Nanofiber and piezoelectric polymer composite solid electrolyte membrane, preparation method thereof, and secondary battery

Abstract

The application discloses a nanofiber and piezoelectric polymer composite solid-state electrolyte membrane and a preparation method and a secondary battery thereof, relates to the technical field of batteries, and the raw materials of the solid-state electrolyte membrane include nanofibers and a piezoelectric polymer, the raw materials of the piezoelectric polymer include a piezoelectric polymer, a zinc salt and an ionic liquid; the nanofibers are used in the form of a nanofiber membrane as a framework, and the piezoelectric polymer is arranged on the nanofiber membrane. The preparation method comprises the following steps: preparing a spinning liquid by using a polymer material, performing spinning treatment, and obtaining a nanofiber membrane; dissolving the piezoelectric polymer, the zinc salt and the ionic liquid, uniformly laying the piezoelectric polymer, the zinc salt and the ionic liquid on the nanofiber membrane, and drying, and the solid-state electrolyte membrane is obtained. The secondary battery comprises the solid-state electrolyte membrane. The nanofiber reinforced solid-state electrolyte membrane realizes uniform distribution of current and electric field, provides ideal conditions for zinc deposition, the piezoelectric polymer is injected as an ion transmission medium, the zinc salt and the ionic liquid are introduced, and the ionic conductivity is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to an electrolyte material in a battery, in particular to a solid-state electrolyte membrane composed of nanofibers and piezoelectric polymers, a preparation method thereof and a secondary battery, and belongs to the field of new energy materials and electrochemistry. BACKGROUND

[0002] Among the currently commercialized rechargeable secondary batteries, lithium-ion batteries are widely used in hybrid / pure electric vehicles and portable electronic devices due to their high energy density and excellent cycle stability. However, lithium-ion batteries often lose control during the dissolution / deposition process at the negative electrode, forming lithium dendrites. These dendrites may pierce the separator as they grow, leading to short circuits between the positive and negative electrodes. At high current densities, the local heating caused by dendrite growth, combined with the flammable organic electrolyte, can easily cause fires and explosions and other safety problems. In addition, the scarcity of lithium metal resources results in high costs, further limiting the application of lithium-ion batteries. Therefore, there is an urgent need for other rechargeable secondary battery technologies with high safety and low cost.

[0003] Among the many candidate batteries, zinc-ion batteries have become one of the most promising energy storage systems due to their low redox potential, high theoretical capacity, abundant resources, and environmental friendliness. Compared with organic electrolytes, aqueous zinc-ion batteries have lower cost, are easier to assemble, and have higher ionic conductivity. However, zinc-ion batteries also face the problem of dendrite growth caused by uneven dissolution / deposition at the zinc negative electrode, which can cause short circuits and affect battery performance. In addition, the corrosion, hydrogen evolution, and passivation problems of the zinc negative electrode also need to be addressed to improve the cycle life and coulombic efficiency of zinc-ion batteries.

[0004] Compared with liquid electrolytes, polymer electrolytes not only have higher safety and stability, but also have good thermodynamic properties and stable ion transport capacity. In addition, polymer electrolytes have good mechanical properties and are expected to achieve lightweight and flexible zinc-ion batteries. Therefore, polymer electrolytes play an important role in the development of future energy storage. Currently, the definition of solid-state polymer electrolytes and quasi-solid-state electrolytes is not very clear. Generally, people are used to dividing polymer electrolytes into two categories, namely gel polymer electrolytes and solid-state polymer electrolytes. The presence or absence of liquid plasticizers in the electrolyte is the main basis for distinguishing solid-state polymer electrolytes from gel polymer electrolytes. Typical gel polymer matrices include polyvinyl alcohol-based hydrogels, gelatin-based hydrogels, and polyacrylamide-based hydrogels, as well as polymer matrices derived from these gel polymer matrices by physical and chemical methods. However, the mechanical strength of the currently reported gel electrolytes is poor and the Zn 2+The low conductivity limits its application. Compared with gel electrolyte, solid-state polymer electrolyte not only provides mechanical stability, but also eliminates the problem of solvent evaporation, thereby stabilizing the electrode / electrolyte interface, so the advantage of solid-state polymer electrolyte is more obvious.

[0005] The polymer electrolyte can effectively alleviate the dissolution of the electrode material and maintain the relative stability of the electrochemical performance, avoiding the leakage and evaporation problems of traditional aqueous electrolyte. The gel polymer electrolyte is not a solid-state electrolyte in the actual sense because its water content is still a hidden danger. The presence of water still limits the voltage window of the gel polymer electrolyte, although the hydrogen evolution reaction can be inhibited within a suitable voltage window, but after continuous cycling accumulation, there is still a certain safety hazard. In contrast, since the solid-state polymer electrolyte does not contain solvent at all, the problem of side reactions caused by active water is solved, and the prospect of solid-state polymer electrolyte is more promising. However, the conductivity of the polymer matrix itself is generally poor, and the conductivity at room temperature is usually between 10 -7 and 10 -6 S / cm. Through traditional methods such as adding inorganic fillers, the conductivity can be improved by 1 to 2 orders of magnitude, but it still cannot meet the actual demand. In recent years, some innovative works have emerged, such as in-situ synthesis of amorphous polymer electrolyte, which fully taps the conduction capacity of amorphous regions, and the conductivity is improved to the order of 10 -2 S / cm. In addition to using a polymer matrix, the polymer matrix can also be made to have multiple excellent properties through methods such as grafting, blending of multiple polymers, and cross-linking. SUMMARY

[0006] The purpose of the present application is to at least solve one of the technical problems existing in the prior art, and to provide a solid-state electrolyte membrane composed of nanofibers and piezoelectric polymers, as well as a preparation method and application thereof, in order to solve the problems of low ion conductivity and uneven deposition of metal zinc of existing solid-state electrolyte membranes.

[0007] The technical solution of the present application is as follows:

[0008] In order to achieve the above application purpose, the first aspect of the present application provides a solid-state electrolyte membrane composed of nanofibers and piezoelectric polymers.

[0009] The preparation raw materials of the solid-state electrolyte membrane composed of nanofibers and piezoelectric polymers of the present application include piezoelectric polymer and nanofiber membrane, and the preparation raw materials of the piezoelectric polymer include piezoelectric polymer, zinc salt and ionic liquid;

[0010] The nanofiber is in the form of nanofiber membrane as the skeleton of the solid-state electrolyte membrane, and the piezoelectric polymer is arranged on the nanofiber membrane to form the solid-state electrolyte membrane.

[0011] The technical core of the present application is to select nanofiber as the skeleton of solid-state electrolyte, inject piezoelectric polymer as ion conduction medium, introduce zinc salt and ionic liquid, and use nanofiber to make up for the insufficient strength of piezoelectric polymer. The solid-state electrolyte film prepared by the present application has high capacity and high ionic conductivity, and has excellent structure and cycle stability, and excellent mechanical properties. The preparation method can ensure the stability of the structure and electrochemical properties of the solid-state electrolyte film, and has high efficiency. The zinc ion battery has high capacity, excellent cycle performance and good rate performance.

