Zinc-iodine battery positive electrode preparation method and product and application thereof

Abstract

The invention relates to the technical field of zinc-iodine soft package batteries, in particular to a zinc-iodine battery positive electrode preparation method and a product and application thereof. The preparation method comprises the following steps: dissolving a polyamide thermoplastic elastomer in a lithium bis (trifluoromethanesulfonate) solution to obtain a mixed solution, mixing elemental iodine and carbon powder, heating to obtain carbon-iodine composite powder, adding the carbon-iodine composite powder into a solution dissolved with TPAE, uniformly stirring to obtain slurry, pouring the slurry into a mold, and carrying out heat treatment to obtain a finished product. The preparation method comprises the following steps: adding a carbon-iodine compound into a mold, adding a conductive current collector during charging operation, finally immersing the mold into deionized water, performing phase inversion on slurry, dissolving LiTFSI into water from the slurry, curing TPAE, the carbon-iodine compound and the current collector to form a whole, taking out a pole piece, washing with water, and cutting to obtain the positive pole piece which can be directly used for assembling a high-load zinc-iodine soft package battery. According to the invention, the characteristics of high load, long service life and flexibility of the soft package battery can be realized, and the LiTFSI used in the preparation process can be recycled.

Description

Technical Field

[0001] This invention relates to the field of zinc-iodine pouch cell technology, specifically to a method for preparing a zinc-iodine battery cathode, its products, and applications. Background Technology

[0002] Batteries, as a highly efficient and flexible electrochemical energy storage technology, represent a crucial development direction for energy storage systems today. Currently, mainstream lithium-ion batteries are limited in large-scale application due to the flammability of their organic electrolytes and their relatively high production costs. Compared to organic electrolytes, aqueous electrolytes offer higher safety and lower production costs, making them promising candidates for developing novel environmentally friendly aqueous rechargeable batteries. Among the numerous aqueous rechargeable batteries currently under research, aqueous zinc-ion batteries (AZIBs) have attracted widespread attention due to the advantages of zinc metal anodes, such as low redox potential (-0.76 V vs. SHE), high compatibility, abundant reserves, and low price. The cathode materials used in AZIBs mainly include manganese oxides, vanadium oxides, Prussian blue analogues, and halogens. Iodine, in particular, possesses a favorable operating potential (0.536 V vs. SHE), high theoretical capacity (211 mAh g⁻¹), and high natural abundance (55 μg L⁻¹ in the ocean). Therefore, aqueous zinc-iodine batteries, due to their inherent safety and low cost, have broad application prospects in grid-scale energy storage.

[0003] Elemental iodine itself has poor electrical conductivity, therefore high-surface-area activated carbon (AC) is required as a host material to provide a conductive network and redox reaction sites. The nonpolar, hydrophobic surface of activated carbon facilitates the adsorption of nonpolar iodine molecules via van der Waals forces, while its porous structure effectively traps iodine within its pores. Due to the nonpolar nature of elemental iodine, its solubility in water is extremely low (only 0.33 g·L⁻¹). -1 In aqueous media, this system facilitates the migration of iodine molecules from the aqueous phase to the surface of activated carbon, achieving directional migration and efficient anchoring. In contrast, negatively charged polyiodides (such as I) 3- I 5- The high polarity of these molecules reduces their affinity for activated carbon, leading to a significant increase in their solubility in polar aqueous electrolytes. This causes them to spontaneously dissociate from the binding of activated carbon, increasing their solubility in the electrolyte and thus creating a shuttle effect.

