Manganese dioxide-manganese phosphide heterojunction material for zinc ion battery and preparation method thereof

Abstract

The invention relates to the field of zinc ion batteries, in particular to a zinc ion battery manganese dioxide-manganese phosphide heterojunction material and a preparation method thereof.The preparation method comprises the steps that potassium peroxydisulfate, potassium sulfate and divalent manganese salt are dissolved in deionized water and added into a concentrated sulfuric acid solution, and a first reaction solution is obtained; keeping the temperature at 140 DEG C for 12-24 hours to obtain a second reaction solution; washing and drying to obtain first powder; adding deionized water, stirring and uniformly dispersing to obtain a third reaction solution; performing ultrasonic dispersion on the graphene slurry in ethanol to obtain a fourth reaction solution; uniformly stirring the third reaction solution and the fourth reaction solution, and washing and drying a second solid precipitate obtained by filtering to obtain second powder; carrying out heat preservation on the second powder and hypophosphite in a nitrogen atmosphere at 450 DEG C for 2-4 hours, and washing and drying an obtained third solid precipitate; the manganese dioxide-manganese phosphide heterojunction material for the zinc ion battery can improve the electron transmission efficiency of manganese dioxide.

Description

Technical Field

[0001] The present application relates to the field of zinc ion batteries, and in particular to a zinc ion battery manganese dioxide-manganese phosphide heterojunction material and a preparation method thereof. Background Art

[0002] In the related technologies, aqueous zinc-ion batteries, as a new type of safe aqueous battery, use compounds such as manganese, vanadium, and Prussian blue as positive electrodes. They have the advantages of being non-toxic and low-cost, and have potential application prospects in the future in the fields of new energy vehicles and smart wearables. However, most of these positive electrode materials show poor electrochemical properties and low coulombic efficiency. One of the reasons is that Zn 2+ There are strong electrostatic interactions with the host material and Zn 2+ The diffusion distance is long, resulting in Zn 2+ The diffusion rate is slow, and it is difficult to improve the electrochemical performance. Since the electron transfer rate of the manganese dioxide positive electrode is low, the diffusion rate of the hydrated ions is limited, which reduces the overall performance of the electrode. Summary of the invention

[0003] The present application aims to solve at least one of the technical problems existing in the prior art. To this end, the present application proposes a zinc ion battery manganese dioxide-manganese phosphide heterojunction material and a preparation method thereof, which can improve the electron transmission efficiency of manganese dioxide.

[0004] According to the preparation method of the zinc ion battery manganese dioxide-manganese phosphide heterojunction material of the first aspect embodiment of the present application, S1: potassium persulfate, potassium sulfate and divalent manganese salt are dissolved in deionized water and added to a concentrated sulfuric acid solution to obtain a first reaction liquid; S2: the first reaction liquid is kept at 140°C for 12 to 24 hours to obtain a second reaction liquid; S3: the second reaction liquid is naturally cooled to room temperature, filtered, and the obtained first solid precipitate is washed and dried to obtain a first powder; S4: the first powder is added to deionized water and stirred and dispersed uniformly to obtain a third reaction liquid; S5: the graphene slurry is ultrasonically dispersed in ethanol to obtain a fourth reaction liquid; S6: the third reaction liquid and the fourth reaction liquid are uniformly mixed and stirred, filtered, and the filtered second solid precipitate is washed and dried to obtain a second powder; S7: the second powder and hypophosphite are kept at 450°C in a nitrogen atmosphere for 2 to 4 hours, and the obtained third solid precipitate is washed and dried to obtain a zinc ion battery manganese dioxide-manganese phosphide heterojunction material.

[0005] The zinc ion battery manganese dioxide-manganese phosphide heterojunction material according to the embodiment of the present application has at least the following beneficial effects: Because the zinc-ion battery manganese dioxide-manganese phosphide heterojunction material has a microspherical nanostructure and is coated with graphene material, it has a large specific surface area. Nanomaterials with high specific surface area will have more active sites, which is conducive to the improvement of its catalytic activity; in addition, its surface energy will be higher, which is conducive to the adsorption and activation of reaction molecules. Zinc phosphate itself is a zinc ion conductor and a good choice for semiconductor insertion host. The diffusion rate of zinc-ion battery manganese dioxide-manganese phosphide heterojunction material in the heterojunction anode is significantly enhanced. The introduction of zinc phosphate can accelerate the charge transfer of the active material manganese dioxide. Therefore, the zinc-ion battery manganese dioxide-manganese phosphide heterojunction material has more superior electrochemical properties.

