Graphene-based zinc oxide / manganese dioxide-polyaniline composite nickel-zinc battery negative electrode material, preparation method thereof and nickel-zinc battery

Abstract

The invention belongs to the field of nickel-zinc batteries, and particularly relates to a graphene-based zinc oxide / manganese dioxide-polyaniline composite nickel-zinc battery negative electrode material, a preparation method thereof and a nickel-zinc battery. The graphene-based zinc oxide / manganese dioxide-polyaniline composite nickel-zinc battery negative electrode material comprises a three-dimensional graphene substrate, composite particles loaded on the three-dimensional graphene substrate, and a sulfonated modified polyaniline layer coating the surfaces of the composite particles. The composite particles comprise zinc oxide and manganese dioxide. Through directional coordination of-SO3H groups in the sulfonated polyaniline layer and zinc ions, uniform deposition of the zinc ions on the surface of the electrode is effectively guided, and generation of dendritic crystals is inhibited. In addition, the sulfonated polyaniline layer also has good alkali resistance and conductivity, can still maintain a stable interface environment under a high-temperature condition, effectively inhibits the occurrence of side reactions, and enables the nickel-zinc battery to still maintain high coulombic efficiency under a high-temperature environment of 50 DEG C.

Description

Technical Field

[0001] This invention relates to the field of nickel-zinc battery technology, specifically to a graphene-based zinc oxide / manganese dioxide-polyaniline composite nickel-zinc battery anode material, its preparation method, and the nickel-zinc battery itself. Background Technology

[0002] With the continuous growth of global energy demand and the increasing severity of environmental pollution, the development of efficient, environmentally friendly, and sustainable energy storage technologies has become one of the key directions of current scientific research. Among various rechargeable battery systems, nickel-zinc batteries are considered one of the most promising green batteries due to their high energy density, low cost, and environmental friendliness. However, in practical applications, nickel-zinc batteries still face a series of technical bottlenecks.

[0003] First, the negative electrode material of nickel-zinc batteries is mainly metallic zinc or zinc-containing compounds. During charging and discharging, zinc ions tend to deposit unevenly on the electrode surface, forming needle-like or dendritic structures. These dendrites not only damage the electrode structure but also penetrate the separator, causing internal short circuits and posing serious safety hazards.

[0004] Secondly, nickel-zinc batteries typically use strongly alkaline electrolytes, in which the zinc anode is prone to corrosion, especially at higher operating temperatures where the corrosion rate accelerates significantly, leading to a rapid decrease in the coulombic efficiency of the anode. Simultaneously, high temperatures exacerbate the pulverization of the zinc anode, accelerating the shedding of active material and further reducing the battery's cycle stability.

[0005] Therefore, there is a need to provide a nickel-zinc battery anode material that is resistant to dendrite formation and performs better under high-temperature operating conditions. Summary of the Invention

[0006] (a) Technical problems to be solved

[0007] To address the problems of dendrite growth and poor performance at high temperatures in existing nickel-zinc battery anode materials, this invention provides a graphene-based zinc oxide / manganese dioxide-polyaniline composite nickel-zinc battery anode material, its preparation method, and a nickel-zinc battery.

[0008] (II) Technical Solution

[0009] To achieve the above objectives, the main technical solutions adopted by the present invention include:

[0010] In a first aspect, the present invention provides a graphene-based zinc oxide / manganese dioxide-polyaniline composite nickel-zinc battery anode material, comprising a three-dimensional graphene substrate, composite particles loaded on the three-dimensional graphene substrate, and a sulfonated modified polyaniline layer coated on the surface of the composite particles.

[0011] The composite particles include zinc oxide and manganese dioxide.

[0012] Secondly, the present invention provides a method for preparing the above-mentioned graphene-based zinc oxide / manganese dioxide-polyaniline composite nickel-zinc battery anode material, comprising the following steps:

[0013] S1: Three-dimensional graphene is dispersed in a precursor solution containing zinc salt, a pH adjuster is added, and three-dimensional graphene with zinc oxide particles loaded on the surface is obtained through hydrothermal reaction.