[0004] During battery charging and discharging, polyiodine intermediates (such as I) 3- I 5-The dissolution and shuttle effect of iodine leads to irreversible capacity loss and zinc anode corrosion, severely hindering the practical application of AZIBs. Furthermore, elemental iodine itself has poor conductivity, requiring high specific surface area activated carbon (AC) as a carrier to provide a conductive network and redox reaction sites. However, carbon materials have limited adsorption capacity for iodine and cannot suppress the shuttle effect during long-term cycling. Additionally, from an application perspective, using a low areal capacity cathode (<20 mg / cm³) is problematic. 2 This can lead to a higher proportion of inactive components in the finished battery, thus significantly reducing the overall energy density. If traditional aqueous binders (such as CMC, SBR, PAA / PAN) are used to prepare the slurry, when the positive electrode loading is increased, obvious binder migration will occur during the electrode drying process, resulting in internal cracking or delamination with the current collector. This ultimately limits the production of high-loading electrodes. Currently, there are basically no reported cases of aqueous zinc-iodine batteries reaching a capacity of 1Ah. Summary of the Invention

[0005] To address the problems existing in the prior art, the first technical objective of this invention is to provide a method for preparing a zinc-iodine battery cathode.

[0006] In view of the problems existing in the prior art, the second technical objective of the present invention is to provide a zinc-iodine battery positive electrode.

[0007] In view of the problems existing in the prior art, the third technical objective of the present invention is to provide an application of the positive electrode of a zinc-iodine battery.

[0008] The first technical objective of this invention is achieved through the following solution: A method for preparing a zinc-iodine battery cathode includes the following steps: Preparation of S1 solution A: Polyamide thermoplastic elastomer TPAE, lithium bis(trifluoromethanesulfonate)imideLiTFSI solution, and ultrapure water are mixed in a certain proportion and heated and stirred until TPAE is completely dissolved to obtain solution A; Preparation of S2 Mixed Carbon Powder B: Activated carbon powder and conductive carbon powder are mixed evenly in a certain mass ratio to obtain mixed carbon powder B; Preparation of S3 carbon-iodine composite powder C: Elemental iodine powder and mixed carbon powder B are mixed in a certain mass ratio, sealed in a glass bottle, and heated to obtain carbon-iodine composite powder C; S4 Slurry D Preparation: Weigh the mixture C and solution A according to a certain mass ratio, stir evenly to obtain slurry D; S5 Positive Electrode Preparation: Prepare a Teflon mold of the corresponding size according to the designed pouch battery dimensions. The mold thickness must be greater than the designed positive electrode thickness. According to the positive electrode design capacity of the zinc-iodine battery, pour half of the weighed slurry D into the mold. Then, place the cut current collector on the surface of the slurry, and pour in the other half of the slurry D. After the slurry is smooth and wetted, transfer it along with the Teflon mold to a container containing sufficient deionized water. The water level must be submerged in the mold. During the reverse rotation process, LiTFSI will dissolve from the slurry into the external deionized water. This aqueous solution can be concentrated and reused. After the slurry solidifies, TPAE, carbon-iodine composite powder, and current collector will solidify into a whole. After removing the electrode, wash it with water and cut it to obtain a positive electrode that can be directly used for high-load zinc-iodine pouch battery assembly.

[0009] This application aims to simultaneously solve the technical problems of low iodine-based cathode loading and multi-iodine compound shuttle in aqueous zinc batteries, so as to achieve long-life and stable cycle of pouch batteries.

[0010] This invention provides a method for preparing a zinc-iodine battery positive electrode based on a water-based phase inversion method. This positive electrode can effectively suppress the shuttle of polyiodides, achieving high load capacity, high stability, high rate performance and long cycle life of the pouch battery.

[0011] Preferably, the thermoplastic elastomer contains polyamide groups; Preferably, the thermoplastic elastomer has a relative molecular weight of 20,000 to 100,000.

[0012] Preferably, polyamide thermoplastic elastomer (TPAE), lithium bis(trifluoromethanesulfonate)imide (LiTFSI), and ultrapure water are mixed at a ratio of 5% to 10% of TPAE by mass, and heated and stirred at 70°C to 80°C until TPAE is completely dissolved to obtain solution A.

[0013] Optionally, activated carbon powder and conductive carbon powder are mixed evenly at a mass ratio of 1:0.3 to 1:1.0 to obtain mixed carbon powder B; Optionally, elemental iodine and mixed carbon powder B are mixed evenly at a mass ratio of 1:0.3 to 1:1.2 and then heated in a sealed container to obtain carbon-iodine composite powder C; Optionally, the mixed powder C and solution A are weighed in a mass ratio of 1:3 to 1:5, and stirred evenly to obtain slurry D; Optionally, slurry D and current collector are placed in a Teflon mold in the order of slurry-current collector-slurry, and then the mold is completely immersed in deionized water. TPAE, composite carbon powder and current collector will solidify into a whole. After washing and cutting, a positive electrode sheet that can be directly used for high-load zinc-iodine soft-pack battery assembly is obtained.

