A water-based zinc ion secondary battery positive electrode material, a preparation method and application thereof

Abstract

This invention discloses a cathode material for aqueous zinc-ion secondary batteries, its preparation method, and its application, belonging to the field of metal-ion battery technology. The key technical points of this invention are: using organic matter and graphite as carbon sources, an in-situ solid-state synthesis technique is employed to prepare a MnO / MnOS / C composite material. Further, by doping with functional metal elements, the cycle stability and rate performance of the composite material are effectively improved. When the MnO / MnOS / C composite material or the metal-doped MnO / MnOS / C composite material prepared by this invention is applied to the cathode of an aqueous zinc-ion secondary battery, it exhibits superior rate performance and ultra-long cycle stability. The preparation process of this composite material is very simple and easily scalable.

Description

Technical Field

[0001] This invention belongs to the field of zinc-ion secondary battery technology, specifically relating to an aqueous zinc-ion secondary battery cathode material, its preparation method, and its application. Background Technology

[0002] Aqueous zinc-ion batteries are a new type of rechargeable battery that has emerged in recent years. They feature high energy density, high power density, safety, low cost, and simple manufacturing process. Aqueous zinc-ion batteries mainly consist of four parts: positive and negative electrodes, current collectors, a separator, and an electrolyte. Among these, the positive electrode material has the greatest impact on the electrochemical performance of aqueous zinc-ion batteries, and obtaining a superior positive electrode material remains a challenging problem that researchers are striving to overcome.

[0003] In aqueous zinc-ion secondary batteries, manganese-based cathode materials have attracted much attention due to their high energy density and abundant reserves. However, their poor conductivity and weak structural stability in electrolyte environments have limited their further development. Research has found that by integrating different active components to construct electrode materials with heterostructures, the heterogeneous interfaces between different phases can induce synergistic effects, promoting electron and ion diffusion and transport, effectively improving the reversible capacity and rate performance of the electrode materials. In addition, carbon coating of the electrode materials can stabilize the electrode-electrolyte interface. To date, the combination of heterostructure treatment of MnO materials with carbon materials has made significant progress, but a key factor restricting its development is the cumbersome and relatively inefficient preparation process. Therefore, finding a simple, efficient, and large-scale synthetic strategy for manganese-based composite materials is currently an important means to promote the development of aqueous zinc-ion secondary batteries. Summary of the Invention

[0004] The technical problem solved by this invention is to provide an aqueous zinc-ion secondary battery cathode material and its preparation method. The aqueous zinc-ion secondary battery prepared using this cathode material has high specific energy, excellent rate performance and excellent cycle life.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] A method for preparing a positive electrode material for an aqueous zinc-ion secondary battery, characterized by the following specific steps:

[0007] Step S1: Disperse manganese sulfate or manganese sulfate and functional metal salt in deionized water to prepare a mixed salt solution, wherein the functional metal salt is one or more of nickel sulfate, cobalt sulfate, copper sulfate, alum sulfate, molybdenum sulfate, titanium sulfate, aluminum sulfate, bismuth sulfate, antimony sulfate, ytterbium sulfate, yttrium sulfate, erbium sulfate or lanthanum sulfate.

[0008] Step S2: Disperse the organic carbon source in deionized water to prepare an organic carbon source solution, wherein the organic carbon source is one or more of acrylamide, polyacrylamide, polyvinyl alcohol, citric acid, acrylate, ascorbic acid or glucose.

[0009] Step S3: Mix the mixed salt solution obtained in step S1 and the organic carbon source solution obtained in step S2 evenly and dry them to obtain the precursor;

[0010] Step S4: Under an inert atmosphere, the precursor obtained in step S3 is heat-treated at 500-800℃ for 1-24 hours, ground, and sieved to obtain an aqueous zinc-ion secondary battery cathode material or a metal-doped aqueous zinc-ion secondary battery cathode material.

[0011] Further specifying, when manganese sulfate is added, the mass ratio of manganese sulfate to organic carbon source is 10:1 to 20; when manganese sulfate and functional metal salt are added, the mass ratio of manganese sulfate, functional metal salt and organic carbon source is 10:0.1 to 5:1 to 20.