[0012] Further, the mass ratio of the nanofiber and the piezoelectric polymer is 1:2-1:10.

[0013] Further, the nanofiber is at least one of polyester, polyamide, polyimide, polyamide amide, polyimide amide, polyamide imide, polyamide amide amide, polyvinyl alcohol, polyacrylonitrile, polyethylene oxide, polymethyl methacrylate, and polyurethane high polymer material.

[0014] Further, the piezoelectric polymer is at least one of polystyrene, polyvinylidene fluoride, polytrifluoroethylene, polyethylene difluoride, polyethylene vinyl acetate, polytrifluorochloroethylene, and a multi-component copolymer thereof.

[0015] Further, the zinc salt is at least one of zincous chloride, zinc acetate, zinc sulfate, zinc nitrate, and zinc trifluoromethyl sulfonate.

[0016] Further, the ionic liquid is at least one of 1-ethyl-3-methyl imidazole zinc nitrate, 1-butyl-trimethyl imidazole zinc nitrate, 1-ethyl-trimethyl imidazole zinc hexafluorophosphate, 1-ethyl-trimethyl imidazole zinc tetrafluoroborate, and 1-ethyl-trimethyl imidazole zinc trifluorosulfonate.

[0017] Further, the content of the raw material of the piezoelectric polymer is as follows: the mass percentage content of the piezoelectric polymer is 30%-80%, the mass percentage content of the zinc salt is 5%-35%, and the mass percentage content of the ionic liquid is 5%-35%.

[0018] In a second aspect, the present application provides a preparation method of the solid-state electrolyte film prepared by the nanofiber and the piezoelectric polymer. The preparation method of the solid-state electrolyte film prepared by the nanofiber and the piezoelectric polymer is as follows:

[0019] Dissolve the polymer material in an organic solvent to prepare a spinning solution, and perform spinning treatment on the obtained spinning solution to obtain a nanofiber film.

[0020] The piezoelectric polymer, zinc salt and ionic liquid are dissolved in an organic solvent and heated and stirred until they are homogeneous to obtain a mixed solution.

[0021] The mixed solution was evenly spread on the nanofiber membrane and dried to obtain the piezoelectric polymer.

[0022] The obtained transparent solution was uniformly coated onto the nanofiber membrane, and then left to dry at room temperature to allow the solvent to evaporate. After the solvent had completely evaporated, a solid electrolyte membrane was obtained.

[0023] Furthermore, the spinning process is an electrostatic process, and the conditions for the electrostatic process are as follows:

[0024] The needle inner diameter is 0.6–2.2 mm; the voltage is 10–20 kV; the temperature is 35–45℃; the relative humidity is 43–47% RH; and the injection speed is 3–6 mL / h. -1 The receiving distance is 10-20cm, and the receiver rotation speed is 100-500rpm.

[0025] Furthermore, in the spinning solution, the mass concentration of the organic solvent is 80%–90%, and the mass concentration of the polymer material is 10%–20%.

[0026] Furthermore, the organic solvent includes at least one of N,N-dimethylformamide, N-methylpyrrolidone, and dimethyl sulfoxide.

[0027] Furthermore, the heating temperature of the piezoelectric polymer, zinc salt, and ionic liquid is 20℃~95℃.

[0028] Further, the mixed solution is evenly spread on the nanofiber membrane, placed at room temperature, and dried to evaporate and remove the solvent, with an evaporation time of 10–60 min.

[0029] In a third aspect, the present invention provides a secondary battery comprising a solid electrolyte, wherein the solid electrolyte is the solid electrolyte of the present invention.

[0030] Furthermore, the secondary battery is an all-solid-state zinc-ion battery, and the solid electrolyte membrane in the all-solid-state zinc-ion battery is the solid electrolyte membrane of this invention.

[0031] This invention has at least one of the following beneficial effects:

[0032] This invention proposes a solid-state electrolyte membrane. By introducing a nanofiber membrane prepared using electrospinning technology as the framework material, a composite membrane with high ionic conductivity and excellent interfacial properties is constructed, significantly improving battery performance. This design not only endows the solid-state electrolyte membrane with high structural stability and interfacial properties but also effectively inhibits zinc corrosion. The nanofiber-reinforced solid-state electrolyte membrane achieves a uniform distribution of current and electric field, providing ideal conditions for zinc deposition. Furthermore, by injecting piezoelectric polymers as ion transport media and introducing zinc salts and ionic liquids, the ionic conductivity is further improved, providing a more reliable foundation for the preparation of the electrolyte membrane. This electrolyte makes a significant contribution to suppressing zinc dendrite formation.

[0033] The secondary battery provided by this invention has the advantages of high capacity, excellent cycle performance, and good rate capability. Moreover, it can be a flexible battery with excellent mechanical properties. Therefore, the secondary battery prepared using the solid electrolyte membrane of this invention can improve the stability of the electrochemical performance of the secondary battery and extend its life. Attached Figure Description

[0034] Figure 1 This is a physical image of the solid electrolyte membrane composed of nanofibers and piezoelectric polymers in Embodiment A1 of this application;

[0035] Figure 2 This is a photograph of the solid electrolyte membrane composed of piezoelectric polymers in Comparative Example A1 of this application.

[0036] Figure 3 This is a photograph of the solid electrolyte membrane composed of piezoelectric polymers in Comparative Example A4 of this application.

[0037] Figure 4 This is a scanning electron microscope (SEM) image of the solid electrolyte membrane composed of A7 nanofibers and piezoelectric polymers, which is a comparative example of this application.

[0038] Figure 5 This is a scanning electron microscope (SEM) image of the solid electrolyte membrane composed of nanofibers and piezoelectric polymers in Embodiment A1 of this application.

[0039] Figure 6 This is a dielectric constant curve of the zinc-ion battery in Embodiment B1 of this application;

[0040] Figure 7 These are X-ray diffraction comparison images of the solid electrolyte membranes of Example A1 and Comparative Examples A1 and A4 of this application;

[0041] Figure 8 This is a comparison of the Raman spectra of the solid electrolyte membranes of Example A1 and Comparative Examples A1 and A4 in this application;

[0042] Figure 9This is a comparison diagram of the electrochemical stability of the solid electrolyte membranes in Example A1 of this application and Comparative Examples A1 and A4;

[0043] Figure 10 This is an ionic conductivity diagram of the solid electrolyte membrane composed of nanofibers and piezoelectric polymers in Example A1 of this application;

[0044] Figure 11 This is a cycle performance diagram of the zinc-ion battery in Embodiment B1 of this application;

[0045] Figure 12 This is a high and low temperature performance curve of the zinc-ion battery in Embodiment B1 of this application;

[0046] Figure 13 This is a cycle performance curve of the zinc-iodine battery in Embodiment B2 of this application. Detailed Implementation

[0047] To make the technical problems solved, the technical solutions, and the beneficial effects of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0048] An embodiment of the present invention provides a solid electrolyte membrane, the raw materials for which include nanofibers and piezoelectric polymers. The raw materials for preparing the piezoelectric polymers include piezoelectric polymers, zinc salts, and ionic liquids. The nanofibers serve as the framework of the solid electrolyte membrane in the form of a nanofiber membrane, and the piezoelectric polymers are disposed on the nanofiber membrane to form the solid electrolyte membrane.

