Gel electrolyte for battery as well as preparation method and application of gel electrolyte

Abstract

The invention belongs to the technical field of battery material preparation, and relates to a gel electrolyte for a battery as well as a preparation method and application thereof. Aiming at the technical problems of relatively low room-temperature ionic conductivity, insufficient mechanical strength, poor interface stability and poor inorganic filler dispersity of a hydrogel electrolyte in the prior art, the invention provides the gel electrolyte for the battery, which comprises polyvinyl alcohol as a matrix polymer; polyethylene glycol is used as an auxiliary agent; lTA zeolite is used as a doping material; the mass ratio of the polyvinyl alcohol to the polyethylene glycol to the LTA zeolite is 1: (0.05-0.10): (0.05-0.15). The invention also provides a preparation method of the gel electrolyte for the battery. The preparation method comprises the following steps: adding polyvinyl alcohol, polyethylene glycol and LTA zeolite into a solvent; freezing and unfreezing treatment is repeated; according to the scheme, the technical problems that an existing preparation technology is complex, the crosslinking efficiency is low, and uniform compounding of inorganic components is difficult to achieve can be solved. Meanwhile, the invention also provides application of the gel electrolyte for the battery.

Description

Technical Field

[0001] This invention belongs to the field of battery material preparation technology, specifically relating to gel electrolytes for batteries, their preparation methods, and applications. Background Technology

[0002] With the rapid development of renewable energy and large-scale energy storage technologies, aqueous zinc-ion batteries have become a research hotspot for next-generation energy storage systems due to their advantages such as high safety, low cost, environmental friendliness, moderate voltage platform, and high power density. Traditional aqueous zinc-ion batteries typically use liquid electrolytes, but liquid systems suffer from problems such as easy electrolyte leakage, unstable interfacial contact, and susceptibility to dendrite puncture of the separator, resulting in limited battery cycle life and safety that cannot meet long-term usage requirements. Therefore, developing solid-state or quasi-solid-state electrolytes has become an important direction for improving the overall performance of aqueous zinc-ion batteries.

[0003] Gel electrolytes have attracted widespread attention in aqueous batteries due to their combination of solid-state and liquid-state ion transport advantages. These electrolytes can effectively improve system safety, reduce electrolyte loss, and provide good flexibility and interface compatibility. However, commonly used single-network polymer gels (such as PVA gels, PAM gels, etc.) generally have the following shortcomings: (1) Insufficient room temperature ionic conductivity. The single polymer chain segments are tightly arranged and lack continuous and efficient ion transport channels, resulting in low ionic conductivity at room temperature, which is not conducive to the performance of high-rate performance. (2) Weak mechanical properties. Traditional gels rely on a single physical or chemical cross-linking structure, and their network strength is limited, making it difficult to achieve both high toughness and puncture resistance at the same time, and unable to effectively resist the mechanical damage caused by zinc dendrite growth. (3) Poor interface stability and difficulty in suppressing side reactions. Due to the high water activity and loose gel network structure, side reactions such as hydrogen evolution, corrosion and uneven deposition are prone to occur on the zinc anode surface, resulting in low cycle efficiency and shortened life.

[0004] In summary, there is an urgent need for a gel electrolyte material that has a simple preparation process, avoids the use of toxic chemical crosslinking agents, and possesses high ionic conductivity, excellent mechanical strength, and good electrochemical stability, in order to promote the development and industrial application of high-performance aqueous zinc-ion batteries. Summary of the Invention

[0005] 1. The technical problem the invention aims to solve. In view of the technical problems of low room temperature ionic conductivity, insufficient mechanical strength, poor interfacial stability and poor dispersibility of inorganic fillers in existing hydrogel electrolytes, this application provides a gel electrolyte for batteries.

[0006] Furthermore, this application also provides a method for preparing the gel electrolyte for batteries, in order to solve the technical problems of complex preparation processes, low crosslinking efficiency, and difficulty in achieving uniform composite of inorganic components.

[0007] This application also provides the application of the gel electrolyte for the battery.