[0014] S2: Disperse the three-dimensional graphene with zinc oxide particles on the surface in deionized water to obtain a mixture. Add potassium permanganate solution and manganese sulfate solution to the mixture, mix evenly, and then carry out a hydrothermal reaction to obtain three-dimensional graphene with composite particles on the surface.

[0015] S3: Three-dimensional graphene with surface-loaded composite particles is immersed in a mixed solution containing aniline, sulfosalicylic acid and ammonium persulfate to carry out an in-situ polymerization reaction, so that sulfonated modified polyaniline is coated on the surface of the composite particles to obtain graphene-based zinc oxide / manganese dioxide-polyaniline composite nickel-zinc battery anode material.

[0016] In the preparation method of the graphene-based zinc oxide / manganese dioxide-polyaniline composite nickel-zinc battery anode material as described above, preferably, in step S1, the zinc salt is zinc nitrate or zinc acetate, and the concentration of zinc ions in the precursor solution is 0.15-0.2 mol / L.

[0017] In the preparation method of the graphene-based zinc oxide / manganese dioxide-polyaniline composite nickel-zinc battery anode material as described above, preferably, in step S1, the hydrothermal reaction temperature is 100-120℃ and the reaction time is 4-8h.

[0018] In the preparation method of the graphene-based zinc oxide / manganese dioxide-polyaniline composite nickel-zinc battery anode material as described above, preferably, in step S2, the concentration of potassium permanganate solution is 0.02-0.03M, the molar ratio of potassium permanganate to manganese sulfate is 2:1, and the molar ratio of potassium permanganate to zinc oxide is (1-3):1.

[0019] In the preparation method of the graphene-based zinc oxide / manganese dioxide-polyaniline composite nickel-zinc battery anode material as described above, preferably, in step S2, the hydrothermal reaction temperature is 180-200℃ and the reaction time is 6-10h.

[0020] In the preparation method of the graphene-based zinc oxide / manganese dioxide-polyaniline composite nickel-zinc battery anode material as described above, preferably, in step S3, the concentration of aniline in the mixed solution is 0.2-0.3 mol / L, the molar ratio of sulfosalicylic acid to aniline is (1.2-1.5):1, and the molar ratio of ammonium persulfate to aniline is (0.5-0.8):1.

[0021] In the preparation method of the graphene-based zinc oxide / manganese dioxide-polyaniline composite nickel-zinc battery anode material as described above, preferably, in step S3, the temperature of the in-situ polymerization reaction is 0-5℃ and the reaction time is 6-12h.

[0022] Thirdly, the present invention also provides a nickel-zinc battery, comprising the above-mentioned graphene-based zinc oxide / manganese dioxide-polyaniline composite nickel-zinc battery anode material or the graphene-based zinc oxide / manganese dioxide-polyaniline composite nickel-zinc battery anode material prepared by the above-mentioned preparation method.

[0023] (3) Beneficial effects

[0024] First, in the nickel-zinc battery anode material of the present invention, the -SO3H groups in the sulfonated polyaniline layer can form a directional coordination effect with zinc ions, effectively guiding the uniform deposition of zinc ions on the electrode surface, thereby significantly reducing the deposition overpotential, suppressing the formation of dendrites, and improving battery safety.

[0025] Secondly, the sulfonated polyaniline layer of this invention also possesses excellent alkali resistance and conductivity, maintaining a stable interfacial environment even at high temperatures, effectively suppressing side reactions, and enabling the nickel-zinc battery to maintain a high coulombic efficiency even at 50°C. Furthermore, zinc oxide, as an active material, directly participates in the electrochemical reaction, while the introduction of manganese dioxide not only enhances the conductivity of the composite particles but also, to a certain extent, inhibits the dissolution of zinc oxide in strongly alkaline electrolytes, improving the overall cycle stability of the material.