[0049] This invention constructs a composite membrane with high ionic conductivity and excellent interfacial properties by using nanofiber membranes as the framework material, significantly improving battery performance. It not only endows the solid electrolyte membrane with high structural stability and interfacial properties but also effectively inhibits zinc corrosion. The nanofiber-reinforced solid electrolyte membrane achieves a uniform distribution of current and electric field, providing ideal conditions for zinc deposition. Furthermore, by injecting piezoelectric polymers as ion transport media and introducing zinc salts and ionic liquids, the ionic conductivity is further improved, providing a more reliable foundation for electrolyte membrane preparation and suppressing zinc dendrite formation.

[0050] In one specific embodiment of the present invention, the nanofibers are formed into a nanofiber membrane by electrospinning.

[0051] In one specific embodiment of the present invention, a solution is obtained by dissolving the raw materials for preparing the piezoelectric polymer in a solvent, and then the solution is cast onto the nanofiber membrane to form the solid electrolyte membrane. Preferably, the solvent is DMF.

[0052] Since the nanofiber membrane in this invention is a three-dimensional self-supporting fiber skeleton, that is, a membrane; the raw materials for the preparation of piezoelectric polymer are dissolved in DMF, and then the solution is cast onto the nanofiber membrane. The solution will penetrate into the skeleton of the nanofiber membrane. After the solution solidifies, a solid electrolyte membrane is obtained.

[0053] In one specific embodiment of the present invention, the mass ratio of the nanofibers to the piezoelectric polymer is 1:2 to 1:10, preferably 1:2 to 1:8, and more preferably 1:2 to 1:6. Specifically, the mass ratio of the nanofibers to the piezoelectric polymer is 1:2, 1:2.5, 1:3, 1:3.5, 1:4, 1:4.5, or 1:5, etc.

[0054] In one specific embodiment of the present invention, the nanofiber is at least one selected from polyester, polyamide, polyimide, polyamide amide, polyimide amide, polyamide imide, polyamide amide amide, polyvinyl alcohol, polyacrylonitrile, polyethylene oxide, polymethyl methacrylate, and polyurethane polymer materials.

[0055] In one specific embodiment of the present invention, the piezoelectric polymer is at least one selected from polystyrene, polyvinylidene fluoride, polytrifluoroethylene, polyethylene difluoride, polyethylene vinyl acetate, polychlorotrifluoroethylene, and their multi-component copolymers.

[0056] In one specific embodiment of the present invention, the zinc salt is at least one selected from zinc chloride, zinc acetate, zinc sulfate, zinc nitrate, and zinc trifluoromethanesulfonate.

[0057] In one specific embodiment of the present invention, the ionic liquid is at least one selected from 1-ethyl-3-methylimidazolium zinc nitrate, 1-butyl-trimethylimidazolium zinc nitrate, 1-ethyl-trimethylimidazolium zinc hexafluorophosphate, 1-ethyl-trimethylimidazolium zinc tetrafluoroborate, and 1-ethyl-trimethylimidazolium trifluorosulfonate.

[0058] In one specific embodiment of the present invention, the piezoelectric polymer contains 30% to 80% piezoelectric polymer by mass, 5% to 35% zinc salt by mass, and 5% to 35% ionic liquid by mass.

[0059] Preferably, the piezoelectric polymer has a mass percentage content of 40% to 70%, the zinc salt has a mass percentage content of 10% to 30%, and the ionic liquid has a mass percentage content of 10% to 30%.

[0060] More preferably, the piezoelectric polymer has a mass percentage content of 50% to 60%, the zinc salt has a mass percentage content of 15% to 25%, and the ionic liquid has a mass percentage content of 15% to 25%.

[0061] Specifically, the piezoelectric polymer has a mass percentage content of 30%, the zinc salt has a mass percentage content of 35%, and the ionic liquid has a mass percentage content of 35%; or, the piezoelectric polymer has a mass percentage content of 40%, the zinc salt has a mass percentage content of 30%, and the ionic liquid has a mass percentage content of 30%; or, the piezoelectric polymer has a mass percentage content of 50%, the zinc salt has a mass percentage content of 25%, and the ionic liquid has a mass percentage content of 25%; or, the piezoelectric polymer has a mass percentage content of 60%, the zinc salt has a mass percentage content of 20%, and the ionic liquid has a mass percentage content of 20%; or, the piezoelectric polymer has a mass percentage content of 70%, the zinc salt has a mass percentage content of 15%, and the ionic liquid has a mass percentage content of 15%; or, the piezoelectric polymer has a mass percentage content of 60%, the zinc salt has a mass percentage content of 20%, and the ionic liquid has a mass percentage content of 20%; or, the piezoelectric polymer has a mass percentage content of 80%, the zinc salt has a mass percentage content of 10%, and the ionic liquid has a mass percentage content of 10%.

[0062] Another embodiment of the present invention provides a method for preparing a solid electrolyte membrane, comprising the following steps:

[0063] Polymer materials are dissolved in organic solvents to prepare spinning solutions, and the resulting spinning solutions are then subjected to spinning treatment to obtain nanofiber membranes.

[0064] The piezoelectric polymer, zinc salt and ionic liquid are dissolved in an organic solvent and heated and stirred until they are homogeneous to obtain a mixed solution.

[0065] The mixed solution was evenly spread on the nanofiber membrane and dried to obtain a solid electrolyte membrane.

[0066] This invention introduces electrospinning technology to prepare nanofiber membranes, in which the mixed solution is uniformly spread on the nanofiber membrane. The preparation method is simple and easy to control.

[0067] In one specific embodiment of the present invention, a piezoelectric polymer is dissolved in an organic solvent and heated and stirred on a magnetic stirrer until completely dissolved; a zinc salt is added to the mixed solution and heated and stirred until completely dissolved; an ionic liquid is added to the mixed solution and heated and stirred until completely dissolved, thus obtaining a mixed solution.

[0068] In one specific embodiment of the present invention, the spinning process is an electrospinning process, and the conditions for the electrospinning process are as follows:

[0069] The needle inner diameter is 0.6–2.2 mm; the voltage is 10–20 kV; the temperature is 35–45℃; the relative humidity is 43–47% RH; and the injection speed is 3–6 mL / h.-1 The receiving distance is 10-20cm, and the receiver rotation speed is 100-500rpm;

[0070] Preferably, the needle inner diameter is 0.8–2 mm; the voltage is 12–18 kV; the temperature is 37–43 °C; the relative humidity is 44–47% RH; and the injection speed is 4–6 mL / h. -1 The receiving distance is 12-18cm, and the receiver rotation speed is 150-450rpm.

[0071] More preferably, the needle inner diameter is 1–1.8 mm; the voltage is 14–16 kV; the temperature is 39–41 °C; the relative humidity is 44–46% RH; and the injection speed is 4–5 mL / h. -1 The receiving distance is 14-16cm, and the receiver rotation speed is 200-400rpm;

[0072] In the spinning solution, the organic solvent has a mass concentration of 80%–90%, and the polymeric material has a mass concentration of 10%–20%; preferably, the organic solvent has a mass concentration of 82%–88%, and the polymeric material has a mass concentration of 12%–18%; more preferably, the organic solvent has a mass concentration of 84%–86%, and the polymeric material has a mass concentration of 14%–16%.

