A high-capacity stable manganese-iodine composite material, a preparation method and use thereof, a preparation method of a positive electrode material, a positive electrode sheet and a zinc ion battery

Abstract

This invention relates to the field of electrochemical energy storage technology, specifically providing a high-capacity stable manganese-iodine composite material, its preparation method and application, a cathode material preparation method, a cathode sheet, and a zinc-ion battery. The manganese-iodine composite material comprises manganese oxide, iodide, and a conductive agent. To address the issue of low intrinsic conductivity of manganese oxide, the introduction of highly conductive iodide significantly improves the electronic conductivity of the composite material. The iodide, through a rapid redox reaction, constructs a three-dimensional permeable electron transport network, thereby greatly improving the electronic conductivity of the composite material. A precisely matched redox potential synergistic system is formed between the iodide and manganese oxide. This nearly overlapping electrochemical window enables a "potential relay" synergistic reaction mechanism, effectively reducing the Mn content. 4+ / Mn 3+ The activation energy barrier and reaction kinetics of the reaction. These characteristics together constitute a high-performance, highly stable aqueous zinc-manganese battery system.

Description

Technical Field

[0001] This application relates to the field of electrochemical energy storage technology, and in particular to a manganese-iodine composite material and its preparation method and uses, a method for preparing a cathode material, a cathode sheet and a zinc-ion battery. Background Technology

[0002] Aqueous zinc-ion batteries have become a popular candidate for next-generation energy storage technology due to their significant advantages such as high safety, low cost, and environmental friendliness. However, traditional manganese dioxide (MnO2) cathode materials face many challenges in practical applications: their poor intrinsic conductivity, severe capacity decay caused by manganese dissolution during charge and discharge, and the formation of irreversible byproducts (such as ZnMn2O4) by side reactions, which greatly limit their performance and commercial application prospects. Although manganese dioxide cathodes have a high theoretical capacity (based on the two-electron transfer reaction Mn...) 4+ / Mn 3+ The theoretical capacity can reach 308 mAh g - ¹) and suitable operating voltage have attracted much attention, but their inherent defects, such as Jahn-Teller distortion, low conductivity and slow ion diffusion kinetics, result in actual capacity that is far lower than theoretical value, and poor cycle stability and rate performance.

[0003] To address these issues, researchers have begun exploring ways to improve the performance of manganese dioxide by introducing highly conductive materials. Iodides, due to their excellent conductivity, chemical stability, and ability to modulate ion transport pathways, have shown great potential in energy storage. Iodides can not only significantly enhance the electron conduction rate of manganese dioxide, but their introduction can also optimize ion transport pathways in the electrolyte, promoting reversible ion insertion / extraction and effectively suppressing side reactions. Although the synergistic mechanism between iodides and manganese dioxide has not yet been fully elucidated, preliminary studies indicate that the addition of iodides can significantly improve the specific capacity, cycle stability, and rate performance of cathode materials, providing new insights for developing high-performance aqueous zinc-ion batteries.

[0004] This application is submitted in order to address the aforementioned issues. Summary of the Invention

[0005] This application provides a high-capacity stable manganese-iodine composite material, its preparation method, a positive electrode sheet, and a zinc-ion battery, to improve the specific capacity and cycle stability of the manganese dioxide positive electrode in aqueous zinc-ion batteries.

[0006] The first aspect of this application provides a manganese-iodine composite material, which includes: iodide, conductive agent and manganese oxide.

[0007] Preferably, the mass ratio of the iodide to the manganese oxide is (0.2~0.5):1.

[0008] The manganese oxide is one or more of manganese dioxide, manganese trioxide, or manganese tetroxide.

[0009] Preferably, the manganese dioxide is tunnel-type α-manganese dioxide.

[0010] A second aspect of this application provides a method for preparing a manganese-iodine composite material, the method comprising the following steps:

[0011] Place the iodide and conductive agent in a mortar in a predetermined ratio and grind thoroughly until a fine powder is formed. Add an appropriate amount of solvent to the powder and stir to form a uniformly dispersed solution. Transfer the mixed solution to a sealed reaction vessel and place it in an oven at 120°C for 2 hours.

[0012] After the reaction is complete, allow the reactor to cool naturally to room temperature, then add a predetermined amount of manganese oxide to the solution inside the reactor and stir thoroughly.

[0013] The resulting mixed slurry was centrifuged to collect the solid product. The solid product was washed repeatedly with deionized water (3-5 times) to remove impurities. The washed solid product was then freeze-dried to finally obtain the highly conductive manganese-iodine composite material.