[0012] A method for preparing a positive electrode material for an aqueous zinc-ion secondary battery, characterized by the following specific steps:

[0013] Step S1: Manganese sulfate and graphite carbon source or manganese sulfate, functional metal salt and graphite carbon source are mixed and a precursor is prepared by high-energy ball milling. The graphite carbon source is one or more of the following: graphite-based anode material from waste lithium-ion batteries, natural graphite or artificial graphite. The functional metal salt is one or more of the following: nickel sulfate, cobalt sulfate, copper sulfate, vanadium sulfate, molybdenum sulfate, titanium sulfate, aluminum sulfate, bismuth sulfate, antimony sulfate, ytterbium sulfate, yttrium sulfate, erbium sulfate or lanthanum sulfate.

[0014] Step S2: Under an inert atmosphere, the precursor obtained in step S1 is heat-treated at 500-800℃ for 1-24 hours, pulverized, and sieved to obtain an aqueous zinc-ion secondary battery cathode material or a metal-doped aqueous zinc-ion secondary battery cathode material.

[0015] Further specified, when manganese sulfate and graphite carbon source are added, the mass ratio of manganese sulfate to graphite carbon source is 10:1 to 10; when manganese sulfate, functional metal salt and graphite carbon source are added, the mass ratio of manganese sulfate, functional metal salt and graphite carbon source is 10:1 to 10:0.1 to 5.

[0016] A positive electrode material for an aqueous zinc-ion secondary battery, characterized in that it is prepared by the above method, wherein the aqueous zinc-ion secondary battery positive electrode material is a MnO / MnOS / C composite material, and the functional metal element doped in the metal-doped aqueous zinc-ion secondary battery positive electrode material is one or more of Ni, Co, Cu, V, Mo, Ti, Al, Bi, Sb, Yb, Y, Er or La.

[0017] A positive electrode plate for an aqueous zinc-ion secondary battery, characterized in that: the positive electrode plate for the aqueous zinc-ion secondary battery is prepared from the above-mentioned positive electrode material for an aqueous zinc-ion secondary battery.

[0018] Further defining the positive electrode plate of the aqueous zinc-ion secondary battery, the positive electrode plate includes a positive electrode substrate and an active material disposed on or inside the positive electrode substrate. The active material is prepared from the following raw materials in the following weight percentages: 50%-90% aqueous zinc-ion secondary battery positive electrode material, 1%-40% conductive agent and 0.5%-10% binder.

[0019] A method for preparing a positive electrode plate for an aqueous zinc-ion secondary battery, characterized by the following steps: First, 50wt%-90wt% of aqueous zinc-ion secondary battery positive electrode material, 1wt%-40wt% of conductive agent and 0.5wt%-10wt% of binder are mixed evenly, and then added to the solvent N-methylpyrrolidone. The mixture is stirred and mixed evenly to prepare an active material slurry. The prepared active material slurry is then coated onto the positive electrode substrate, and after drying, pressing, punching, and welding of tabs, an aqueous zinc-ion secondary battery positive electrode plate is obtained.

[0020] Further specified, the conductive agent is one or more of conductive graphite, Ketjen black, conductive carbon black, carbon nanotubes, or graphene; the binder is polytetrafluoroethylene or polyvinylidene fluoride; and the positive electrode substrate is perforated steel strip, three-dimensional steel strip, stainless steel mesh, foamed iron, or titanium mesh.

[0021] An aqueous zinc-ion secondary battery includes a battery casing, an electrode assembly sealed within the battery casing, and an electrolyte, wherein the electrode assembly includes a positive electrode plate, a negative electrode plate, and a separator, characterized in that: the positive electrode plate is the above-mentioned aqueous zinc-ion secondary battery positive electrode plate.

[0022] Compared with existing technologies, this invention has the following advantages and beneficial effects: The aqueous zinc-ion secondary battery cathode material prepared by this invention, through the coating or doping of carbon materials and the doping of sulfur, greatly improves its structural stability and rate performance during charge-discharge cycles, improves the capacity performance of the material, significantly improves the conductivity of the electrode, reduces electrochemical polarization, and improves the rate performance and cycle stability of the battery. By controlling the mass ratio of the synthesis raw materials, the ratio of MnO and MnOS in the material can be controlled. Through the synergistic effect of sulfur and carbon elements, the 0.1Ag of this cathode material can be made more efficient. -1 The discharge capacity at the current density reaches 335.1 mAh g. -1 4Ag -1 The discharge capacity at the current density reaches 83.6 mAh g. -1 The cathode material is in 2Ag -1After 3000 cycles at the current density, the capacity retention rate is 90.36%, and the coulombic efficiency is close to 100%. The aqueous zinc-ion secondary battery prepared using this novel cathode material has high specific energy, excellent rate performance, and good cycle life. Attached Figure Description

[0023] Figure 1 This is a scanning electron microscope image of the aqueous zinc-ion secondary battery cathode material prepared in Example 2;

[0024] Figure 2 The X-ray diffraction patterns of the aqueous zinc-ion secondary battery cathode materials prepared in Examples 1, 2, and 3 are shown.