[0008] 2. Technical Solution To achieve the above objectives, the provided technical solution is as follows: In accordance with the objectives of this invention, a first aspect of this invention provides a gel electrolyte for batteries, the gel electrolyte for batteries comprising: Polyvinyl alcohol is used as the base polymer; Polyethylene glycol was used as an additive. LTA zeolite as a doping material; The mass ratio of polyvinyl alcohol, polyethylene glycol and LTA zeolite is 1:(0.05-0.10):(0.05-0.15).

[0009] Preferably, PVA, PEG, and LTA zeolite form a double-crosslinked composite structure through freeze-thaw crosslinking, wherein the double-crosslinked network comprises: (1) The physical cross-linking network of PVA formed by repeated freeze-thaw cycles; (2) Intermolecular crosslinks formed between PVA and PEG through hydrogen bonding; Furthermore, the addition of LTA zeolite was used to construct continuous ion transport channels to improve the room temperature ionic conductivity and mechanical properties of the gel electrolyte.

[0010] According to any embodiment of the first aspect of the present invention, the gel electrolyte for batteries, wherein the coordinating cation of the LTA zeolite is Zn. 2+ .

[0011] Using Zn 2+ As a coordinating cation of LTA zeolite, it can enhance the Zn content in the zeolite framework. 2+ The local electric field distribution is better matched to the transport requirements of zinc ions in the electrolyte system, thereby enhancing the Zn content inside the gel. 2+ Migration rate. Zn 2+ The exchanged LTA microporous structure provides a more stable zinc ion adsorption-desorption environment, which helps to form continuous and uniform ion transport channels and further reduces ion diffusion resistance. Furthermore, Zn... 2+ It has better compatibility with PVA / PEG matrix than Na + The presence of cations can improve the stability of the gel structure and enhance zinc ion deposition behavior, thus giving the gel electrolyte better anti-dendritic ability during long-term cycling.

[0012] According to any embodiment of the first aspect of the present invention, the gel electrolyte for batteries contains a mixed electrolyte of 1 mol / L to 2 mol / L ZnSO4·H2O and 0.05 mol / L to 0.1 mol / L MnSO4·7H2O.

[0013] Introducing a mixed electrolyte of ZnSO4·H2O and MnSO4·7H2O into a gel electrolyte can help retain Zn... 2+ While maintaining high concentration transport capabilities, it also utilizes Mn 2+ The participation of Mn in regulating the interface chemistry of the negative electrode makes zinc deposition more uniform. 2+ It can effectively mitigate the generation of side reactions (such as hydrogen evolution and corrosion) and form a more stable SEI-type interface layer, thereby significantly improving the cycle life and rate performance of the battery. Furthermore, the mixed electrolyte is more uniformly distributed in the gel network, which can prevent dendrite induction points caused by local high ion concentrations and improve the safety and reliability of the battery under high current density.

[0014] Preferably, the gel electrolyte contains a mixed electrolyte of 2 mol / L ZnSO4·H2O and 0.1 mol / L MnSO4·7H2O.

[0015] Based on the objectives of this invention, a second aspect of this invention provides a method for preparing a gel electrolyte for batteries, comprising the following steps: Step S1: Add polyvinyl alcohol, polyethylene glycol, and LTA zeolite in a mass ratio of 1:(0.05~0.10):(0.05~0.15) to a solvent and dissolve to obtain a precursor solution; Preferably, the solvent is dimethyl sulfoxide, and the precursor solution is obtained by stirring at 95 °C for 3 h.

[0016] Preferably, the precursor solution is subjected to vacuum degassing under the condition of vacuuming at room temperature for 24 hours.

[0017] Step S2: Repeat the freezing and thawing process of the precursor solution to obtain a gel precursor; Preferably, the freezing and thawing process is repeated three times in a mold.

[0018] Step S3: Immerse the gel precursor in the electrolyte to absorb the liquid, thereby obtaining the gel electrolyte for the battery.

[0019] According to any embodiment of the second aspect of the present invention, in the method for preparing a gel electrolyte for batteries, step S1, the preparation of the LTA zeolite includes the following steps: Step SS1: Dissolve 4 g to 4.5 g of sodium silicate nonahydrate and 2 g to 2.5 g of sodium aluminate in deionized water, add 0.6 g of NaOH to each solution, stir and age, slowly add the sodium silicate nonahydrate to the sodium aluminate solution, mix, and then perform hydrothermal reaction, washing and freeze-drying to obtain sodium-type LTA zeolite; Step SS2: Immerse the sodium-type LTA zeolite in a zinc acetate solution for ion exchange, wash and dry to obtain the LTA zeolite.