[0014] Preferably, the mass ratio of the iodide to the manganese oxide is (0.1~0.5):1.

[0015] The mass ratio of the conductive agent to the iodide is (0.1 ~ 2.0): 2.

[0016] Preferably, the solvent is selected from one or more of deionized water, acetonitrile, and ethanol.

[0017] Preferably, the stirring time is 2 to 12 hours.

[0018] The third aspect of this application provides the use of the manganese-iodine composite material described in the first aspect as a positive electrode material for zinc-ion batteries.

[0019] The fourth aspect of this application provides a method for preparing a positive electrode material, the method comprising the following steps: adding the manganese-iodine composite material of the first aspect: conductive agent: binder in a mass ratio of (7 ~ 8): (2 ~ 1): 1 to a solvent, grinding and mixing, coating or rolling onto a current collector, and drying to obtain the positive electrode material.

[0020] Preferably, the conductive agent includes one or more of graphene, acetylene black, activated carbon, carbon nanotubes, and YP-80F.

[0021] Preferably, the solvent is water, ethanol, or N-methylpyrrolidone.

[0022] Preferably, the loading amount of the manganese-iodine composite material on the current collector is 1.0 ~ 30.0 mg cm⁻¹. 2 .

[0023] Preferably, the current collector is selected from carbon cloth, titanium foil, or stainless steel mesh.

[0024] The drying conditions were 60°C for 12 hours.

[0025] Preferably, the binder is selected from polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), and carboxymethyl cellulose (CMC).

[0026] The resulting cathode material contains the manganese-iodine composite material of the first aspect.

[0027] The fifth aspect of this application provides a positive electrode sheet, the positive electrode sheet comprising: a positive electrode material layer; the positive electrode material layer comprising the manganese-iodine composite material described in any one of the first aspects or the positive electrode material prepared by the preparation method described in the fourth aspect.

[0028] The sixth aspect of this application provides a zinc-ion battery, the battery comprising the positive electrode sheet described in the fifth aspect.

[0029] Preferably, the electrolyte of the battery includes manganese sulfate and zinc sulfate.

[0030] Preferably, the molar concentration of manganese sulfate is 0.05~0.6M, and the molar concentration of zinc sulfate is 0.05~3M. The negative electrode of the battery is a zinc foil. The thickness of the zinc foil is 30~100 micrometers, and it is sealed and assembled into a CR2032 battery under a pressure of 50~70MPa for electrochemical performance testing.

[0031] The technical solution of this application has the following advantages compared with the prior art:

[0032] 1. This application proposes a manganese-iodine composite material based on the synergistic effect of activated carbon, manganese dioxide (MnO2), and iodine. First, the iodide and conductive agent are solvotherm-treated, followed by the addition of manganese oxide. This effectively avoids adverse reactions of the oxide at high temperatures and precisely controls the interaction and spatial distribution of the three components (manganese, iodine, and conductive agent), ensuring a tight bond between the conductive agent and the active material. This is the core of achieving the material's "high conductivity." During this process, the positive charge on the surface of manganese dioxide and the adsorption capacity of activated carbon work synergistically, promoting a tight bond between the iodide, manganese dioxide, and conductive agent, forming a composite structure with a continuous conductive network and a stable interface. This structure not only improves the material's electronic conductivity but also inhibits the loss of active material through a dual mechanism of chemical bonding and physical adsorption, significantly enhancing the material's electrochemical stability.

