Method for preparing zinc-based solid electrolyte membrane based on polycarbonate-based ionic liquid

Abstract

This invention discloses a method for preparing a zinc-based solid electrolyte membrane based on a polycarbonate-based ionic liquid. In the presence of a catalyst, carbon dioxide and epichlorohydrin are alternately copolymerized at 25-70°C and 2.0-4.0 MPa carbon dioxide to obtain a polycarbonate with chloromethyl side groups, which is then purified by dissolution / precipitation. A side group substitution reaction is carried out by adding 1-methylimidazolium to a polar solvent to obtain an imidazolium halide-type ionized polycarbonate. Subsequently, a zinc-free solution is used... 2+ The zinc-based solid polymer electrolyte membrane was obtained by anion exchange with TFSI-salt followed by desalting and purification. The ionic liquid was then mixed with zinc salt, and a membrane was fabricated using a casting method, followed by drying and peeling to obtain the membrane. The large volume and high degree of charge delocalization of anions in the ionic liquid are beneficial for reducing ion-pair interactions, providing a better ion transport environment for the zinc-based solid electrolyte membrane and addressing the issue of Zn content in existing zinc-based solid electrolytes. 2+ It has strong interactions with anions and polymer polar groups, which can easily lead to increased resistance to ion migration.

Description

Technical Field

[0001] This invention relates to the field of electrochemical energy storage materials and polymer electrolyte technology, and in particular to a method for preparing a zinc-based solid electrolyte membrane based on polycarbonate-based ionic liquid. Background Technology

[0002] Carbon dioxide (CO2) is an abundant, inexpensive, and renewable carbon resource. Utilizing CO2 to prepare polymer materials is an important way to achieve carbon emission reduction and resource recycling. In recent years, the copolymerization of CO2 with epoxy monomers such as epichlorohydrin to prepare polycarbonate materials has attracted widespread attention due to its green and sustainable characteristics.

[0003] Polyionic liquids (PILs) are a class of functional materials that combine the properties of ionic liquids and polymers. They typically exhibit good thermal stability, structural tunability, and certain ion transport capabilities, thus showing broad application prospects in electrolyte materials, separation materials, and functional polymers. Existing research has focused on constructing PIL materials by introducing ionic liquid groups such as imidazolium into the polymer side chains, aiming to balance film-forming properties, thermal stability, electrochemical stability, and ion transport performance. Furthermore, optimizing the side chain structure and pairing anions can further improve chain segment mobility and ion dissociation behavior to some extent.

[0004] However, in zinc-based electrochemical systems, especially in anhydrous or low-aqueous solid / quasi-solid polymer electrolyte systems, Zn 2+ It is often difficult to simultaneously achieve effective conduction, zinc anode interface stability, side reaction suppression, dendrite growth control, and the mechanical stability of membrane materials. On the one hand, Zn 2+ The strong interaction between polymers and anions and polar polymer groups can easily lead to increased resistance to ion migration. Furthermore, the flexibility, mechanical strength, and interfacial compatibility of polymer films are difficult to simultaneously meet application requirements. Therefore, developing a polyionic liquid material that combines film-forming properties, structural tunability, and suitability for compounding with zinc salts to construct anhydrous or low-aqueous zinc-based solid / quasi-solid polymer electrolytes is of significant research importance and application value. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this invention is to provide a method for preparing a zinc-based solid electrolyte membrane based on polycarbonate-based ionic liquids, aiming to solve the problem of Zn content in existing zinc-based solid electrolytes. 2+ It has strong interactions with anions and polymer polar groups, which can easily lead to increased resistance to ion migration.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A method for preparing a zinc-based solid electrolyte membrane based on a polycarbonate-based ionic liquid, the method comprising: Step 1: Weigh epichlorohydrin and add it to a high-pressure reactor. Under the condition of catalyst, CO2 is introduced and copolymerization reaction is carried out under stirring. After the reaction is completed, the temperature is lowered to room temperature to release the remaining CO2. The resulting polymer is dissolved in an organic solvent, and after precipitation, filtration and vacuum drying, CO2-based polycarbonate with chloromethyl (-CH2Cl) side group is obtained. Step 2: Weigh CO2-based polycarbonate with chloromethyl (-CH2Cl) side group and dissolve it in a polar solvent. Add 1-methylimidazole under stirring and carry out a nucleophilic substitution reaction at 40-90℃ for 24-48h. After the reaction is completed, pour the reaction solution into excess ethyl acetate or acetone to precipitate and filter. Wash the precipitate and dry it under vacuum to obtain imidazole onium chloride type polycarbonate. Step 3: Imidazolium chloride-type polycarbonate is dissolved in deionized water or a polar organic solvent, and a salt solution containing TFSI- anions is added at room temperature. Anion exchange reaction is carried out under stirring for 6-24 hours. After the reaction is completed, the precipitate is washed and washed 3-5 times with distilled water. It is then dried under vacuum at 60-80℃ for 8-12 hours to obtain CO2-based imidazolium-TFSI polycarbonate-based ionic liquid. Step 4: Weigh CO2-based imidazolium-TFSI polycarbonate-based ionic liquid and mix it with zinc salt, dissolve it in deionized water or a polar organic solvent; cast it into a film on polytetrafluoroethylene or a treated glass plate, evaporate some of the solvent at room temperature, and then vacuum dry it at 60°C for 24-48 hours, and peel it off to obtain a zinc-based solid polymer electrolyte membrane.

[0007] Further, in step 1, 20.0 mL of epichlorohydrin is weighed, and a tetranuclear organoboron catalyst is used. The molar ratio of epichlorohydrin to catalyst is approximately 500:1. The reactor is evacuated and replaced with an inert gas to remove moisture and oxygen. Dichloromethane is used as the organic solvent. Excess methanol is added to the solution to precipitate the polymer. The solution is filtered, and the precipitate is dried under vacuum at 60°C for 12 hours.

[0008] Furthermore, in step 1, the pressure at which CO2 is introduced into the high-pressure reactor is 2.0-4.0 MPa.

[0009] Furthermore, in step 1, the reaction temperature in the high-pressure reactor is 25-70℃.

[0010] Further, in step 2, 2.00 g of CO2-based polycarbonate with a side group containing chloromethyl (-CH2Cl) was weighed, and N,N-dimethylformamide with a volume of 20.0 mL was used as the polar solvent. 0.5 g of 1-methylimidazole was added to the reaction system. The system was washed three times with ethyl acetate, and dried at 70°C for 12 h.

