Multifunctional conductive polymer composite material and preparation method thereof, and positive electrode material

Abstract

This invention discloses a multifunctional conductive polymer composite material, its preparation method, and a cathode material. The preparation method includes: providing a first mixed solution and a second mixed solution; the first mixed solution is composed of a PEDOT:PSS aqueous solution, ethylene glycol, and a PVA aqueous solution; the second mixed solution is composed of β-cyclodextrin, tannic acid, and water; under stirring conditions, dispersing the second mixed solution into the first mixed solution to obtain a pre-composite system; dispersing a crosslinking agent into the pre-composite system to obtain a co-crosslinking precursor solution; and preparing the co-crosslinking precursor solution into a film to obtain the multifunctional conductive polymer composite material. This invention successfully transforms the conformation of the PEDOT chain into a highly conductive quinone structure by introducing dopants ethylene glycol (EG) and β-cyclodextrin and tannic acid (TA), significantly improving the conductivity of the composite material. Simultaneously, the introduction of the PVA polymer network comprehensively regulates the water solubility of the conductive polymer composite material, greatly improving the stability of the cathode material.

Description

Technical Field

[0001] This invention relates to the field of aqueous zinc-halogen battery technology, and in particular to a multifunctional conductive polymer composite material and its preparation method, as well as a cathode material. Background Technology

[0002] Aqueous zinc-ion batteries have become an important candidate for large-scale energy storage systems due to their high safety, low cost, and the theoretical capacity advantage of zinc anodes (820 mAh / g). However, the development of this technology has long been limited by the inherent defects of cathode materials: vanadium-based oxides, although possessing high specific capacity (>300 mAh / g), suffer from the biotoxicity and scarcity of vanadium, which drives up manufacturing costs, and are prone to layered structure collapse during charge and discharge; manganese-based materials (such as MnO2) suffer from irreversible phase transitions caused by Jahn-Teller distortion and manganese dissolution problems, leading to a sharp drop in cycle life (typically <500 cycles). More seriously, zinc anodes face multiple challenges in traditional sulfate electrolytes, including dendrite growth, hydrogen evolution reaction, and interface passivation, resulting in low coulombic efficiency (<95%) and battery failure. These predicaments have forced the academic community to seek metal-free cathode materials that combine high specific capacity, environmental friendliness, and structural stability to overcome the commercialization bottleneck of zinc batteries.

[0003] Among numerous metal-free cathodes, halogen-based materials (e.g., iodine-based materials) stand out due to their high theoretical capacity of 211 mAh / g and high redox potential (Ig). - / I2≈1.2V vs. Zn 2+ The abundance of zinc-iodine pools (Zn) and its elements has attracted much attention. However, the practical application of zinc-iodine pools is hampered by the presence of polyiodide ions (I3). - / I5 - The dissolution and shuttle effect of iodine: On the one hand, the migration of soluble polyiodides to the negative electrode triggers self-discharge, reducing the coulombic efficiency to below 80%; on the other hand, the irreversible loss of active iodine leads to rapid capacity decay of the positive electrode (>30%@100 cycles). While existing carbon-based supports (such as activated carbon) can physically adsorb elemental iodine, their hydrophobic surfaces (contact angle >120°) hinder electrolyte wetting and cannot anchor iodine through chemical action. - / I3 - Conductive polymers (such as PEDOT:PSS) not only have good conductivity, but can also enhance the adsorption capacity of iodine species through chemical modification, promoting the efficient conversion of iodine species. Therefore, the development of such conductive polymer materials can serve as a new type of carrier to improve the zinc storage capacity of halogen materials. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention proposes a multifunctional conductive polymer composite material and its preparation method, as well as a cathode material, aiming to solve the severe halogen dissolution and shuttle effect problems of existing aqueous zinc-halogen battery cathode materials. Specifically:

[0005] In a first aspect, embodiments of the present invention provide a method for preparing a multifunctional conductive polymer composite material, comprising:

[0006] A first mixed solution and a second mixed solution are provided; the first mixed solution consists of PEDOT:PSS aqueous solution, ethylene glycol and PVA aqueous solution; the second mixed solution consists of β-cyclodextrin, tannic acid and water;

[0007] Under stirring conditions, the second mixed solution is dispersed into the first mixed solution to obtain a pre-composite system;

[0008] The crosslinking agent is dispersed into the precomposite system to obtain a blended crosslinking precursor solution;

[0009] The blended crosslinked precursor solution was used to prepare a film to obtain a multifunctional conductive polymer composite material.

