, which was named ethyl methyl sulfone acrylate (MSEA).
[0034] 4) Add 0.5 mol / L LiPF6 and LiFSI to 1 mL MSEA and dissolve them at 40 °C. After no obvious solid is found, add 0.5% benzoin dimethyl ether (DMPA) and dissolve to obtain a transparent solution, which is denoted as polysulfone prepolymer solution.
[0035] 5) Add 0.5 mol / L LiNO3 and LiFSI to 1 mL of polyethylene glycol monomethyl ether acrylate (PEGDA) and dissolve at 40 °C. After no obvious solid is found, add 0.5% benzoin dimethyl ether (DMPA) and dissolve to obtain a transparent solution, which is denoted as polyether prepolymer solution.
[0036] 6) The polyether prepolymer solution is dropped onto the PE membrane in a glove box and completely filled. It is then irradiated and cured for 3 minutes using a 365nm ultraviolet light source. After that, the polysulfone prepolymer solution is dropped onto the membrane and completely covered. Then it is cured for 3 minutes using a 365nm ultraviolet light source to obtain a transparent polysulfone-polyether bilayer polymer solid electrolyte.
[0037] 7) Mix 160mg of high-nickel ternary cathode material, 20mg of polyvinylidene fluoride, and 20mg of conductive carbon black in a glove box and grind them for 120min using an agate mortar. Add a small amount of N-methylpyrrolidone and mix to form a uniform coating. Then transfer it to carbon-coated aluminum foil and coat it with a coating tool to form a 300μm thick coating. Transfer it to a heating stage and dry the solvent at 120℃ for 12h to obtain a high-voltage cathode coating.
[0038] 8) The assembly of the negative electrode shell, spring gasket, stainless steel gasket, lithium sheet, polysulfone-polyether bilayer polymer solid electrolyte (polyether layer close to lithium layer), positive electrode coating and positive electrode shell from bottom to top is called a high-voltage lithium metal solid battery.
[0039] 9) The initial specific capacity of the high-voltage lithium metal solid-state battery was found to be 270 mAh / g.
[0040] Example 2
[0041] 1) Place 1 mmol hydroxyethyl sulfone, 1.05 mmol acryloyl chloride and 1.2 mmol triethylamine in a three-necked flask, and dissolve them in 100 mL of dichloromethane. React for 12 h in an ice bath at 0 °C. After the reaction is complete, filter to remove the solid and obtain the filtrate.
[0042] 2) Place the filtrate into a separatory funnel and add an equal volume of 0.1 mol / L hydrochloric acid solution for extraction for 3 min. After extraction, collect the oil phase, add it back into the separatory funnel, add an equal volume of saturated sodium bicarbonate solution, and extract for 3 min. After extraction, collect the oil phase.
[0043] 3) The collected oil phase was evaporated to remove the solvent, resulting in a yellow transparent oil. The oil was then vacuum dried at 60°C. Calcium hydride was added to the dried oil and allowed to stand for 48 hours. The oil was then filtered to obtain a transparent oil, which was named ethyl methyl sulfone acrylate (MSEA).
[0044] 4) Add 0.5 mol / L LiPF6 and LiFSI to 1 mL MSEA and dissolve them at 40 °C. After no obvious solid is found, add 0.5% benzoin dimethyl ether (DMPA) and dissolve to obtain a transparent solution, which is denoted as polysulfone prepolymer solution.
[0045] 5) Add 0.5 mol / L LiNO3 and LiFSI to 1 mL of polyethylene glycol monomethyl ether acrylate (PEGDA) and dissolve at 40 °C. After no obvious solid is found, add 0.5% benzoin dimethyl ether (DMPA) and dissolve to obtain a transparent solution, which is denoted as polyether prepolymer solution.
[0046] 6) The polyether prepolymer solution is dropped onto the PE membrane in a glove box and completely filled. It is then irradiated and cured for 3 minutes using a 365nm ultraviolet light source. After that, the polysulfone prepolymer solution is dropped onto the membrane and completely covered. Then it is cured for 3 minutes using a 365nm ultraviolet light source to obtain a transparent polysulfone-polyether bilayer polymer solid electrolyte.