[0026] Third, the three-dimensional graphene substrate, acting as a carrier, provides a high specific surface area support platform for the zinc oxide and manganese dioxide composite particles, which helps to uniformly disperse and stably attach the active materials, thereby maintaining the structural integrity of the electrode during cycling. Simultaneously, graphene's excellent conductivity enables the construction of a continuous conductive network within the electrode, significantly improving the overall electrochemical reaction kinetics performance of the electrode. Detailed Implementation

[0027] To better explain and facilitate understanding of the present invention, the present invention will be described in detail below with reference to specific embodiments.

[0028] This invention provides a graphene-based zinc oxide / manganese dioxide-polyaniline composite nickel-zinc battery anode material, comprising a three-dimensional graphene substrate, composite particles loaded on the three-dimensional graphene substrate, and a sulfonated modified polyaniline layer coated on the surface of the composite particles, wherein the composite particles comprise zinc oxide and manganese dioxide.

[0029] In the nickel-zinc battery anode material of the present invention, the -SO3H groups in the sulfonated polyaniline layer can form a directional coordination with zinc ions, effectively guiding the uniform deposition of zinc ions on the electrode surface, thereby significantly reducing the deposition overpotential, suppressing dendrite formation, and improving battery safety.

[0030] The sulfonated polyaniline layer of this invention also possesses excellent alkali resistance and conductivity, maintaining a stable interfacial environment even at high temperatures, effectively suppressing side reactions, and enabling the nickel-zinc battery to maintain a high coulombic efficiency even at 50°C. Furthermore, zinc oxide directly participates in the electrochemical reaction as an active material, while the introduction of manganese dioxide not only enhances the conductivity of the composite particles but also inhibits the dissolution of zinc oxide in strongly alkaline electrolytes to a certain extent, improving the overall cycle stability of the material.

[0031] The three-dimensional graphene substrate serves as a carrier, providing a high specific surface area support platform for the zinc oxide and manganese dioxide composite particles. This facilitates the uniform dispersion and stable adhesion of the active materials, thereby maintaining the structural integrity of the electrode during cycling. Simultaneously, graphene's excellent conductivity enables the construction of a continuous conductive network within the electrode, significantly enhancing the overall electrochemical reaction kinetics performance of the electrode.

[0032] The present invention also provides a method for preparing the above-mentioned graphene-based zinc oxide / manganese dioxide-polyaniline composite nickel-zinc battery anode material, comprising the following steps:

[0033] S1: Three-dimensional graphene is dispersed in a precursor solution containing zinc salt, a pH adjuster is added, and three-dimensional graphene with zinc oxide particles loaded on the surface is obtained through hydrothermal reaction.

[0034] S2: Disperse three-dimensional graphene with zinc oxide particles on its surface in deionized water to obtain a mixture. Add potassium permanganate solution and manganese sulfate solution to the mixture, mix evenly, and then carry out a hydrothermal reaction to obtain three-dimensional graphene with composite particles on its surface.

[0035] S3: Three-dimensional graphene with surface-loaded composite particles is immersed in a mixed solution containing aniline, sulfosalicylic acid and ammonium persulfate to carry out an in-situ polymerization reaction, so that sulfonated modified polyaniline is coated on the surface of the composite particles to obtain graphene-based zinc oxide / manganese dioxide-polyaniline composite nickel-zinc battery anode material.

[0036] Preferably, in step S1 above, the zinc salt is zinc nitrate or zinc acetate, the concentration of zinc ions in the precursor solution is 0.15-0.2 mol / L, and the added pH adjuster is preferably ammonia, which is used to maintain the pH of the system at 9-10 to ensure the formation of zinc oxide in the hydrothermal reaction. More preferably, in step S1, the hydrothermal reaction temperature is 100-120℃, and the reaction time is 4-8 h. Furthermore, the three-dimensional graphene used in this invention can be prepared by subjecting graphite powder to two oxidation treatments.