[0010] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. The purpose and beneficial effects of the present invention can be better achieved and realized through the following preferred technical solutions.

[0011] As a preferred technical solution, the method for preparing the multifunctional conductive polymer composite material, wherein the crosslinking precursor solution is prepared into a film to obtain the multifunctional conductive polymer composite material, includes:

[0012] The blended crosslinking precursor solution was added to a mold, and a film was formed by drop coating.

[0013] The mold containing the blended crosslinking precursor solution is placed in a baking device and baked at a temperature of 30-50°C to obtain the multifunctional conductive polymer composite material.

[0014] As a preferred technical solution, in the preparation method of the multifunctional conductive polymer composite material, the water content of the obtained multifunctional conductive polymer composite material is 10-20 wt.%.

[0015] As a preferred technical solution, in the preparation method of the multifunctional conductive polymer composite material, the mass fraction of the PVA aqueous solution is 5-15 wt.%.

[0016] As a preferred technical solution, in the preparation method of the multifunctional conductive polymer composite material, the molar ratio of β-cyclodextrin to tannic acid in the second mixed solution is 1:2-4.

[0017] As a preferred technical solution, the preparation method of the multifunctional conductive polymer composite material, wherein the crosslinking agent includes: glutaraldehyde, boric acid and epichlorohydrin.

[0018] As a preferred technical solution, in the preparation method of the multifunctional conductive polymer composite material, the mass fraction of PEDOT:PSS in the blend crosslinking precursor solution is 50-90 wt.%; and the mass fraction of the crosslinking agent relative to PVA is 0.2-0.45 wt.%.

[0019] As a preferred technical solution, the method for preparing the multifunctional conductive polymer composite material, wherein, under stirring conditions, the second mixed solution is dispersed into the first mixed solution to obtain a pre-composite system, comprising:

[0020] The second mixed solution is added dropwise to the first mixed solution, and the mixture is continuously stirred at an ambient temperature of 20-25°C to obtain the pre-composite system; the pre-composite system is a molecular-level pre-composite system.

[0021] In a second aspect, a multifunctional conductive polymer composite material is provided, wherein the multifunctional conductive polymer composite material is prepared by any of the preparation methods described above.

[0022] Thirdly, a positive electrode material for an aqueous zinc-halogen battery, wherein the positive electrode material comprises the multifunctional conductive polymer composite material described in the second aspect.

[0023] Beneficial effects: Compared with the prior art, the embodiments of the present invention have the following advantages:

[0024] This invention successfully transforms the conformation of the PEDOT chain into a highly conductive quinone structure by introducing secondary dopants ethylene glycol (EG) and β-cyclodextrin and tannic acid (TA), significantly improving the conductivity of the composite material. Simultaneously, the abundant hydroxyl functional groups in components such as PVA, TA, and β-CD endow the material with excellent hydrophilicity (water contact angle as low as 51°). This "electron / ion construction" ensures rapid charge transport and sufficient wetting of electrolyte ions, laying the foundation for excellent rate performance. The core design of this invention lies in the fundamental suppression of the shuttle effect. On one hand, the unique "internal hydrophobic-external hydrophilic" cup-shaped molecular structure of β-cyclodextrin can, through host-guest chemical interactions, transfer hydrophobic polyiodide ions (I3) to the hydrophobic polyiodide ions (I3). - I5 -The tannic acid and PVA molecules are physically encapsulated within their cavities. On the other hand, the phenolic and alcoholic hydroxyl groups densely distributed on the tannic acid and PVA molecular chains can "anchor" polyiodide ions through strong chemical interactions such as hydrogen bonds. This synergistic effect of physical confinement and chemical adsorption greatly inhibits the dissolution and shuttle movement of the active material, as confirmed by in-situ spectroscopy. Benefiting from the above structural and functional advantages, the multifunctional conductive polymer composite (PePS) cathode prepared in this invention exhibits excellent performance in zinc-halogen batteries. Even more remarkable is its superior rate performance, even at 50 Ag. -1 Even at ultra-high current densities, it can still maintain a considerable capacity and achieve an ultra-long cycle life of over 50,000 cycles, which is leading among reported aqueous zinc-halogen batteries. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of the preparation method of the multifunctional conductive polymer composite material provided by the present invention.

