MOF-based nanometer positive electrode material and application thereof in aqueous zinc ion battery

Abstract

The invention provides an MOF-based nano positive electrode material and application thereof in an aqueous zinc ion battery, and relates to the field of electrochemical energy storage devices, and the MOF-based nano positive electrode material comprises a bimetallic MOF which is formed by bimetallic cluster nodes composed of divalent manganese ions and trivalent vanadium ions; the organic ligand is a polydentate carboxylic acid ligand containing a rigid aromatic ring structure, the organic ligand and the bimetallic cluster node are in coordination connection to form a three-dimensional frame structure, and the three-dimensional frame structure is provided with hierarchical pore channels. According to the MOF-based nano positive electrode material, a three-dimensional continuous conductive coating layer is constructed on the surface of a bimetal MOF by adopting nitrogen-doped carbon nanofibers, Mn-N and V-N coordination bonds are formed at an interface, firm heterogeneous interface bonding and an efficient electron transport network are realized, the mechanical stress of electrode particles is effectively buffered in the circulation process, and the electrochemical performance of the electrode particles is improved. The conductive network is prevented from cracking or falling off, and the overall conductive continuity of the electrode is ensured.

Description

A MOF-based nano-cathode material and its application in aqueous zinc-ion batteries Technical Field

[0001] This invention relates to the field of electrochemical energy storage device technology, specifically to a MOF-based nano cathode material and its application in aqueous zinc-ion batteries. Background Technology

[0002] Aqueous zinc-ion batteries, characterized by high safety, low cost, and environmental friendliness, have become a candidate for large-scale energy storage technology. Current research focuses on developing high-performance cathode materials to match zinc anodes. Vanadium-based oxides, such as vanadium pentoxide, possess high specific capacity and are widely studied cathode materials. Manganese-based oxides, including manganese dioxide and its hydrates, are abundant and structurally diverse. Prussian blue analogues, with their open framework structure, provide convenient channels for zinc ion transport. These materials operate using an intercalation-type electrochemical mechanism, accommodating zinc ions during charge and discharge. Researchers employ nanoengineering techniques to control material morphology, shortening ion diffusion paths and increasing the contact area between the electrode and electrolyte. Organic cathode materials, utilizing the reversible reactions of active functional groups, show application potential. Electrolyte optimization and interface modification strategies are often used to synergistically improve overall battery performance.

[0003] However, existing cathode materials face a fundamental challenge: the instability of their crystal structure during cycling. Zinc ions carry two positive charges and exhibit strong polarization, generating significant stress during their insertion and extraction from the cathode material lattice. This repeated lattice stress easily induces irreversible phase transitions in the material structure or leads to the gradual collapse of the crystal framework. Specifically, this manifests as the stripping of active material from the current collector, loss of active sites, and disruption of the conductive network. For layered materials, interlayer collapse or spacing changes occur, hindering continuous ion diffusion. For tunnel structures or open-framework materials, host-guest interactions can lead to channel blockage or framework dissolution. This structural degradation directly causes rapid capacity decay and insufficient cycle life, severely restricting the practical application of aqueous zinc-ion batteries. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a MOF-based nano-cathode material and its application in aqueous zinc-ion batteries. The technical problem this invention aims to solve is: how to construct a composite structure of a bimetallic MOF with hierarchical channels and a nitrogen-doped carbon nanofiber conductive coating layer to address the limitations of Zn in aqueous zinc-ion batteries. 2+ The problem of unstable crystal structure and easy failure of conductive network during the insertion and extraction process.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solution: a MOF-based nano cathode material, comprising: a bimetallic MOF: formed by bimetallic cluster nodes composed of divalent manganese ions and trivalent vanadium ions.

[0006] Organic ligand: a multidentate carboxylic acid ligand containing a rigid aromatic ring structure, wherein the organic ligand and the bimetallic cluster nodes are coordinated to form a three-dimensional framework structure, and the three-dimensional framework structure has hierarchical channels.

[0007] Conductive coating layer: The conductive coating layer is nitrogen-doped carbon nanofibers, which are coated on the surface of the bimetallic MOF to form a three-dimensional continuous network on the surface of the bimetallic MOF.