[0073] The organic solvent includes at least one of N,N-dimethylformamide, N-methylpyrrolidone, and dimethyl sulfoxide;

[0074] The heating temperature of the piezoelectric polymer, zinc salt, and ionic liquid is 20℃~95℃, preferably 30℃~80℃, and more preferably 40℃~70℃.

[0075] Another embodiment of the present invention provides a secondary battery including the above-described solid electrolyte membrane.

[0076] In one specific embodiment of the present invention, the secondary battery is an all-solid-state zinc-ion battery, and the solid electrolyte in the all-solid-state zinc-ion battery is the solid electrolyte membrane of the present invention.

[0077] The secondary battery provided by this invention has the advantages of high capacity, excellent cycle performance, and good rate capability. Moreover, it can be a flexible battery with excellent mechanical properties. Therefore, the secondary battery prepared using the solid electrolyte membrane of this invention can improve the stability of the electrochemical performance of the secondary battery and extend its life.

[0078] The present invention will be further described in detail below with reference to specific embodiments, but the present invention is not limited to the following specific embodiments.

[0079] 1. Examples of Nanofiber Piezoelectric Polymer Composite Solid Electrolyte Membranes

[0080] Example A1

[0081] This embodiment provides a nanofiber piezoelectric polymer composite solid electrolyte membrane and its preparation method. The physical sample of the nanofiber piezoelectric polymer composite solid electrolyte membrane is shown below. Figure 1 As shown.

[0082] The preparation method of nanofiber piezoelectric polymer composite solid electrolyte membrane includes the following steps:

[0083] S1. Weigh 3.2g of polyimide polymer (molecular weight 14w) and dissolve it in N,N-dimethylformamide to prepare a polymer solution with a certain concentration, wherein the mass concentration of polyimide in the spinning solution is 16%.

[0084] S2. Inject the spinning solution prepared in step S1 into syringes equipped with stainless steel needles of different sizes. Adjust parameters such as voltage, temperature, humidity, feed speed, receiving distance, and receiver rotation speed to perform electrospinning and form a polyimide nanofiber membrane. The stainless steel needles used for electrospinning are 12G to 20G (i.e., needle inner diameter of 0.6 to 2.2 mm); the voltage is 25 kV; the temperature is controlled at 45 ± 2℃; the relative humidity is controlled at 45 ± 2% RH; and the feed speed is 5 mL / h. -1 The receiving distance is 15cm and the receiver rotation speed is 500rpm.

[0085] S3. Weigh 6g of polyvinylidene fluoride-trifluoroethylene-chlorotrifluoroethylene terpolymer and add it to 30mL of organic solvent N,N-dimethylformamide. Under constant temperature of 50℃, continue heating and stirring until the copolymer is completely dissolved. The resulting solution is a colorless, transparent liquid with a certain viscosity.

[0086] S4. Add 2.4g of zinc trifluoromethanesulfonate to the colorless, transparent, viscous liquid obtained in step S3 above, and continue heating and stirring at 50°C until the zinc trifluoromethanesulfonate is completely dissolved in the solution, so that the final solution is still a colorless, transparent, and viscous liquid.

[0087] S5. Add 0.96g of the ionic liquid 1-ethyl-trimethylimidazolium trifluorosulfonate to the solution obtained in step S4, and continue heating and stirring at a constant temperature of 50°C to ensure that all components are completely dissolved, and finally obtain a colorless, transparent and viscous solution.

[0088] S6. Spread the polyimide nanofiber membrane prepared in step S2 evenly on a glass plate, then coat the colorless, transparent, viscous liquid obtained in step S5 evenly on the surface of the spread polyimide nanofiber membrane, and then let it stand at room temperature for 60 minutes to allow the solvent to fully evaporate. After the solvent has completely evaporated, a piezoelectric polymer composite solid electrolyte membrane with a nanofiber structure can be obtained.

[0089] Example A2

[0090] This embodiment provides a nanofiber piezoelectric polymer composite solid electrolyte membrane and its preparation method. The preparation method of the nanofiber piezoelectric polymer composite solid electrolyte membrane includes the following steps:

[0091] S1. Weigh 2.4g of polyamide-imide polymer (molecular weight 3w) and dissolve it in N,N-dimethylformamide to prepare a polymer solution with a certain concentration. In the spinning solution, the mass concentration of polyimide is 12%.

[0092] S2. Inject the spinning solution prepared in step S1 into syringes equipped with stainless steel needles of different sizes. Adjust parameters such as voltage, temperature, humidity, feed speed, receiving distance, and receiver rotation speed to perform electrospinning and form a polyimide nanofiber membrane. The stainless steel needles used for electrospinning are 12G to 20G (i.e., needle inner diameter of 0.6 to 2.2 mm); the voltage is 25 kV; the temperature is controlled at 45 ± 2℃; the relative humidity is controlled at 45 ± 2% RH; and the feed speed is 5 mL / h. -1 The receiving distance is 15cm and the receiver rotation speed is 500rpm.

[0093] S3. Weigh 6g of polytrifluoroethylene and add it to 30mL of organic solvent N,N-dimethylformamide. Under constant temperature of 60℃, continue heating and stirring until the copolymer is completely dissolved. The resulting solution is a colorless, transparent liquid with a certain viscosity.

[0094] S4. Add 2.4g of zinc chloride to the colorless, transparent, viscous liquid obtained in step S3 above, and continue heating and stirring at 60°C until the zinc chloride is completely dissolved in the solution, so that the final solution is still a colorless, transparent, and viscous liquid.

[0095] S5. Add 0.48g of ionic liquid 1-butyl-trimethylimidazolium zinc nitrate to the solution obtained in step S4, and continue heating and stirring at a constant temperature of 60°C to ensure that all components are completely dissolved, and finally obtain a colorless, transparent and viscous solution.

[0096] S6. Spread the nanofiber membrane prepared in step S2 evenly on a glass plate, and then coat the colorless, transparent, viscous liquid obtained in step S5 evenly on the surface of the spread nanofiber membrane. Then let it stand at room temperature for 60 minutes to allow the solvent to evaporate fully. After the solvent has completely evaporated, a piezoelectric polymer composite solid electrolyte membrane with a nanofiber structure can be obtained.

[0097] Example A3

[0098] This embodiment provides a nanofiber piezoelectric polymer composite solid electrolyte membrane and its preparation method. The preparation method of the nanofiber piezoelectric polymer composite solid electrolyte membrane includes the following steps:

[0099] S1. Weigh 2.8g of polyethylene oxide polymer (molecular weight 20w) and dissolve it in N,N-dimethylformamide to prepare a polymer solution with a certain concentration. In the spinning solution, the mass concentration of polyimide is 14%.