[0033] 2. The manganese-iodine composite material provided in this application significantly improves the specific capacity and cycle stability of the manganese oxide cathode in aqueous zinc-ion batteries, as shown in the following details: Figure 3 As shown in Figure 4, the charge-discharge curves of the manganese-iodine cathode material show a significant increase in iodine (I₂) content. - / I 0 The redox platform indicates that the introduction of iodine provides additional electrochemical active sites, significantly improving the specific capacity of the material. Compared with the unmodified manganese dioxide cathode, its specific capacity is significantly increased, exhibiting a higher energy density. Figure 8 As shown, at 1.0 A g - At a current density of ¹, after 2000 charge-discharge cycles, the capacity retention of the cathode material in Example 1 was almost perfectly maintained at 100%, and its specific capacity was still as high as 318 mAh g⁻¹. - ¹, exhibiting excellent cycle stability. This superior performance is mainly due to the synergistic effect of ions / electrons resulting from the introduction of iodine, which effectively suppresses the influence of byproducts during discharge and significantly improves the reversibility of the reaction; simultaneously, the robust conductive network formed by the three components of manganese, iodine, and the conductive agent further enhances the overall structural stability of the material. Figure X As shown, the cathode material of Example 9 was tested at concentrations of 0.5, 1.0, 1.5, 2.0, 3.0, 5.0, and 10.0 Ag. - At current densities of ¹, the discharge specific capacities were 310.5, 271.9, 242.0, 231.6, 195.7, 165.5, and 133.2 mAh g, respectively. - ¹. Its high capacity output and stable performance with varying current density are significantly superior to the unmodified manganese dioxide cathode (Comparative Example 1), fully demonstrating the excellent performance of manganese-iodine composite materials at high rates. For example... Figure 10 As shown in Figure 11, at 5000 mA g -¹ At high current densities, the cathode material of Example 1 exhibits remarkable long-term cycling stability. After 60,000 charge-discharge cycles, its capacity retention remains as high as 64%, and its specific capacity remains at a good level. Attached Figure Description

[0034] Figure 1 Scanning electron microscope (SEM) image and EDS of the manganese-iodine composite material provided in Example 1 of this application;

[0035] Figure 2 This is the XPS spectrum of the I3d of the cathode material provided in Example 1 of this application and Comparative Example 1;

[0036] Figure 3 This is Example 1 of the present application, showing the cyclic voltammetry curve of the cathode material provided in Comparative Example 1;

[0037] Figure 4 As Example 1 of this application, the cathode material provided in Comparative Example 1 is at 0.5A g. -1 Charge-discharge curves at current density;

[0038] Figure 5 This is Example 1 of this application, and the electrochemical impedance spectroscopy of the cathode material provided in Comparative Example 1 in the fully discharged state.

[0039] Figure 6 This is Example 1 of this application, and the constant current intermittent titration (GITT) curve of the cathode material provided in Comparative Example 1.

[0040] Figure 7 This is Example 1 of this application, showing the ion diffusion coefficient of the cathode material provided in Comparative Example 1 at different potentials.

[0041] Figure 8 As Example 1 of this application, the positive electrode material provided in Comparative Example 1, as the positive electrode of a zinc-ion battery, achieves a current density of 1000 mA / g (abbreviated as @1.0 A g). 1 The charge-discharge long-cycle graph under (the curves corresponding to the left arrows are the specific capacity at different numbers of cycles, and the curves corresponding to the right arrows are the coulombic efficiency at different numbers of cycles);

[0042] Figure 9 The electrochemical rate performance diagrams of the cathode materials provided in Example 1 and Comparative Example 1 of this application as cathodes of zinc-ion batteries are shown, with current densities of 0.5, 1, 1.5, 2, 3, 5, and 10 A g, respectively. 1 ;

[0043] Figure 10As Example 1 of this application, the cathode material provided in Comparative Example 1 was used as the cathode of a zinc-ion battery at a current density of 5000 mA / g (abbreviated as @5.0 A g). 1 A comparison chart of charge-discharge long-cycle cycles;

[0044] Figure 11 The cathode materials provided in Embodiment 1 and Comparative Example 1 of this application were used as cathodes in zinc-ion batteries at a current density of 5000 mA / g (abbreviated as @5.0 A g). 1 The chart shows a comparison of charge-discharge long-cycle operation (the two curves near the left arrow represent the specific capacity of MnO2-I and MnO2 cathodes at different number of cycles, and the right arrow represents the coulombic efficiency of MnO2-I and MnO2 cathodes at different number of cycles). Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0046] Unless otherwise specified, all raw materials, reagents, instruments, and equipment used in this application are commercially available or can be prepared using existing methods. Experimental methods in the following examples that do not specify specific conditions are generally performed according to national standards. If no corresponding national standard exists, general international standards, standard conditions, or conditions recommended by the manufacturer shall be followed.

[0047] The manganese dioxide used in the examples and comparative examples was purchased and, upon characterization, was found to be tunnel-type manganese dioxide with nanowires of 50 to 500 nanometers in length.

[0048] Example 1

[0049] A method for preparing a positive electrode material, the method comprising:

[0050] S1. Place zinc iodide and activated carbon in a mortar in a ratio of 2:1 and grind thoroughly until a fine powder is formed. Add an appropriate amount of solvent to the powder and stir to form a uniformly dispersed solution. Transfer the mixed solution to a sealed reaction vessel and place it in an oven to heat to 120°C and react for 2 hours.