[0006] According to some embodiments of the present application, the divalent manganese salt is at least one of manganese sulfate, manganese dichloride, manganese dibromide or manganese nitrate.

[0007] According to some embodiments of the present application, the molar ratio of potassium disulfate, potassium sulfate and divalent manganese salt is 1:1:1.

[0008] According to some embodiments of the present application, the hypophosphite is at least one of ammonium hypophosphite and manganese hypophosphite.

[0009] According to some embodiments of the present application, the molar ratio of hypophosphite to divalent manganese salt is 1:10.

[0010] According to some embodiments of the present application, the mass percentage of the concentrated sulfuric acid solution is 98%.

[0011] According to some embodiments of the present application, the mass ratio of concentrated sulfuric acid solution to divalent manganese salt is 1:1.

[0012] According to some embodiments of the present application, in S2, the first reaction liquid is transferred to a hydrothermal reactor with a polytetrafluoroethylene lining for insulation.

[0013] According to some embodiments of the present application, the washing in S3 and S7 is washing with deionized water and anhydrous ethanol alternately for 3 times, and the drying is drying in an oven at 60° C. for 12 hours.

[0014] According to some embodiments of the present application, a zinc ion battery manganese dioxide-manganese phosphide heterojunction material prepared by the above-mentioned zinc ion battery manganese dioxide-manganese phosphide heterojunction material preparation method is proposed.

[0015] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present application is further described below in conjunction with the accompanying drawings and embodiments, wherein: Figure 1 A schematic diagram of a process for preparing a manganese dioxide-manganese phosphide heterojunction material for a zinc ion battery according to an embodiment of the present application; Figure 2 This is a schematic diagram of an emission scanning electron microscope (SEM) of a manganese dioxide-manganese phosphide heterojunction material for a zinc ion battery according to an embodiment of the present application; Figure 3 A schematic diagram of the cycle performance and coulombic efficiency of a battery assembled with a manganese dioxide-manganese phosphide heterojunction material as the positive electrode material for a zinc ion battery prepared in an embodiment of the present application;

[0017] Figure 4 A schematic diagram of the charge and discharge curves of a battery assembled with the manganese dioxide-manganese phosphide heterojunction material as the positive electrode material for the zinc ion battery prepared in an embodiment of the present application. Implementation

[0018] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.

[0019] In the description of this application, "several" means more than one, "more" means more than two, "greater than", "less than", "exceed", etc. are understood to exclude the number itself, and "above", "below", "within", etc. are understood to include the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0020] In the description of the present application, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0021] The following is a further description of the present invention, rather than a limitation of the present invention. Example

[0022] like Figure 1 As shown, this embodiment prepares a zinc ion battery manganese dioxide-manganese phosphide heterojunction material, and the specific process is: (1) 4 mmol each of potassium persulfate, potassium sulfate and manganese sulfate monohydrate were added to 30 ml of deionized water and placed in a magnetic stirrer and stirred evenly.

[0023] (2) Add 1 ml of 98% by mass sulfuric acid, and place the mixture in a magnetic stirrer and stir evenly until the solid is completely dissolved. The resulting solution is the first reaction solution.

[0024] (3) The first reaction liquid is placed in a container with a polytetrafluoroethylene liner, and then placed in a high-pressure reactor, set at 140° C., and kept warm for 12 hours. The resulting solution is the second reaction liquid.

[0025] (4) The second reaction solution is cooled naturally to room temperature, and the obtained solid precipitate is washed by centrifugation, washed alternately with deionized water and anhydrous ethanol for 3 times, and then placed in an oven at 60° C. and dried for 12 h to obtain a powder having a manganese dioxide microspherical nanostructure, i.e., the first powder.

[0026] (5) The first powder is added to 50 ml of deionized water and the mixture is placed in a magnetic stirrer to uniformly stir the resulting dispersion, i.e., the third reaction solution.

[0027] (6) 0.05 g of the graphene slurry was ultrasonically dispersed in 30 ml of ethanol for 1 h to destroy the restacking of the graphene, thereby obtaining a dispersion containing graphene, i.e., the fourth reaction solution.

