Composite positive electrode material and preparation method and application thereof

Abstract

The application provides a composite positive electrode material and a preparation method and application thereof, and the method comprises the following steps: S01, annealing treatment is performed on citrate; a preconfigured sulfuric acid solution is mixed with black solid material for stirring; a reagent containing a vanadium source and an ammonium source is dissolved in deionized water together with porous carbon material and oxalic acid dihydrate; the mixed solution is transferred to a reaction kettle for hydrothermal reaction; the porous carbon coupled composite material and an aqueous solution of a reducing agent are sequentially mixed, centrifuged, washed and dried; the porous carbon and oxygen defect jointly acting composite material and a PVDF binder are mixed, and then added to N-methyl pyrrolidone solvent for stirring to form slurry, and the slurry is coated on the surface of a metal foil current collector, and a modified battery positive electrode sheet is obtained after drying. The composite positive electrode material prepared by the application has high discharge specific capacity, large current rate bearing capacity and excellent cycle stability when applied to a water-based zinc ion battery.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of positive electrode material preparation, and in particular to a composite positive electrode material and a preparation method and application thereof. BACKGROUND

[0002] Nowadays, the increasing demand for clean energy has driven extensive exploration of renewable energy such as solar energy, wind energy and tidal energy. However, such energy generally has problems such as intermittency, strong volatility and difficulty in regulation, and it is difficult to meet the demand for continuous and stable energy supply. Therefore, developing efficient, stable and sustainable energy storage systems has become an urgent task in the global energy field. Battery technology realizes the storage and release of electric energy through electrochemical energy conversion, has advantages such as long cycle life, high energy efficiency and small pollution, and provides a key solution for large-scale utilization of intermittent renewable energy. Among various battery technologies, lithium-ion batteries have been widely used in many energy storage application scenarios due to their high energy density and long cycle life. However, its further development still faces problems such as scarcity of lithium metal resources and safety hazards of organic electrolyte systems. In recent years, aqueous zinc-ion batteries (AZIBs) have attracted widespread attention due to their high safety, low cost and environmental friendliness. Compared with other negative electrode materials, zinc metal negative electrode shows a high theoretical capacity (820 mAh g -1 and 5855 mAh cm -3 ) and a low electrochemical potential (-0.76 V relative to the standard hydrogen electrode). In addition, the research on the matching electrolyte system is constantly advancing, which further promotes the development and optimization of AZIBs technology. Due to these characteristics, AZIBs are a strong competitor in the competition of the next generation of secondary batteries and have good application prospects in future energy storage systems. However, the slow dissolution and diffusion rate of the positive electrode material compatible with AZIBs has become a key bottleneck hindering the large-scale commercialization of AZIBs, thereby hindering the wide application of AZIBs. At present, the positive electrode material mainly consists of manganese-based oxides, vanadium-based oxides, prussian blue analogues and organic polymers. Among them, the vanadium-based positive electrode material of the aqueous zinc-ion battery is concerned due to its high theoretical capacity, multi-valence characteristics and resource abundance, but still faces many core problems in practical application. During the charging and discharging process, the repeated deintercalation of Zn 2+ in the crystal structure easily causes the structure collapse and irreversible phase transition of the V-O layer, leading to rapid capacity decay; and the vanadium-based material is prone to dissolution in the acidic electrolyte, which will cause irreversible loss of the vanadium-based active material. The existence of these problems makes the vanadium-based positive electrode material have poor structural stability. Zn 2+The strong electrostatic interaction between the vanadium-based material lattice will lead to high ion diffusion energy barrier and low migration rate, which will affect the rate performance. This problem limits ion conduction and aggravates the kinetic barrier, and the reaction kinetics is slow. Researchers have developed methods such as amorphous regulation, ion pre-embedding, defect engineering and composite carbon materials to solve these problems. However, a single modification strategy cannot comprehensively cover the problems of vanadium-based materials. SUMMARY

[0003] The purpose of the present application is to provide a composite positive electrode material and its preparation method and application, aiming to solve the problem that a single modification strategy cannot comprehensively cover the problems of vanadium-based materials, so as to improve the conductivity and structural stability of the material and accelerate the diffusion kinetics of aqueous zinc ion batteries.