[0051] S2. After the reaction is complete, allow the reactor to cool naturally to room temperature, then add a measured amount of manganese dioxide to the solution inside the reactor and stir thoroughly.

[0052] S3. Centrifuge the obtained mixed slurry to collect the solid product. Wash the solid product repeatedly with deionized water to remove impurities. Freeze-dry the washed solid product to finally obtain the highly conductive manganese-iodine composite material.

[0053] S4. Mix the highly conductive manganese-iodine composite material, conductive agent (carbon nanotubes), and binder (polyvinylidene fluoride, PVDF) in a mass ratio of 8:1:1, add N-methylpyrrolidone (NMP), grind and mix well, then coat the mixture onto the current collector of carbon cloth and dry it at 60°C for 12 hours to obtain the manganese-iodine cathode material (MnO2-I).

[0054] Example 2

[0055] S1. Place ammonium iodide and activated carbon in a mortar in a 1:1 ratio and grind thoroughly until a fine powder is formed. Add an appropriate amount of solvent to the powder and stir to form a uniformly dispersed solution. Transfer the mixed solution to a sealed reaction vessel and place it in an oven to heat to 120°C and react for 4 hours.

[0056] S2. After the reaction is complete, allow the reactor to cool naturally to room temperature, then add a measured amount of manganese dioxide to the solution inside the reactor and stir thoroughly.

[0057] S3. Centrifuge the obtained mixed slurry to collect the solid product. Wash the solid product repeatedly with deionized water to remove impurities. Freeze-dry the washed solid product to finally obtain the highly conductive manganese-iodine composite material.

[0058] S4. Mix the highly conductive manganese-iodine composite material, conductive agent (carbon nanotubes), and binder (carboxymethyl cellulose, CMC) in a mass ratio of 8:1:1, add N-methylpyrrolidone (NMP), grind and mix well, then coat the mixture onto the current collector of carbon cloth and dry it at 60°C for 12 hours to obtain the manganese-iodine cathode material (MnO2-I).

[0059] Example 3

[0060] S1. Place iodine and activated carbon in a mortar in a 1:1 ratio and grind thoroughly until a fine powder is formed. Add an appropriate amount of solvent to the powder and stir to form a uniformly dispersed solution. Transfer the mixed solution to a sealed reaction vessel and place it in an oven at 120°C for 4 hours.

[0061] S2. After the reaction is complete, allow the reactor to cool naturally to room temperature, then add a measured amount of manganese dioxide to the solution inside the reactor and stir thoroughly.

[0062] S3. Centrifuge the obtained mixed slurry to collect the solid product. Wash the solid product repeatedly with deionized water to remove impurities. Freeze-dry the washed solid product to finally obtain the highly conductive manganese-iodine composite material.

[0063] S4. Mix the highly conductive manganese-iodine composite material, conductive agent (YP-80F), and binder (carboxymethyl cellulose, CMC) in a mass ratio of 8:1:1, add N-methylpyrrolidone (NMP), grind and mix well, then coat the mixture onto the current collector of carbon cloth and dry it at 60°C for 12 hours to obtain the manganese-iodine cathode material (MnO2-I).

[0064] Example 4

[0065] S1. Place iodine and activated carbon in a mortar in a 1:1 ratio and grind thoroughly until a fine powder is formed. Add an appropriate amount of solvent to the powder and stir to form a uniformly dispersed solution. Transfer the mixed solution to a sealed reaction vessel and place it in an oven at 120°C for 4 hours.

[0066] S2. After the reaction is complete, allow the reactor to cool naturally to room temperature, then add a measured amount of manganese trioxide to the solution in the reactor and stir thoroughly.

[0067] S3. Centrifuge the obtained mixed slurry to collect the solid product. Wash the solid product repeatedly with deionized water to remove impurities. Freeze-dry the washed solid product to finally obtain the highly conductive manganese-iodine composite material.

[0068] S4. Mix the highly conductive manganese-iodine composite material, conductive agent (acetylene black), and binder (polytetrafluoroethylene, PTFE) in a mass ratio of 8:1:1, add N-methylpyrrolidone (NMP), grind and mix well, then coat the mixture onto the current collector of carbon cloth and dry it at 60°C for 12 hours to obtain the manganese-iodine cathode material (MnO2-I).

[0069] Comparative Example 1

[0070] Manganese dioxide, conductive agent, and binder (polyvinylidene fluoride, PVDF) were added to NMP at a mass ratio of 7:2:1, ground and mixed, then coated onto carbon cloth and dried at 80°C for 24 hours to obtain manganese dioxide cathode material.