[0027] Figure 2 Images of the water solubility of pure PEDOT and PePS provided by this invention.

[0028] Figure 3 The X-ray diffraction patterns of pure PEDOT and PePS provided by this invention.

[0029] Figure 4 The infrared spectra of pure PEDOT and PePS provided by this invention.

[0030] Figure 5 The conductivity diagrams of pure PEDOT and PePS provided by this invention.

[0031] Figure 6 The contact angle diagrams for commercial activated carbon, pure PEDOT, and PePS provided by this invention are shown.

[0032] Figure 7 Cyclic voltammetry curves of pure PEDOT and PePS for the zinc-iodine battery provided by this invention.

[0033] Figure 8 The zinc-iodine battery provided by this invention exhibits cycling performance of pure PEDOT and PePS at a current density of 50 A / g.

[0034] Figure 9 The rate performance of the zinc-iodine battery provided by this invention is that of pure PEDOT and PePS.

[0035] Figure 10 Cyclic voltammetry curves of the PePS zinc-bromine battery provided by this invention.

[0036] Figure 11 The cycling performance of the PePS zinc-bromine battery provided by this invention at a current density of 10 A / g is shown. Detailed Implementation

[0037] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. 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.

[0038] This invention aims to overcome the problems of severe iodine shuttle effect, insufficient electrode conductivity and wettability, limited zinc ion diffusion, and unsatisfactory cycle life in existing aqueous zinc-iodine battery cathode materials. It provides the following technical solution, such as... Figure 1 As shown, a method for preparing a multifunctional conductive polymer composite material includes the following steps:

[0039] S10. Provide a first mixed solution and a second mixed solution; the first mixed solution is composed of PEDOT:PSS aqueous solution, ethylene glycol and PVA aqueous solution; the second mixed solution is composed of β-cyclodextrin, tannic acid and water.

[0040] Specifically, an aqueous solution of PEDOT:PSS is mixed with a secondary dopant, ethylene glycol (EG), and a certain mass fraction of PVA aqueous solution, and magnetically stirred at room temperature to obtain a homogeneous mixed solution (the first mixed solution). The addition of ethylene glycol aims to induce phase separation between PEDOT (poly(3,4-ethylenedioxythiophene)) and PSS (poly(styrene sulfonic acid)), altering the conformation of the PEDOT chains and thus improving conductivity. PVA serves as the film-forming and hydrophilic framework. PEDOT:PSS serves as the conductive polymer matrix.

[0041] β-Cyclodextrin (β-CD) and tannic acid (TA) were dissolved in deionized water at a specific molar ratio and stirred continuously at room temperature to allow them to fully complex, forming a clear second mixed solution. This second mixed solution is also known as a supramolecular solvent (SMS).

[0042] S20. Under stirring conditions, the second mixed solution is dispersed into the first mixed solution to obtain a pre-composite system.

[0043] Specifically, the prepared supramolecular solvent is slowly added dropwise to the first mixed solution, and magnetic stirring continues at room temperature. During this process, β-CD and TA molecules in SMS will interpenetrate and interact with PEDOT:PSS and PVA chains, forming a molecular-level pre-complex system.

[0044] S30. Disperse the crosslinking agent into the precomposite system to obtain a blended crosslinking precursor solution.