[0004] In a first aspect, the present application provides a preparation method of a composite positive electrode material, comprising:

[0005] Step S01, annealing citrate to obtain black solid material;

[0006] Step S02, mixing and stirring the pre-configured sulfuric acid solution with the black solid material to separate out black powder and wash to neutral, and then drying to obtain a porous carbon material;

[0007] Step S03, dissolving the reagent containing vanadium source and ammonium source, the porous carbon material and oxalic acid dihydrate in deionized water, and then obtaining a mixed solution after sufficient stirring;

[0008] Step S04, transferring the mixed solution to a reaction kettle for hydrothermal reaction to obtain a porous carbon-coupled NH4V4O 10 / C composite material;

[0009] Step S05, mixing and stirring the porous carbon-coupled NH4V4O 10 / C composite material and the aqueous reducing agent solution in sequence, centrifugal washing and drying to obtain a NVO / C composite material with the combined action of porous carbon and oxygen defects;

[0010] Step S06, mixing the NVO / C composite material with the combined action of porous carbon and oxygen defects and a PVDF binder, and then adding to an N-methyl pyrrolidone solvent to stir uniformly to form a slurry, and then coating the slurry on the surface of a metal foil current collector to obtain a modified battery positive electrode sheet after drying.

[0011] Further, in step S01, the citrate is potassium citrate or sodium citrate dihydrate;

[0012] The heating rate during the annealing process is 2-5 °C / min, the annealing temperature is 700-1000 °C, and the annealing time is 1-3 h.

[0013] Further, in step S02, the concentration of the pre-prepared sulfuric acid solution is 0.1-1.5 mmol / mL; the mixing and stirring time is 1-5 h; deionized water is used for washing, and the washing frequency is 3-5 times; the drying temperature is 40-120 °C, and the drying time is 10-24 h.

[0014] Further, in step S03, the reagent containing a vanadium source and an ammonium source is at least one of ammonium metavanadate, ammonium vanadate pentahydrate or ammonium peroxovanadate, the mass ratio of the reagent containing a vanadium source and an ammonium source to the porous carbon material is 5:1-60:1, and the mass ratio of the reagent containing a vanadium source and an ammonium source to the oxalic acid dihydrate is 0.8:1-1.6:1.

[0015] Further, in step S04, the hydrothermal reaction temperature is 100-200 °C, and the hydrothermal reaction time is 3-24 h.

[0016] Further, in step S05, the reducing agent is hydrazine hydrate or sodium borohydride; the mixing and stirring time is 20-60 min; the drying temperature is 60 °C, and the drying time is 12 h.

[0017] Further, in step S06, the mass ratio of the porous carbon and oxygen defect co-acting NVO / C composite material to the PVDF binder is 5:1-8:1, and the mass ratio of the PVDF binder to the N-methyl pyrrolidone solvent is 1:26-1:34.

[0018] In a second aspect, the present application provides a composite positive electrode material, which is prepared according to the preparation method of the composite positive electrode material.

[0019] In a third aspect, the present application provides an application of the composite positive electrode material in a water-based zinc ion battery, which includes:

[0020] Assembling a CR2032 type button cell in room temperature air, the positive electrode is the composite positive electrode material, the negative electrode is metal zinc, the separator is glass fiber, and the electrolyte is zinc trifluoromethane sulfonate.

[0021] Compared with the prior art, the present application has the following advantages:

[0022] 1. The vanillate / carbon composite positive electrode material prepared by the present application has a nanoflower-like micro-morphology composed of nanosheets, combines the coupling of porous carbon and oxygen defects, and the synergistic effect between the two increases the specific surface area of the material to obtain more active sites, reduces the Zn 2+ adsorption energy, reduces the electrostatic interaction between Zn 2+ and the lattice, and reduces the Zn2+ Diffusion barrier enhances the structural stability of materials.

[0023] 2. The ammonium vanadate / carbon composite cathode material for aqueous zinc-ion batteries prepared in this invention exhibits excellent performance when assembled into aqueous zinc-ion batteries, such as at 0.2 A g. -1 and 5 A g -1 The discharge specific capacity at the rate was 431.3 mAh g. -1 and 324.0 mAh g -1 And in 5 Ag -1 The capacity retention rate is 84.4% after 1000 cycles at the specified current density.