[0020] The zeolite preparation method in this application, by controlling the molar ratio of silicon to aluminum sources, alkalinity, and aging conditions, results in LTA crystals with high purity, a regular microporous structure, and good specific surface area, which is beneficial for subsequent embedding into gel networks. (The text abruptly ends here, likely due to an incomplete sentence or missing information.) 2+ LTA zeolite obtained by ion exchange has a uniform distribution of zinc ions in its pores, which can significantly enhance the gel's ability to hold Zn. 2+ This method improves conductivity and enhances interfacial electrochemical stability. The preparation process is highly controllable, ensuring stable LTA zeolite quality and thus improving the overall consistency of the gel electrolyte's performance.

[0021] In the method for preparing a gel electrolyte for batteries according to any embodiment of the second aspect of the present invention, in step S2, the freezing temperature is -15 ℃ to -25 ℃ and the freezing time is 2 h to 3 h.

[0022] By controlling the freezing temperature to -15 ℃ to -25 ℃ and the freezing time to 2 h to 3 h, the crystalline regions of PVA can grow more fully, forming a uniform and dense physical cross-linked network, which helps to improve the mechanical strength and dimensional stability of the entire gel. Suitable freeze-thaw conditions can promote the uniform distribution of PEG segments and LTA zeolite in the gel network, allowing for more complete formation of continuous ion transport channels, thereby improving the room temperature ionic conductivity of the gel electrolyte. This selection of conditions makes the gel structure more controllable and improves the stability and repeatability of the preparation process.

[0023] Preferably, the freezing temperature in step S3 is -20 °C.

[0024] According to any embodiment of the second aspect of the present invention, in the method for preparing a battery gel electrolyte, in step S3, the battery gel electrolyte contains a mixed electrolyte of 1 mol / L to 2 mol / L ZnSO4·H2O and 0.05 mol / L to 0.1 mol / L MnSO4·7H2O.

[0025] In step S3, the gel undergoes electrolyte absorption treatment, and the concentration range of ZnSO4 and MnSO4 is limited. This ensures that a reasonable ion concentration gradient is formed in the gel after absorption, resulting in a moderate ion content and structural stability within the gel. This concentration range avoids excessively high concentrations that could lead to gel volume expansion or ion segregation, and also avoids excessively low concentrations that could result in insufficient ionic conductivity. By properly controlling the absorption process, the cycling stability and interfacial compatibility of the gel electrolyte can be further enhanced, making it more suitable for high-rate aqueous zinc-ion batteries.

[0026] According to any embodiment of the second aspect of the present invention, the preparation method of the battery gel electrolyte involves replacing the electrolyte every 8 h to 16 h, and repeating the process 1 to 4 times.

[0027] During the liquid absorption process, the electrolyte should be changed every 8 to 16 hours and repeated 1 to 4 times. This promotes the full wetting of the gel with electrolyte, allowing Zn to... 2+ With Mn 2+ The distribution within the gel network is more uniform, avoiding uneven concentration gradients or localized low concentrations caused by insufficient liquid absorption in a single cycle. Multiple liquid absorptions can increase the ion saturation of the gel electrolyte, significantly improving its conductivity and interfacial stability. This method can improve the microenvironment inside the gel, ultimately enhancing the battery's stability, reliability, and longevity during cycling.

[0028] Preferably, the electrolyte is replaced every 12 hours, and this is repeated 3 times.

[0029] In view of the purpose of this invention, a third aspect of this invention provides a battery containing a battery gel electrolyte, wherein the battery gel electrolyte is the aforementioned battery gel electrolyte; or, the battery gel electrolyte is a battery gel electrolyte prepared by the aforementioned preparation method.