[0028] (7) The third reaction liquid and the fourth reaction liquid are mixed at room temperature, placed in a magnetic stirrer for uniform stirring, washed alternately with deionized water and anhydrous ethanol for 3 times, and then placed in an oven at 60° C. for 12 h to obtain a powder having a graphene-coated manganese dioxide microspherical nanostructure, i.e., the second powder.

[0029] (8) The second powder and 8 mmol of ammonium hypophosphite were added into a high-pressure reactor with a nitrogen atmosphere, the temperature was set to 450° C., and the temperature was kept for 2 h to obtain a zinc ion battery manganese dioxide-manganese phosphide heterojunction material. Example

[0030] This embodiment prepares a zinc ion battery manganese dioxide-manganese phosphide heterojunction material, and the specific process is as follows: (1) Add 6 mmol of potassium persulfate, potassium sulfate and manganese dichloride to 45 ml of deionized water and place in a magnetic stirrer and stir evenly.

[0031] (2) Add 1.5 ml of 98% by mass sulfuric acid, and place the mixture in a magnetic stirrer and stir evenly until the solid is completely dissolved. The resulting solution is the first reaction solution.

[0032] (3) The first reaction liquid was placed in a container with a polytetrafluoroethylene liner, and then placed in a high-pressure reactor, set at 140° C., and kept warm for 16 hours. The obtained solution was the second reaction liquid.

[0033] (4) The second reaction solution is cooled naturally to room temperature, and the obtained solid precipitate is washed by centrifugation, washed alternately with deionized water and anhydrous ethanol for 3 times, and then placed in an oven at 60° C. and dried for 12 h to obtain a powder having a manganese dioxide microspherical nanostructure, i.e., the first powder.

[0034] (5) The first powder is added to 50 ml of deionized water and the mixture is placed in a magnetic stirrer to uniformly stir the resulting dispersion, i.e., the third reaction solution.

[0035] (6) 0.075 g of the graphene slurry was ultrasonically dispersed in 30 ml of ethanol for 1 h to destroy the restacking of the graphene, thereby obtaining a dispersion containing graphene, i.e., the fourth reaction solution.

[0036] (7) The third reaction liquid and the fourth reaction liquid are mixed at room temperature, placed in a magnetic stirrer for uniform stirring, washed alternately with deionized water and anhydrous ethanol for 3 times, and then placed in an oven at 60° C. for 12 h to obtain a powder having a graphene-coated manganese dioxide microspherical nanostructure, i.e., the second powder.

[0037] (8) The second powder and 12 mmol of manganese hypophosphite were added into a high-pressure reactor with a nitrogen atmosphere, the temperature was set to 450° C., and the temperature was kept for 2 h to obtain a manganese dioxide-manganese phosphide heterojunction material for a zinc ion battery. Example

[0038] This embodiment prepares a zinc ion battery manganese dioxide-manganese phosphide heterojunction material, and the specific process is as follows: (1) Add 8 mmol of potassium persulfate, potassium sulfate and manganese dibromide to 60 ml of deionized water and place in a magnetic stirrer and stir evenly.

[0039] (2) Add 2 ml of 98% by mass sulfuric acid, and place the mixture in a magnetic stirrer and stir evenly until the solid is completely dissolved. The resulting solution is the first reaction solution.

[0040] (3) The first reaction liquid is placed in a container with a polytetrafluoroethylene liner, and then placed in a high-pressure reactor, set at 140° C., and kept warm for 18 hours. The resulting solution is the second reaction liquid.

[0041] (4) The second reaction solution is cooled naturally to room temperature, and the obtained solid precipitate is washed by centrifugation, washed alternately with deionized water and anhydrous ethanol for 3 times, and then placed in an oven at 60° C. and dried for 12 h to obtain a powder having a manganese dioxide microspherical nanostructure, i.e., the first powder.

[0042] (5) The first powder is added to 50 ml of deionized water and the mixture is placed in a magnetic stirrer to uniformly stir the resulting dispersion, i.e., the third reaction solution.

[0043] (6) 0.1 g of the graphene slurry was ultrasonically dispersed in 30 ml of ethanol for 1 h to destroy the restacking of the graphene, thereby obtaining a dispersion containing graphene, i.e., the fourth reaction solution.