[0014] Preferably, the mass ratio of elemental iodine powder to mixed carbon powder B is 1:0.3 to 1:1.2, the heating temperature after mixing is 70 to 90°C, and the heating time is 2 to 3 hours; the mass ratio of composite powder C to solution A is 1:3 to 1:5.

[0015] Polyamide thermoplastic elastomer (TPAE), commonly known as nylon, is a solid at room temperature and insoluble in water and common organic solvents. However, it is soluble in high-concentration lithium bis(trifluoromethanesulfonate)imide (LiTFSI) solutions. The ionic association between the amide groups on the polyamide (PA) chain and LiTFSI breaks the hydrogen bonds, forming a flowable slurry. When the concentration of the LiTFSI aqueous solution is higher than 6 mol / L, TPAE can depolymerize in the aqueous solution and appear in a dissolved state. When the concentration of the LiTFSI aqueous solution decreases, TPAE will precipitate from the solution and return to a solid elastic state. This invention utilizes the characteristic that TPAE has different states in LiTFSI aqueous solutions of different concentrations to achieve material mixing and integrated molding. LiTFSI is a soluble lithium salt, and its aqueous solution does not lose solute during evaporation and concentration. It can be recycled as a dissolving medium for TPAE throughout the entire positive electrode preparation process. Before each reuse, excess water in the TPAE aqueous solution needs to be removed, and its concentration needs to be increased to above 6 mol / L. The trace amount of iodine (0.03%) dissolved in the solution can be deducted accordingly during recycling.

[0016] Elemental iodine has a sublimation temperature of 45~77℃ and a melting point of 113.7℃ under normal pressure. Generally, iodine is sublimated by heating at around 80℃. Due to the poor conductivity of elemental iodine, it must be attached to a conductive carrier when used as a positive electrode active material. Generally, elemental iodine is mixed with carbon powder and then heated for composite processing. Elemental iodine is uniformly attached to the carbon powder through sublimation. Activated carbon and conductive carbon provide a high specific surface area and a large number of conductive sites, respectively, to better utilize the charge and discharge efficiency of elemental iodine.

[0017] The second technical objective of this invention is achieved through the following solution: A zinc-iodine battery cathode is obtained by the above preparation method.

[0018] The third technical objective of this invention is achieved through the following solution: An application of a zinc-iodine battery cathode, including its use in the fabrication of high-load zinc-iodine pouch cells.

[0019] The assembly conditions and steps of the soft-pack battery of this invention are as follows: the negative electrode is a zinc plate with surface interface protection, the electrolyte is a 1mol / L zinc sulfate solution, the separator is glass fiber, and the battery assembly is completed in an atmospheric environment according to the traditional soft-pack battery assembly method. The assembled soft-pack battery has high load, long life (more than 1000 cycles) and flexibility. The capacity of the soft-pack battery reaches more than 1Ah, and the LiTFSI used in the preparation process can be recycled.

[0020] Compared with existing technologies, it has the following beneficial effects: The polyamide thermoplastic elastomer used in this application can chemically adsorb polyiodide ions, effectively inhibiting polyiodide ion shuttle. Furthermore, it can achieve high loading capacity of the positive electrode, with an areal capacity of 30~80 mg / cm³. 2 With flexible adjustment, the capacity of the assembled soft-pack battery can reach more than 1Ah, enabling high load, long life and stable cycle. Attached Figure Description