[0100] S2. Inject the spinning solution prepared in step S1 into syringes equipped with stainless steel needles of different sizes. Adjust parameters such as voltage, temperature, humidity, feed speed, receiving distance, and receiver rotation speed to perform electrospinning and form a polyimide nanofiber membrane. The stainless steel needles used for electrospinning are 12G to 20G (i.e., needle inner diameter of 0.6 to 2.2 mm); the voltage is 25 kV; the temperature is controlled at 45 ± 2℃; the relative humidity is controlled at 45 ± 2% RH; and the feed speed is 5 mL / h. -1 The receiving distance is 15cm and the receiver rotation speed is 500rpm.

[0101] S3. Weigh 6g of polyethylene difluoride and add it to 30mL of organic solvent N,N-dimethylformamide. Under constant temperature of 70℃, continue heating and stirring until the copolymer is completely dissolved. The resulting solution is a colorless, transparent liquid with a certain viscosity.

[0102] S4. Add 2.4g of zinc acetate to the colorless, transparent, viscous liquid obtained in step S3 above, and continue heating and stirring at 70°C until the zinc acetate is completely dissolved in the solution, so that the final solution is still a colorless, transparent, and viscous liquid.

[0103] S5. Add 1.44g of ionic liquid 1-ethyl-trimethylimidazolium hexafluorophosphate to the solution obtained in step S4, and continue heating and stirring at a constant temperature of 70°C to ensure that all components are completely dissolved, and finally obtain a colorless, transparent and viscous solution.

[0104] S6. Spread the nanofiber membrane prepared in step S2 evenly on a glass plate, and then coat the colorless, transparent, viscous liquid obtained in step S5 evenly on the surface of the spread nanofiber membrane. Then let it stand at room temperature for 60 minutes to allow the solvent to evaporate fully. After the solvent has completely evaporated, a piezoelectric polymer composite solid electrolyte membrane with a nanofiber structure can be obtained.

[0105] Example A4

[0106] This embodiment provides a nanofiber piezoelectric polymer composite solid electrolyte membrane and its preparation method. The preparation method of the nanofiber piezoelectric polymer composite solid electrolyte membrane includes the following steps:

[0107] S1. Weigh 3.6g of polyvinyl alcohol polymer (molecular weight 14w) and dissolve it in N,N-dimethylformamide to prepare a polymer solution with a certain concentration. In the spinning solution, the mass concentration of polyimide is 18%.

[0108] S2. Inject the spinning solution prepared in step S1 into syringes equipped with stainless steel needles of different sizes. Adjust parameters such as voltage, temperature, humidity, feed speed, receiving distance, and receiver rotation speed to perform electrospinning and form a polyimide nanofiber membrane. The stainless steel needles used for electrospinning are 12G to 20G (i.e., needle inner diameter of 0.6 to 2.2 mm); the voltage is 25 kV; the temperature is controlled at 45 ± 2℃; the relative humidity is controlled at 45 ± 2% RH; and the feed speed is 5 mL / h. -1 The receiving distance is 15cm and the receiver rotation speed is 500rpm.

[0109] S3. Weigh 6g of polyethylene vinyl acetate and add it to 30mL of organic solvent N,N-dimethylformamide. Under constant temperature of 80℃, continue heating and stirring until the copolymer is completely dissolved. The resulting solution is a colorless, transparent liquid with a certain viscosity.

[0110] S4. Add 1.2g of zinc salt zinc nitrate to the colorless, transparent, viscous liquid obtained in step S3 above, and continue heating and stirring at 80°C until the zinc nitrate is completely dissolved in the solution, so that the final solution is still a colorless, transparent, and viscous liquid.

[0111] S5. Add 0.96g of ionic liquid 1-ethyl-3-methylimidazolium zinc nitrate to the solution obtained in step S4, and continue heating and stirring at a constant temperature of 80°C to ensure that all components are completely dissolved, and finally obtain a colorless, transparent and viscous solution.

[0112] S6. Spread the nanofiber membrane prepared in step S2 evenly on a glass plate, and then coat the colorless, transparent, viscous liquid obtained in step S5 evenly on the surface of the spread nanofiber membrane. Then let it stand at room temperature for 60 minutes to allow the solvent to evaporate fully. After the solvent has completely evaporated, a piezoelectric polymer composite solid electrolyte membrane with a nanofiber structure can be obtained.

[0113] Example A5

[0114] This embodiment provides a nanofiber piezoelectric polymer composite solid electrolyte membrane and its preparation method. The preparation method of the nanofiber piezoelectric polymer composite solid electrolyte membrane includes the following steps:

[0115] S1. Weigh 4g of polymethyl methacrylate polymer (molecular weight 60w) and dissolve it in N,N-dimethylformamide to prepare a polymer solution with a certain concentration. In the spinning solution, the mass concentration of polyimide is 20%.

[0116] S2. Inject the spinning solution prepared in step S1 into syringes equipped with stainless steel needles of different sizes. Adjust parameters such as voltage, temperature, humidity, feed speed, receiving distance, and receiver rotation speed to perform electrospinning and form a polyimide nanofiber membrane. The stainless steel needles used for electrospinning are 12G to 20G (i.e., needle inner diameter of 0.6 to 2.2 mm); the voltage is 25 kV; the temperature is controlled at 45 ± 2℃; the relative humidity is controlled at 45 ± 2% RH; and the feed speed is 5 mL / h. -1 The receiving distance is 15cm and the receiver rotation speed is 500rpm.

[0117] S3. Weigh 6g of polyethylene difluoride and add it to 30mL of organic solvent N,N-dimethylformamide. Under constant temperature of 90℃, continue heating and stirring until the copolymer is completely dissolved. The resulting solution is a colorless, transparent liquid with a certain viscosity.

[0118] S4. Add 3.4g of zinc sulfate to the colorless, transparent, viscous liquid obtained in step S3 above, and continue heating and stirring at 90°C until the zinc sulfate is completely dissolved in the solution, so that the final solution is still a colorless, transparent, and viscous liquid.

[0119] S5. Add 0.96g of ionic liquid 1-ethyl-trimethylimidazolium tetrafluoroborate to the solution obtained in step S4, and continue heating and stirring at a constant temperature of 90°C to ensure that all components are completely dissolved, and finally obtain a colorless, transparent and viscous solution.

[0120] S6. Spread the nanofiber membrane prepared in step S2 evenly on a glass plate, and then coat the colorless, transparent, viscous liquid obtained in step S5 evenly on the surface of the spread nanofiber membrane. Then let it stand at room temperature for 60 minutes to allow the solvent to evaporate fully. After the solvent has completely evaporated, a piezoelectric polymer composite solid electrolyte membrane with a nanofiber structure can be obtained.

[0121] Comparative Example A1

[0122] This comparative example provides a piezoelectric polymer solid electrolyte membrane and its preparation method. The physical sample of the prepared nanofiber piezoelectric polymer composite solid electrolyte membrane is shown below. Figure 2 As shown. The difference from Example A1 is that it does not contain a polyimide nanofiber membrane. The preparation method of this piezoelectric polymer electrolyte membrane includes the following steps:

[0123] S1. Weigh 6g of polyvinylidene fluoride-trifluoroethylene-chlorotrifluoroethylene terpolymer and add it to 30mL of organic solvent N,N-dimethylformamide. Under constant temperature of 50℃, continuously heat and stir until the copolymer is completely dissolved. The resulting solution is a colorless, transparent liquid with a certain viscosity.