[0011] Furthermore, in step 3, the polar organic solvent used is acetonitrile / methanol solvent with a volume ratio of 1:1. 2.20g of salt solution containing TFSI- anions is added based on the imidazole site. During stirring, the mixture is first stirred at room temperature for 12h, and then stirred further at 30℃ for 18h to complete the anion exchange. After the reaction, the mixture is washed twice with methanol and then washed with deionized water until the washing solution is free of free small molecule salts.

[0012] Furthermore, in step 4, the zinc salt is Zn(TFSI)2, the CO2-based imidazolium-TFSI polycarbonate-based ionic liquid is used in a mass ratio of 80:20, 70:30 or 60:40, the polar organic solvent is acetonitrile / N,N-dimethylformamide solvent in a volume ratio of 1:1, and the film thickness is controlled at 30-200µm by the casting gap.

[0013] Furthermore, in step 4, ionic liquid plasticizer IL is added. CO2-based imidazolium-TFSI polycarbonate-based ionic liquid, zinc salt and ionic liquid plasticizer IL are weighed and mixed in a mass ratio of 60:20:20.

[0014] Furthermore, in step 4, an inorganic filler is added, the amount of which is 1 wt% of the total mass of the zinc-based solid electrolyte membrane; the inorganic filler is first ultrasonically dispersed in a polar organic solvent, and then mixed with imidazolium-TFSI polycarbonate-based ionic liquid and zinc salt.

[0015] Further, in step 4, inorganic filler and ionic liquid plasticizer IL are added. CO2-based imidazolium-TFSI polycarbonate-based ionic liquid, zinc salt, ionic liquid plasticizer IL and inorganic filler are mixed at a mass ratio of 60:20:20:1. The amount of ionic liquid plasticizer IL added is 20 wt% of the total mass of the zinc-based solid electrolyte membrane, and the amount of inorganic filler added is 1 wt% of the total mass of the zinc-based solid electrolyte membrane. The inorganic filler is first ultrasonically dispersed in a polar organic solvent, and then mixed evenly with CO2-based imidazolium-TFSI polycarbonate-based ionic liquid, zinc salt and ionic liquid plasticizer IL.

[0016] The technical solution adopted in this invention has the following beneficial effects: This invention uses polycarbonate obtained by copolymerizing CO2 and epichlorohydrin as the backbone, combining the value of CO2 resource utilization with the foundation of polymer film formation. Through imidazole onionization of the side chains, fixed cation sites can be introduced into the polymer, thereby enhancing the material's polarity and improving the structural tunability of the zinc salt complex system. By anion exchange between a TFSI-containing salt and the aforementioned polycarbonate-based ionic liquid, a polycarbonate-based ionic liquid with TFSI- anions is obtained. This anion has a large volume and high charge delocalization, which helps reduce ion-pair interactions and provides a better ion transport environment for subsequent use as a zinc-based solid electrolyte membrane, thus solving the problem of Zn content in existing zinc-based solid electrolytes. 2+ It has strong interactions with anions and polymer polar groups, which can easily lead to increased resistance to ion migration.

[0017] Polycarbonate-based ionic liquids, as film-forming polymer matrices or key polymer components in zinc-based solid or quasi-solid polymer electrolyte membranes, can be combined with zinc salts, ionic liquid plasticizers, and inorganic fillers to regulate the ion transport performance, interfacial compatibility, and mechanical stability of the membrane. Attached Figure Description

[0018] Figure 1 A schematic diagram of the synthetic route for polycarbonate-based ionic liquids; Figure 2 This is a structural diagram of a repeating unit cell in a polycarbonate-based ionic liquid (PIL-PC). Figure 3 The image shows a comparison of the Fourier transform infrared (FT-IR) spectra of the samples before and after imidazole intumination. Figure 4 The image shows a comparison of the infrared spectra (FT-IR) of the samples before and after anion exchange (TFSI-introduction). Figure 5 GPC diagram of chloromethyl polycarbonate (PCPC) with side chain; Figure 6 This is a schematic diagram of the transport mechanism of zinc ions in polycarbonate-based polyionic liquid solid electrolytes. Detailed Implementation

[0019] In this invention, the zinc-based electrolyte membrane is preferably used in anhydrous or low-aqueous solid / quasi-solid polymer electrolyte systems, and does not involve aqueous gel electrolytes with a large amount of water as the continuous phase. The polycarbonate-based ionic liquid is preferably first purified by anion exchange and desalting to obtain a TFSI-type polymer, and then composited with zinc salt to form a membrane, in order to avoid interference from residual salts from anion exchange on the subsequent membrane performance attribution.

[0020] A method for preparing a zinc-based solid electrolyte membrane based on a polycarbonate-based ionic liquid, the method comprising: Step 1: Weigh epichlorohydrin and add it to a high-pressure reactor. Under the condition of catalyst, CO2 is introduced and copolymerization reaction is carried out under stirring. After the reaction is completed, the temperature is lowered to room temperature to release the remaining CO2. The resulting polymer is dissolved in an organic solvent, and after precipitation, filtration and vacuum drying, CO2-based polycarbonate with chloromethyl (-CH2Cl) side group is obtained. In this process, 20.0 mL of epichlorohydrin was weighed out, and a tetranuclear organoboron catalyst was used, with a molar ratio of epichlorohydrin to catalyst of approximately 500:1. The reactor was evacuated and purged with an inert gas to remove moisture and oxygen. Dichloromethane was used as the organic solvent. Excess methanol was added to the solution to precipitate the polymer. The precipitate was filtered and dried under vacuum at 60°C for 12 hours. The pressure of CO2 introduced into the high-pressure reactor was 2.0-4.0 MPa. The reaction temperature in the high-pressure reactor was 25-70°C.

[0021] Step 2: Weigh CO2-based polycarbonate with chloromethyl (-CH2Cl) side group and dissolve it in a polar solvent. Add 1-methylimidazole under stirring and carry out a nucleophilic substitution reaction at 40-90℃ for 24-48h. After the reaction is completed, pour the reaction solution into excess ethyl acetate or acetone to precipitate and filter. Wash the precipitate and dry it under vacuum to obtain imidazole onium chloride type polycarbonate. In this process, 2.00 g of CO2-based polycarbonate with a side group containing chloromethyl (-CH2Cl) was weighed, and N,N-dimethylformamide with a volume of 20.0 mL was used as the polar solvent. 0.5 g of 1-methylimidazole was added to the reaction system. The system was washed three times with ethyl acetate, and dried at 70°C for 12 h.