[0047] 7) Mix 160 mg of lithium-rich manganese-based cathode material, 20 mg of polyvinylidene fluoride, and 20 mg of conductive carbon black in a glove box and grind them in an agate mortar for 120 min. Add a small amount of N-methylpyrrolidone and mix into a uniform coating. Then transfer it to carbon-coated aluminum foil and coat it with a coating tool to form a 300 μm thick coating. Transfer it to a heating stage and dry the solvent at 120 °C for 12 h to obtain a high-voltage cathode coating.
[0048] 8) The assembly of the negative electrode shell, spring gasket, stainless steel gasket, lithium sheet, polysulfone-polyether bilayer polymer solid electrolyte (polyether layer close to lithium layer), positive electrode coating and positive electrode shell from bottom to top is called a high-voltage lithium metal solid battery.
[0049] 9) The initial specific capacity of the high-voltage lithium metal solid-state battery was found to be 170 mAh / g.
[0050] Example 3
[0051] 1) Place 1 mmol hydroxyethyl sulfone, 1.05 mmol acryloyl chloride and 1.2 mmol triethylamine in a three-necked flask, and dissolve them in 100 mL of dichloromethane. React for 12 h in an ice bath at 0 °C. After the reaction is complete, filter to remove the solid and obtain the filtrate.
[0052] 2) Place the obtained filtrate into a separatory funnel and add an equal volume of 0.1 mol / L hydrochloric acid solution for extraction for 3 min. After extraction, collect the oil phase, add it back into the separatory funnel, add an equal volume of saturated sodium bicarbonate solution for extraction for 3 min, and collect the oil phase after extraction.
[0053] 3) The collected oil phase was evaporated to remove the solvent, resulting in a yellow transparent oil. The oil was then vacuum dried at 60°C. Calcium hydride was added to the dried oil and allowed to stand for 48 hours. The oil was then filtered to obtain a transparent oil, which was named ethyl methyl sulfone acrylate (MSEA).
[0054] 4) Add 0.5 mol / L LiPF6 and LiFSI to 1 mL MSEA and dissolve them at 40 °C. After no obvious solid is found, add 0.5% benzoin dimethyl ether (DMPA) and dissolve to obtain a transparent solution, which is denoted as polysulfone prepolymer solution.
[0055] 5) Add 0.5 mol / L LiNO3 and LiFSI to 1 mL of polyethylene glycol monomethyl ether acrylate (PEGDA) and dissolve at 40 °C. After no obvious solid is found, add 0.5% benzoin dimethyl ether (DMPA) and dissolve to obtain a transparent solution, which is denoted as polyether prepolymer solution.
[0056] 6) The polyether prepolymer solution is dropped onto the PE membrane in a glove box and completely filled. It is then irradiated and cured for 3 minutes using a 365nm ultraviolet light source. After that, the polysulfone prepolymer solution is dropped onto the membrane and completely covered. Then it is cured for 3 minutes using a 365nm ultraviolet light source to obtain a transparent polysulfone-polyether bilayer polymer solid electrolyte.
[0057] 7) Mix 160 mg of lithium cobalt oxide cathode material, 20 mg of polyvinylidene fluoride, and 20 mg of conductive carbon black in a glove box and grind them for 120 min using an agate mortar. Add a small amount of N-methylpyrrolidone and mix to form a uniform coating. Then transfer it to carbon-coated aluminum foil and use a coater to coat it into a 300 μm thick coating. Transfer it to a heating stage and dry the solvent at 120 °C for 12 h to obtain a high-voltage cathode coating.
[0058] 8) The assembly of the negative electrode shell, spring gasket, stainless steel gasket, lithium sheet, polysulfone-polyether bilayer polymer solid electrolyte (polyether layer close to lithium layer), positive electrode coating and positive electrode shell from bottom to top is called a high-voltage lithium metal solid battery.
[0059] 9) The initial specific capacity of the high-voltage lithium metal solid-state battery was found to be 220 mAh / g.