[0124] S2. Add 2.4g of zinc trifluoromethanesulfonate to the colorless, transparent, viscous liquid obtained in step S1 above, and continue heating and stirring at 50°C until the zinc trifluoromethanesulfonate is completely dissolved in the solution, so that the final solution is still a colorless, transparent, and viscous liquid.

[0125] S3. Add 0.96g of the ionic liquid 1-ethyl-trimethylimidazolium trifluorosulfonate to the solution obtained in step S2, and continue heating and stirring at a constant temperature of 50°C to ensure that all components are completely dissolved, and finally obtain a colorless, transparent and viscous solution.

[0126] S4. Coat the colorless, transparent, viscous liquid obtained in step S3 evenly onto a glass plate / culture dish, and then let it stand at room temperature for 30 to 60 minutes to allow the solvent to evaporate fully. Once the solvent has completely evaporated, a piezoelectric polymer solid electrolyte membrane can be obtained.

[0127] Comparative Example A2

[0128] This comparative example provides a piezoelectric polymer solid electrolyte membrane and its preparation method. The difference from Example A1 is that the amount of ionic liquid added is modified to 0.2 g. The piezoelectric polymer electrolyte membrane is prepared by referring to the method for preparing the piezoelectric polymer solid electrolyte membrane in Comparative Example A1.

[0129] Comparative Example A3

[0130] This comparative example provides a piezoelectric polymer solid electrolyte membrane and its preparation method. The difference from Example A1 is that the amount of ionic liquid added is modified to 5g. The piezoelectric polymer electrolyte membrane is prepared by referring to the method for preparing the piezoelectric polymer solid electrolyte membrane in Comparative Example A1.

[0131] Comparative Example A4

[0132] This comparative example provides a solid electrolyte membrane of a piezoelectric polymer and its preparation method. The physical sample of the prepared nanofiber piezoelectric polymer composite solid electrolyte membrane is shown below. Figure 3 As shown. The difference from Example A1 is that it does not contain a polyimide nanofiber membrane and an ionic liquid. The preparation method of this piezoelectric polymer electrolyte membrane includes the following steps:

[0133] S1. Weigh 6g of polyvinylidene fluoride-trifluoroethylene-chlorotrifluoroethylene terpolymer and add it to 30mL of organic solvent N,N-dimethylformamide. Under constant temperature of 50℃, continuously heat and stir until the copolymer is completely dissolved. The resulting solution is a colorless, transparent liquid with a certain viscosity.

[0134] S2. Add 2.4g of zinc trifluoromethanesulfonate to the colorless, transparent, viscous liquid obtained in step S1 above, and continue heating and stirring at 50°C until the zinc trifluoromethanesulfonate is completely dissolved in the solution, so that the final solution is still a colorless, transparent, and viscous liquid.

[0135] S3. The colorless, transparent, viscous liquid obtained in step S2 is uniformly coated onto a glass plate / culture dish, and then left to stand at room temperature for 30 to 60 minutes to allow the solvent to fully evaporate. Once the solvent has completely evaporated, a piezoelectric polymer solid electrolyte membrane can be obtained.

[0136] Comparative Example A5

[0137] This comparative example provides a solid electrolyte membrane of a piezoelectric polymer and its preparation method. The difference from Example A1 is that the amount of zinc salt added is modified to 0.3 g. The preparation method of this piezoelectric polymer electrolyte membrane is the same as that used in Comparative Example A4 for preparing a solid electrolyte membrane of a piezoelectric polymer.

[0138] Comparative Example A6

[0139] This comparative example provides a solid electrolyte membrane of a piezoelectric polymer and its preparation method. The difference from Example A1 is that the amount of zinc salt added is modified to 5g. The preparation method of this piezoelectric polymer electrolyte membrane is the same as that used in Comparative Example A4.

[0140] Comparative Example A7

[0141] This comparative example provides a solid electrolyte membrane composed of nanofibers and piezoelectric polymers, and its preparation method. The difference from Example A1 is that it does not contain an ionic liquid. The preparation method of this nanofiber and piezoelectric polymer electrolyte membrane is the same as that used in Example A1.

[0142] 2. Zinc-ion battery example

[0143] Example B1

[0144] Example B1 provides a zinc-ion battery that is assembled according to the following method:

[0145] Preparation of solid electrolyte membrane: The solid electrolyte membrane composed of nanofibers and piezoelectric polymers provided in Example A1 is cut into a shape and size suitable for installation in a button battery;

[0146] Positive electrode: Cut 200mm thick zinc foil into a shape and size suitable for installation in a button cell;

[0147] Negative electrode: Cut 200mm thick zinc foil into a shape and size suitable for installation in a button cell;

[0148] Assembly of zinc-ion battery: The solid electrolyte membrane composed of nanofibers and piezoelectric polymers provided in Example A1 is assembled together with the above-cut positive and negative electrode sheets to form the zinc-ion battery in Example B1.

[0149] Example B2

[0150] Example B2 provides a zinc-iodine battery, which is assembled into a zinc-iodine battery according to the following method:

[0151] Preparation of solid electrolyte membrane: The solid electrolyte membrane composed of nanofibers and piezoelectric polymers provided in Example A1 is cut into a shape and size suitable for installation in a button battery;

[0152] Preparation of the positive electrode: The positive electrode is prepared according to the following steps: Activated carbon, conductive carbon, and polyvinylidene fluoride are mixed evenly in a mass ratio of 7:2:1. An appropriate amount of N-methylpyrrolidone is added dropwise, and the mixture is dispersed evenly to obtain an activated carbon slurry. The activated carbon slurry is evenly coated onto graphite paper to prepare an activated carbon electrode. Then, the activated carbon electrode is placed in iodine vapor for adsorption for 12 hours to obtain an iodine positive electrode, which is used as the positive electrode of the zinc-iodine battery.

[0153] Negative electrode: Cut 200mm thick zinc foil into a shape and size suitable for installation in a button cell;

[0154] Assembly of zinc-iodine battery: The solid electrolyte membrane composed of nanofibers and piezoelectric polymers provided in Example A1 is assembled together with the above-mentioned positive and negative electrode sheets to form the zinc-iodine battery in Example B2.

[0155] Example B3

[0156] Example B3 provides a zinc-iodine battery, which is assembled in the same way as in Example B2, except that it uses the solid electrolyte provided in Example A2.

[0157] Example B4

[0158] Example B4 provides a zinc-iodine battery, which is assembled in the same way as in Example B2, except that it uses the solid electrolyte provided in Example A3.

[0159] Example B5

[0160] Example B5 provides a zinc-iodine battery, which is assembled in the same way as in Example B2, except that it uses the solid electrolyte provided in Example A4.

[0161] Comparative Example B1

[0162] Comparative Example B1 provides a zinc-iodine battery, which is assembled in the same way as in Example B2, except that it uses the solid electrolyte provided in Comparative Example A1.