[0030] The battery described in this application significantly improves the electrochemical performance of aqueous zinc-ion batteries. Its superior mechanical properties suppress the risk of dendrite puncture of the separator, the continuous ion conduction network reduces ohmic impedance, and uniform interfacial contact contributes to improved cycle life and rate performance. This battery exhibits a more stable charge-discharge platform at high current densities and demonstrates higher capacity retention and lower side reaction levels during long-term cycling, making it suitable for applications requiring high safety, such as energy storage systems and wearable devices.

[0031] Preferably, the battery is an aqueous zinc-ion battery.

[0032] Based on the purpose of this invention, a third aspect of this invention provides the application of a battery gel electrolyte, wherein the battery gel electrolyte, or the battery gel electrolyte prepared by the preparation method, is applied to the fabrication of a flexible energy storage device.

[0033] Any embodiment of any aspect of the present invention can be combined with other embodiments without contradiction. Furthermore, in any embodiment of any aspect of the present invention, any technical feature can be applied to the same technical feature in other embodiments without contradiction.

[0034] Without causing contradictions, any technical feature of any aspect or embodiment of the present invention is equally applicable to any other embodiment or embodiment of any other aspect. Of course, when applicable to each other, appropriate modifications may be made to the corresponding features as necessary. The various aspects and features of the present invention are further described below.

[0035] 3. Beneficial effects Compared with existing known technologies, the technical solution provided by this invention has the following beneficial effects: (1) The battery gel electrolyte of this application achieves high ion migration efficiency, excellent mechanical stability, and significantly improved electrode interface wettability through a multi-level composite structure composed of a polyvinyl alcohol (PVA) main network, polyethylene glycol (PEG) flexible segments, and LTA molecular sieve regular micropores. In the gel electrolyte, PVA forms a physical cross-linked network through freeze-thaw cycles and interpenetrates with LTA molecular sieves to construct a tough and stable double network structure, which effectively enhances the mechanical strength and toughness of the gel and can inhibit zinc dendrite penetration; the flexible segments of PEG provide additional ion transport channels and promote ion migration, and the microporous structure of LTA molecular sieve is Zn 2+ It provides a continuous and rapid migration path, and the synergistic effect of the three factors significantly improves the ionic conductivity; at the same time, the gel has good flexibility and water retention, which can form a tight and stable interfacial contact with the electrode, reduce interfacial impedance, and improve the stability of the electrode interface during cycling.

[0036] (2) The preparation method of the battery gel electrolyte of this application has a clear process route, simple steps, mild reaction conditions, and can complete the material construction under normal pressure and low energy consumption. This method achieves crosslinking of PVA and PEG through freeze-thaw physical crosslinking and uniformly disperses LTA molecular sieves in the polymer network without the need for chemical crosslinking agents, thus avoiding toxic substance pollution. The preparation process has good controllability of the mixing uniformity of raw material components and network structure formation, thereby ensuring that the obtained gel electrolyte has a stable microstructure and batch-to-batch consistency. In addition, this method does not require complex equipment or special atmospheres and can be prepared on a large scale through conventional industrial production equipment. It has high operational safety, strong repeatability, and low cost, providing a reliable foundation for the large-scale application of gel electrolytes in the battery industry.

[0037] (3) The application of the gel electrolyte for batteries in this application can significantly improve long-standing technical problems such as interface instability, zinc dendrite growth, and accumulation of side reactions during cycling. Batteries using the gel electrolyte of this application exhibit a stable voltage plateau and high capacity retention under high current density and long-term cycling conditions, improving the rate performance and cycle life of the battery. The gel electrolyte can uniformly cover the electrode surface, achieving a more stable electrode / electrolyte interface structure, reducing interface impedance, and improving safety and reliability. At the same time, the gel electrolyte has a regulatory effect on zinc ion deposition behavior, effectively suppressing dendrite growth, and possesses high ionic conductivity, excellent interface compatibility, and good dimensional stability without relying on additional additives, making it suitable for large-scale energy storage systems, portable energy storage devices, and applications with high safety requirements. Attached Figure Description