[0021] Figure 1 This is a schematic diagram showing the state of the zinc-iodine battery positive electrode sheet after preparation is completed. Figure 2 This is a schematic diagram showing the thickness of the positive electrode sheet of the zinc-iodine battery of the present invention; Figure 3 This is a schematic diagram showing the state of the positive electrode sheet of the zinc-iodine battery under different forces according to the present invention; Figure 4 This is a schematic diagram of a soft-pack battery assembled using a positive electrode sheet in the zinc-iodine battery of the present invention; Figure 5 This is a schematic diagram of the cycle data of the zinc-iodine soft-pack battery in Embodiment 1 of the present invention; Figure 6 A schematic diagram of the surface of the positive electrode sheet prepared using CMC as a binder in a comparative example; Figure 7 This is a schematic diagram of the surface of the positive electrode sheet prepared by using TPAE as a binder in this invention; Figure 8 Comparison of coin cell operation data for positive electrode preparation of TPAE and CMC; Figure 9 For comparative examples I2@AC and I 3- @AC in electrolyte state; Figure 10 Comparative Example I 3- @AC electrode in electrolyte I 3- Signal detection; Figure 11 For the present invention TPAE@I 3- Its state in the electrolyte; Figure 12 For the present invention TPAE@I3- I in the electrolyte of the electrode 3- Signal detection; Figure 13 For the TPAE thin film of the present invention in I 3- Adsorption experiment in solution. Detailed Implementation

[0022] To make the purpose, technical solution, and advantages of this application clearer, the following will be discussed in conjunction with the appendices of this application. Figure 1-13 The technical solutions in this application are clearly and completely described. Obviously, the described embodiments are only some, not all, of the embodiments in this application. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0023] Unless otherwise specified, the experimental methods used in the embodiments of this application are conventional methods. In the following embodiments, unless otherwise specified, all raw materials can be obtained by commercial purchase or conventional methods.

[0024] Example 1

[0025] Weigh 10g of polyamide thermoplastic elastomer (TPAE), 90g of lithium bis(trifluoromethanesulfonate)imide (LiTFSI), and 30g of ultrapure water. Mix the three and heat at 80℃ with stirring until TPAE is completely dissolved to obtain solution A. Weigh 3g of activated carbon powder and 3g of carbon black, and mix them evenly to obtain mixed carbon powder B. Weigh 8g of elemental iodine and 4g of mixed carbon powder B, mix the elemental iodine and carbon powder B evenly, and seal them in a glass bottle. Heat at 80℃ for 2 hours to obtain iodine composite carbon powder C. Weigh 10g of mixed powder C and 30g of solution A, and stir evenly to obtain slurry D. Prepare a 10cm×10cm Teflon mold according to the designed soft-pack battery dimensions. Pour 20g of slurry D into the mold, place the cut titanium mesh on the surface of the slurry, and pour in another 20g of slurry D. After the slurry is smooth and soaked, transfer it along with the Teflon mold to a container filled with sufficient deionized water, ensuring the mold is submerged. During the reverse inversion process, LiTFSI will dissolve from the slurry into the external deionized water. This aqueous solution can be concentrated and reused. After the slurry solidifies, TPAE, conductive carbon powder, and titanium mesh current collector will solidify into a whole. After removing the electrode sheet, wash it with water and cut it to obtain a positive electrode sheet that can be directly used for assembling high-load zinc-iodine soft-pack batteries. Using this electrode sheet, a soft-pack battery with a capacity of 1.5Ah can be assembled.

[0026] Example 2

[0027] Weigh 13.0g of polyamide thermoplastic elastomer (TPAE), 90.0g of lithium bis(trifluoromethanesulfonate)imide (LiTFSI), and 30.0g of ultrapure water. Mix the three and heat at 70℃ with stirring until TPAE is completely dissolved to obtain solution A. Weigh 5.0g of activated carbon powder and 1.5g of graphene and mix them evenly to obtain mixed carbon powder B. Weigh 3.6g of elemental iodine and 3.0g of mixed carbon powder B. Mix the elemental iodine and carbon powder B evenly and seal them in a glass bottle. Heat at 85℃ for 3 hours to obtain iodine composite carbon powder C. Weigh 6.0g of mixed powder C and 30.0g of solution A and stir evenly to obtain slurry D. Prepare a 7cm×7cm slurry according to the designed soft-pack battery size. For the Teflon mold, pour 18.0g of slurry D into the mold, then place the cut stainless steel mesh on the surface of the slurry, and pour in another 18.0g of slurry D. After the slurry is evenly soaked, transfer it along with the Teflon mold to a container filled with sufficient deionized water, ensuring the mold is completely submerged. During the reverse inversion process, LiTFSI will dissolve from the slurry into the external deionized water. This aqueous solution can be concentrated and reused. After the slurry solidifies, TPAE, conductive carbon powder, and stainless steel mesh current collector will solidify into a single unit. After removing the electrode sheet, wash it with water and cut it to obtain a positive electrode sheet that can be directly used for assembling high-load zinc-iodine soft-pack batteries. This electrode sheet can be used to assemble a soft-pack battery with a capacity of 1.3Ah.