[0008] Preferably, the divalent manganese ions and the trivalent vanadium ions are connected by oxygen bridge bonds to form the bimetallic cluster node, and the molar ratio of the divalent manganese ions to the trivalent vanadium ions in the bimetallic cluster node is 1:0.8-1:1.2.

[0009] Preferably, the bimetallic MOF has a microstructure of one-dimensional nanowires with a diameter of 20 nm-100 nm and a length of 1 μm-10 μm, and the bimetallic MOF has a specific surface area of ​​200 m². 2 / g-1200m 2 / g.

[0010] Preferably, the hierarchical pore structure includes micropores, mesopores, and macropores, wherein the pore size of the micropores is <2 nm, the pore size of the mesopores is 2 nm-50 nm, the pore size of the macropores is 50 nm-200 nm, and the loading of the organic ligand in the bimetallic MOF is 0.5 mmol / g-2.0 mmol / g.

[0011] Preferably, the polydentate carboxylic acid ligand is 2,6-naphthalenedicarboxylic acid, and the angle between the aromatic ring plane of the polydentate carboxylic acid ligand and the plane of the bimetallic MOF layer is 70°-110°.

[0012] Preferably, the nitrogen-doped carbon nanofibers have an average diameter of 60 nm to 300 nm, the conductive coating layer has a thickness of 5 nm to 50 nm, the mass ratio of the bimetallic MOF to the conductive coating layer is 10:1 to 1:1, and the nitrogen-doped carbon nanofibers and the bimetallic MOF form Mn-N coordination bonds and VN coordination bonds at the interface.

[0013] Preferably, the three-dimensional continuous network has a coverage of 20%–60% on the surface of the bimetallic MOF, and the porosity of the three-dimensional continuous network is 10%–60%.

[0014] An application of a MOF-based nano cathode material in an aqueous zinc-ion battery includes: the application of the MOF-based nano cathode material in preparing an aqueous zinc-ion battery cathode with a capacity retention of not less than 90% after 500 cycles at 1C.

[0015] This invention provides a MOF-based nano-cathode material and its application in aqueous zinc-ion batteries. It offers the following advantages: This invention constructs a material based on Mn... 2+ / V 3+ A one-dimensional nanowire MOF framework with hierarchical channels, composed of bimetallic cluster nodes and rigid aromatic ring polydentate carboxylic acid ligands, alleviates Zn 2+ The lattice stress and volume changes caused by the insertion / deintercalation process suppress interlayer collapse, framework dissolution, and irreversible phase transitions, maintaining the crystal structure integrity and active site effectiveness of the cathode material, and improving the cycle stability of aqueous zinc-ion batteries. The hierarchical pore structure also provides a continuous electrolyte wetting path and multi-scale Zn... 2+ Diffusion channels reduce ion transport resistance and improve the utilization rate of active materials and specific capacity output.

[0016] This MOF-based nano-cathode material utilizes nitrogen-doped carbon nanofibers to construct a three-dimensional continuous conductive coating layer on the surface of a bimetallic MOF, forming Mn–N and V–N coordination bonds at the interface. This achieves a robust heterogeneous interface bond and a highly efficient electron transport network, effectively buffering the mechanical stress of electrode particles during cycling and preventing cracking or detachment of the conductive network, thus ensuring the overall conductivity continuity of the electrode. Thanks to the synergistic optimization of structural stability and conductivity, when applied to aqueous zinc-ion batteries, this MOF-based nano-cathode material achieves a capacity retention of no less than 90% after 500 cycles at 1C, exhibiting both long cycle life and excellent rate performance. This is beneficial for promoting the engineering application of aqueous zinc-ion batteries in large-scale energy storage and other fields. Attached Figure Description

[0017] Figure 1 is a schematic diagram of the bimetallic MOF nanowire structure of the present invention; Figure 2 is a schematic diagram of the three-dimensional framework and hierarchical pore structure of the present invention; Figure 3 is a schematic diagram of the application of the MOF-based nano cathode material of the present invention in an aqueous zinc-ion battery. Detailed Implementation