[0038] Figure 1 The images are FT-IR spectra of the PZ-0, PZ-10, and PP5-Z-10 electrolyte materials prepared in this application. Figure 2 XRD patterns of the PZ-0, PZ-10, and PP5-Z-10 electrolyte materials prepared in this application; Figure 3 SEM images of the polyethylene glycol-doped and LTA zeolite-doped electrolytes prepared in this application are shown, where (bd) represents LTA zeolite doping and (ef) represents polyethylene glycol doping. Figure 4 EIS diagrams of the polyethylene glycol-doped and LTA zeolite-doped electrolytes prepared in this application; Figure 5 The stress-strain curves of PZ-0, PZ-10, and PP5-Z-10 obtained in this application are shown. Figure 6 The variable rate test curves are for the polyethylene glycol-doped and LTA zeolite-doped electrolytes prepared in this application, where (a) is the LTA zeolite-doped electrolyte and (b) is the polyethylene glycol-doped electrolyte. Detailed Implementation

[0039] The present invention will be further described below with reference to specific embodiments.

[0040] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0041] Example 1 The method for preparing a battery gel electrolyte in this embodiment includes the following steps: Preparation of LTA zeolite: Step SS1: Dissolve 4 g of sodium silicate nonahydrate and 2 g of sodium aluminate in deionized water, respectively, add 0.6 g of NaOH in each solution, stir and age, slowly add the sodium silicate nonahydrate to the sodium aluminate solution, mix, and then obtain sodium-type LTA zeolite through hydrothermal reaction, washing and freeze-drying.

[0042] Step SS2: The sodium-type LTA zeolite is immersed in a zinc acetate solution for ion exchange, washed, and dried to obtain the LTA zeolite. The coordinating cation of the LTA zeolite is Zn. 2+ .

[0043] Preparation of gel electrolytes for batteries: Step S1: Polyvinyl alcohol, polyethylene glycol, and LTA zeolite in a mass ratio of 1:0.05:0.05 are added to a solvent (dimethyl sulfoxide), and the mixture is stirred at 95°C for 3 h to dissolve and obtain the precursor solution. The precursor solution is then subjected to vacuum degassing at room temperature for 24 h.

[0044] Step S2: The precursor solution is repeatedly subjected to freezing and thawing treatment to obtain a gel precursor; the freezing and thawing treatment is repeated 3 times in a mold. The freezing temperature is -15 to -25 ℃, and the freezing time is 2 to 3 hours.

[0045] Step S3: Immerse the gel precursor in the electrolyte to obtain the gel electrolyte for the battery. The gel electrolyte contains a mixed electrolyte of 1 mol / L ZnSO4·H2O and 0.05 mol / L MnSO4·7H2O. Replace the electrolyte every 12 h, repeating 3 times.

[0046] The battery gel electrolyte PP5-Z-5 prepared in this embodiment.

[0047] The battery gel electrolyte prepared in this embodiment has a conductivity of 5.95 × 10⁻⁶. -3 S·cm -1 Its shear modulus reaches 1.8 MPa.

[0048] Example 2 The method for preparing a battery gel electrolyte in this embodiment includes the following steps: Preparation of LTA zeolite: Step SS1: Dissolve 4.5 g of sodium silicate nonahydrate and 2.5 g of sodium aluminate in deionized water, add 0.6 g of NaOH to each solution, stir and age. Slowly add the sodium silicate nonahydrate to the sodium aluminate solution. After mixing, perform hydrothermal reaction, washing and freeze-drying to obtain sodium-type LTA zeolite.

[0049] Step SS2: The sodium-type LTA zeolite is immersed in a zinc acetate solution for ion exchange, washed, and dried to obtain the LTA zeolite. The coordinating cation of the LTA zeolite is Zn. 2+ .

[0050] Preparation of gel electrolytes for batteries: Step S1: Polyvinyl alcohol, polyethylene glycol, and LTA zeolite in a mass ratio of 1:0.1:0.1 are added to a solvent (dimethyl sulfoxide), and the mixture is stirred at 95 °C for 3 h to dissolve and obtain the precursor solution. The precursor solution is then subjected to vacuum degassing at room temperature for 24 h.

[0051] Step S2: The precursor solution is repeatedly subjected to freezing and thawing treatment to obtain a gel precursor; the freezing and thawing treatment is repeated 3 times in a mold. The freezing temperature is -15 to -25 ℃, and the freezing time is 2 to 3 hours.