[0037] Preferably, in step S2 above, the concentration of potassium permanganate solution is 0.02-0.03M, the molar ratio of potassium permanganate to manganese sulfate is 2:1, the molar ratio of potassium permanganate to zinc oxide is (1-3):1, the temperature of hydrothermal reaction is 180-200℃, and the reaction time is 6-10h.

[0038] In step S2 above, potassium manganate and manganese sulfate undergo a hydrothermal reaction to generate manganese dioxide. Zinc oxide particles have high surface energy and abundant surface hydroxyl groups. These functional groups can provide more active sites, which is beneficial to the nucleation and growth of manganese dioxide.

[0039] Preferably, in step S3 above, the concentration of aniline in the mixed solution is 0.2-0.3 mol / L, the molar ratio of sulfosalicylic acid to aniline is (1.2-1.5):1, the molar ratio of ammonium persulfate to aniline is (0.5-0.8):1, the temperature of the in-situ polymerization reaction is 0-5℃, and the reaction time is 6-12 h.

[0040] In step S3 above, aniline is the monomer for the polymerization reaction. After the polymerization reaction, polyaniline is generated. Sulfosalicylic acid is used to provide sulfonic acid groups to sulfonate and modify polyaniline, so that polyaniline has better conductivity and stability. Ammonium persulfate is used as an oxidizing initiator to initiate the polymerization reaction of aniline monomer.

[0041] To further clarify the present invention and its technological advancements, the following description is provided in conjunction with specific embodiments and technical effects.

[0042] Example 1

[0043] This embodiment provides a method for preparing a graphene-based zinc oxide / manganese dioxide-polyaniline composite nickel-zinc battery anode material, comprising the following steps:

[0044] S1: Three-dimensional graphene was dispersed in a precursor solution containing zinc nitrate. Ammonia was added to adjust the pH to 9.5, and the mixture was subjected to a hydrothermal reaction at 110℃ for 6 hours. After washing and drying, three-dimensional graphene with zinc oxide particles loaded on its surface was obtained. The concentration of zinc ions in the precursor solution was 0.18 mol / L.

[0045] S2: Three-dimensional graphene with zinc oxide particles loaded on its surface was dispersed in deionized water to obtain a mixture. Potassium permanganate solution and manganese sulfate solution were added to the mixture, and after thorough mixing, it was hydrothermally reacted at 190℃ for 8 hours. After washing and drying, three-dimensional graphene with composite particles loaded on its surface was obtained. The concentration of the potassium permanganate solution was 0.025M, the molar ratio of potassium permanganate to manganese sulfate was 2:1, and the molar ratio of potassium permanganate to zinc oxide was 2:1.

[0046] S3: Three-dimensional graphene with surface-loaded composite particles was immersed in a mixed solution containing aniline, sulfosalicylic acid, and ammonium persulfate, and reacted at 4°C for 8 hours. After washing and drying, graphene-based zinc oxide / manganese dioxide-polyaniline composite nickel-zinc battery anode material was obtained. In this step, the concentration of aniline in the mixed solution was 0.25 mol / L, the molar ratio of sulfosalicylic acid to aniline was 1.3:1, and the molar ratio of ammonium persulfate to aniline was 0.6:1.

[0047] Example 2

[0048] This embodiment provides a method for preparing a graphene-based zinc oxide / manganese dioxide-polyaniline composite nickel-zinc battery anode material, comprising the following steps:

[0049] S1: Three-dimensional graphene was dispersed in a precursor solution containing zinc acetate, and ammonia was added to adjust the pH to 9. The mixture was then subjected to a hydrothermal reaction at 120°C for 4 hours. After washing and drying, three-dimensional graphene with zinc oxide particles loaded on its surface was obtained. The concentration of zinc ions in the precursor solution was 0.15 mol / L.