[0024] 3. The synergistic effect of porous carbon and oxygen defects effectively improves the material's conductivity, inhibits vanadium dissolution, and enhances structural stability. Aqueous zinc-ion batteries assembled with this ammonium vanadate / carbon composite cathode material achieve performance at 5 A g. -1 Even at a current rate of 324.0 mAh g, its discharge specific capacity can still reach 324.0 mAh g. -1 It also exhibits excellent long-term cycling stability.

[0025] 4. This invention uses ammonium vanadate pentahydrate, potassium citrate, oxalic acid dihydrate, and hydrazine hydrate as raw materials, which can achieve the controllable preparation of ammonium vanadate / carbon composite cathode materials with specific compositions. The method is simple, has low production cost, and is suitable for industrial production. Attached Figure Description

[0026] Figure 1 The X-ray diffraction pattern of the ammonium vanadate / carbon composite cathode material prepared in Example 1 is shown below.

[0027] Figure 2 This is a scanning electron microscope image of the ammonium vanadate / carbon composite cathode material prepared in Example 1;

[0028] Figure 3 The X-ray photoelectron spectroscopy spectrum of the ammonium vanadate / carbon composite cathode material prepared in Example 1 is shown below.

[0029] Figure 4 The fine X-ray photoelectron spectroscopy (XPS) spectrum of the ammonium vanadate / carbon composite cathode material prepared in Example 1 is shown in the image.

[0030] Figure 5 This is a schematic diagram of the long-cycle performance of an aqueous zinc-ion battery assembled with the ammonium vanadate / carbon composite cathode material prepared in Example 1.

[0031] Figure 6A rate performance schematic diagram of a water-based zinc ion battery assembled by using the ammonium vanadate / carbon composite positive electrode material prepared in Example 1.

[0032] The following detailed description will further illustrate the present application in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0033] For the purpose, technical solutions and advantages of the embodiments of the present application to be clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application. Unless otherwise defined, the technical terms or scientific terms used herein should be understood as the usual meanings understood by those of ordinary skill in the art to which the present application belongs. The terms such as “include” and the like used herein mean that the elements or objects before the terms encompass the elements or objects listed after the terms and their equivalents, without excluding other elements or objects.

[0034] Example 1

[0035] A preparation method and application of a water-based zinc ion battery ammonium vanadate / carbon composite positive electrode material, comprising the following steps:

[0036] S1: 5 g of potassium citrate was placed in a porcelain boat and transferred to a tube furnace to be annealed at 800 °C for 1 h at a heating rate of 5 °C, to obtain a black solid material;

[0037] S2: Concentrated sulfuric acid was mixed with deionized water (concentration of 1 mmol / mL), and a clear solution was obtained after stirring for 15 min;

[0038] S3: The S1 black solid material was mixed with the S2 clear solution and stirred for 1 h, the black powder was separated and washed with deionized water for 3 times until neutral, and then dried at 80 °C for 24 h to obtain a porous carbon material;

[0039] S4: 0.64 g of ammonium vanadate pentahydrate, 0.8 g of oxalic acid dihydrate and 50 mg of porous carbon were dissolved in 80 mL of deionized water, and a mixed solution was obtained after stirring for 60 min;

[0040] S5: The mixed solution obtained in S4 was transferred to a 100 mL reaction kettle, and a porous carbon-coupled NH4V4O 10 / C material was obtained after hydrothermal reaction at 180 °C for 3 h;

[0041] S6: The 300 mg of porous carbon-coupled NH4V4O 10The porous carbon and oxygen defect co-acting NVO / C composite material was obtained by mixing and stirring 0.8 g of the / C material and 2.4 mL of a hydrazine and 108 mL of water solution for 45 min, washing 3 times by centrifugation and drying at 60 °C for 12 h.

[0042] S7: After mixing 70 mg of the porous carbon and oxygen defect co-acting NVO / C composite material and 10 mg of the PVDF binder, the mixture was added into 300 mg of N-methyl pyrrolidone solvent to form a slurry, the slurry was coated on the surface of a titanium foil current collector with a thickness of 200 μm, and a modified battery positive electrode sheet was obtained after drying at 80 °C for 12 h.

[0043] Example 2

[0044] This example is basically the same as Example 1, except that the amount of the porous carbon in step S4 is adjusted to 0.8 g, i.e. the mass ratio of the vanadium ammonium source and the porous carbon is 8:1.