[0045] Specifically, glutaraldehyde, a crosslinking agent, is added to the pre-composite system obtained in step S20 and stirred rapidly. Glutaraldehyde will react with the hydroxyl groups on the PVA chain and possibly with some of the phenolic hydroxyl groups on tannic acid to form a three-dimensional network structure, thereby enhancing the mechanical stability and structural integrity of the composite material.

[0046] S40. The blended crosslinking precursor solution is used to prepare a film to obtain a multifunctional conductive polymer composite material.

[0047] Specifically, the final crosslinked precursor solution is poured into a petri dish or other mold and film is formed by drop coating. The petri dish containing the solution is then placed in an oven at 40°C and dried for 8 to 12 hours to obtain a multifunctional conductive polymer composite material (PePS).

[0048] In the embodiments of the present invention, the multifunctional conductive polymer composite material (PePS), its preparation method, and its application provided by the present invention have the following significant advantages and positive effects:

[0049] Synergistic Enhancement of Conductivity and Hydrophilicity: This invention successfully transforms the conformation of the PEDOT chain into a highly conductive quinone structure by introducing the secondary dopant EG and the supramolecular solvent SMS, significantly improving the conductivity of the composite material. Simultaneously, the abundant hydroxyl functional groups in components such as PVA, TA, and β-CD endow the material with excellent hydrophilicity (water contact angle as low as 51°). This "electron / ion construction" ensures rapid charge transport and sufficient wetting of electrolyte ions, laying the foundation for excellent rate performance.

[0050] A highly efficient polyiodide ion "capture-conversion" synergistic mechanism: The core design of this invention lies in the fundamental suppression of the shuttle effect. On the one hand, the unique "internal hydrophobic-external hydrophilic" cup-shaped molecular structure of β-cyclodextrin can capture and convert hydrophobic polyiodide ions (I3+) through host-guest chemical interactions. - I5 -The tannins and PVA molecules are physically encapsulated within their cavities. On the other hand, the polar functional groups, such as phenolic and alcoholic hydroxyl groups, densely packed on the tannin and PVA molecular chains, can "anchor" polyiodide ions through strong chemical interactions such as hydrogen bonds. This synergistic effect of physical confinement and chemical adsorption greatly inhibits the dissolution and migration of the active substances, as confirmed by in-situ spectroscopy.

[0051] Superior Electrochemical Performance: Benefiting from the aforementioned structural and functional advantages, the PePS cathode prepared in this invention exhibits excellent performance in zinc-halogen batteries. Even more remarkable is its superior rate performance, even at 50 Ag. -1 Even at ultra-high current densities, it can still maintain a considerable capacity and achieve an ultra-long cycle life of over 50,000 cycles, which is leading among reported aqueous zinc-halogen batteries.

[0052] Simple and controllable preparation process: The preparation method of this invention employs mild process conditions such as liquid-phase blending, drop-coating film formation, and low-temperature drying, requiring no complex equipment or harsh environment, and is easy to scale up for production. The proportions of each component and the final water content can be precisely controlled, providing convenience for performance optimization and customization, and showing good prospects for industrial application.

[0053] In one implementation of this invention, the mass fraction of the PVA aqueous solution is 5-15 wt.%, such as 5-10 wt.% or 10-15 wt.%. By controlling the PVA content, appropriate amounts of polar functional groups such as phenolic and alcoholic hydroxyl groups are provided without affecting the performance of the final product. These groups "anchor" polyiodide ions through strong chemical interactions such as hydrogen bonds. This effectively suppresses self-discharge caused by the migration of soluble polyiodides to the negative electrode, improves cycle stability, and prevents a decrease in coulombic efficiency.

[0054] In one embodiment of the present invention, the molar ratio of β-cyclodextrin to tannic acid is 1:2-4, such as 1:3. This synergistic effect of the ratio optimizes the cavitation physical confinement effect of β-cyclodextrin and the chemisorption effect of the abundant phenolic hydroxyl groups in tannic acid.