[0018] The technical solutions in the embodiments of the present invention have been clearly and completely described. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] Example 1, as shown in Figures 1-3, provides a MOF-based nano-cathode material, comprising a bimetallic MOF: formed by bimetallic cluster nodes composed of divalent manganese ions and trivalent vanadium ions. The divalent manganese ions and trivalent vanadium ions are connected by oxygen bridges to form the bimetallic cluster nodes, with a molar ratio of divalent manganese ions to trivalent vanadium ions in the bimetallic cluster nodes of 1:0.8. The microstructure of the bimetallic MOF is a one-dimensional nanowire with a diameter of 20 nm and a length of 1 μm. The specific surface area of ​​the bimetallic MOF is 200 m². 2 / g.

[0020] The organic ligand is a polydentate carboxylic acid ligand containing a rigid aromatic ring structure. The organic ligand and the bimetallic cluster nodes coordinate to form a three-dimensional framework structure with hierarchical pores. The hierarchical pore structure includes micropores, mesopores, and macropores. The micropore diameter is <2 nm, the mesopore diameter is 2 nm, and the macropore diameter is 50 nm. The loading of the organic ligand in the bimetallic MOF is 0.5 mmol / g. The polydentate carboxylic acid ligand is 2,6-naphthalenedicarboxylic acid, and the angle between the aromatic ring plane of the polydentate carboxylic acid ligand and the plane of the bimetallic MOF layer is 70°.

[0021] Conductive Coating: The conductive coating is composed of nitrogen-doped carbon nanofibers, which are coated on the surface of the bimetallic MOF to form a three-dimensional continuous network. The average diameter of the nitrogen-doped carbon nanofibers is 60 nm, the thickness of the conductive coating is 5 nm, and the mass ratio of the bimetallic MOF to the conductive coating is 1:1. Mn-N and VN coordination bonds are formed between the nitrogen-doped carbon nanofibers and the bimetallic MOF at the interface. The three-dimensional continuous network covers 20% of the bimetallic MOF surface, and its porosity is 10%.

[0022] An application of a MOF-based nano cathode material in an aqueous zinc-ion battery includes: the application of the MOF-based nano cathode material in preparing an aqueous zinc-ion battery cathode with a capacity retention of not less than 90% after 500 cycles at 1C.

[0023] Structural characteristics of bimetallic MOFs: Bimetallic MOFs consist of bimetallic cluster nodes composed of divalent manganese ions and trivalent vanadium ions, possessing a one-dimensional nanowire structure with a diameter of 20 nm, a length of 1 μm, and a specific surface area of ​​200 m². 2 / g. The microstructure helps to enhance electrochemical performance.

[0024] The role of organic ligands: Employing polydentate carboxylic acid ligands with rigid aromatic ring structures forms a three-dimensional framework structure with hierarchical channels. This hierarchical channel structure helps improve the ion conductivity of the battery.

[0025] Innovation in conductive coating: Nitrogen-doped carbon nanofibers, with a thickness of 5 nm, are used as a conductive coating layer to cover the surface of a bimetallic MOF, forming a three-dimensional continuous network. The conductive coating layer is bonded to the bimetallic MOF through Mn-N and VN coordination bonds, enhancing the conductivity of the material.

[0026] Application in aqueous zinc-ion batteries: MOF-based nano-cathode materials exhibit good cycle stability in aqueous zinc-ion batteries. After 500 cycles at 1C, the capacity retention is no less than 90%, demonstrating excellent electrochemical performance.

[0027] Example 2 This example describes a material with a specific surface area of ​​1200 m² 2 A bimetallic MOF-based nano cathode material with a nanowire diameter of 100 nm per g exhibits excellent electrochemical performance and higher capacity retention, making it suitable for high-performance aqueous zinc-ion batteries.

[0028] Bimetallic MOFs are formed by bimetallic cluster nodes composed of divalent manganese ions and trivalent vanadium ions. The divalent manganese ions and trivalent vanadium ions are connected by oxygen bridges to form bimetallic cluster nodes, with a molar ratio of 1:1.2. The microstructure of the bimetallic MOF is that of one-dimensional nanowires, with a diameter of 100 nm and a length of 10 μm. The specific surface area of ​​the bimetallic MOF is 1200 m². 2 / g.