[0045] Example 3

[0046] This example is basically the same as Example 1, except that the amount of the ammonium vanadate pentahydrate in step S4 is adjusted to 1 g, i.e. the mass ratio of the vanadium ammonium source and the porous carbon is 20:1.

[0047] Comparative Example 1

[0048] This comparative example is basically the same as Example 1, except that steps S1 to S4 are deleted, and the porous carbon material is prepared according to the existing patent CN109301233A, and the specific preparation process is as follows: (1) wash the lychee shell clean, take 3 g of lychee shell and 500 ml of deionized water to wash for 1 hour under the action of ultrasonic wave at room temperature, and then dry at 80 °C for 12 hours under vacuum; (2) take the dried lychee shell in step (1) and place it in a crucible, and then perform calcination using a tube furnace, with the conditions being: Ar atmosphere, 300 °C, holding for 3 hours, and a heating rate of 3 °C / min, take out the crucible, and then grind the obtained black solid into powder using a mortar; (3) add the pre-carbonized lychee shell powder obtained in step (2) and KOH according to a mass ratio of pre-carbonized lychee shell: KOH of 1:3 into 10 ml of deionized water, and then wash for 1 hour under the action of ultrasonic wave, and then dry the obtained mixture in a blast drying oven at 45 °C for 12 hours; (4) place the mixture in step (3) in a crucible, and then perform calcination using a tube furnace, with the conditions being: Ar atmosphere, 800 °C, holding for 3 hours, and a heating rate of 5 °C / min, take out the crucible, and then grind the obtained black solid uniformly to obtain a porous carbon material, and the subsequent steps use the porous carbon material.

[0049] Comparative Example 2

[0050] The comparative example is basically the same as example 1, except that step S4 is deleted, and modified as: NH4V4O 10 The material is prepared according to the existing patent CN115566284A, specifically: 1.170 g of ammonium metavanadate is dissolved in 60 mL of deionized water, stirred for 10 minutes, and then a mixture of 1.894 g of oxalic acid and 1.5 mmol of ammonium fluoride is added, the obtained solution is transferred to a 100 mL high-pressure hydrothermal kettle, heated to 180 ℃, and continuously heated for 48 h. The bronze-colored precipitate obtained is washed several times with deionized water, centrifuged and collected, and then freeze-dried for 2 days to obtain a greenish powder, and then the oxygen-deficient NH4V4O 10 The material is compounded with a porous carbon material to obtain NH4V4O 10 / C composite material, and the subsequent steps use the NH4V4O 10 / C composite material.

[0051] Comparative Example 3

[0052] The comparative example is basically the same as example 1, except that steps S1 to S4 are deleted, and the porous carbon material prepared in comparative example 1 and the oxygen-deficient NH4V4O prepared in comparative example 2 are used. 10 The material is compounded to obtain NH4V4O 10 / C composite material, and the subsequent steps use the NH4V4O 10 / C composite material.

[0053] Comparative Example 4

[0054] The comparative example is basically the same as example 1, except that step S5 is deleted, i.e. the porous carbon-coupled NH4V4O 10 The / C composite material is mixed with a PVDF binder.

[0055] Comparative Example 5

[0056] The comparative example is basically the same as example 1, except that the amount of porous carbon in step S4 is adjusted to 0, i.e. no porous carbon material is added.

[0057] The positive electrode sheets of examples 1, comparative examples 1 to 5 are assembled into batteries by the following method, and electrochemical tests are performed:

[0058] CR2032 type button cells are assembled in room temperature air, the positive electrode is the positive electrode sheet, the negative electrode is metal zinc, the separator is glass fiber, and the electrolyte is 2 M zinc trifluoromethanesulfonate.

[0059] Figure 1 The X-ray diffraction pattern of the NVO / C composite material prepared in example 1 is shown, which is obtained by Figure 1It can be seen that the synthesized product is NH4V4O 10 It has high phase purity and is compatible with NH4V4O 10 The standard card JCPDF No. 31-0075 is highly consistent with the structure of a monoclinic crystal system, space group C2 / m1, a=11.71 Å, b=3.66 Å, c=9.72 Å. (001) The decrease in the diffraction angle corresponding to the crystal plane represents the expansion of the interplanar spacing.