[0052] Step S3: Immerse the gel precursor in the electrolyte to obtain the gel electrolyte for the battery. The gel electrolyte contains a mixed electrolyte of 2 mol / L ZnSO4·H2O and 0.05 mol / L MnSO4·7H2O. Replace the electrolyte every 12 h, repeating 3 times.

[0053] The battery gel electrolyte PP10-Z-10 prepared in this embodiment is shown.

[0054] The battery gel electrolyte prepared in this embodiment has a conductivity of 5.45 × 10⁻⁶. -3 S·cm -1 Its shear modulus reaches 1.84 MPa.

[0055] Example 3 The method for preparing a battery gel electrolyte in this embodiment includes the following steps: Preparation of LTA zeolite: Step SS1: Dissolve 4.25 g of sodium silicate nonahydrate and 2.25 g of sodium aluminate in deionized water, add 0.6 g of NaOH to each solution, stir and age. Slowly add the sodium silicate nonahydrate to the sodium aluminate solution. After mixing, perform hydrothermal reaction, washing and freeze-drying to obtain sodium-type LTA zeolite.

[0056] Step SS2: The sodium-type LTA zeolite is immersed in a zinc acetate solution for ion exchange, washed, and dried to obtain the LTA zeolite. The coordinating cation of the LTA zeolite is Zn. 2+ .

[0057] Preparation of gel electrolytes for batteries: Step S1: Polyvinyl alcohol, polyethylene glycol, and LTA zeolite in a mass ratio of 1:0.05:0.1 are added to a solvent (dimethyl sulfoxide), and the mixture is stirred at 95 °C for 3 h to dissolve and obtain the precursor solution. The precursor solution is then subjected to vacuum degassing at room temperature for 24 h.

[0058] Step S2: The precursor solution is repeatedly subjected to freezing and thawing treatment to obtain a gel precursor; the freezing and thawing treatment is repeated 3 times in a mold. The freezing temperature is -15 to -25 ℃, and the freezing time is 2 to 3 hours.

[0059] Step S3: Immerse the gel precursor in the electrolyte to obtain the gel electrolyte for the battery. The gel electrolyte contains a mixed electrolyte of 2 mol / L ZnSO4·H2O and 0.1 mol / L MnSO4·7H2O. Replace the electrolyte every 12 h, repeating 3 times.

[0060] The battery gel electrolyte PP5-Z-10 prepared in this embodiment is shown.

[0061] The battery gel electrolyte prepared in this embodiment has a conductivity of 7.74 × 10⁻⁶. -3 S·cm -1 Its shear modulus reaches 2.7 MPa.

[0062] Comparative Example 1 1. Preparation process of PZ-0 hydrogel electrolyte: (1) Weigh 1.8 g PVA, add 12 mL DMSO, put the mixed solution into an oil bath and heat at 90 °C with slow stirring for 3 h, then let the solution stand at room temperature for 24 h to remove bubbles.

[0063] (2) Pour the solution into a polytetrafluoroethylene mold with a diameter of 22 mm and scrape off the excess solution on the surface with a scraper. Put the mold in the freezer for 12 h and then take it out. Thaw it at room temperature for 2 h. Repeat the above operation and then demold the gel in the mold.

[0064] (3) Immerse the hydrogel electrolyte in deionized water and change the deionized water every 8 hours. After 48 hours, immerse the hydrogel in the electrolyte and change the electrolyte every 8 hours. After 48 hours, take out the hydrogel to obtain pure PVA hydrogel, which is denoted as PZ-0.

[0065] 2. Preparation process of PZ-5 hydrogel electrolyte: The difference between the preparation process of PZ-0 hydrogel electrolyte and that of PZ-5 hydrogel electrolyte is that an additional 0.09 g of zeolite is added. All other steps are the same, and PZ-5 hydrogel electrolyte is finally obtained.

[0066] 3. Preparation process of PZ-10 hydrogel electrolyte The difference between the preparation process of PZ-10 hydrogel electrolyte and that of PZ-0 hydrogel electrolyte is that an additional 0.18 g of zeolite is added. All other steps are the same, and PZ-10 hydrogel electrolyte is finally obtained.

[0067] 4. Preparation process of PZ-15 hydrogel electrolyte The difference between the preparation process of PZ-0 hydrogel electrolyte material and that of PZ-15 hydrogel electrolyte is that an additional 0.27 g of zeolite is added. All other steps are the same.