[0025] Figure 3 The discharge curves of the aqueous zinc-ion secondary battery cathode material prepared in Example 2 are shown at different current densities.

[0026] Figure 4 The specific capacity diagrams of the aqueous zinc-ion secondary battery cathode materials prepared in Examples 1, 2, and 3 are shown at different current densities.

[0027] Figure 5 The graph shows the cycle life of the aqueous zinc-ion secondary battery cathode material prepared in Example 2. Detailed Implementation

[0028] The following examples further illustrate the above-described content of the present invention, but it should not be construed as limiting the scope of the subject matter of the present invention to the following examples. All technologies implemented based on the above-described content of the present invention fall within the scope of the present invention.

[0029] Example 1

[0030] 1g of manganese sulfate was dispersed in 10mL of deionized water to prepare a manganese salt solution, and 2g of acrylamide monomer was dispersed in 10mL of deionized water to prepare an acrylamide monomer solution. The two solutions were mixed and stirred until homogeneous, and then dried for 24h to obtain a precursor. The precursor was carbonized at 800℃ for 120min under nitrogen atmosphere to obtain the aqueous zinc-ion secondary battery cathode material, namely the MnO / MnOS / C composite material.

[0031] Preparation of the positive electrode plate:

[0032] The prepared MnO / MnOS / C composite material, conductive carbon black, and polyvinylidene fluoride were mixed in a mass ratio of 8:1:1. An appropriate amount of N-methylpyrrolidone solvent was added, and the mixture was stirred for 20 hours to obtain a black, viscous slurry. The slurry was then evenly coated onto a stainless steel mesh current collector electrode using a spatula, with an average electrode loading of approximately 1.0-2.0 mg / cm². 2The positive electrode plate is obtained by vacuum drying at 90℃ for 12 hours, followed by drying, pressing, punching, and welding of tabs.

[0033] Example 2

[0034] 2g of manganese sulfate was dispersed in 10mL of deionized water to prepare a manganese salt solution, and 1g of acrylamide monomer was dispersed in 10mL of deionized water to prepare an acrylamide monomer solution. The two solutions were mixed, stirred until homogeneous, and dried for 30 hours to obtain the precursor. The precursor was then carbonized at 700℃ for 120 minutes under nitrogen atmosphere to obtain the aqueous zinc-ion secondary battery, i.e., the MnO / MnOS / C composite material. SEM images of this MnO / MnOS / C composite material are shown below. Figure 1 .

[0035] Preparation of the positive electrode plate:

[0036] The prepared MnO / MnOS / C composite material, conductive carbon black, and polyvinylidene fluoride were mixed in a mass ratio of 7:2:1. An appropriate amount of N-methylpyrrolidone solvent was added, and the mixture was stirred for 12 hours to obtain a black, viscous slurry. The slurry was then evenly coated onto a stainless steel mesh current collector electrode using a scraper, with an average electrode loading of approximately 1.0-2.0 mg / cm². 2 The positive electrode plate is obtained by vacuum drying at 80℃ for 12 hours, followed by drying, pressing, punching, and welding of tabs.

[0037] Example 3

[0038] 3g of manganese sulfate was dispersed in 10mL of deionized water to prepare a manganese salt solution, and 1g of acrylamide monomer was dispersed in 10mL of deionized water to prepare an acrylamide monomer solution. The two solutions were mixed and stirred until homogeneous, and then dried for 24h to obtain a precursor. The precursor was carbonized at 800℃ for 360min under nitrogen atmosphere to obtain the aqueous zinc-ion secondary battery cathode material, namely the MnO / MnOS / C composite material.