[0060] Figure 2 The image shown is a scanning electron microscope (SEM) image of the NVO / C composite material prepared in Example 1. Figure 2 It can be seen that the composite material is in the form of nanoflowers composed of nanosheets, with a width of about 55 nm.

[0061] Figure 3 The image shows the overall X-ray photoelectron spectroscopy (XPS) spectrum of the NVO / C composite material prepared in Example 1. After correction, the CC peak is located at 284.4 eV. Figure 3 Clearly demonstrates that it belongs to NH4V4O 10 The signals of N, O, and V, and the relatively strong C 1s peak, originating from porous carbon, confirm the successful preparation of the ammonium vanadate / carbon composite cathode material, which is consistent with the aforementioned XRD and SEM analysis results.

[0062] Figure 4 The image shows the fine 1s O spectrum of the ammonium vanadate / carbon composite cathode material. The peaks at 530.3 eV, 530.8 eV, and 533.2 eV are attributed to lattice oxygen, oxygen defects, and bound water, respectively. Figure 4 The large proportion of oxygen vacancies in the middle indicates the presence of abundant oxygen defects within the lattice.

[0063] Figure 5 The figure shows the long-cycle performance of the aqueous zinc-ion battery assembled from the NVO / C composite material prepared in Example 1. Figure 5 It can be seen that the zinc-ion battery (CR2032 type button cell) assembled with the modified cathode has a performance of 5A g. -1 It exhibits long-term cycling performance, with an initial discharge specific capacity of 324.0 mAh g⁻¹. -1 It still maintains 273.3 mAh g after 1000 cycles. -1 The capacity retention rate was 84.4%.

[0064] Figure 6 The figure shows the rate performance of an aqueous zinc-ion battery assembled from the NVO / C composite material prepared in Example 1. Figure 6 It can be seen that the aqueous zinc-ion battery assembled with the modified cathode exhibits excellent rate performance and reversibility. At 0.2, 0.5, 1, 2, 3, and 5 A g...-1 the discharge specific capacity at 0.2 A g -1 -415.9 mAh g -1 -397.9 mAh g -1 -376.6 mAh g -1 -360.4 mAh g -1 and 324.0 mAh g -1 .

[0065] The performance data of the aqueous zinc-ion batteries assembled with the positive electrode sheets prepared by Comparative Examples 1 to 5 are shown in Table 1 as follows:

[0066] Table 1

[0067]

[0068] It can be seen from Examples 1 to 3 that the mass ratio of the porous carbon material and ammonium vanadate pentahydrate is too large or too small, which greatly affects the performance of the prepared positive electrode material. In addition, the capacity retention rate of Example 1 is as high as 84.4% after 1000 cycles at a high rate of 5 A g -1 -1, which is not only much higher than all the comparative examples, but also significantly better than Example 3 (51.5%) with the weakest performance due to insufficient carbon content, which shows that the type of carbon source, the compounding method and the defect engineering provided by the present application together ensure the excellent structural integrity of the electrode material. Secondly, in terms of rate performance, Example 1 exhibits the highest or nearly highest discharge specific capacity in the full test current density range of 0.2 A g -1 -5 A g -1 , especially 324.0 mAh g -1 at 5 A g -1 , which is in sharp contrast to the performance of Comparative Example 1 (biomass carbon, 76.3 mAh g -1 ) and Comparative Example 5 (no carbon matrix, 0.1 mAh g -1 ), revealing the decisive role of the continuous and highly conductive carbon network constructed by the present application in achieving excellent rate capability. In addition, it can be seen from Example 1 and Comparative Example 3 that the material obtained by compounding the existing porous carbon and NH4V4O 10 material with oxygen defects is different in performance and physical and chemical properties, which indirectly proves that the composite positive electrode material prepared by the present application is a new substance and cannot be obtained by combining the prior art. It can be seen from Example 1 and Comparative Examples 1 to 4 that the preparation of the new high-performance positive electrode material can only be achieved by using specific materials and specific steps.