[0163] Comparative Example B2

[0164] Comparative Example B2 provides a zinc-iodine battery, which is assembled in the same way as Example B2, except that it uses the solid electrolyte provided in Comparative Example A2.

[0165] Comparative Example B3

[0166] Comparative Example B3 provides a zinc-iodine battery, which is assembled in the same way as in Example B2, except that it uses the solid electrolyte provided in Comparative Example A3.

[0167] Comparative Example B4

[0168] Comparative Example B4 provides a zinc-iodine battery, which is assembled in the same way as in Example B2, except that it uses the solid electrolyte provided in Comparative Example A4.

[0169] Comparative Example B5

[0170] Comparative Example B5 provides a zinc-iodine battery, which is assembled in the same way as in Example B2, except that it uses the solid electrolyte provided in Comparative Example A5.

[0171] Comparative Example B6

[0172] Comparative Example B6 provides a zinc-iodine battery, which is assembled in the same way as in Example B2, except that it uses the solid electrolyte provided in Comparative Example A6.

[0173] Comparative Example B7

[0174] Comparative Example B7 provides a zinc-iodine battery, which is assembled in the same way as in Example B2, except that it uses the solid electrolyte provided in Comparative Example A7.

[0175] Related feature tests

[0176] 1. Structural characterization of solid electrolyte membranes composed of nanofibers and piezoelectric polymers:

[0177] The solid electrolyte membranes composed of nanofibers and piezoelectric polymers in Example A1 and Comparative Example A7 were analyzed by SEM: The SEM image of the solid electrolyte membrane composed of nanofibers and piezoelectric polymers in Example A1 is shown below. Figure 5 As shown, the SEN diagram of the solid electrolyte membrane composed of nanofibers and piezoelectric polymers in Comparative Example A7 is as follows. Figure 4 As shown in the SEM images, the solid electrolyte membrane composed of nanofibers and piezoelectric polymers in this embodiment possesses a complete nanofiber structure. These nanofibers act as a nanoskeleton in the solid electrolyte membrane, and their surfaces are covered by ionic liquids, forming a loose and porous ion conduction space, thereby significantly improving ion conductivity. In contrast, the solid electrolyte membrane composed of nanofibers and piezoelectric polymers in Comparative Example A7 suffers from poor interfacial contact, severe zinc dendrite growth, accelerated hydrogen evolution, and decreased battery stability. This demonstrates that adding ionic liquids can significantly improve ion conductivity and construct a stable reaction interface.

[0178] Example A1 (corresponding to) Figure 7 The solid electrolyte membrane composed of nanofibers and piezoelectric polymers in the piezoelectric polymer-ionic liquid-nanofiber composite (as described in Comparative Example A1) is compared with that in Comparative Example A1 (corresponding to...). Figure 7 (piezoelectric polymer-ionic liquid) and A4 (corresponding to)Figure 7 X-ray diffraction (XRD) analysis was performed on the piezoelectric polymer solid electrolyte membrane in Example A1. The XRD patterns of the nanofiber and piezoelectric polymer composite solid electrolyte membrane in Example A1 are compared with those of the piezoelectric polymer solid electrolyte membranes in Comparative Examples A1 and A4. Figure 7 As shown in the XRD pattern, the solid electrolyte membrane composed of nanofibers and piezoelectric polymers in this embodiment has the same peak position as the piezoelectric polymer solid electrolyte membrane in the comparative example, but the carbon peak value of the three samples changed. This is due to the addition of ionic liquid and nanofibers. The ionic liquid contains multiple carbon-containing groups such as methyl, ethyl, and imidazole, thus strengthening the carbon peak; the nanofibers contain carbon-containing groups such as imide rings, which also leads to the strengthening of the carbon peak. Therefore, the enhancement of the carbon peak in the figure indicates that ionic liquid and nanofibers were successfully introduced in Example A1 and are well integrated. No new peaks appeared, indicating that the electrolyte membrane in Example A1 of this application has high purity.

[0179] Example A1 (corresponding to) Figure 8 The solid electrolyte membrane composed of nanofibers and piezoelectric polymers in the piezoelectric polymer-ionic liquid-nanofiber composite and the comparative example A1 (corresponding to Figure 8 (piezoelectric polymer-ionic liquid) and A4 (corresponding to) Figure 8 Raman spectroscopy analysis was performed on the piezoelectric polymer solid electrolyte membrane in Example A1. A comparison of the Raman spectra of the nanofiber and piezoelectric polymer composite solid electrolyte membrane in Example A1 and Comparative Examples A1 and A4 is shown in the figure below. Figure 8 As shown in the figure. The Raman spectrum indicates that the solid electrolyte membrane composed of nanofibers and piezoelectric polymers in this embodiment of the application has a wavelength of 759.2 cm⁻¹. -1 1032.2cm -1 and 1426.7cm -1 There are distinct characteristic peaks, which correspond to the CH bonds in polyimide and 1-ethyl-3-methylimidazolium (759.2 cm⁻¹). -1 The CS bond (1032.2 cm⁻¹) in zinc trifluoromethanesulfonate and zinc 1-ethyl-trimethylimidazolium trifluorosulfonate. -1 CN bonds in polyimide and 1-ethyl-3-methylimidazolium (1426.7 cm) -1 These characteristic peaks further demonstrate the uniform mixing of nanofibers, piezoelectric polymers, and zinc salts in the composite solid electrolyte membrane.

[0180] Electrochemical stability analysis was performed on the solid electrolyte membrane composed of nanofibers and piezoelectric polymers in Example A1 and the piezoelectric polymer solid electrolyte membranes in Comparative Examples A1 and A4: Example A1 (corresponding to...) Figure 9The solid electrolyte membrane composed of nanofibers and piezoelectric polymers in PI-PTC-IL and the comparative example A1 (corresponding to Figure 9 PTC-IL) and A4 (corresponding to Figure 9 A comparison of the electrochemical stability of piezoelectric polymer solid electrolyte membranes in PTC is shown in the figure below. Figure 9 As shown in the electrochemical stability comparison chart, the solid electrolyte membrane composed of nanofibers and piezoelectric polymers in Example A1 has a higher voltage stability window compared to the piezoelectric polymer solid electrolyte membranes in Comparative Examples A1 and A4. This demonstrates the strong stability of the solid electrolyte membranes composed of nanofibers and piezoelectric polymers in these examples.

[0181] The ionic conductivity of the solid electrolyte membrane composed of nanofibers and piezoelectric polymers from Example A1 was tested: The ionic conductivity graph of the solid electrolyte membrane composed of nanofibers and piezoelectric polymers from Example A1 is shown below. Figure 10 As shown in the diagram, the ionic conductivity graph reveals that the solid electrolyte membrane composed of nanofibers and piezoelectric polymers in this embodiment maintains excellent ionic conductivity even at high temperatures. Furthermore, the ionic conductivity of this membrane tends to stabilize with temperature changes. This demonstrates that the solid electrolyte membrane composed of nanofibers and piezoelectric polymers in this embodiment possesses excellent thermal stability and excellent conductivity.