[0029] The organic ligand is a polydentate carboxylic acid ligand containing a rigid aromatic ring structure. The organic ligand and the bimetallic cluster nodes coordinate to form a three-dimensional framework structure with hierarchical pores. The hierarchical pore structure includes micropores, mesopores, and macropores. The micropore diameter is <2 nm, the mesopore diameter is 50 nm, and the macropore diameter is 200 nm. The loading of the organic ligand in the bimetallic MOF is 2.0 mmol / g. The polydentate carboxylic acid ligand is 2,6-naphthalenedicarboxylic acid, and the angle between the aromatic ring plane of the polydentate carboxylic acid ligand and the plane of the bimetallic MOF layer is 110°.

[0030] Conductive Coating: The conductive coating layer consists of nitrogen-doped carbon nanofibers coated on the surface of the bimetallic MOF, forming a three-dimensional continuous network. The average diameter of the nitrogen-doped carbon nanofibers is 300 nm, the thickness of the conductive coating layer is 50 nm, and the mass ratio of the bimetallic MOF to the conductive coating layer is 10:1. Mn-N and VN coordination bonds are formed between the nitrogen-doped carbon nanofibers and the bimetallic MOF at the interface. The three-dimensional continuous network covers 60% of the bimetallic MOF surface, and its porosity is 60%.

[0031] An application of a MOF-based nano cathode material in an aqueous zinc-ion battery includes: the application of the MOF-based nano cathode material in preparing an aqueous zinc-ion battery cathode with a capacity retention of not less than 90% after 500 cycles at 1C.

[0032] Parameters: Bimetallic MOF: Specific surface area: 1200 m² 2 / g, nanowire diameter: 100nm, nanowire length: 10μm, organic ligand: loading amount is 2.0mmol / g.

[0033] Conductive coating: nitrogen-doped carbon nanofibers, with a coating thickness of 50 nm and a coverage of 60%.

[0034] Conclusion: Under the maximum configuration, the specific surface area of ​​the bimetallic MOF is significantly increased to 1200 m². 2 The increased diameter and length of the nanowires (per g) provide more reaction sites and better electronic conductivity, enhancing the battery's electrochemical performance. The thicker and higher coverage of the nitrogen-doped carbon nanofiber coating enhances conductivity and interfacial stability. After 500 cycles at 1C, the aqueous zinc-ion battery retains at least 90% of its capacity, exhibiting stronger cycle stability and higher capacity. This configuration is suitable for applications with high battery performance requirements, providing extended periods of high efficiency.

[0035] Example 3 This example describes a material with a specific surface area of ​​700 m² 2 A bimetallic MOF-based nano-cathode material with a nanowire diameter of 60 nm / g provides balanced electrochemical performance, suitable for aqueous zinc-ion batteries with moderate performance requirements.

[0036] Bimetallic MOFs are formed by bimetallic cluster nodes composed of divalent manganese ions and trivalent vanadium ions. The divalent manganese ions and trivalent vanadium ions are connected by oxygen bridges to form bimetallic cluster nodes, with a molar ratio of 1:1.0. The microstructure of the bimetallic MOF is that of one-dimensional nanowires, with a diameter of 60 nm and a length of 5.5 μm. The specific surface area of ​​the bimetallic MOF is 700 m². 2 / g.

[0037] The organic ligand is a polydentate carboxylic acid ligand containing a rigid aromatic ring structure. The organic ligand and the bimetallic cluster nodes coordinate to form a three-dimensional framework structure with hierarchical pores. The hierarchical pore structure includes micropores, mesopores, and macropores. The micropore diameter is <2 nm, the mesopore diameter is 26 nm, and the macropore diameter is 125 nm. The loading of the organic ligand in the bimetallic MOF is 1.25 mmol / g. The polydentate carboxylic acid ligand is 2,6-naphthalenedicarboxylic acid, and the angle between the aromatic ring plane of the polydentate carboxylic acid ligand and the plane of the bimetallic MOF layer is 90°.