[0055] In one embodiment of the present invention, the water content in the obtained multifunctional conductive polymer composite material is 10-20 wt.%. An appropriate amount of structural water not only helps maintain the flexibility and ionic conductivity of the material, but also participates in the solvation and binding of polyiodide ions.

[0056] It should be noted that, in the embodiments of the present invention, the ratio of PEDOT:PSS, PVA and SMS can be adjusted, such as the ratio of PEDOT:PSS being 50-90%.

[0057] Based on the same inventive concept, this invention also provides a multifunctional conductive polymer composite material, which is prepared using the above-described preparation method. The specific preparation method has been described in detail above and will not be repeated here.

[0058] The multifunctional conductive polymer composite material provided in this invention exhibits high conductivity and electron mobility, ensuring an efficient charge transport pathway. Due to its excellent hydrophilicity and surface wettability, this composite material, when used as a positive electrode material, promotes electrolyte wetting and uniform distribution of zinc ions. Its high specific surface area and uniform, continuous particle morphology facilitate rapid ion diffusion.

[0059] Based on the same inventive concept, this invention also provides a positive electrode material for an aqueous zinc halide battery, wherein the positive electrode material comprises the aforementioned multifunctional conductive polymer composite material. This composite film can be directly used as a self-supporting flexible positive electrode, or it can be coated onto carbon cloth. Using ZnI2 or ZnSO4+NaI (or KI) as the electrolyte and zinc foil as the negative electrode, a PePS / ZnI2 / Zn battery is assembled. The zinc-iodine battery test voltage window is 0.5-1.6V. Using ZnBr2 or ZnSO4+NaBr (or KBr) as the electrolyte and zinc foil as the negative electrode, a PePS / ZnBr2 / Zn battery is assembled. The zinc-bromine battery test voltage window is 0.5-1.6V, and the zinc-bromine battery test window is 0.5-2V.

[0060] The PePS conductive polymer composite film prepared by this invention, as a positive electrode material for zinc-halogen batteries, can significantly improve the battery's capacity retention, conductivity, and rate performance, extend battery life, and promote the practical application of aqueous zinc-halogen battery technology.

[0061] The technical solutions provided by the present invention will be further explained and illustrated below through specific embodiments.

[0062] Example 1

[0063] PEDOT:PSS aqueous solution was mixed with secondary dopant ethylene glycol (EG) and PVA aqueous solution with a mass fraction of 10 wt.%, and magnetically stirred for 10 minutes at room temperature to obtain a homogeneous mixed solution A.

[0064] β-Cyclodextrin (β-CD) and tannic acid (TA) were dissolved in deionized water at a molar ratio of 1:3 and stirred continuously at room temperature to allow them to fully complex, forming a clear SMS aqueous solution B.

[0065] Glutaraldehyde (GA), a crosslinking agent, was added to the composite solution and stirred rapidly for 3 minutes to obtain a co-crosslinking precursor solution. This solution was then poured into a petri dish and deposited as a film using a drop-coating method. The petri dish containing the solution was placed in an oven at 40°C and dried for 12 hours. The final water content in the composite film was controlled to be approximately 10 wt.%, thus obtaining the composite material.

[0066] Example 2

[0067] PEDOT:PSS aqueous solution was mixed with secondary dopant ethylene glycol (EG) and PVA aqueous solution with a mass fraction of 5 wt.%, and magnetically stirred for 10 minutes at room temperature to obtain a homogeneous mixed solution A.

[0068] β-Cyclodextrin (β-CD) and tannic acid (TA) were dissolved in deionized water at a molar ratio of 1:2 and stirred continuously at room temperature to allow them to fully complex, forming a clear SMS aqueous solution B.

[0069] Glutaraldehyde (GA), a crosslinking agent, was added to the composite solution and stirred rapidly for 5 minutes to obtain a co-crosslinking precursor solution. This solution was then poured into a petri dish and deposited as a film using a drop-coating method. The petri dish containing the solution was placed in an oven at 30°C and dried for 8 hours. The final water content in the composite film was controlled to be approximately 20 wt.%, yielding the composite material.