[0039] Preparation of the positive electrode plate:

[0040] The prepared MnO / MnOS / C composite material, conductive carbon black, and polyvinylidene fluoride were mixed in a mass ratio of 7:2:1. An appropriate amount of N-methylpyrrolidone solvent was added, and the mixture was stirred for 10 hours to obtain a black, viscous slurry. The slurry was then evenly coated onto a stainless steel mesh current collector electrode using a spatula, with an average electrode loading of approximately 1.0-2.0 mg / cm². 2 The positive electrode plate is obtained by vacuum drying at 85℃ for 12 hours, followed by drying, pressing, punching, and welding of tabs.

[0041] Example 4

[0042] 3g of manganese sulfate, 0.1g of nickel sulfate, 0.1g of bismuth sulfate, and 0.1g of yttrium sulfate were dispersed in 10mL of deionized water to prepare a mixed salt solution. 1g of acrylamide monomer was dispersed in 10mL of deionized water to prepare an acrylamide monomer solution. The two solutions were mixed and stirred until homogeneous. The mixture was then dried for 48h to obtain a precursor. The precursor was carbonized at 800℃ for 120min under nitrogen atmosphere to obtain the aqueous zinc-ion secondary battery cathode material, namely the Ni, Bi, Y doped MnO / MnOS / C composite material.

[0043] Preparation of the positive electrode plate: The preparation process of the positive electrode plate is the same as in Example 2.

[0044] Example 5

[0045] 3g of manganese sulfate, 0.1g of copper sulfate, 0.1g of lanthanum sulfate, and 0.1g of molybdenum sulfate were dispersed in 10mL of deionized water to prepare a mixed salt solution. 1g of acrylamide monomer was dissolved in 10mL of deionized water to prepare an acrylamide monomer solution. The two solutions were mixed and stirred until homogeneous. The mixture was then dried for 26 hours to obtain a precursor. The precursor was carbonized at 800℃ for 120 minutes under nitrogen atmosphere to obtain an aqueous zinc-ion secondary battery cathode material, namely a Cu, La, Mo-doped MnO / MnOS / C composite material.

[0046] Preparation of the positive electrode plate: The preparation process of the positive electrode plate is the same as in Example 2.

[0047] Example 6

[0048] 3g of manganese sulfate, 0.1g of vanadium sulfate, 0.1g of antimony sulfate, and 0.1g of ytterbium sulfate were dispersed in 10mL of deionized water to prepare a mixed salt solution. 1g of acrylamide monomer was dispersed in 10mL of deionized water to prepare an acrylamide monomer solution. The two solutions were mixed and stirred until homogeneous. The mixture was then dried for 33h to obtain a precursor. The precursor was carbonized at 700℃ for 480min under nitrogen atmosphere to obtain an aqueous zinc-ion secondary battery cathode material, namely a V, Sb, Yb-doped MnO / MnOS / C composite material.

[0049] Preparation of the positive electrode plate: The preparation process of the positive electrode plate is the same as in Example 2.

[0050] Example 7

[0051] 3g of manganese sulfate, 0.1g of copper sulfate, 0.1g of nickel sulfate, and 0.1g of titanium sulfate were dispersed in 10mL of deionized water to prepare a mixed salt solution. 1g of acrylamide monomer was dispersed in 10mL of deionized water to prepare an acrylamide monomer solution. The two solutions were mixed and stirred until homogeneous. The mixture was then dried for 24 hours to obtain a precursor. The precursor was carbonized at 800℃ for 120 minutes under nitrogen atmosphere to obtain the aqueous zinc-ion secondary battery cathode material, namely the Cu, Ni, Ti doped MnO / MnOS / C composite material.

[0052] Preparation of the positive electrode plate: The preparation process of the positive electrode plate is the same as in Example 2.

[0053] Example 8

[0054] 3g of manganese sulfate, 0.1g of copper sulfate, and 0.1g of cobalt sulfate were dispersed in 10mL of deionized water to prepare a mixed salt solution. 1g of acrylamide monomer was dispersed in 10mL of deionized water to prepare an acrylamide monomer solution. The two solutions were mixed and stirred until homogeneous. The mixture was then dried for 40h to obtain a precursor. The precursor was carbonized at 800℃ for 480min under nitrogen atmosphere to obtain the positive electrode material for aqueous zinc-ion secondary batteries, namely the Cu, Co doped MnO / MnOS / C composite material.

[0055] Preparation of the positive electrode plate: The preparation process of the positive electrode plate is the same as in Example 2.