[0050] S2: Three-dimensional graphene with zinc oxide particles loaded on its surface was dispersed in deionized water to obtain a mixture. Potassium permanganate solution and manganese sulfate solution were added to the mixture, and after mixing evenly, the mixture was subjected to hydrothermal reaction at 180℃ for 10 h. After washing and drying, three-dimensional graphene with composite particles loaded on its surface was obtained. The concentration of potassium permanganate solution was 0.02 M, the molar ratio of potassium permanganate to manganese sulfate was 2:1, and the molar ratio of potassium permanganate to zinc oxide was 1:1.

[0051] S3: Three-dimensional graphene with surface-loaded composite particles was immersed in a mixed solution containing aniline, sulfosalicylic acid, and ammonium persulfate, and reacted at 0°C for 6 hours. After washing and drying, graphene-based zinc oxide / manganese dioxide-polyaniline composite nickel-zinc battery anode material was obtained. In this step, the concentration of aniline in the mixed solution was 0.2 mol / L, the molar ratio of sulfosalicylic acid to aniline was 1.2:1, and the molar ratio of ammonium persulfate to aniline was 0.5:1.

[0052] Example 3

[0053] This embodiment provides a method for preparing a graphene-based zinc oxide / manganese dioxide-polyaniline composite nickel-zinc battery anode material, comprising the following steps:

[0054] S1: Three-dimensional graphene was dispersed in a precursor solution containing zinc nitrate or zinc acetate. Ammonia was added to adjust the pH to 10, and the mixture was subjected to a hydrothermal reaction at 100°C for 8 hours. After washing and drying, three-dimensional graphene with zinc oxide particles loaded on its surface was obtained. The concentration of zinc ions in the precursor solution was 0.2 mol / L.

[0055] S2: Three-dimensional graphene with zinc oxide particles loaded on its surface was dispersed in deionized water to obtain a mixture. Potassium permanganate solution and manganese sulfate solution were added to the mixture, and after thorough mixing, it was hydrothermally reacted at 200℃ for 6 hours. After washing and drying, three-dimensional graphene with composite particles loaded on its surface was obtained. The concentration of the potassium permanganate solution was 0.03M, the molar ratio of potassium permanganate to manganese sulfate was 2:1, and the molar ratio of potassium permanganate to zinc oxide was 3:1.

[0056] S3: Three-dimensional graphene with surface-loaded composite particles was immersed in a mixed solution containing aniline, sulfosalicylic acid, and ammonium persulfate, and reacted at 5°C for 12 h. After washing and drying, graphene-based zinc oxide / manganese dioxide-polyaniline composite nickel-zinc battery anode material was obtained. In this step, the concentration of aniline in the mixed solution was 0.3 mol / L, the molar ratio of sulfosalicylic acid to aniline was 1.5:1, and the molar ratio of ammonium persulfate to aniline was 0.8:1.

[0057] Example 4

[0058] This embodiment provides a method for preparing a graphene-based zinc oxide / manganese dioxide-polyaniline composite nickel-zinc battery anode material, comprising the following steps:

[0059] S1: Three-dimensional graphene was dispersed in a precursor solution containing zinc nitrate. Ammonia was added to adjust the pH to 9.3, and the mixture was subjected to a hydrothermal reaction at 105℃ for 5 hours. After washing and drying, three-dimensional graphene with zinc oxide particles loaded on its surface was obtained. The concentration of zinc ions in the precursor solution was 0.19 mol / L.

[0060] S2: Three-dimensional graphene with zinc oxide particles loaded on its surface was dispersed in deionized water to obtain a mixture. Potassium permanganate solution and manganese sulfate solution were added to the mixture, and after mixing evenly, the mixture was subjected to hydrothermal reaction at 195℃ for 7 hours. After washing and drying, three-dimensional graphene with composite particles loaded on its surface was obtained. The concentration of potassium permanganate solution was 0.03M, the molar ratio of potassium permanganate to manganese sulfate was 2:1, and the molar ratio of potassium permanganate to zinc oxide was 2.5:1.