[0070] Example 3

[0071] PEDOT:PSS aqueous solution was mixed with secondary dopant ethylene glycol (EG) and PVA aqueous solution with a mass fraction of 15 wt.%, and magnetically stirred for 12 minutes at room temperature to obtain a homogeneous mixed solution A.

[0072] β-Cyclodextrin (β-CD) and tannic acid (TA) were dissolved in deionized water at a molar ratio of 1:4 and stirred continuously at room temperature to allow them to fully complex, forming a clear SMS aqueous solution B.

[0073] Glutaraldehyde (GA), a crosslinking agent, was added to the composite solution and stirred rapidly for 5 minutes to obtain a co-crosslinking precursor solution. This solution was then poured into a petri dish and deposited as a film using a drop-coating method. The petri dish containing the solution was placed in an oven at 50°C and dried for 8 hours. The final water content in the composite film was controlled to be approximately 15 wt.%, thus obtaining the composite material.

[0074] The PePS prepared in Examples 1-3 were verified, such as... Figure 2 As shown, when pure PEDOT:PSS and PePS are added to water, it can be seen that PEDOT:PSS, due to the large number of hydrophilic groups in its water-soluble components, causes the membrane electrode to dissolve significantly after being immersed in the aqueous solution for one hour. In contrast, the PePS electrode, due to the chelation between the supramolecular solvent and PVA molecules, enhances its hydrogen bond network and exhibits better water stability.

[0075] like Figure 3 As shown, X-ray diffraction (XRD) patterns reveal significant differences between PEDOT:PSS and PePS. PEDOT:PSS exhibits a weak peak near 2θ≈26°, indicating its disordered conjugated backbone. In contrast, PePS shows enhanced and shifted diffraction peaks, suggesting an increase or alteration in interlayer spacing due to modification. This trend suggests that doping or structural rearrangement during PePS synthesis may affect crystallinity, potentially influencing charge transport properties.

[0076] like Figure 4 As shown, FTIR provides further insights into the chemical structure of materials. At 1640 cm⁻¹... -1 1076cm -1 and 879cm -1 The nearby peaks correspond to the C=C stretching, SO stretching, and CS stretching vibrations of the sulfonic acid group in PSS, respectively. Notably, the C=C stretching of the quinone-like EDOT starts at 1633 cm⁻¹. -1 Blue shifted to 1642cm -1 This is likely due to an effective p-electron dislocation conformation—a linear conformation—which is consistent with Raman results. Notably, the prominent broad absorption band in PePS centers at 3400 cm⁻¹. -1 This is attributed to the -OH stretching of PVA and SMS, which is consistent with the enhancement of the material's hydrophilicity.

[0077] like Figure 5 As shown, PePS exhibits higher conductivity compared to the original PEDOT:PSS. The significant increase in conductivity in PePS can be attributed to the improved charge mobility resulting from EG and SMS doping.

[0078] like Figure 6 As shown, water contact angle analysis provides crucial information about the wettability of the material surface. The contact angle of PePS (51°) is significantly smaller than that of AC (120°) and PEDOT:PSS (77°). The hydrophilic-enhanced surface structure of the PePS electrode can accelerate electrolyte penetration, allowing iodine species and Zn at the interface to... 2+ Evenly distributed.

[0079] like Figure 7 As shown, the high specific surface area of ​​AC activated carbon provides physical adsorption sites, primarily storing charge through double-layer capacitance (non-Radidatic reaction) rather than intrinsic redox reactions, representing a typical non-long-distance charge storage mechanism. The electrolyte contains I... -The I₂ redox couple may only undergo weak adsorption or ion intercalation due to the inertness of the AC surface, without triggering significant electron transfer. PEDOT:PSS exhibits a clear pair of redox peaks: a sharp anodic peak (oxidation peak, positive current) at approximately 1.2 V; and a cathodic peak (reduction peak, negative current) at approximately 1.1 V. The symmetrical peak shapes and small inter-peak potential differences indicate good reversibility of the redox reaction. PePS, on the other hand, displays more pronounced redox peaks with less polarization, suggesting that the hydroxyl groups on the PePS surface effectively enhance the chemical transformation of iodine species.