[0022] Step 3: Imidazolium chloride-type polycarbonate is dissolved in deionized water or a polar organic solvent, and a salt solution containing TFSI- anions is added at room temperature. Anion exchange reaction is carried out under stirring for 6-24 hours. After the reaction is completed, the precipitate is washed and washed 3-5 times with distilled water. It is then dried under vacuum at 60-80℃ for 8-12 hours to obtain CO2-based imidazolium-TFSI polycarbonate-based ionic liquid. The polar organic solvent used was acetonitrile / methanol solvent with a volume ratio of 1:1. 2.20g of salt solution containing TFSI- anions was added based on the imidazole site. During stirring, the mixture was first stirred at room temperature for 12h, and then stirred further at 30℃ for 18h to complete the anion exchange. After the reaction, the mixture was washed twice with methanol and then washed with deionized water until the washing solution was free of free small molecule salts.

[0023] Step 4: Weigh CO2-based imidazolium-TFSI polycarbonate-based ionic liquid and mix it with zinc salt, dissolve it in deionized water or a polar organic solvent; cast it into a film on polytetrafluoroethylene or a treated glass plate, evaporate some of the solvent at room temperature, and then place it in a vacuum dryer at 60°C for 24-48 hours, and peel it off to obtain a zinc-based solid polymer electrolyte membrane. The zinc salt used is Zn(TFSI)2, and the CO2-based imidazolium-TFSI polycarbonate-based ionic liquid is used in a mass ratio of 80:20, 70:30, or 60:40. The polar organic solvent used is acetonitrile / N,N-dimethylformamide solvent with a volume ratio of 1:1. The film thickness is controlled between 30 and 200 µm by the casting gap.

[0024] In this embodiment, in step 4, an ionic liquid plasticizer IL can be added. The CO2-based imidazolium-TFSI polycarbonate-based ionic liquid, zinc salt, and ionic liquid plasticizer IL are weighed and mixed at a mass ratio of 60:20:20; or an inorganic filler is added, with the amount being 1 wt% of the total mass of the zinc-based solid electrolyte membrane; the inorganic filler is first ultrasonically dispersed in a polar organic solvent, and then mixed with the imidazolium-TFSI polycarbonate-based ionic liquid and zinc salt; or the inorganic filler and ionic liquid plasticizer IL are added, and the CO2-based imidazolium-TFSI polycarbonate-based ionic liquid is mixed with the zinc salt. 2-Imidazolium-TFSI polycarbonate-based ionic liquid, zinc salt, ionic liquid plasticizer IL, and inorganic filler are mixed at a mass ratio of 60:20:20:1. The amount of ionic liquid plasticizer IL added is 20wt% of the total mass of the zinc-based solid electrolyte membrane, and the amount of inorganic filler added is 1wt% of the total mass of the zinc-based solid electrolyte membrane. The inorganic filler is first ultrasonically dispersed in a polar organic solvent, and then mixed evenly with CO2-based imidazolium-TFSI polycarbonate-based ionic liquid, zinc salt, and ionic liquid plasticizer IL.

[0025] In this invention, the designation "PCPC" represents a polycarbonate with a chloromethyl (-CH2Cl) side group obtained by alternating copolymerization of carbon dioxide and epichlorohydrin; the designation "PIL-PC" represents a TFSI-type polycarbonate-based ionic liquid obtained after imidazole intumination and anion exchange. The number-average molecular weight Mn can be determined by gel permeation chromatography (GPC); the molecular structure can be determined by FT-IR infrared spectroscopy.

[0026] The chemical structure of the polycarbonate-based ionic liquid prepared in steps 1-3 of this invention is as follows: like Figure 1As shown, the polycarbonate-based ionic liquid of the present invention uses polycarbonate obtained by alternating copolymerization of carbon dioxide and epichlorohydrin as the backbone, and introduces imidazolium ionic liquid groups onto the side chains of polycarbonate, followed by anion exchange with TFSI- to form the polycarbonate-based ionic liquid. Specifically, firstly, a polycarbonate precursor (PCPC) with chloromethyl (-CH2Cl) side groups is obtained by copolymerization of CO2 and epichlorohydrin; subsequently, a nucleophilic substitution / quaternization reaction is performed on the -CH2Cl site using 1-methylimidazolium, causing a stable imidazolium cationic side chain to form on the N atom of the imidazolium ring, thereby obtaining an ionized polycarbonate that is resistant to halide ions (such as Cl-), i.e., a polycarbonate-based ionic liquid; finally, by ion exchange with a salt containing TFSI-, the paired anion on the imidazolium cation is converted from the halide ion Cl- to TFSI-, yielding the target polycarbonate-based ionic liquid (PIL-PC). Figure 2 As shown, the imidazolium cation is immobilized on the polymer side chain, while TFSI- is a large-volume anion with a high degree of charge delocalization. Both endow the material with polyionic liquid characteristics. At the same time, the polycarbonate backbone provides strength, flexibility and film-forming properties, enabling the material to have both structural stability and ionic conductivity.

[0027] like Figure 3 As shown, spectrum A is the PCPC FT-IR spectrum produced by this invention; spectrum B is the FT-IR spectrum of imidazolium chloride-type polycarbonate ionic liquid. Figure 4 Spectral line A and Figure 3 Spectrum B is the same curve, and spectral line B is the FT-IR spectrum of the zinc-based polycarbonate ionic liquid of this invention.

[0028] like Figure 4 As shown, compared with the imidazolium chloride type polycarbonate sample, the sample after anion exchange at 1350 cm⁻¹... -1 and 1190 cm -1 New characteristic absorption peaks appear nearby, which are attributed to the symmetric and antisymmetric stretching vibrations of the –SO2– group in the TFSI⁻ anion, respectively; simultaneously, at 1050 cm⁻¹... -1 A C–F related vibrational absorption peak appeared nearby. The appearance of the above characteristic peaks indicates that the TFSI⁻ anion has been successfully introduced into the polycarbonate-based ionic liquid system, indicating that the anion exchange reaction was successfully completed and the target CO2-based imidazolium-TFSI polycarbonate-based ionic liquid was obtained.