[0044] (7) The third reaction liquid and the fourth reaction liquid are mixed at room temperature, placed in a magnetic stirrer for uniform stirring, washed alternately with deionized water and anhydrous ethanol for 3 times, and then placed in an oven at 60° C. for 12 h to obtain a powder having a graphene-coated manganese dioxide microspherical nanostructure, i.e., the second powder.

[0045] (8) The second powder and 16 mmol of manganese hypophosphite were added into a high-pressure reactor with a nitrogen atmosphere, the temperature was set to 450° C., and the temperature was kept for 3 hours to obtain a zinc ion battery manganese dioxide-manganese phosphide heterojunction material. Example

[0046] This embodiment prepares a zinc ion battery manganese dioxide-manganese phosphide heterojunction material, and the specific process is as follows: (1) Add 10 mmol each of potassium persulfate, potassium sulfate and manganese nitrate to 75 ml of deionized water and place in a magnetic stirrer and stir evenly.

[0047] (2) Add 2.5 ml of 98% by mass sulfuric acid, and place the mixture in a magnetic stirrer and stir evenly until the solid is completely dissolved. The resulting solution is the first reaction solution.

[0048] (3) The first reaction liquid is placed in a container with a polytetrafluoroethylene liner, and then placed in a high-pressure reactor, set at 140° C., and kept warm for 20 hours. The resulting solution is the second reaction liquid.

[0049] (4) The second reaction solution is cooled naturally to room temperature, and the obtained solid precipitate is washed by centrifugation, washed alternately with deionized water and anhydrous ethanol for 3 times, and then placed in an oven at 60° C. and dried for 12 h to obtain a powder having a manganese dioxide microspherical nanostructure, i.e., the first powder.

[0050] (5) The first powder is added to 50 ml of deionized water and the mixture is placed in a magnetic stirrer to uniformly stir the resulting dispersion, i.e., the third reaction solution.

[0051] (6) 0.125 g of the graphene slurry was ultrasonically dispersed in 30 ml of ethanol for 1 h to destroy the restacking of the graphene, thereby obtaining a dispersion containing graphene, i.e., the fourth reaction solution.

[0052] (7) The third reaction liquid and the fourth reaction liquid are mixed at room temperature, placed in a magnetic stirrer for uniform stirring, washed alternately with deionized water and anhydrous ethanol for 3 times, and then placed in an oven at 60° C. for 12 h to obtain a powder having a graphene-coated manganese dioxide microspherical nanostructure, i.e., the second powder.

[0053] (8) The second powder, 10 mmol of ammonium hypophosphite, and 10 mmol of manganese hypophosphite were added into a high-pressure reactor with a nitrogen atmosphere, the temperature was set to 450° C., and the temperature was kept for 3 hours to obtain a zinc ion battery manganese dioxide-manganese phosphide heterojunction material. Example

[0054] This embodiment prepares a zinc ion battery manganese dioxide-manganese phosphide heterojunction material, and the specific process is as follows: (1) 12 mmol each of potassium persulfate and potassium sulfate, and 3 mmol each of manganese sulfate, manganese dichloride, manganese dibromide and manganese nitrate, are added to 90 ml of deionized water and placed in a magnetic stirrer and stirred evenly.

[0055] (2) Add 3 ml of 98% by mass sulfuric acid, and place the mixture in a magnetic stirrer and stir evenly until the solid is completely dissolved. The resulting solution is the first reaction solution.

[0056] (3) The first reaction liquid is placed in a container with a polytetrafluoroethylene liner, and then placed in a high-pressure reactor, set at 140° C., and kept warm for 24 hours. The resulting solution is the second reaction liquid.

[0057] (4) The second reaction solution is cooled naturally to room temperature, and the obtained solid precipitate is washed by centrifugation, washed alternately with deionized water and anhydrous ethanol for 3 times, and then placed in an oven at 60° C. and dried for 12 h to obtain a powder having a manganese dioxide microspherical nanostructure, i.e., the first powder.

[0058] (5) The first powder is added to 50 ml of deionized water and the mixture is placed in a magnetic stirrer to uniformly stir the resulting dispersion, i.e., the third reaction solution.

[0059] (6) 0.15 g of the graphene slurry was ultrasonically dispersed in 30 ml of ethanol for 1 h to destroy the restacking of the graphene, thereby obtaining a dispersion containing graphene, i.e., the fourth reaction solution.