[0061] S3: Three-dimensional graphene with surface-loaded composite particles was immersed in a mixed solution containing aniline, sulfosalicylic acid, and ammonium persulfate, and reacted at 2°C for 11 h. After washing and drying, graphene-based zinc oxide / manganese dioxide-polyaniline composite nickel-zinc battery anode material was obtained. In this step, the concentration of aniline in the mixed solution was 0.29 mol / L, the molar ratio of sulfosalicylic acid to aniline was 1.4:1, and the molar ratio of ammonium persulfate to aniline was 0.7:1.

[0062] Comparative Example 1

[0063] This comparative example provides a method for preparing a nickel-zinc battery anode material. The difference from Example 1 is that step S3 is not performed.

[0064] Comparative Example 2

[0065] This comparative example provides a method for preparing a nickel-zinc battery anode material. The difference from Example 1 is that step S3 does not contain sulfosalicylic acid.

[0066] Comparative Example 3

[0067] This comparative example provides a method for preparing a nickel-zinc battery anode material. The difference from Example 1 is that step S2 is not performed.

[0068] The negative electrode materials prepared in Examples 1-4 and Comparative Examples 1-3 were used to prepare nickel-zinc battery negative electrodes. A nickel-zinc battery positive electrode and an electrolyte were also provided. The components were assembled to obtain a nickel-zinc battery. The electrochemical performance of each nickel-zinc battery was tested (unless otherwise specified, all tests were performed at room temperature), and the results are shown in Table 1.

[0069] Long cycle life test: 300 complete charge-discharge cycles were performed at a current density of 0.1C (1C = 90mAh / g). The discharge capacity was recorded for each cycle, and the capacity retention rate after the 300th cycle was calculated, which is the ratio of the discharge capacity of the 300th cycle to the discharge capacity of the first cycle, expressed as a percentage.

[0070] Self-discharge performance test: After charging the nickel-zinc battery to full capacity, leave it for 7 days, and then conduct a discharge test again. Compare the difference in discharge capacity before and after the leave period, and calculate the percentage of capacity loss of the battery. The percentage of capacity loss is calculated using the following formula:

[0071] Capacity loss percentage = (1 - (discharge capacity after storage / discharge capacity before storage)) × 100%;

[0072] Rate performance test: The first discharge capacity of the nickel-zinc battery was tested at current densities of 0.1C and 5C respectively, and the percentage of the first discharge capacity at 5C current density to the first discharge capacity at 0.1C current density was calculated.

[0073] After the nickel-zinc battery was stabilized in an environment of 50°C for a period of time, it was subjected to 100 complete charge-discharge cycles at a current density of 0.1C, and the coulombic efficiency of the 100th cycle was recorded.

[0074] Table 1. Statistical table of electrochemical performance of nickel-zinc batteries corresponding to Examples 1-4 and Comparative Examples 1-3.

[0075]

[0076] As shown in Table 1, the zinc-nickel batteries of Examples 1-4 maintained a capacity retention rate of over 87% after 300 cycles, while the nickel-zinc batteries of Comparative Examples 1-3 showed a significant decrease in capacity retention rate after 300 cycles. This indicates that the present invention can significantly inhibit the growth of zinc dendrites through sulfonate groups, thereby improving the cycle life of nickel-zinc batteries. Looking at the percentage of capacity loss after 7 days of storage, the average capacity loss of Examples 1-4 was approximately 2.1%, while that of Comparative Examples 1-3 generally exceeded 5%, reaching a maximum of 7.91%. This demonstrates that the sulfonated polyaniline coating layer and manganese dioxide in the present invention can work together to reduce the self-discharge rate and improve the long-term storage stability of the battery. The nickel-zinc batteries of Examples 1-4 achieved 79-83% of the initial discharge capacity at 0.1C at a current density of 5C, indicating good high-rate performance. Comparative Examples 1-3, lacking a polyaniline layer, without sulfonation modification of the polyaniline, and without the addition of manganese dioxide, exhibited poor rate performance. The nickel-zinc batteries in Examples 1-4 can achieve a coulombic efficiency of over 90% at a high temperature of 50°C, while the efficiency of Comparative Examples 1-3 is significantly reduced.