[0056] Example 9

[0057] 3g of manganese sulfate, 0.1g of cobalt sulfate, 0.1g of copper sulfate, and 0.1g of nickel sulfate were dispersed in 10mL of deionized water to prepare a mixed salt solution. 1g of acrylamide monomer was dispersed in 10mL of deionized water to prepare an acrylamide monomer solution. The two solutions were mixed and stirred until homogeneous. The mixture was then dried for 36 hours to obtain a precursor. The precursor was carbonized at 700℃ for 360 minutes under nitrogen atmosphere to obtain an aqueous zinc-ion secondary battery cathode material, namely a Co, Cu, Ni-doped MnO / MnOS / C composite material.

[0058] Preparation of the positive electrode plate: The preparation process of the positive electrode plate is the same as in Example 2.

[0059] Example 10

[0060] 3g of manganese sulfate, 0.1g of cobalt sulfate, 0.1g of erbium sulfate, and 0.1g of lanthanum sulfate were dispersed in 10mL of deionized water to prepare a mixed salt solution. 1g of acrylamide monomer was dispersed in 10mL of deionized water to prepare an acrylamide monomer solution. The two solutions were mixed and stirred until homogeneous. The mixture was then dried for 31h to obtain a precursor. The precursor was carbonized at 800℃ for 120min under nitrogen atmosphere to obtain an aqueous zinc-ion secondary battery cathode material, namely a Co, Er, and La-doped MnO / MnOS / C composite material.

[0061] Preparation of the positive electrode plate: The preparation process of the positive electrode plate is the same as in Example 2.

[0062] Example 11

[0063] 3g of manganese sulfate, 0.1g of cobalt sulfate, and 0.1g of nickel sulfate were dispersed in 10mL of deionized water to prepare a mixed salt solution. 1g of acrylamide monomer was dispersed in 10mL of deionized water to prepare an acrylamide monomer solution. The two solutions were mixed and stirred until homogeneous. The mixture was then dried for 32 hours to obtain a precursor. The precursor was carbonized at 800℃ for 5 hours under nitrogen atmosphere to obtain the aqueous zinc-ion secondary battery cathode material, namely the Ni, Co-doped MnO / MnOS / C composite material.

[0064] Preparation of the positive electrode plate: The preparation process of the positive electrode plate is the same as in Example 2.

[0065] Example 12

[0066] 3g of manganese sulfate and 1.5g of recycled graphite-based negative electrode material from waste lithium-ion batteries were mixed and ground evenly to obtain a precursor. The precursor was then carbonized at 800℃ for 100min under nitrogen atmosphere to obtain the aqueous zinc-ion secondary battery positive electrode material, namely the MnO / MnOS / C composite material.

[0067] Preparation of the positive electrode plate: The preparation process of the positive electrode plate is the same as in Example 2.

[0068] Example 13

[0069] 3g of manganese sulfate, 0.1g of nickel sulfate, 0.1g of erbium sulfate, 0.1g of lanthanum sulfate, and 1.5g of recycled graphite-based anode material from waste lithium-ion batteries were mixed and ground evenly to obtain a precursor. The precursor was then carbonized at 800℃ for 110 minutes under nitrogen atmosphere to obtain an aqueous zinc-ion secondary battery cathode material, namely a Ni, Er, La-doped MnO / MnOS / C composite material.

[0070] Preparation of the positive electrode plate: The preparation process of the positive electrode plate is the same as in Example 2.

[0071] Example 14

[0072] 3g of manganese sulfate, 0.1g of cobalt sulfate, 0.1g of aluminum sulfate, 0.1g of molybdenum sulfate, and 1.5g of recycled graphite-based anode material from waste lithium-ion batteries were mixed and ground evenly to obtain a precursor. The precursor was then carbonized at 800℃ for 6 hours under nitrogen atmosphere to obtain an aqueous zinc-ion secondary battery cathode material, namely a Co, Al, Mo-doped MnO / MnOS / C composite material.

[0073] Preparation of the positive electrode plate: The preparation process of the positive electrode plate is the same as in Example 2.

[0074] Example 15

[0075] 3g of manganese sulfate, 0.1g of cobalt sulfate, 0.1g of vanadium sulfate and 1.5g of recycled graphite-based negative electrode material from waste lithium-ion batteries were mixed and ground evenly to obtain a precursor. The precursor was then carbonized at 800℃ for 90 minutes under nitrogen atmosphere to obtain an aqueous zinc-ion secondary battery positive electrode material, namely a Co,V doped MnO / MnOS / C composite material.