[0029] like Figure 5 As shown, the chloromethyl polycarbonate (PCPC) with side chains exhibited a single-peak distribution in gel permeation chromatography (GPC), indicating that the obtained polymer had a relatively concentrated molecular weight distribution and the polymerization process was controllable; its number-average molecular weight (Mn) was in the range of 10³ to 10⁻⁶. 5Within the order of magnitude range, this indicates that the obtained polycarbonate has a high molecular weight, which is beneficial to improving the film-forming properties and mechanical stability of subsequent materials, and provides a good matrix support for constructing zinc-based solid polymer electrolyte membranes.

[0030] like Figure 6 As shown, the transport of zinc ions in polycarbonate-based polyionic liquid solid electrolyte membranes is mainly achieved through the synergistic effect of polymer chain segment movement and ionic liquid structure: on the one hand, the polycarbonate backbone has a certain degree of flexibility, and its chain segment movement can provide continuous migration channels for Zn²⁺; on the other hand, the imidazolium cation is fixed on the side chain, forming a weak coordination environment with the TFSI⁻ anion, which is conducive to the dissociation of zinc salt, thereby improving the effective migration rate of Zn²⁺. Simultaneously, the TFSI⁻ anion has a large volume and a high degree of charge delocalization, resulting in a weak coordination effect on Zn²⁺, which can reduce the ion pair binding strength and decrease ion migration resistance. Furthermore, the polyionic liquid structure can also, to a certain extent, regulate the interfacial polarity and ion distribution of the electrolyte membrane, helping to suppress uneven deposition of Zn²⁺ at the interface, thereby improving the stability of the zinc deposition / stripping process.

[0031] Example 1: Preparation of PIL-PC / Zn(TFSI)2 electrolyte membrane (1) Preparation of chloromethyl polycarbonate (PCPC) with side chain 20.0 mL of epichlorohydrin (ECH) and a tetranuclear organoboron catalyst (prepared according to literature) were added to a high-pressure reactor, with the molar ratio of ECH to catalyst being approximately 500:1. The reactor was evacuated and purged with an inert gas to remove moisture and oxygen; then CO2 was introduced to 2.5 MPa, and the reaction was carried out at 25 °C with stirring to perform alternating copolymerization of CO2 and ECH. After the reaction was completed, unreacted CO2 was slowly released, and unreacted monomers were evaporated. The crude polymer obtained from the reaction was dissolved in dichloromethane (DCM), and excess methanol was added to the solution to precipitate the polymer. After filtration, the resulting solid was dried under vacuum at 60 °C for 12 h to obtain CO2-based polycarbonate containing chloromethyl side groups.

[0032] (2) Preparation of imidazolium chloride-type polycarbonate ionic liquids 2.00 g of PCPC was dissolved in 20.0 mL of N,N-dimethylformamide (DMF), and 0.5 g of 1-methylimidazole was added to the reaction system. The mixture was magnetically stirred at 70 °C for 24 h. After the reaction was complete, the reaction solution was slowly poured into a large amount of ethyl acetate to precipitate the solid. The precipitate was filtered and washed three times with ethyl acetate. The resulting solid was dried under vacuum at 70 °C for 12 h to obtain an imidazole onium chloride type polycarbonate ionic liquid. FT-IR was used to compare and analyze the correctness of the structure. Infrared spectral analysis is shown in [reference needed]. Figure 3 .

[0033] like Figure 3As shown, compared with the unimidazolized polymer, the imidazolized sample exhibits an enhanced absorption peak near 1541 cm⁻¹, which can be attributed to the C=C characteristic vibration of the imidazolium ring skeleton; the absorption peak near 1233 cm⁻¹ can be attributed to the CN stretching vibration associated with the imidazolium structure; and the absorption peak near 1098 cm⁻¹ can be attributed to the CNC vibration. The appearance and enhancement of these characteristic peaks indicate that the imidazolium group was successfully introduced into the PCPC side group.

[0034] (3) Preparation of TFSI-type polycarbonate-based ionic liquid (PIL-PC) by anion exchange The above imidazolium chloride-type polycarbonate ionic liquid sample was dissolved in acetonitrile / methanol (volume ratio 1:1), and 2.20 g of NaTFSI was added based on the imidazolium sites. The mixture was stirred at room temperature for 12 h, then stirred further at 30 °C for 18 h to complete anion exchange. After the reaction, the sample was washed twice with methanol and then with deionized water until the washings were free of free small molecule salts. Finally, the solution was dried to obtain the TFSI-type polycarbonate-based ionic liquid (PIL-PC). (4) Preparation of zinc-based solid or quasi-solid polymer electrolyte membranes PIL-PC and Zn(TFSI)2 were weighed and mixed at a mass ratio of 80:20, and dissolved in acetonitrile / DMF (volume ratio 1:1) to form a homogeneous solution. The solution was cast onto a polytetrafluoroethylene (PTFE) or treated glass plate, and after partial solvent evaporation at room temperature, it was vacuum dried at 60°C for 24–48 h to remove residual solvent. The resulting zinc-based solid polymer electrolyte membrane was then peeled off. The membrane thickness could be controlled between 30 and 200 µm, preferably 50–120 µm, by adjusting the casting gap.

[0035] Examples 2-6, while maintaining consistent PIL-PC preparation conditions, only varied the zinc salt ratio, ionic liquid plasticizer, and inorganic filler conditions in subsequent compounding into the membrane to investigate the effects of different formulation factors on the performance of zinc-based solid / quasi-solid polymer electrolyte membranes.

[0036] Example 2: Preparation of PIL-PC / Zn(TFSI)2 electrolyte membrane (1) Preparation of chloromethyl polycarbonate (PCPC) with side chain PCPC was prepared according to the method of Example 1 (step (1)).

[0037] (2) Preparation of imidazolium chloride-type polycarbonate ionic liquids Imidazoliumization was performed according to the method in Example 1 (step (2)).

[0038] (3) Preparation of TFSI-type polycarbonate-based ionic liquid (PIL-PC) by anion exchange Following the method in Example 1 (step (3)), anion exchange was performed with NaTFSI to obtain PIL-PC, which was then purified and dried.

[0039] (4) Preparation of zinc-based solid or quasi-solid polymer electrolyte membranes Weigh PIL-PC and Zn(TFSI)2 and mix them at a mass ratio of 70:30. Dissolve and cast into a film according to Example 1 (step (4)), dry and peel off to obtain an electrolyte membrane with a thickness of 30–200µm (preferably 50–120µm).