[0069] In summary, the application has mild reaction conditions, simple preparation method, and the obtained product has obvious structural advantages. The nanoflower structure can better contact with the electrolyte, shorten the diffusion path of zinc ions, accelerate mass transfer, and thus improve the electrochemical performance. In addition, by preparing carbon materials with high specific surface area and electrical conductivity, the electronic transmission of the material can be increased, more adsorption sites for zinc ions can be provided, faster electron transfer and more active sites can be provided for the positive electrode material to bring higher discharge specific capacity. In addition, the regulation of oxygen defects can adjust the charge distribution, further increase the electrical conductivity of the material, and accelerate the electrochemical reaction process. The composite positive electrode material prepared by the application has high discharge specific capacity, large current rate capacity, and excellent cycle stability, and has wide application prospect in water-based zinc ion battery positive electrode materials.

[0070] While the embodiments of the application have been illustrated and described in detail, it will be apparent to those skilled in the art that various modifications and changes can be made to the embodiments without departing from the scope and spirit of the application as recited in the claims. Moreover, the application described herein can have other embodiments and be practiced or implemented in various ways.

Claims

1. A method for preparing a modified battery cathode electrode sheet, characterized by, The preparation method comprises: Step S01, annealing citrate to obtain black solid material; Step S02, mixing and stirring the pre-configured sulfuric acid solution with the black solid material to separate out black powder and wash to neutral, and drying to obtain porous carbon material; Step S03, dissolving the reagent containing vanadium source and ammonium source, the porous carbon material and oxalic acid dihydrate in deionized water, and stirring to obtain a mixed solution; Step S04, transferring the mixed solution to a reaction kettle for hydrothermal reaction to obtain a porous carbon-coupled NH4V4O 10 / C composite material; Step S05, the porous carbon-coupled NH4V4O 10 The porous carbon and the oxygen-defect-coupled NVO / C composite material are obtained by sequentially mixing and stirring, centrifugal washing and drying. Step S06, mixing the porous carbon and oxygen defect co-acting NVO / C composite material and PVDF binder, then adding into N-methyl pyrrolidone solvent to stir uniformly to form slurry, and then coating the slurry on the surface of metal foil current collector to obtain the modified battery positive electrode sheet after drying.

2. The method of claim 1, wherein the modified battery cathode electrode sheet is prepared by the steps of: In step S01, the citrate is potassium citrate or sodium citrate dihydrate; The heating rate in the annealing process is 2-5 °C / min, the annealing temperature is 700-1000 °C, and the annealing time is 1-3 h.

3. The method of claim 1, wherein the modified battery cathode electrode sheet is prepared by the steps of: In step S02, the concentration of the pre-configured sulfuric acid solution is 0.1-1.5 mmol / mL; the mixing and stirring time is 1-5 h; deionized water is used for washing, and the washing frequency is 3-5 times; the drying temperature is 40-120 °C, and the drying time is 10-24 h.

4. The method of making a modified battery cathode electrode sheet of claim 1, wherein, In step S03, the reagent containing vanadium source and ammonium source is at least one of ammonium metavanadate, ammonium vanadate pentahydrate or ammonium peroxovanadate, the mass ratio of the reagent containing vanadium source and ammonium source to the porous carbon material is 5:1-60:1, and the mass ratio of the reagent containing vanadium source and ammonium source to the oxalic acid dihydrate is 0.8:1-1.6:

1.

5. The method of making a modified battery cathode electrode sheet of claim 1, wherein, In step S04, the hydrothermal reaction temperature is 100-200 °C, and the hydrothermal reaction time is 3-24 h.

6. The method of making a modified battery cathode electrode sheet of claim 1, wherein, In step S05, the reducing agent is hydrazine hydrate or sodium borohydride; the mixing and stirring time is 20-60 min; the drying temperature is 60 °C, and the drying time is 12 h.

7. The method of making a modified battery cathode electrode sheet of claim 1, wherein, In step S06, the mass ratio of the porous carbon and oxygen defect co-acting NVO / C composite material to the PVDF binder is 5:1-8:1, and the mass ratio of the PVDF binder to the N-methyl pyrrolidone solvent is 1:26-1:

34.

8. A modified battery cathode electrode sheet, characterized by, The modified battery positive electrode sheet is prepared according to the preparation method of the modified battery positive electrode sheet in any one of claims 1-7.

9. Use of the modified battery cathode electrode sheet according to claim 8 in an aqueous-based zinc ion battery, characterized in that, The application comprises: Assembling a CR2032 type button cell in room temperature air, the positive electrode being the modified battery positive electrode sheet, the negative electrode being metal zinc, the separator being glass fiber, and the electrolyte being zinc trifluoromethane sulfonate.

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