[0028] Example 3

[0029] Weigh 8.0g of polyamide thermoplastic elastomer (TPAE), 90.0g of lithium bis(trifluoromethanesulfonate)imide (LiTFSI), and 20.0g of ultrapure water. Mix the three and heat at 80℃ with stirring until TPAE is completely dissolved to obtain solution A. Weigh 7.0g of activated carbon powder and 3.0g of carbon nanotubes and mix them evenly to obtain mixed carbon powder B. Weigh 5.0g of elemental iodine and 6.0g of mixed carbon powder B. Mix the elemental iodine and carbon powder B evenly and seal them in a glass bottle. Heat at 70℃ for 3 hours to obtain iodine composite carbon powder C. Weigh 10g of mixed powder C and 40g of solution A and stir evenly to obtain slurry D. Prepare 8cm×8cm slurry according to the designed soft-pack battery dimensions. Using a Teflon mold measuring cm, pour 20g of slurry D into the mold, then place the cut titanium foil on the surface of the slurry, and pour in another 20g of slurry D. After the slurry is evenly soaked, transfer it along with the Teflon mold to a container filled with sufficient deionized water, ensuring the mold is completely submerged. During the reverse inversion process, LiTFSI will dissolve from the slurry into the external deionized water. This aqueous solution can be concentrated and reused. After the slurry solidifies, TPAE, conductive carbon powder, and titanium foil current collector will solidify into a single unit. After removing the electrode, wash it with water and cut it to obtain a positive electrode that can be directly used for assembling high-load zinc-iodine soft-pack batteries. Using this electrode, a soft-pack battery with a capacity of 1.4Ah can be assembled.

[0030] Example 4

[0031] Weigh 12.0g of polyamide thermoplastic elastomer (TPAE), 90.0g of lithium bis(trifluoromethanesulfonate)imide (LiTFSI), and 10.0g of ultrapure water. Mix the three and heat at 78℃ with stirring until TPAE is completely dissolved to obtain solution A. Weigh 7.0g of activated carbon and 4.0g of acetylene black and mix them evenly to obtain mixed carbon powder B. Weigh 8g of elemental iodine and 10g of mixed carbon powder B. Mix the elemental iodine and carbon powder B evenly and seal them in a glass bottle. Heat at 80℃ for 2 hours to obtain iodine composite carbon powder C. Weigh 15g of mixed powder C and 45g of solution A and stir evenly to obtain slurry D. Prepare a 12cm×12cm slurry according to the designed soft-pack battery size. The process involves using a Teflon mold, pouring 30.0g of slurry D into the mold, placing the cut titanium foil on the surface of the slurry, and then pouring in another 30.0g of slurry D. After the slurry is evenly soaked, it is transferred along with the Teflon mold to a container filled with sufficient deionized water, ensuring the mold is completely submerged. During the reverse inversion process, LiTFSI will dissolve from the slurry into the external deionized water. This aqueous solution can be concentrated and reused. After the slurry solidifies, TPAE, composite carbon powder, and current collector will solidify into a single unit. The electrode sheet is then removed, washed with water, and cut to obtain a positive electrode sheet that can be directly used for assembling high-load zinc-iodine soft-pack batteries. This electrode sheet can be used to assemble a soft-pack battery with a capacity of 1.2Ah.