[0077] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A graphene-based zinc oxide / manganese dioxide-polyaniline composite nickel-zinc battery anode material, characterized in that, It includes a three-dimensional graphene substrate, composite particles loaded on the three-dimensional graphene substrate, and a sulfonated modified polyaniline layer coated on the surface of the composite particles; The composite particles include zinc oxide and manganese dioxide.

2. A method for preparing the graphene-based zinc oxide / manganese dioxide-polyaniline composite nickel-zinc battery anode material according to claim 1, characterized in that, Includes the following steps: S1: Three-dimensional graphene is dispersed in a precursor solution containing zinc salt, a pH adjuster is added, and three-dimensional graphene with zinc oxide particles loaded on the surface is obtained through hydrothermal reaction. S2: Disperse the three-dimensional graphene with zinc oxide particles on the surface in deionized water to obtain a mixture. Add potassium permanganate solution and manganese sulfate solution to the mixture, mix evenly, and then carry out a hydrothermal reaction to obtain three-dimensional graphene with composite particles on the surface. S3: Three-dimensional graphene with surface-loaded composite particles is immersed in a mixed solution containing aniline, sulfosalicylic acid and ammonium persulfate to carry out an in-situ polymerization reaction, so that sulfonated modified polyaniline is coated on the surface of the composite particles to obtain graphene-based zinc oxide / manganese dioxide-polyaniline composite nickel-zinc battery anode material.

3. The preparation method of the graphene-based zinc oxide / manganese dioxide-polyaniline composite nickel-zinc battery anode material according to claim 2, characterized in that, In step S1, the zinc salt is zinc nitrate or zinc acetate, and the concentration of zinc ions in the precursor solution is 0.15-0.2 mol / L.

4. The preparation method of the graphene-based zinc oxide / manganese dioxide-polyaniline composite nickel-zinc battery anode material according to claim 2, characterized in that, In step S1, the hydrothermal reaction temperature is 100-120℃ and the reaction time is 4-8h.

5. The preparation method of the graphene-based zinc oxide / manganese dioxide-polyaniline composite nickel-zinc battery anode material according to claim 2, characterized in that, In step S2, the concentration of potassium permanganate solution is 0.02-0.03M, the molar ratio of potassium permanganate to manganese sulfate is 2:1, and the molar ratio of potassium permanganate to zinc oxide is (1-3):

1.

6. The preparation method of the graphene-based zinc oxide / manganese dioxide-polyaniline composite nickel-zinc battery anode material according to claim 2, characterized in that, In step S2, the hydrothermal reaction temperature is 180-200℃, and the reaction time is 6-10h.

7. The preparation method of the graphene-based zinc oxide / manganese dioxide-polyaniline composite nickel-zinc battery anode material according to claim 2, characterized in that, In step S3, the concentration of aniline in the mixed solution is 0.2-0.3 mol / L, the molar ratio of sulfosalicylic acid to aniline is (1.2-1.5):1, and the molar ratio of ammonium persulfate to aniline is (0.5-0.8):

1.

8. The preparation method of the graphene-based zinc oxide / manganese dioxide-polyaniline composite nickel-zinc battery anode material according to claim 2, characterized in that, In step S3, the temperature of the in-situ polymerization reaction is 0-5℃, and the reaction time is 6-12h.

9. A nickel-zinc battery, characterized in that, The graphene-based zinc oxide / manganese dioxide-polyaniline composite nickel-zinc battery anode material as described in claim 1, or the graphene-based zinc oxide / manganese dioxide-polyaniline composite nickel-zinc battery anode material prepared by the preparation method described in any one of claims 2-8.

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