[0040] Example 3: Preparation of PIL-PC / Zn(TFSI)2 electrolyte membrane (1) Preparation of chloromethyl polycarbonate (PCPC) with side chain PCPC was prepared according to the method of Example 1 (step (1)).

[0041] (2) Preparation of imidazolium chloride-type polycarbonate ionic liquids Imidazoliumization was performed according to the method in Example 1 (step (2)).

[0042] (3) Preparation of TFSI-type polycarbonate-based ionic liquid (PIL-PC) by anion exchange PIL-PC was obtained by anion exchange and purification according to the method of Example 1 (step (3)).

[0043] (4) Preparation of zinc-based solid or quasi-solid polymer electrolyte membranes Weigh PIL-PC and Zn(TFSI)2 and mix them at a mass ratio of 60:40. Dissolve them in acetonitrile / DMF (1:1). Cast and dry the mixture according to Example 1 (step (4)) to form an electrolyte membrane. Peel off the membrane to obtain the electrolyte membrane.

[0044] Example 4: Preparation of PIL-PC / Zn(TFSI)2 / IL electrolyte membrane The preparation method is basically the same as in Example 1; the difference is that an ionic liquid plasticizer (IL) is added as a softening and ion-conducting aid.

[0045] (1) Preparation of chloromethyl polycarbonate (PCPC) with side chain PCPC was prepared according to Example 1 (step (1)).

[0046] (2) Preparation of imidazolium chloride-type polycarbonate ionic liquids Imidazoliumization was performed according to Example 1 (step (2)).

[0047] (3) Preparation of TFSI-type polycarbonate-based ionic liquid (PIL-PC) by anion exchange Anion exchange was performed according to Example 1 (step (3)).

[0048] (4) Preparation of zinc-based solid or quasi-solid polymer electrolyte membranes (including ionic liquid plasticizers) PIL-PC, Zn(TFSI)2, and ionic liquid plasticizer IL were weighed and mixed at a mass ratio of 60:20:20 (PIL-PC:Zn(TFSI)2:IL=60:20:20), dissolved in acetonitrile / DMF (1:1), and mixed thoroughly. The mixture was then cast into a film according to Example 1 (step (4)) and vacuum dried to obtain a composite solid electrolyte membrane. The added IL was used as a plasticizer and could improve the room temperature ionic conductivity and membrane flexibility.

[0049] Example 5: Preparation of PIL-PC / Zn(TFSI)2 / filler electrolyte membrane The preparation method is the same as in Example 1, but a trace amount of inorganic filler is introduced to enhance the mechanical / interface properties.

[0050] (1) Preparation of chloromethyl polycarbonate (PCPC) with side chain PCPC was prepared according to Example 1 (step (1)).

[0051] (2) Preparation of imidazolium chloride-type polycarbonate ionic liquids Imidazoliumization was performed according to Example 1 (step (2)).

[0052] (3) Preparation of TFSI-type polycarbonate-based ionic liquid (PIL-PC) by anion exchange Anion exchange and purification were performed according to Example 1 (step (3)).

[0053] (4) Preparation of zinc-based solid or quasi-solid polymer electrolyte membranes (including inorganic fillers) An inorganic filler was selected and added at a concentration of 1 wt% (relative to the total mass of the electrolyte membrane). The filler was first ultrasonically dispersed in a solvent, then mixed with PIL-PC and Zn(TFSI)2 (mass ratio 70:30). After thorough mixing, the mixture was cast into a film and vacuum dried at 60°C for 24–48 h. The resulting composite electrolyte membrane containing 1 wt% filler was then peeled off. This filler can be used to improve mechanical strength and interfacial stability.

[0054] Example 6: Preparation of PIL-PC / Zn(TFSI)2 / IL / Inorganic Filler Electrolyte Membrane Based on Example 4, inorganic fillers are introduced to balance ion conductivity and mechanical interface stability.

[0055] (1) Preparation of chloromethyl polycarbonate (PCPC) with side chain PCPC was prepared according to Example 1 (step (1)).

[0056] (2) Preparation of imidazolium chloride-type polycarbonate ionic liquids Imidazoliumization was performed according to Example 1 (step (2)).

[0057] (3) Preparation of TFSI by anion exchange - Polycarbonate-based ionic liquid (PIL-PC) Anion exchange and purification were performed according to Example 1 (step (3)).

[0058] (4) Preparation of zinc-based solid or quasi-solid polymer electrolyte membranes (including IL and fillers) PIL-PC, Zn(TFSI)2, ionic liquid (IL, 20wt%), and inorganic filler (1wt%) were mixed at a mass ratio of 60:20:20:1. The filler was first ultrasonically dispersed in a solvent, then mixed uniformly with the polymer / salt / IL, cast, and vacuum dried at 60°C for 24–48 h, followed by exfoliation to obtain a composite electrolyte membrane. This formulation aims to balance room-temperature ionic conductivity, membrane flexibility, and mechanical / interfacial stability.

[0059] Example 7: Preparation of PIL-PC / Zn(TFSI)2 electrolyte membrane (1) Preparation of chloromethyl polycarbonate (PCPC) with side chain 20.0 mL of epichlorohydrin (ECH) and a tetranuclear organoboron catalyst, prepared according to literature, were added to a high-pressure reactor, with a molar ratio of ECH to catalyst of approximately 500:1. The reactor was evacuated and purged with an inert gas to remove moisture and oxygen; then CO2 was introduced to 2 MPa, and the reaction was carried out at 25 °C with stirring for 24 h to perform alternating copolymerization of CO2 and ECH. After the reaction was completed, unreacted CO2 was slowly released, and unreacted monomers were evaporated. The crude polymer obtained from the reaction was dissolved in dichloromethane (DCM), and excess methanol was added to the solution to precipitate the polymer. After filtration, the resulting solid was dried under vacuum at 60 °C for 12 h to obtain CO2-based polycarbonate containing chloromethyl side groups.

[0060] (2) Preparation of imidazolium chloride-type polycarbonate ionic liquids Imidazoliumization was performed according to the method in Example 1 (step (2)).

[0061] (3) Preparation of TFSI-type polycarbonate-based ionic liquid (PIL-PC) by anion exchange PIL-PC was obtained by anion exchange and purification according to the method of Example 1 (step (3)).