[0032] Comparative Examples

[0033] Comparison test of TPAE and traditional adhesives To compare the electrode preparation and application of TPAE and the traditional binder sodium carboxymethyl cellulose (CMC) under high load conditions, this invention uses the same formula as Example 1. 3g of activated carbon powder and 3g of carbon black are mixed evenly to obtain mixed carbon powder B. 8g of elemental iodine and 4g of mixed carbon powder B are weighed, and the elemental iodine and carbon powder B are mixed evenly and then sealed in a glass bottle. After heating at 80°C for 2 hours, iodine composite carbon powder C is obtained. 10g of mixed powder C is weighed, mixed evenly with 1.5g of CMC, and then fixed on a titanium mesh for coin cell assembly experiments under the same conditions.

[0034] Experimental results show that when CMC is used as a binder, the loading of the granules reaches 25 mg / cm³. 2 At that time, obvious cracking and peeling appeared on the surface of the graded sheet. Figure 6 ); while the tablets prepared using TPAE achieved a loading of 65 mg / cm³. 2 At that time, no cracks appeared on the electrode sheet, and the overall uniformity was consistent. Figure 7 ).

[0035] The prepared electrodes were assembled into button cells, and their electrochemical performance was tested. The data are as follows: Figure 8 As shown, using a CMC coin cell, the loading capacity is 23.2 mg / cm³.2 The battery failed after less than 1200 cycles, while the TPAE coin cell battery had a load capacity of 71.5 mg / cm³. 2 The battery still works normally after 1600 cycles, demonstrating significant advantages in cycle stability and load capacity.

[0036] Comparative Experiment of Multiiodine Ion Shuttle Effect

[0037] Elemental iodine has extremely low solubility in water. However, its solubility increases significantly when it combines with negatively charged iodide ions to form polyiodide ions. During battery operation, this polyiodide ions react with the zinc anode, accelerating corrosion and causing capacity loss. To verify the effects of carbon powder and TPAE on elemental iodine and polyiodide ions (I-), further research was conducted. 3- I 5- Several comparative experiments were conducted to investigate different chemisorption effects. Dissolving elemental iodine in a ZnI₂ solution simulates the solution environment of polyiodide ions; this solution is yellow. Placing carbon powder and TPAE in this solution simulates the adsorption of polyiodide ions, and I₂ can be detected using UV-Vis spectroscopy. 3- Signal.

[0038] like Figure 9-13 As shown: Figure 9 CMC is used as a binder to bond iodine-loaded activated carbon powder (I2@AC) and polyiodine-loaded activated carbon powder (I... 3- @AC) were fixed on titanium foil respectively, and the state of the electrode in 1 mol / L ZnSO4 electrolyte was compared. 3- Polyiodide ions on the AC electrode diffuse rapidly in water, and can be detected using ultraviolet-visible spectroscopy. 3- Signal; real-time concentration visible Figure 10 ; And such Figure 11 and Figure 2 As shown, TPAE-immobilized polyiodide ion activated carbon powder (TPAE@I) 3- The same immersion experiment and UV-Vis spectroscopy were performed, and no yellow substance appeared in the electrolyte, nor was I detected in the electrolyte. 3- This indicates that TPAE affects I 3- It has a significant immobilization and adsorption effect.

[0039] To further confirm the strong adsorption effect of TPAE on polyiodide ions, a thin film prepared with TPAE was placed in a ZnI2 solution containing elemental iodine. Figure 13 The color change of the solution shows that TPAE will reduce the I in the solution. 3- Adsorbed on the surface, the film changed from white to yellow, and the solution changed from yellow to clear, further confirming that amide groups can react with I in the electrolyte system of zinc-iodine batteries. 3-Ion interactions can capture I 3- The polar amide group has a strong binding force to polar polyiodides.

[0040] This specific embodiment is merely an explanation of the present invention and is not intended to limit the invention. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they are within the scope of the claims of the present invention.