[0060] (7) The third reaction liquid and the fourth reaction liquid are mixed at room temperature, placed in a magnetic stirrer for uniform stirring, washed alternately with deionized water and anhydrous ethanol for 3 times, and then placed in an oven at 60° C. for 12 h to obtain a powder having a graphene-coated manganese dioxide microspherical nanostructure, i.e., the second powder.

[0061] (8) The second powder, 12 mmol of ammonium hypophosphite, and 10 mmol of manganese hypophosphite were added to a high-pressure reactor with a nitrogen atmosphere, the temperature was set to 450° C., and the temperature was kept for 4 hours to obtain a zinc ion battery manganese dioxide-manganese phosphide heterojunction material.

[0062] Working principle: In concentrated sulfuric acid solution, hydrothermal reaction is adopted, and the redox reaction of potassium disulfate, potassium sulfate and divalent manganese salt is used. By controlling the reaction temperature and time, the crystal form and morphology are affected, and α-MnO2 with a nano-microsphere structure is synthesized. Then, the above product is added to the suspension of graphene oxide, filtered and dried to obtain graphene-coated α-MnO2 with a nano-microsphere structure. Due to the microspherical nanostructure, the specific surface area is large. Nanomaterials with high specific surface area will have more active sites, which is conducive to the improvement of its catalytic activity; in addition, its surface energy will be higher, which is conducive to the adsorption and activation of reaction molecules, increasing the ion transfer rate, and the graphene coating also enhances the electron transfer rate. Then, the graphene-coated α-MnO2 with a nano-microsphere structure is added to the hypophosphite powder, and the reaction is carried out in a closed container, and nitrogen is passed to prevent oxidation. The temperature and reaction time are controlled to sinter the phosphate so that the phosphate is doped into the surface of the graphene-coated α-MnO2 with a nano-microsphere structure. After the reaction is completed, the material is filtered, washed with water, and dried to obtain a zinc ion battery manganese dioxide-manganese phosphide heterojunction material. During the electrochemical reaction, manganese phosphide is hydrolyzed and reacts with zinc salts in the electrolyte to form zinc phosphate. The zinc phosphate heterojunction can provide support sites between the MnO2 structure layers, maintain the stability of the MnO2 structure, and form ion channels between MnO2 and the electrolyte, thereby increasing the reaction kinetics of zinc ions and improving the ion transfer rate. Therefore, the electrochemical performance of α-MnO2 with a heterojunction is better than that of a single material. The different band structures of the two semiconductors produce BEFS, which realizes charge redistribution and balances the Fermi level at the heterojunction interface. Because zinc phosphate itself is a zinc ion conductor, the diffusion rate of zinc ions in the heterojunction anode is significantly enhanced, which not only accelerates the charge transfer of the active material manganese dioxide, but also improves the structural collapse of the active material MnO2 in the cycle test. Therefore, compared with pure manganese dioxide and zinc ion battery manganese dioxide-manganese phosphide heterojunction materials, this composite material has superior electrochemical performance. The obtained zinc ion battery manganese dioxide-manganese phosphide heterojunction material was tested, and the results are as follows Figures 2 to 4 shown.

[0063] The prepared zinc ion battery manganese dioxide-manganese phosphide heterojunction material was mixed with carbon black conductive agent and binder (PVDF) in a mass ratio of 92:5:3, and N-methyl-2-pyrrolidone (NMP) was used as solvent. The above materials were stirred into a slurry and coated on titanium foil, and then dried in a 130°C drying oven for 24 hours to obtain a pole piece. The above-prepared pole piece was used as the positive electrode, the copper foil coated with zinc powder was used as the negative electrode, the sulfonated PP film was used as the diaphragm, and 2 mol / L ZnSO4 was used as the electrolyte. The CR2025 button cell was assembled in an air atmosphere to test the electrochemical performance of the material. Using the LAND battery test system, the battery was activated at 1-1.9V, 0.05C, and then cycled at 1-1.9V, 1C, and 5C.

[0064] The obtained zinc ion battery manganese dioxide-manganese phosphide heterojunction material was made into a working electrode according to the method provided by the present invention and the corresponding performance tests were carried out. The results are shown in Table 1.