[0076] Preparation of the positive electrode plate: The preparation process of the positive electrode plate is the same as in Example 2.

[0077] Example 16

[0078] 3g of manganese sulfate, 0.1g of cobalt sulfate, 0.1g of nickel sulfate and 1.5g of recycled graphite-based anode material from waste lithium-ion batteries were mixed and ground evenly to obtain a precursor. The precursor was then carbonized at 800℃ for 180min under nitrogen atmosphere to obtain the aqueous zinc-ion secondary battery cathode material, namely the Ni, Co doped MnO / MnOS / C composite material.

[0079] Preparation of the positive electrode plate: The preparation process of the positive electrode plate is the same as in Example 2.

[0080] Example 17

[0081] 3g of manganese sulfate, 0.1g of copper sulfate, 0.1g of cobalt sulfate, 0.1g of nickel sulfate, and 1.5g of recycled graphite-based anode material from waste lithium-ion batteries were mixed and ground evenly to obtain a precursor. The precursor was then carbonized at 800℃ for 120 minutes under nitrogen atmosphere to obtain an aqueous zinc-ion secondary battery cathode material, namely a Cu, Ni, Co-doped MnO / MnOS / C composite material.

[0082] Preparation of the positive electrode plate: The preparation process of the positive electrode plate is the same as in Example 2.

[0083] Negative electrode plate manufacturing: Purchase commercial zinc sheets with a thickness of 0.01mm, grind them, and ultrasonically clean them with deionized water and acetone. Cut them into 2cm diameter round pieces to make negative electrode plates for later use.

[0084] Battery assembly: A glass fiber separator is sandwiched between the pure zinc sheet negative electrode plate and the positive electrode plate, and the plate is inserted into a CR2025 button cell. 2M ZnSO4 and 0.2M MnSO4 electrolyte as additives are injected, and the plate is sealed using a sealing machine to assemble a sealed aqueous zinc-ion secondary button cell.

[0085] Sample characterization:

[0086] Figure 1 The microstructure of the product obtained in Example 2 is shown. The surface sample exhibits carbon-coated nanoparticles with an average size of approximately 50 nm. Figure 2 The X-ray diffraction (XRD) phase analysis results of the products obtained in Examples 1 to 3 are shown in the figure. As can be seen from the figure, the diffraction peaks of the prepared samples are consistent with the peaks of the standard card, indicating that the products prepared by this method are MnO / MnOS composite materials.

[0087] Battery performance test:

[0088] Capacity testing: The prepared simulated battery was subjected to a 0.1 mV s test. -1 After activation for several cycles, use 0.1 Ag. -1 0.2Ag -1 0.5Ag -1 1Ag -1 2Ag -1 3Ag -1 and 4Ag -1 The capacity performance of the cathode material was determined under the conditions of current density and voltage window of 0.8-1.9V.

[0089] Battery cycle performance test: The prepared battery was subjected to an ambient temperature of 25°C and a charge of 2Ag. -1 The current density was subjected to constant current charge-discharge test for 3000 cycles.

[0090] The battery performance test results are shown in Table 1.

[0091] Table 1 Battery Performance Test

[0092]

[0093] The test results above show that the aqueous zinc-ion secondary battery cathode material prepared by the method of this invention has high specific capacity, excellent rate performance and excellent cycle stability. These performance improvements are mainly attributed to: (1) the optimization of the synthesis method, especially the use of in-situ solid-phase synthesis to achieve uniform coating of carbon materials, which plays a crucial role in the development of the cycle stability of the sample; (2) the composite doping of carbon materials improves the conductivity of the material, which is beneficial to capacity development and application in a larger current environment; (3) the modification and regulation of the lattice structure of the doped material by S element greatly improves the capacity performance and cycle stability of the material; (4) it has been found that the electrode preparation formula will greatly affect the performance of MnO electrode, so optimizing the electrode formula is one of the important means to improve the overall performance of the material.

[0094] The above embodiments describe the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the present invention. Various changes and modifications can be made to the present invention without departing from its principles, and all such changes and modifications fall within the scope of protection of the present invention.