[0080] like Figure 8 As shown, after 50,000 cycles at a current density of 50 A / g, PePS clearly exhibits higher specific capacity and cycling stability, benefiting from its stable chemisorption.

[0081] like Figure 9 As shown, PePS exhibits better rate performance at different current densities, which is higher than that of PEDOT:PSS and activated carbon. This is because PePS has abundant iodophilic groups with good conductivity, which is conducive to the rapid transport of iodide ions.

[0082] like Figure 10 As shown, the cyclic voltammetry curve of the PePS zinc-bromine battery exhibits a pair of distinct redox peaks between 1.5 and 2.0 volts, corresponding to the reversible conversion of bromide ions to elemental bromine.

[0083] like Figure 11 As shown, in Zn(OTf)2 and ZnBr2 electrolytes, PePS can achieve a reversible capacity of 110 mA / g at a current density of 10 A / g after 2000 cycles, and remains stable after 2000 cycles.

[0084] It should be understood that the present invention is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

[0085] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a multifunctional conductive polymer composite material, characterized in that, include: Provide a first mixed solution and a second mixed solution; The first mixed solution consists of PEDOT:PSS aqueous solution, ethylene glycol, and PVA aqueous solution; The second mixed solution consists of β-cyclodextrin, tannic acid and water; Under stirring conditions, the second mixed solution is dispersed into the first mixed solution to obtain a pre-composite system; The crosslinking agent is dispersed into the precomposite system to obtain a blended crosslinking precursor solution; The blended crosslinked precursor solution was used to prepare a film to obtain a multifunctional conductive polymer composite material.

2. The method for preparing the multifunctional conductive polymer composite material according to claim 1, characterized in that, The blended crosslinking precursor solution is used to prepare a film to obtain a multifunctional conductive polymer composite material, comprising: The blended crosslinking precursor solution was added to a mold, and a film was formed by drop coating. The mold containing the blended crosslinking precursor solution is placed in a baking device and baked at a temperature of 30-50°C to obtain the multifunctional conductive polymer composite material.

3. The method for preparing the multifunctional conductive polymer composite material according to claim 2, characterized in that, The obtained multifunctional conductive polymer composite material has a water content of 10-20 wt.%.

4. The method for preparing the multifunctional conductive polymer composite material according to claim 1, characterized in that, The PVA aqueous solution has a mass fraction of 5-15 wt.%.

5. The method for preparing the multifunctional conductive polymer composite material according to claim 1, characterized in that, The molar ratio of β-cyclodextrin to tannic acid in the second mixed solution is 1:2-4.

6. The method for preparing the multifunctional conductive polymer composite material according to claim 1, characterized in that, The crosslinking agents include: glutaraldehyde, borax, boric acid, and epichlorohydrin.

7. The method for preparing the multifunctional conductive polymer composite material according to claim 1, characterized in that, The mass fraction of PEDOT:PSS in the blended crosslinking precursor solution is 50-90 wt.%; the mass fraction of the crosslinking agent relative to PVA is 0.2-0.45 wt.%.

8. The method for preparing the multifunctional conductive polymer composite material according to claim 1, characterized in that, Under stirring conditions, the second mixed solution is dispersed into the first mixed solution to obtain a pre-composite system, comprising: The second mixed solution is added dropwise to the first mixed solution, and the mixture is continuously stirred at an ambient temperature of 20-25°C to obtain the pre-composite system; the pre-composite system is a molecular-level pre-composite system.

9. A multifunctional conductive polymer composite material, characterized in that, The multifunctional conductive polymer composite material was prepared using the preparation method described in any one of claims 1-8.

10. A positive electrode material for an aqueous zinc-halogen battery, characterized in that, The positive electrode material comprises the multifunctional conductive polymer composite material as described in claim 9.

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