[0071] Material characterization and performance testing:

[0072] Scanning electron microscopy tests were performed on the cathode materials provided in Examples 1 to 4 and Comparative Example 1. Since the results are similar, the test results of Example 1 will be used as an example for illustration below.

[0073] Figure 1SEM and EDS of the manganese-iodine cathode material provided in Example 1 are shown. This cathode material is a conductive network that supports the overall structure, formed by unique nano-flower-like manganese dioxide, bulk activated carbon, and linear carbon nanotubes. EDS analysis confirmed the uniform distribution of manganese dioxide, iodine, and carbon elements.

[0074] Figure 2 The I3d XPS spectra of the cathode materials of Example 1 and Comparative Example 1 are shown. The MnO2-I composite material exhibits obvious double peaks of I3d5 / 2 and I3d3 / 2 at binding energies of 620.5 eV and 632.5 eV. This characteristic signal confirms that iodine has been successfully introduced into the material system.

[0075] Figure 3 As Example 1, Comparative Example 1 provides cyclic voltammetry curves of the cathode material. The results show that the redox peak potential difference of the sample with iodine introduced is significantly reduced, indicating that the incorporation of iodine effectively reduces the overpotential of the electrode reaction and promotes the electrochemical conversion kinetics.

[0076] Figure 4 As Example 1 of this application, the cathode material provided in Comparative Example 1 is at 0.5A g. -1 The charge-discharge curves at current density show that the MnO2-I cathode material exhibits a clear charging plateau at 1.4V and 1.75V, while the specific capacity is significantly increased to 330mAh g. -1 This confirms that the introduction of iodine effectively promotes the electrochemical conversion of the material and improves the reversibility of the reaction.

[0077] Figure 6 This is Example 1 of this application, and the constant current intermittent titration (GITT) curve of the cathode material provided in Comparative Example 1.

[0078] Figure 7 This is Example 1 of this application, showing the ion diffusion coefficient of the cathode material provided in Comparative Example 1 at different potentials.

[0079] Figure 5 As Example 1 of this application, the electrochemical impedance spectroscopy of the cathode material provided in Comparative Example 1 under fully discharged state shows that the charge transfer resistance of MnO2-I is significantly reduced to 20 ohms, which is much lower than the 1000 ohms of MnO2. This indicates that the introduction of iodine not only greatly improves the electronic conductivity of the material, but also effectively reduces the charge transfer resistance at the electrode interface, significantly improves the reaction kinetics and suppresses the occurrence of side reactions.

[0080] Figure 6Example 1 of this application compares the galvanostatic intermittent titration (GITT) curves of the cathode material provided in Comparative Example 1. The results show that MnO2-I exhibits a stable relaxation time, which confirms that the material has excellent capacity retention and can effectively suppress rapid self-discharge in a short period of time, demonstrating the stability of the material. Figure 7 This is Example 1 of the present application, comparing the ion diffusion coefficients of the cathode material provided in Comparative Example 1 at different potentials. It was found that MnO2-I exhibited a higher ion diffusion rate across all test potential ranges, with a diffusion coefficient reaching 1.0 × 10⁻⁶ at an operating potential of 1.0 V. -9 cm² / s, compared to MnO2 material (1.0×10⁻⁶ cm² / s). -11 This represents an improvement of nearly two orders of magnitude in cm² / s, a result consistent with... Figure 6 The excellent electrochemical performance observed in the samples corroborates each other, fully demonstrating the significant effect of iodine modification on improving the ion transport kinetics of the materials.

[0081] The cathode materials provided in Examples 1 to 4 were subjected to long charge-discharge cycle tests. Since the results are similar, the test results of Example 1 will be used as an example for illustration below. Figure 8 The cathode materials provided in Example 1 and Comparative Example 1 are used as cathodes in zinc-ion batteries at 500 mA g. 1 Long-cycle charge-discharge conditions at current density. (From...) Figure 8 It can be seen that at a current density of 1.0 A g 1 Under these conditions, after 2000 charge-discharge cycles, it can be clearly observed that the modified MnO2-I cathode material exhibits near-perfect electrochemical stability, with its capacity retention rate consistently maintained at 100% of the initial level, and the discharge specific capacity stably maintained at 318 mAh g⁻¹. - The high value¹ fully demonstrates the material's excellent structural stability and cycle durability. The unmodified MnO2 cathode material showed significantly inferior performance under the same testing conditions; after 2000 cycles, its capacity retention decreased to 60% of its initial value, and its discharge specific capacity dropped drastically to 90 mAh g⁻¹. - ¹.