[0068] 5. PP5-Z-10 is taken from Example 3. The difference between the preparation process of PP5-Z-10 hydrogel electrolyte material and that of PZ-5 hydrogel electrolyte material is that an additional 0.09g of polyethylene glycol is added. All other steps are the same, and the final product is PP5-Z-10 hydrogel electrolyte.

[0069] 6. PP10-Z-10 is taken from Example 2. The difference between the preparation process of PP5-Z-10 hydrogel electrolyte material and that of PZ-5 hydrogel electrolyte material is that an additional 0.18g of polyethylene glycol is added. All other steps are the same, and the final product is PP5-Z-10 hydrogel electrolyte.

[0070] The performance of the hydrogel electrolyte prepared above was characterized, and the results are as follows: Figure 1 The figures show the FT-IR spectra of PZ-0 electrolyte, PZ-10 electrolyte, and PP5-Z-10 electrolyte. As can be seen from the figures, after the addition of LTA zeolite, the typical PVA concentration at 3302 cm⁻¹... -1 The broad peak resulting from the -OH stretching vibration is at 2939 cm⁻¹, caused by the CH stretching vibration (alkyl group). -1 And CO vibration at 1089 cm -1The peak intensity was increased, and the overall intensity was enhanced after zeolite doping. After the addition of PEG, the characteristic peaks of intramolecular and intermolecular hydrogen bond vibrations in PVA underwent a red shift, with the peak corresponding to PP5-Z-10 shifting from 3301 cm⁻¹ for PVA. -1 Moved to 3284 cm -1 This corresponds to the free hydroxyl groups in PVA being bound by PEG, i.e., cross-linking occurs.

[0071] Figure 2 The XRD patterns of PZ-0, PZ-10, and PP5-Z-10 electrolyte materials prepared in the examples are shown in the figures. As can be seen from the figures, the XRD patterns clearly show that the main peak angle of PVA is 19.5°. After the addition of PEG, the position of the main peak did not increase or shift. The strong peak at around 5.5° and the secondary strong peak after 22° after the addition of zeolite can prove the successful doping of zeolite.

[0072] Figure 3 The images show SEM images of PZ and PPZ electrolytes. It can be seen that the pore size is smaller after zeolite doping, and the PVA structure gradually coarsens with thicker pore walls. This is because during freeze-thaw cycles, zeolite particles hinder the free movement of PVA chain segments, forcing the polymer chains to pack more tightly, increasing gel crystallinity. Furthermore, the hydrogen bonds between the two enhance the binding force between polymer chains, forming a coarser aggregate structure. With appropriate zeolite doping, the pore size distribution is more uniform than without doping, which is beneficial for more uniform ion transport. With the addition of PEG, a more ordered and uniformly distributed porous structure appears. This is attributed to the network structure formed by PEG and PVA. During freeze-thaw cycles, PVA undergoes high entanglement and combines with the -OH terminals of PEG, forming a stable network structure. In contrast, the porous structure of PP-10 is loose and lacks uniformity, with highly uneven polymer thickness. This indicates that PEG has a larger molecular weight and weaker chain segment mobility, making it difficult to mix uniformly with PVA. Additionally, the strength and density of the hydrogen bonds between the two are insufficient to completely suppress phase separation.

[0073] Figure 4 The EIS plots for PVA electrolyte, PZ electrolyte, and PPZ electrolyte are shown. As can be seen from the plot, the PP5-Z-10 electrolyte exhibits the lowest impedance, and its calculated impedance at room temperature is 1.72 × 10⁻⁶. -2 S·cm -1 Its ionic conductivity is 2.9 times that of PZ-0.

[0074] Figure 5The stress-strain curves of PZ-0 electrolyte, PZ-10 electrolyte, and PP5-Z-10 electrolyte are shown in the figure. As can be seen from the figure, the addition of PEG will reduce the mechanical strength, but the addition of LTA zeolite will result in the tensile strength of PP5-Z-10 electrolyte reaching 2.7 MPa and the elongation at break reaching 410.1%, which is 1.5 times that of PZ-0.