Claims

1. A positive electrode material for an aqueous zinc-ion secondary battery, characterized in that: The positive electrode material of this aqueous zinc-ion secondary battery is a metal-doped MnO / MnOS / C composite material, and the doped functional metal element is one or more of Ni, Co, Cu, V, Mo, Ti, Al, Bi, Sb, Yb, Y, Er or La; The specific preparation steps for the aqueous zinc-ion secondary battery cathode material are as follows: Step S1: Disperse manganese sulfate and functional metal salt in deionized water to prepare a mixed salt solution, wherein the functional metal salt is one or more of nickel sulfate, cobalt sulfate, copper sulfate, alum sulfate, molybdenum sulfate, titanium sulfate, aluminum sulfate, bismuth sulfate, antimony sulfate, ytterbium sulfate, yttrium sulfate, erbium sulfate, or lanthanum sulfate. Step S2: Disperse the organic carbon source in deionized water to prepare an organic carbon source solution, wherein the organic carbon source is one or more of acrylamide, polyacrylamide, polyvinyl alcohol, citric acid, acrylate, ascorbic acid or glucose, and the mass ratio of manganese sulfate, functional metal salt to organic carbon source is 10:0.1~5:1~20. Step S3: Mix the mixed salt solution obtained in step S1 and the organic carbon source solution obtained in step S2 evenly and dry them to obtain the precursor; Step S4: Under an inert atmosphere, the precursor obtained in step S3 is heat-treated at 800℃ for 1-24h, ground, and sieved to obtain a metal-doped aqueous zinc-ion secondary battery cathode material. Alternatively, the specific preparation steps for the aqueous zinc-ion secondary battery cathode material are as follows: Step S1: Manganese sulfate, functional metal salt, and graphite carbon source are mixed and a precursor is prepared by high-energy ball milling. The graphite carbon source is one or more of the following: graphite-based anode material from waste lithium-ion batteries, natural graphite, or artificial graphite. The functional metal salt is one or more of the following: nickel sulfate, cobalt sulfate, copper sulfate, vanadium sulfate, molybdenum sulfate, titanium sulfate, aluminum sulfate, bismuth sulfate, antimony sulfate, ytterbium sulfate, yttrium sulfate, erbium sulfate, or lanthanum sulfate. The mass ratio of manganese sulfate, functional metal salt, and graphite carbon source is 10:1 to 10:0.1 to 5. Step S2: Under an inert atmosphere, the precursor obtained in step S1 is heat-treated at 800℃ for 1-24 hours, pulverized, and sieved to obtain a metal-doped aqueous zinc-ion secondary battery cathode material.

2. A positive electrode plate for an aqueous zinc-ion secondary battery, characterized in that: The aqueous zinc-ion secondary battery positive electrode plate is prepared from the aqueous zinc-ion secondary battery positive electrode material as described in claim 1.

3. The positive electrode plate of the aqueous zinc-ion secondary battery according to claim 2, characterized in that: The aqueous zinc-ion secondary battery positive electrode plate includes a positive electrode substrate and an active material disposed on the positive electrode substrate. The active material is prepared from the following raw materials in the following weight percentages: 50%-90% aqueous zinc-ion secondary battery positive electrode material, 1%-40% conductive agent and 0.5%-10% binder.

4. A method for preparing the positive electrode plate of an aqueous zinc-ion secondary battery according to claim 2, characterized in that... The specific steps are as follows: First, mix 50wt%-90wt% of aqueous zinc-ion secondary battery positive electrode material, 1wt%-40wt% of conductive agent and 0.5wt%-10wt% of binder evenly, then add it to the solvent N-methylpyrrolidone, stir and mix evenly to make an active material slurry, then coat the obtained active material slurry onto the positive electrode substrate, and after drying, pressing, punching and welding the electrode tabs, the aqueous zinc-ion secondary battery positive electrode plate is obtained.

5. The method for preparing the positive electrode plate of an aqueous zinc-ion secondary battery according to claim 4, characterized in that: The conductive agent is one or more of conductive graphite, Ketjen black, conductive carbon black, carbon nanotubes, or graphene; the binder is polytetrafluoroethylene or polyvinylidene fluoride; and the positive electrode substrate is perforated steel strip, three-dimensional steel strip, stainless steel mesh, foamed iron, or titanium mesh.

6. An aqueous zinc-ion secondary battery, comprising a battery casing and an electrode assembly and an electrolyte sealed within the battery casing, wherein the electrode assembly comprises a positive electrode plate, a negative electrode plate, and a separator, characterized in that: The positive electrode plate is the aqueous zinc-ion secondary battery positive electrode plate as described in claim 2.

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