[0082] Charge-discharge tests were conducted on the cathode materials provided in Examples 1 to 4. Since the results are similar, the following description uses only the test results of Example 4 as an example. Figure 9 The results of rate performance tests of the cathode material provided in Example 4 at different current densities are shown. The constant current charge and discharge used current densities of 0.5, 1, 1.5, 2, 3, 5, and 10 A g, respectively. 1The cathode material of Example 1 (illustrated as MnO2-I) was used at concentrations of 0.5, 1, 1.5, 2, 3, 5, and 10 Å g. 1 The average discharge capacities at different times were 310.5, 271.9, 242.0, 231.6, 195.7, 165.5, and 133.2 mAh g, respectively. - ¹. It is worth noting that even at 10 Ag - ¹ Even at ultra-high current densities, this material can still maintain 133.2 mAh g⁻¹ - The MnO2-I cathode exhibits impressive capacity, demonstrating excellent high-current tolerance and stable capacity retention. In contrast, unmodified MnO2 cathode materials show significant performance disadvantages under the same testing conditions, especially under high current density conditions, where their capacity exhibits a rapid decay trend. This significant performance difference is mainly attributed to the increased interfacial impedance caused by byproducts generated by MnO2 during discharge, leading to severe polarization and irreversible capacity loss. The superior rate performance of MnO2-I materials fully demonstrates the significant effect of the iodine modification strategy in suppressing side reactions and reducing interfacial impedance.

[0083] Figure 10 11 is the positive electrode material of Examples 1-4, used as a zinc ion positive electrode material in 5000 mA g. -1 Charge-discharge cycle diagrams at high current densities and charge-discharge curves with different numbers of cycles. At 5000 mA g... - ¹ Under ultra-high current density testing conditions, the MnO2-I series materials exhibit remarkable cycling stability: their initial discharge specific capacity is 150 mAh g⁻¹. - ¹, It still maintains 80 mAh g after 60,000 ultra-long cycles. - ¹Reversible capacity. This superior performance significantly outperforms that of unmodified MnO2 materials (initial capacity 100 mAh g⁻¹). - ¹, Only 25 mAh g remained after cycling. - ¹) The introduction of iodine significantly enhances material properties through multiple synergistic mechanisms. On the one hand, the stable chemical bonds formed between iodine and manganese dioxide construct a three-dimensional conductive network, greatly improving electron transport efficiency. On the other hand, the synergistic reaction mechanism of iodine and manganese dioxide not only promotes reversible ion insertion / extraction reactions but also effectively suppresses side reactions by regulating the interfacial electrochemical environment. This unique synergistic mechanism achieves simultaneous optimization of electron conduction and ion transport, lowers the reaction activation barrier, and thus significantly improves electrode reaction kinetics.

Claims

1. A zinc-ion battery cathode material, characterized in that, The positive electrode material is a manganese-iodine composite material, and the manganese-iodine composite material comprises iodide, conductive agent and manganese oxide; The mass ratio of the iodide and the manganese oxide is (0.1-0.5):1; The manganese oxide is one or more of manganese dioxide, dimanganese trioxide or trimanganese tetraoxide; The iodide is one or more of zinc iodide, potassium iodide, elemental iodine and ammonium iodide; The preparation method of the manganese-iodine composite material comprises the following steps: After the iodide and the conductive agent are uniformly ground, the iodide and the conductive agent are added into a solvent, and then transferred to a reaction kettle after being fully stirred and heated to 120 DEG C for two hours; After cooling, the manganese oxide is added into the solution and fully stirred and mixed; After the reaction is completed, solid-liquid separation is performed, and freeze-drying is performed to obtain the manganese-iodine composite material.

2. A method of preparing a zinc-ion battery cathode material layer, characterized in that, The method comprises the following steps: the manganese-iodine composite material, the conductive agent and the binder are added into a solvent according to a mass ratio of (7-8):(2-1):1, and then uniformly ground, coated on a current collector, dried, and a positive electrode material layer is obtained.

3. A zinc-ion battery positive electrode sheet, characterized by, The positive electrode sheet comprises a positive electrode material layer, and the positive electrode material layer comprises the manganese-iodine composite material or the positive electrode material layer prepared by the preparation method.

4. A zinc-ion battery, characterized in that, The battery comprises the positive electrode sheet.

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