[0062] (4) Preparation of zinc-based solid or quasi-solid polymer electrolyte membranes PIL-PC and Zn(TFSI)2 were weighed and mixed at a mass ratio of 80:20, and dissolved in acetonitrile / DMF (volume ratio 1:1) to form a homogeneous solution. The solution was cast onto a polytetrafluoroethylene (PTFE) or treated glass plate, and after partial solvent evaporation at room temperature, it was vacuum dried at 60°C for 24–48 h to remove residual solvent. The resulting zinc-based solid polymer electrolyte membrane was then peeled off. The membrane thickness could be controlled between 30 and 200 µm, preferably 50–120 µm, by adjusting the casting gap.

[0063] Example 8: Preparation of PIL-PC / Zn(TFSI)2 electrolyte membrane (1) Preparation of chloromethyl polycarbonate (PCPC) with side chain 20.0 mL of epichlorohydrin (ECH) and a tetranuclear organoboron catalyst, prepared according to literature, were added to a high-pressure reactor, with a molar ratio of ECH to catalyst of approximately 500:1. The reactor was evacuated and purged with an inert gas to remove moisture and oxygen; then CO2 was introduced to 3 MPa, and the reaction was stirred at 25 °C for 24 h to perform alternating copolymerization of CO2 and ECH. After the reaction was completed, unreacted CO2 was slowly released, and unreacted monomers were evaporated. The crude polymer obtained from the reaction was dissolved in dichloromethane (DCM), and excess methanol was added to the solution to precipitate the polymer. After filtration, the resulting solid was dried under vacuum at 60 °C for 12 h to obtain CO2-based polycarbonate containing chloromethyl side groups.

[0064] (2) Preparation of imidazolium chloride-type polycarbonate ionic liquids Imidazoliumization was performed according to the method in Example 1 (step (2)).

[0065] (3) Preparation of TFSI-type polycarbonate-based ionic liquid (PIL-PC) by anion exchange PIL-PC was obtained by anion exchange and purification according to the method of Example 1 (step (3)).

[0066] (4) Preparation of zinc-based solid or quasi-solid polymer electrolyte membranes PIL-PC and Zn(TFSI)2 were weighed and mixed at a mass ratio of 80:20, dissolved, and cast into a film according to Example 1 (step (4)), dried, and peeled off to obtain a zinc-based solid polymer electrolyte membrane. The membrane thickness can be controlled between 30 and 200 µm, preferably between 50 and 120 µm.

[0067] Example 9: Preparation of PIL-PC / Zn(TFSI)2 electrolyte membrane (1) Preparation of chloromethyl polycarbonate (PCPC) with side chain 20.0 mL of epichlorohydrin (ECH) and a tetranuclear organoboron catalyst, prepared according to literature, were added to a high-pressure reactor, with a molar ratio of ECH to catalyst of approximately 500:1. The reactor was evacuated and purged with an inert gas to remove moisture and oxygen; then CO2 was introduced to 4 MPa, and the reaction was carried out at 25 °C with stirring for 24 h to perform alternating copolymerization of CO2 and ECH. After the reaction was completed, unreacted CO2 was slowly released, and unreacted monomers were evaporated. The crude polymer obtained from the reaction was dissolved in dichloromethane (DCM), and excess methanol was added to the solution to precipitate the polymer. After filtration, the resulting solid was dried under vacuum at 60 °C for 12 h to obtain CO2-based polycarbonate containing chloromethyl side groups.

[0068] (2) Preparation of imidazolium chloride-type polycarbonate ionic liquids Imidazoliumization was performed according to the method in Example 1 (step (2)).

[0069] (3) Preparation of TFSI-type polycarbonate-based ionic liquid (PIL-PC) by anion exchange PIL-PC was obtained by anion exchange and purification according to the method of Example 1 (step (3)).

[0070] (4) Preparation of zinc-based solid or quasi-solid polymer electrolyte membranes PIL-PC and Zn(TFSI)2 were weighed and mixed at a mass ratio of 80:20, dissolved in acetonitrile / DMF (volume ratio 1:1), and cast and dried according to Example 1 (step (4)) to form a film. The zinc-based electrolyte membrane was then peeled off. The film thickness can be controlled between 30 and 200 µm, preferably between 50 and 120 µm.

[0071] Example 10: Preparation of PIL-PC / Zn(TFSI)2 electrolyte membrane (1) Preparation of chloromethyl polycarbonate (PCPC) with side chain 20.0 mL of epichlorohydrin (ECH) and a tetranuclear organoboron catalyst, prepared according to literature, were added to a high-pressure reactor, with a molar ratio of ECH to catalyst of approximately 500:1. The reactor was evacuated and purged with an inert gas to remove moisture and oxygen; then CO2 was introduced to 2.5 MPa, and the reaction was carried out at 40 °C with stirring for 24 h to perform alternating copolymerization of CO2 and ECH. After the reaction was completed, unreacted CO2 was slowly released, and unreacted monomers were evaporated. The crude polymer obtained from the reaction was dissolved in dichloromethane (DCM), and excess methanol was added to the solution to precipitate the polymer. After filtration, the resulting solid was dried under vacuum at 60 °C for 12 h to obtain CO2-based polycarbonate containing chloromethyl side groups.

[0072] (2) Preparation of imidazolium chloride-type polycarbonate ionic liquids Imidazoliumization was performed according to the method in Example 1 (step (2)).

[0073] (3) Preparation of TFSI-type polycarbonate-based ionic liquid (PIL-PC) by anion exchange PIL-PC was obtained by anion exchange and purification according to the method of Example 1 (step (3)).

[0074] (4) Preparation of zinc-based solid or quasi-solid polymer electrolyte membranes PIL-PC and Zn(TFSI)2 were weighed and mixed at a mass ratio of 80:20, dissolved, and cast into a film according to Example 1 (step (4)), dried, and peeled off to obtain a zinc-based solid polymer electrolyte membrane. The membrane thickness can be controlled between 30 and 200 µm, preferably between 50 and 120 µm.

[0075] Example 11 Preparation of PIL-PC / Zn(TFSI)2 electrolyte membrane (1) Preparation of chloromethyl polycarbonate (PCPC) with side chain 20.0 mL of epichlorohydrin (ECH) and a tetranuclear organoboron catalyst, prepared according to literature, were added to a high-pressure reactor, with a molar ratio of ECH to catalyst of approximately 500:1. The reactor was evacuated and purged with an inert gas to remove moisture and oxygen; then CO2 was introduced to 2.5 MPa, and the reaction was carried out at 55 °C with stirring for 24 h to perform alternating copolymerization of CO2 and ECH. After the reaction was completed, unreacted CO2 was slowly released, and unreacted monomers were evaporated. The crude polymer obtained from the reaction was dissolved in dichloromethane (DCM), and excess methanol was added to the solution to precipitate the polymer. After filtration, the resulting solid was dried under vacuum at 60 °C for 12 h to obtain CO2-based polycarbonate containing chloromethyl side groups.