[0060] in conclusion:
[0061] like Figure 1-7As shown, in Example 1, the battery using the high-nickel ternary cathode material exhibited an initial specific capacity of 270 mAh / g, indicating that the electrolyte can effectively support the high energy output of the high-nickel ternary cathode. In Example 2, the battery using the lithium-rich manganese-based cathode material had an initial specific capacity of 170 mAh / g. Although its specific capacity was slightly lower than that of the high-nickel ternary cathode battery, the lithium-rich manganese-based cathode material itself has a higher theoretical capacity, indicating that the electrolyte can adapt to the characteristics of different cathode materials and fully utilize their performance advantages. In Example 3, the lithium cobalt oxide cathode battery had an initial specific capacity of 220 mAh / g, further demonstrating the universality and stability of the polysulfone-polyether bilayer solid electrolyte.
[0062] In summary, the polysulfone-polyether bilayer solid electrolyte of this invention exhibits good compatibility and stability in different cathode material systems, effectively improving the energy density and cycle performance of lithium metal solid-state batteries. Its unique asymmetric structural design not only broadens the electrochemical window but also reduces interfacial impedance, providing strong technical support for the commercial application of high-voltage lithium metal solid-state batteries.
[0063] The above descriptions are merely embodiments of the present invention, and common technical solutions or characteristics known in the schemes are not described in detail here. For those skilled in the art, various modifications and improvements can be made without departing from the technical solutions of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application shall be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.
Claims
1. A method for preparing a lithium metal solid-state battery polysulfone-polyether double-layer solid-state electrolyte, characterized by, Includes the following steps: Step 1: Add hydroxyethyl sulfone, acryloyl chloride and triethylamine to a three-necked flask in a molar ratio of 1:1.05:1.2, and dissolve them in 100 mL of dichloromethane. React for 12 h under ice bath conditions. After the reaction is complete, filter to remove the solid and obtain the filtrate. Step 2: Place the filtrate into a separatory funnel, add an equal volume of 0.1 mol / L hydrochloric acid solution and extract for 3 min. After extraction, collect the oil phase. Then, place the filtrate into a separatory funnel and add an equal volume of saturated sodium bicarbonate solution and extract for 3 min. After extraction, collect the oil phase. Step 3: Remove the solvent from the collected oil phase by rotary evaporation to obtain a yellow transparent oil. Then, vacuum dry the oil at 60°C. Add calcium hydride to the dried oil and let it stand for 48 hours. Filter to obtain a transparent oil, which is denoted as ethyl methyl sulfone acrylate (MSEA). Step 4: Add 0.5 mol / L LiPF6 and LiFSI to MSEA and dissolve them at 40 °C. After no obvious solid is found, add 0.5% benzoin dimethyl ether (DMPA) and dissolve to obtain a transparent solution, which is denoted as polysulfone prepolymer solution. Step 5: Add 0.5 mol / L LiNO3 and LiFSI to polyethylene glycol monomethyl ether acrylate (PEGDA) and dissolve it at 40°C. After no obvious solid is found, add 0.5% benzoin dimethyl ether (DMPA) and dissolve to obtain a transparent solution, which is denoted as the polyether prepolymer solution. The PEGDA mentioned in Step 5 refers to PEGDA compounds with 7 or more ethoxy repeating units. Step 6: The polyether prepolymer solution is dropped onto the PE membrane in a glove box and completely filled. It is then irradiated and cured for 3 min using a 365 nm ultraviolet light source. After that, the polysulfone prepolymer solution is dropped onto the membrane and completely covered. It is then cured for 3 min using a 365 nm ultraviolet light source to obtain a transparent polysulfone-polyether bilayer polymer solid electrolyte.
2. The method for preparing a polysulfone-polyether bilayer solid electrolyte for a lithium metal solid-state battery according to claim 1, characterized in that: The carrier for the ice bath conditions described in step one is a reactor with magnetic stirring function whose temperature is controlled below 0 ℃.
3. The method for preparing a polysulfone-polyether bilayer solid electrolyte for a lithium metal solid-state battery according to claim 1, characterized in that: The PE diaphragm mentioned in step six is a diaphragm obtained by wet stretching, with a thickness ranging from 7 μm to 20 μm.