[0182] 2. Zinc-ion battery chemical performance testing:

[0183] The zinc-ion battery in Example B1 was tested for high-current cycle stability, high and low temperature adaptability, and dielectric constant; the zinc-iodine battery in Example B2 was tested for high-current cycle stability. The test conditions for cycle stability and high and low temperature performance of the zinc-ion battery and the test conditions for cycle stability of the zinc-iodine battery are as follows:

[0184] The high-current cycle test of zinc-ion batteries is mainly based on 5mAcm. -2 Constant current charge-discharge testing is performed on the critical current. High and low temperature testing assesses battery stability by varying the testing temperature during battery cycling, with a temperature range of -30℃ to 30℃. Cycling testing of zinc-iodine batteries primarily uses a 5mA / cm² current. -2 The critical current was subjected to constant current charge and discharge test.

[0185] The cycle performance curve of the zinc-ion battery in Example B1 is as follows: Figure 11 As shown in the figure, the high and low temperature performance curves are as follows: Figure 12 As shown, the dielectric constant curve is as follows: Figure 6 As shown; the cycle performance curve of the zinc-iodine battery in Example B2 is as follows. Figure 13 As shown; by Figures 11-13It can be seen that the zinc-ion battery and zinc-iodine battery can cycle stably, and can cycle stably for 36,500 cycles at a current density of 5 A / g with a retention rate of 95.37%. This shows that the novel zinc-ion solid electrolyte membrane designed in this invention is very effective in inhibiting the decomposition of iodine and improving the cycle efficiency of zinc-iodine batteries. It further verifies the potential of polyimide fiber network in maintaining the stability of electrolyte membrane.

[0186] The results of cycle performance tests, high and low temperature performance tests, and dielectric constant tests show that the zinc-ion battery in this embodiment exhibits high capacity, strong conductivity, and stable cycle performance. Especially under high current conditions, the battery maintains stable cycle performance. Simultaneously, the battery also demonstrates excellent cycle performance under low temperature conditions. This indicates that the solid electrolyte membrane, composed of nanofibers and piezoelectric polymers, significantly enhances the structural stability of the zinc-ion battery during charge and discharge processes, effectively inhibiting zinc corrosion. This electrolyte membrane endows the battery with high capacity, high conductivity, and strong low-temperature resistance, resulting in excellent capacity characteristics and superior low-temperature performance.

[0187] The performance of the batteries prepared in Examples B2 to B5 and Comparative Examples B1 to B7 was tested, and the results are shown in Table 1.

[0188] Table 1

[0189]

[0190]

[0191] As can be seen from Table 1, the batteries prepared in Examples B2 to B5 have the characteristics of high capacity and excellent cycle performance. Compared with the comparative examples, it can be seen that the specific capacity of Example B2 is better than that of Comparative Example B1 (without polyimide nanofiber membrane), Comparative Example B2 (with less ionic liquid), Comparative Example B4 (without polyimide nanofiber membrane and ionic liquid), Comparative Example B5 (with less zinc salt), Comparative Example B6 (with more zinc salt), and Comparative Example B7 (without ionic liquid). The cycle retention rate of Example B2 is better than that of Comparative Example B1 (without polyimide nanofiber membrane), Comparative Example B2 (with less ionic liquid), Comparative Example B3 (with more ionic liquid), Comparative Example B4 (without polyimide nanofiber membrane and ionic liquid), Comparative Example B5 (with less zinc salt), Comparative Example B6 (with more zinc salt), and Comparative Example B7 (without ionic liquid). This shows that whether or not a polyimide nanofiber membrane is included, whether or not an ionic liquid is included, and the amount of ionic liquid and zinc salt added all affect the battery's capacity and cycle performance.

[0192] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A solid-state electrolyte membrane comprising nanofibers and piezoelectric polymers, wherein the preparation raw materials of the nanofibers and the piezoelectric polymers comprise nanofibers and piezoelectric polymers, respectively; the piezoelectric polymers comprise piezoelectric polymers, zinc salts and ionic liquids; the nanofibers are used as a skeleton of the solid-state electrolyte membrane in the form of a nanofiber membrane; and the piezoelectric polymers are arranged on the nanofiber membrane to form the solid-state electrolyte membrane. The nanofibers are at least one of polyester, polyamide, polyimide, polyamideamide, polyimideamide, polyamideimide, polyamideamideamide, polyvinyl alcohol, polyacrylonitrile, polyethylene oxide, polymethyl methacrylate and polyurethane polymer materials. The piezoelectric polymers are at least one of polystyrene, polyvinylidene fluoride, polytrifluoroethylene, polyethylene difluoride, polyethylene vinyl acetate, polytrifluorochloroethylene and their multi-component copolymers. The ionic liquids are at least one of 1-ethyl-3-methyl imidazole zinc nitrate, 1-butyl-trimethyl imidazole zinc nitrate, 1-ethyl-trimethyl imidazole zinc hexafluorophosphate, 1-ethyl-trimethyl imidazole zinc tetrafluoroborate and 1-ethyl-trimethyl imidazole zinc triflate. The piezoelectric polymers comprise piezoelectric polymers, zinc salts and ionic liquids, and the content of the preparation raw materials of the piezoelectric polymers is as follows: the mass percentage content of the piezoelectric polymers is 30% to 80%, the mass percentage content of the zinc salts is 5% to 35%, and the mass percentage content of the ionic liquids is 5% to 35%. The mass ratio of the nanofibers to the piezoelectric polymers is 1:2 to 1:

10. The zinc salts are at least one of zinc chloride, zinc acetate, zinc sulfate, zinc nitrate and zinc triflate.

2. The solid-state electrolyte film of claim 1, wherein, 4.A method for preparing the solid-state electrolyte membrane according to any one of claims 1 to 3, comprising the following steps:

3. The solid-state electrolyte film of claim 1, wherein, dissolving the polymer material in an organic solvent to prepare a spinning solution, and performing spinning treatment on the obtained spinning solution to obtain a nanofiber membrane; dissolving the piezoelectric polymers, the zinc salts and the ionic liquids using an organic solvent, heating and stirring until the mixture is uniform to obtain a mixed solution; uniformly laying the mixed solution on the nanofiber membrane, and drying to obtain the solid-state electrolyte membrane. The spinning treatment is electrospinning treatment, and the conditions of the electrospinning treatment are as follows: In the spinning solution, the mass concentration of the organic solvent is 80% to 90%, and the mass concentration of the polymer material is 10% to 20%; and / or 5. The preparation method according to claim 4, characterized in that, The organic solvent comprises at least one of N-N dimethylformamide, N-methyl pyrrolidone and dimethyl sulfoxide; and / or Needle inner diameter is 0.6 ~ 2.2 mm; Voltage is 10 ~ 20 kV; Temperature is 35 ~ 45 ℃, relative humidity is 43 ~ 47 % RH, and advancing speed is 3 ~ 6 mL h -1 Receiving distance is 10 ~ 20 cm, and receiver rotating speed is 100 ~ 500 rpm; and / or The heating temperature of the piezoelectric polymers, the zinc salts and the ionic liquids is 20°C to 95°C. The solid-state electrolyte membrane according to any one of claims 1 to 3 or prepared by the method according to any one of claims 4 to 5. ​ 6. A secondary battery characterized by comprising: ​

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