[0076] (2) Preparation of imidazolium chloride-type polycarbonate ionic liquids Imidazoliumization was performed according to the method in Example 1 (step (2)).

[0077] (3) Preparation of TFSI-type polycarbonate-based ionic liquid (PIL-PC) by anion exchange PIL-PC was obtained by anion exchange and purification according to the method of Example 1 (step (3)).

[0078] (4) Preparation of zinc-based solid or quasi-solid polymer electrolyte membranes PIL-PC and Zn(TFSI)2 were weighed and mixed at a mass ratio of 80:20, dissolved in acetonitrile / DMF (volume ratio 1:1), and cast and dried according to Example 1 (step (4)) to form a film. The zinc-based electrolyte membrane was then peeled off. The film thickness can be controlled between 30 and 200 µm, preferably between 50 and 120 µm.

[0079] Example 12 Preparation of PIL-PC / Zn(TFSI)2 electrolyte membrane (1) Preparation of chloromethyl polycarbonate (PCPC) with side chain 20.0 mL of epichlorohydrin (ECH) and a tetranuclear organoboron catalyst, prepared according to literature, were added to a high-pressure reactor, with a molar ratio of ECH to catalyst of approximately 500:1. The reactor was evacuated and purged with an inert gas to remove moisture and oxygen; then CO2 was introduced to 2.5 MPa, and the reaction was carried out at 70 °C with stirring for 24 h to perform alternating copolymerization of CO2 and ECH. After the reaction was completed, unreacted CO2 was slowly released, and unreacted monomers were evaporated. The crude polymer obtained from the reaction was dissolved in dichloromethane (DCM), and excess methanol was added to the solution to precipitate the polymer. After filtration, the resulting solid was dried under vacuum at 60 °C for 12 h to obtain CO2-based polycarbonate containing chloromethyl side groups.

[0080] (2) Preparation of imidazolium chloride-type polycarbonate ionic liquids Imidazoliumization was performed according to the method in Example 1 (step (2)).

[0081] (3) Preparation of TFSI-type polycarbonate-based ionic liquid (PIL-PC) by anion exchange PIL-PC was obtained by anion exchange and purification according to the method of Example 1 (step (3)).

[0082] (4) Preparation of zinc-based solid or quasi-solid polymer electrolyte membranes PIL-PC and Zn(TFSI)2 were weighed and mixed at a mass ratio of 80:20, dissolved in acetonitrile / DMF (volume ratio 1:1), and cast and dried according to Example 1 (step (4)) to form a film. The zinc-based electrolyte membrane was then peeled off. The film thickness can be controlled between 30 and 200 µm, preferably between 50 and 120 µm.

[0083] To illustrate the potential application value of the polycarbonate-based ionic liquid electrolyte membrane described in this invention in zinc-based solid / quasi-solid polymer electrolytes, Table 1 summarizes the typical performance ranges of common polymer-based or inorganic particle-reinforced composite electrolyte membranes in zinc systems. Table 1 is intended to illustrate the general level of existing zinc-based polymer / composite membrane systems in terms of areal capacity adaptability and cycle stability, and does not constitute a strict comparison with other systems.

[0084] Table 1. Typical stability comparison of traditional solid electrolyte membranes in metal-symmetric batteries Based on this, to investigate the influence of different formulation factors on the performance of PIL-PC-based electrolyte membranes, the performance of the electrolyte membranes obtained in Examples 1-6 under zinc metal symmetric battery conditions was summarized, and the results are listed in Table 2. As can be seen from Table 2, with changes in the proportion of zinc salts, ionic liquid plasticizers, and inorganic fillers subsequently incorporated into the membrane, different formulation systems exhibit differences in areal capacity adaptability and stable zinc plating / stripping time. These results indicate that PIL-PC can be used as a feasible film-forming component for zinc-based solid / quasi-solid polymer electrolyte membranes, and the overall performance of the membrane can be further controlled through multi-component compounding.

[0085] Table 2. Comparison of typical stability of different PIL-PC-based zinc electrolyte membranes in zinc metal symmetric cells. Based on Examples 1-6, to further investigate the influence of PIL-PC precursor polymerization conditions on the performance of zinc-based solid or quasi-solid polymer electrolyte membranes, the stable areal capacity and cycle life of the electrolyte membranes obtained in Examples 7-12 in zinc symmetric batteries were compiled, and the results are listed in Table 3. Table 3 shows that, under basically consistent membrane composition, the pressure and temperature of the alternating copolymerization reaction of CO2 and ECH during PCPC preparation have a significant impact on the electrochemical stability of the obtained PIL-PC-based zinc electrolyte membranes. Overall, moderate polymerization pressure and temperature are more conducive to obtaining electrolyte membranes with both high areal capacity and long cycle life. Samples prepared under conditions of 3 MPa and 55 °C generally exhibit superior overall performance, while excessively low or high polymerization pressure and excessively high polymerization temperature may lead to a decrease in membrane stability.

[0086] Table 3. Stable areal capacity and cycle life of zinc-based electrolyte membranes in zinc symmetric batteries according to different embodiments As can be seen from Tables 1, 2, and 3, compared with traditional PEO-based, PVDF-HFP-based, PAN-based, and inorganic composite electrolyte membranes, the PIL-PC-based zinc-based solid or quasi-solid polymer electrolyte membrane provided by this invention exhibits better stable areal capacity adaptability and cycle stability. By controlling the Zn(TFSI)2 content and further introducing ionic liquid plasticizers and inorganic fillers, the ion transport performance, flexibility, interfacial stability, and cycle durability of the electrolyte membrane can be effectively improved; among them, the multi-component synergistic composite system exhibits superior overall performance. Meanwhile, the polymerization pressure and polymerization temperature of the PIL-PC precursor also have a significant impact on the final membrane performance; suitable polymerization conditions are more conducive to forming a high-performance polymer matrix, thereby improving the stable areal capacity and cycle life of the obtained zinc-based electrolyte membrane in zinc symmetric batteries. This indicates that the PIL-PC-based zinc-based solid electrolyte membrane of this invention can achieve stable zinc deposition / stripping cycles for a longer period under high areal capacity conditions and has good interfacial compatibility and anti-instability capabilities, thus possessing good application value in zinc metal batteries and related energy storage devices.