[0065] Example <![CDATA[Initial discharge specific capacity / mAh g -1 > <![CDATA[100th discharge specific capacity / mAh g -1 > <![CDATA[200th discharge specific capacity / mAh g -1 > <![CDATA[300th discharge specific capacity / mAh g -1 > <![CDATA[The specific discharge capacity at the 500th cycle / mAh g -1 > <![CDATA[1000th discharge specific capacity / mAh g -1 > <![CDATA[The specific discharge capacity at the 2000th cycle / mAhg -1 > Example 1 199 215 237 216 205 201 195 Example 2 201 219 229 215 201 205 193 Example 3 199 218 235 211 204 198 195 Example 4 200 215 236 218 204 201 199 Example 5 198 223 241 214 203 201 197 Table 1 shows the cycle performance of the batteries in different embodiments, indicating that the manganese dioxide-manganese phosphide heterojunction material of the zinc ion battery has a long cycle stability when used for the positive electrode of the zinc ion battery.

[0066] The embodiments of the present application are described in detail above in conjunction with the accompanying drawings, but the present application is not limited to the above embodiments. Various changes can be made within the knowledge of ordinary technicians in the relevant technical field without departing from the purpose of the present application. In addition, the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0067] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0068] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a manganese dioxide-manganese phosphide heterojunction material for a zinc ion battery, characterized in that: include: S1: dissolving potassium persulfate, potassium sulfate and divalent manganese salt in deionized water, and adding the mixture into a concentrated sulfuric acid solution to obtain a first reaction solution; S2: keeping the first reaction solution at 140° C. for 12 to 24 hours to obtain a second reaction solution; S3: naturally cooling the second reaction solution to room temperature, filtering it, and washing and drying the obtained first solid precipitate to obtain a first powder; S4: adding the first powder into deionized water and stirring to disperse evenly to obtain a third reaction solution; S5: ultrasonically dispersing the graphene slurry in ethanol to obtain a fourth reaction solution; S6: uniformly mixing and stirring the third reaction liquid and the fourth reaction liquid, filtering, and washing and drying the obtained second solid precipitate to obtain a second powder; S7: The second powder and hypophosphite are placed in a nitrogen atmosphere at 450° C. for 2 to 4 hours, and the obtained third solid precipitate is washed and dried to obtain the zinc ion battery manganese dioxide-manganese phosphide heterojunction material.

2. The method for preparing a zinc ion battery manganese dioxide-manganese phosphide heterojunction material according to claim 1, characterized in that: The divalent manganese salt is at least one of manganese sulfate, manganese dichloride, manganese dibromide or manganese nitrate.

3. The method for preparing a zinc ion battery manganese dioxide-manganese phosphide heterojunction material according to claim 1, characterized in that: The molar ratio of the potassium disulfate, the potassium sulfate and the divalent manganese salt is 1:1:

1.

4. The method for preparing a zinc ion battery manganese dioxide-manganese phosphide heterojunction material according to claim 1, characterized in that: The hypophosphite is at least one of ammonium hypophosphite and manganese hypophosphite.

5. The method for preparing a zinc ion battery manganese dioxide-manganese phosphide heterojunction material according to claim 1, characterized in that: The molar ratio of the hypophosphite to the divalent manganese salt is 1:

10.

6. The method for preparing a zinc ion battery manganese dioxide-manganese phosphide heterojunction material according to claim 1, characterized in that: The mass percentage of the concentrated sulfuric acid solution is 98%.

7. The method for preparing a zinc ion battery manganese dioxide-manganese phosphide heterojunction material according to claim 6, characterized in that: The mass ratio of the concentrated sulfuric acid solution to the divalent manganese salt is 1:

1.

8. The method for preparing a zinc ion battery manganese dioxide-manganese phosphide heterojunction material according to claim 1, characterized in that: In S2, the first reaction liquid is transferred to a hydrothermal reactor with a polytetrafluoroethylene lining for heat preservation.

9. The method for preparing a zinc ion battery manganese dioxide-manganese phosphide heterojunction material according to claim 1, characterized in that: The washing in S3 and S7 is washing with deionized water and anhydrous ethanol alternately for 3 times, and the drying is drying in an oven at 60° C. for 12 hours.

10. A zinc ion battery manganese dioxide-manganese phosphide heterojunction material prepared according to the preparation method according to any one of claims 1 to 9.

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