Claims

1. A method for preparing a zinc-iodine battery cathode, characterized in that... Including the following steps: Preparation of S1 solution A: Polyamide thermoplastic elastomer TPAE, lithium bis(trifluoromethanesulfonate)imideLiTFSI solution, and ultrapure water are mixed in a certain proportion and heated and stirred until TPAE is completely dissolved to obtain solution A; Preparation of S2 Mixed Carbon Powder B: Activated carbon powder and conductive carbon powder are mixed evenly in a certain mass ratio to obtain mixed carbon powder B; Preparation of S3 carbon-iodine composite powder C: Elemental iodine powder and mixed carbon powder B are mixed in a certain mass ratio, sealed in a glass bottle, and heated to obtain carbon-iodine composite powder C; S4 Slurry D Preparation: Weigh the mixture C and solution A according to a certain mass ratio, stir evenly to obtain slurry D; S5 Positive Electrode Preparation: Prepare a Teflon mold of the corresponding size according to the designed pouch battery dimensions. The mold thickness must be greater than the designed positive electrode thickness. According to the positive electrode design capacity of the zinc-iodine battery, pour half of the weighed slurry D into the mold. Then, place the cut current collector on the surface of the slurry, and pour in the other half of the slurry D. After the slurry is smooth and wetted, transfer it along with the Teflon mold to a container containing sufficient deionized water. The water level must be submerged in the mold. During the reverse rotation process, LiTFSI will dissolve from the slurry into the external deionized water. This aqueous solution can be concentrated and reused. After the slurry solidifies, TPAE, carbon-iodine composite powder, and current collector will solidify into a whole. After removing the electrode, wash it with water and cut it to obtain a positive electrode that can be directly used for high-load zinc-iodine pouch battery assembly.

2. The method for preparing the zinc-iodine battery cathode according to claim 1, characterized in that, The cathode material comprises a composite material of polyamide thermoplastic elastomer, elemental iodine, and carbon powder; The mass ratio of polyamide thermoplastic elastomer to total mass in the composite material is 10% to 30%, and the mass ratio of elemental iodine to carbon powder is 1:0.3 to 1.

2.

3. The method for preparing the zinc-iodine battery cathode according to claim 1, characterized in that, The polyamide thermoplastic elastomer contains polyamide functional groups and has a relative molecular mass of 20,000 to 100,000. The mass fraction of TPAE in the mixture of TPAE, LiTFSI, and ultrapure water is 5% to 10%, the mass fraction of LiTFSI is 60% to 80%, and the mass fraction of ultrapure water is 20% to 30%.

4. The method for preparing the zinc-iodine battery cathode according to claim 1, characterized in that, The carbon powder is a mixture of activated carbon and conductive carbon, with the activated carbon having a specific surface area of ​​2000-3500 m². 2 / g, the high specific surface area activated carbon powder is mainly used to adsorb iodine, and the conductive carbon powder is one or more of carbon black SP, acetylene black, graphene, and carbon nanotubes. The mass ratio of activated carbon to conductive carbon is 1:0.3~1.

0.

5. The method for preparing the zinc-iodine battery cathode according to claim 1, characterized in that, The mass ratio of elemental iodine powder to mixed carbon powder B is 1:0.3~1:1.2, and the heating temperature after mixing is 70~90℃, and the heating time is 2~3h; the mass ratio of composite powder C to solution A is 1:3~1:

5.

6. The method for preparing the zinc-iodine battery cathode according to claim 1, characterized in that, The current collector is made of titanium foil, titanium mesh, stainless steel foil, stainless steel mesh, carbon cloth, or carbon paper; the size of the Teflon mold is adjusted according to the size of the electrode and the load, with the length and width ranging from 5 to 25 cm.

7. The method for preparing the zinc-iodine battery cathode according to claim 1, characterized in that, Slurry D needs to undergo phase inversion in deionized water, and LiTFSI dissolves from the slurry into external deionized water, which can be concentrated and reused.

8. The method for preparing the positive electrode of a zinc-iodine battery according to claim 1, characterized in that, The positive electrode sheet solidifies in water in 5-8 hours.

9. A zinc-iodine battery positive electrode, characterized in that, It is obtained by the preparation method described in any one of claims 1 to 8.

10. An application of a zinc-iodine battery positive electrode, characterized in that, This includes materials used to prepare high-load zinc-iodine pouch cells.

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