[0087] This invention introduces polyionic liquid side chains into a polycarbonate skeleton obtained from CO2 resource utilization, which combines green raw material sources, controllable structural design and scalability of solid electrolyte formulations, providing a new material and process route for constructing high-safety and high-stability zinc-based solid electrolyte membranes.

Claims

1. A method for preparing a zinc-based solid electrolyte membrane based on a polycarbonate-based ionic liquid, characterized in that, Preparation methods include: Step 1: Weigh epichlorohydrin and add it to a high-pressure reactor. Under the condition of catalyst, CO2 is introduced and copolymerization reaction is carried out under stirring. After the reaction is completed, the temperature is lowered to room temperature to release the remaining CO2. The resulting polymer is dissolved in an organic solvent, and after precipitation, filtration and vacuum drying, CO2-based polycarbonate with chloromethyl side groups is obtained. Step 2: Weigh CO2-based polycarbonate with chloromethyl side group and dissolve it in a polar solvent. Add 1-methylimidazole under stirring and carry out nucleophilic substitution reaction at 40-90℃ for 24-48h. After the reaction is completed, pour the reaction solution into excess ethyl acetate or acetone to precipitate and filter. Wash the precipitate and vacuum dry it to obtain imidazole onium chloride type polycarbonate. Step 3: Imidazolium chloride-type polycarbonate is dissolved in deionized water or a polar organic solvent, and a salt solution containing TFSI- anions is added at room temperature. Anion exchange reaction is carried out under stirring for 6-24 hours. After the reaction is completed, the precipitate is washed and washed 3-5 times with distilled water. It is then dried under vacuum at 60-80℃ for 8-12 hours to obtain CO2-based imidazolium-TFSI polycarbonate-based ionic liquid. Step 4: Weigh CO2-based imidazolium-TFSI polycarbonate-based ionic liquid and mix it with zinc salt, dissolve it in deionized water or a polar organic solvent; cast it into a film on polytetrafluoroethylene or a treated glass plate, evaporate some of the solvent at room temperature, and then vacuum dry it at 60°C for 24-48 hours, and peel it off to obtain a zinc-based solid polymer electrolyte membrane.

2. The method for preparing a zinc-based solid electrolyte membrane based on a polycarbonate-based ionic liquid according to claim 1, characterized in that, In step 1, 20.0 mL of epichlorohydrin was weighed out, and a tetranuclear organoboron catalyst was used. The molar ratio of epichlorohydrin to catalyst was approximately 500:

1. The reactor was evacuated and replaced with an inert gas to remove moisture and oxygen. Dichloromethane was used as the organic solvent. Excess methanol was added to the solution to precipitate the polymer. The solution was filtered, and the precipitate was dried under vacuum at 60°C for 12 hours.

3. The method for preparing a zinc-based solid electrolyte membrane based on a polycarbonate-based ionic liquid according to claim 1, characterized in that, In step 1, the pressure at which CO2 is introduced into the high-pressure reactor is 2.0-4.0 MPa.

4. The method for preparing a zinc-based solid electrolyte membrane based on a polycarbonate-based ionic liquid according to claim 1, characterized in that, In step 1, the reaction temperature in the high-pressure reactor is 25-70℃.

5. The method for preparing a zinc-based solid electrolyte membrane based on a polycarbonate-based ionic liquid according to claim 1, characterized in that, In step 2, 2.00 g of CO2-based polycarbonate with chloromethyl side groups was weighed, and N,N-dimethylformamide with a volume of 20.0 mL was used as the polar solvent. 0.5 g of 1-methylimidazole was added to the reaction system. The system was washed three times with ethyl acetate, and dried at 70°C for 12 h.

6. The method for preparing a zinc-based solid electrolyte membrane based on a polycarbonate-based ionic liquid according to claim 1, characterized in that, In step 3, the polar organic solvent used is acetonitrile / methanol solvent with a volume ratio of 1:

1. 2.20g of salt solution containing TFSI- anions is added based on the imidazole site. During stirring, the mixture is first stirred at room temperature for 12h, and then stirred further at 30℃ for 18h to complete the anion exchange. After the reaction, the mixture is washed twice with methanol and then washed with deionized water until the washing solution is free of free small molecule salts.

7. The method for preparing a zinc-based solid electrolyte membrane based on a polycarbonate-based ionic liquid according to claim 1, characterized in that, In step 4, the zinc salt is Zn(TFSI)2, the CO2-based imidazolium-TFSI polycarbonate-based ionic liquid is used in a mass ratio of 80:20, 70:30 or 60:40, the polar organic solvent is acetonitrile / N,N-dimethylformamide solvent in a volume ratio of 1:1, and the film thickness is controlled at 30-200µm by the casting gap.

8. The method for preparing a zinc-based solid electrolyte membrane based on a polycarbonate-based ionic liquid according to claim 1, characterized in that, In step 4, add ionic liquid plasticizer IL. Weigh out CO2-based imidazolium-TFSI polycarbonate-based ionic liquid, zinc salt and ionic liquid plasticizer IL and mix them in a mass ratio of 60:20:

20.

9. The method for preparing a zinc-based solid electrolyte membrane based on a polycarbonate-based ionic liquid according to claim 1, characterized in that, In step 4, inorganic filler is added at a rate of 1 wt% of the total mass of the zinc-based solid electrolyte membrane. The inorganic filler is first ultrasonically dispersed in a polar organic solvent, and then mixed with imidazolium-TFSI polycarbonate-based ionic liquid and zinc salt.

10. The method for preparing a zinc-based solid electrolyte membrane based on a polycarbonate-based ionic liquid according to claim 1, characterized in that, In step 4, inorganic filler and ionic liquid plasticizer IL are added. CO2-based imidazolium-TFSI polycarbonate-based ionic liquid, zinc salt, ionic liquid plasticizer IL and inorganic filler are mixed at a mass ratio of 60:20:20:

1. The amount of ionic liquid plasticizer IL added is 20 wt% of the total mass of the zinc-based solid electrolyte membrane, and the amount of inorganic filler added is 1 wt% of the total mass of the zinc-based solid electrolyte membrane. The inorganic filler is first ultrasonically dispersed in a polar organic solvent, and then mixed evenly with CO2-based imidazolium-TFSI polycarbonate-based ionic liquid, zinc salt and ionic liquid plasticizer IL.

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