[0075] Figure 6 The graphs show the rate cycling performance of PZ electrolyte and PPZ electrolyte. As can be seen from the graphs, the addition of PEG significantly improves the capacity due to cross-linking with PEG, especially at high rates. PP5-Z-10 exhibits the best performance at 1000 mA·g. -1 It has a capacity of 62.1 mAh·g -1 It has a discharge specific capacity and retains 81.2% of its capacity after rate cycling.

[0076] Comparative Example 2 The preparation method of the gel electrolyte in this comparative example is basically the same as that in Example 1, except that ordinary zeolite is used.

[0077] The electrochemical performance of the gel electrolyte prepared in this comparative example is worse than that of Example 1.

[0078] The gel electrolytes for batteries described in the embodiments of this application can all be applied to the preparation of aqueous zinc-ion batteries or flexible energy storage devices.

Claims

1. A gel electrolyte for a battery, characterized by: The battery gel electrolyte comprises: polyvinyl alcohol as a base polymer; polyethylene glycol as an auxiliary agent; LTA zeolite as a doping material; The mass ratio of the polyvinyl alcohol, polyethylene glycol and LTA zeolite is 1: (0.05-0.10): (0.05-0.15).

2. The gel electrolyte for a battery according to claim 1, characterized by: The LTA zeolite has a coordination cation of Zn 2 + .

3. The gel electrolyte for a battery according to any one of claims 1 or 2, characterized by: The gel electrolyte contains a mixed electrolyte of 1 mol / L-2 mol / L ZnSO4·H2O and 0.05 mol / L-0.1 mol / L MnSO4·7H2O.

4. A method for preparing a gel electrolyte for a battery, characterized by: The method comprises the following steps: Step S1: adding polyvinyl alcohol, polyethylene glycol and LTA zeolite in a mass ratio of 1: (0.05-0.10): (0.05-0.15) into a solvent to dissolve and obtain a precursor solution; Step S2: repeatedly performing freezing and thawing treatment on the precursor solution to obtain a gel precursor; Step S3: immersing the gel precursor into an electrolyte to absorb the electrolyte and obtain the battery gel electrolyte.

5. The gel electrolyte for a battery according to claim 4, characterized by: In step S1, the preparation of the LTA zeolite comprises the following steps: Step SS1: separately dissolving 4 g-4.5 g sodium silicate nonahydrate and 2 g-2.5 g sodium metaaluminate in deionized water, adding 0.6 g NaOH and stirring and aging, slowly dropping the sodium silicate nonahydrate into the sodium metaaluminate solution, and then performing hydrothermal reaction, washing and freeze-drying to obtain sodium-type LTA zeolite; Step SS2: immersing the sodium-type LTA zeolite in a zinc acetate solution for ion exchange, washing and drying to obtain the LTA zeolite.

6. The method of claim 4, wherein the gel electrolyte for a battery is prepared by adding 0.1 to 10 parts by weight of the polymer to 100 parts by weight of the electrolyte solution. In step S2, the freezing temperature is -15 ℃--25 ℃, and the freezing time is 2 h-3 h.

7. The method of claim 4, wherein the gel electrolyte for a battery is prepared by adding 0.1 to 10 parts by weight of the polymer to 100 parts by weight of the electrolyte solution. In step S3, the battery gel electrolyte contains a mixed electrolyte of 1 mol / L-2 mol / L ZnSO4·H2O and 0.05 mol / L-0.1 mol / L MnSO4·7H2O.

8. The method of claim 7, wherein the gel electrolyte for a battery is prepared by adding 0.1 to 10 parts by weight of the compound of formula (1) to 100 parts by weight of the electrolyte solution. The electrolyte is replaced every 8 h-16 h, and the replacement is repeated 1-4 times.

9. A battery comprising a gel electrolyte for a battery, characterized by: The battery gel electrolyte is the battery gel electrolyte according to any one of claims 1-3; or the battery gel electrolyte is prepared by the preparation method according to any one of claims 4-8.

10. Use of a gel electrolyte for a battery, characterized in that: The battery gel electrolyte according to any one of claims 1-3 or prepared by the preparation method according to any one of claims 4-8 is applied to the preparation of a flexible energy storage device.

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