[0038] Conductive Coating: The conductive coating is composed of nitrogen-doped carbon nanofibers, which are coated on the surface of the bimetallic MOF to form a three-dimensional continuous network. The average diameter of the nitrogen-doped carbon nanofibers is 180 nm, the thickness of the conductive coating is 27.5 nm, and the mass ratio of the bimetallic MOF to the conductive coating is 4.5:1. Mn-N and VN coordination bonds are formed between the nitrogen-doped carbon nanofibers and the bimetallic MOF at the interface. The three-dimensional continuous network covers 40% of the bimetallic MOF surface, and its porosity is 35%.

[0039] An application of a MOF-based nano cathode material in an aqueous zinc-ion battery includes: the application of the MOF-based nano cathode material in preparing an aqueous zinc-ion battery cathode with a capacity retention of not less than 90% after 500 cycles at 1C.

[0040] Parameters: Bimetallic MOF: Specific surface area: 700 m² 2 / g, nanowire diameter: 60nm, nanowire length: 5.5μm, organic ligand: loading of 1.25mmol / g.

[0041] Conductive coating: nitrogen-doped carbon nanofibers, with a coating thickness of 27.5 nm and a coverage of 40%.

[0042] Conclusion: Under the intermediate configuration, the specific surface area of ​​the bimetallic MOF is 700 m². 2 The nanowires, with a moderate diameter and length, are of medium quality. This median material configuration provides a sufficient number of reaction sites while maintaining good conductivity. The nitrogen-doped carbon nanofiber coating, with a thickness of 27.5 nm and a coverage of 40%, supports the battery's stability and electrochemical performance. After 500 cycles at 1C, the capacity retention is no less than 90%. It provides stable battery performance in many applications, meeting the requirements for applications with moderate performance.

[0043] Example 4: In this example, by adjusting the specific surface area, nanowire size, and thickness of the nitrogen-doped carbon nanofiber coating of the bimetallic MOF, three MOF-based nano cathode materials with different properties were prepared, and their capacity retention and cycle stability were tested in an aqueous zinc-ion battery.

[0044] 1. Material selection and preparation: The composition of bimetallic MOFs consists of divalent manganese ions and trivalent vanadium ions.

[0045] Organic ligand: 2,6-naphthalenedicarboxylic acid, the angle between its aromatic ring plane and the MOF layer plane is adjusted according to different implementation steps.

[0046] Nitrogen-doped carbon nanofibers: used to coat bimetallic MOFs to enhance conductivity.

[0047] 2. Synthesis material 1 of bimetallic MOF: Specific surface area: 200 m² 2 / g, nanowire size: diameter 20nm, length 1μm.

[0048] Synthesis method: Bimetallic MOFs were synthesized by solution method. The temperature was controlled at 180℃ and maintained for 2 hours during the reaction to obtain smaller MOF nanowires.

[0049] Material 2: Specific surface area: 1200 m² 2 / g.

[0050] Nanowire dimensions: 100 nm in diameter and 10 μm in length.

[0051] Synthesis method: A solvothermal method was adopted, with the temperature controlled at 220℃ and the reaction time at 4 hours. By changing the amount of reaction liquid and the temperature, bimetallic MOFs with larger specific surface areas were obtained.

[0052] Material 3: Specific surface area: 700 m² 2 / g.

[0053] Nanowire dimensions: 60 nm in diameter and 5.5 μm in length.

[0054] Synthesis method: A combination of solution method and solvothermal method was used, with the temperature set at 200℃ and the reaction time at 3 hours to control the specific surface area and nanowire size.

[0055] 3. Organic ligand loading: Different concentrations of 2,6-naphthalenedicarboxylic acid ligand were added during the synthesis process, with loading amounts of 0.5 mmol / g, 2.0 mmol / g, and 1.25 mmol / g, respectively. The pore structure of the MOF and its effect on battery performance were adjusted by optimizing the amount of ligand added.

[0056] 4. Preparation of nitrogen-doped carbon nanofiber coating material 1: The diameter of the nitrogen-doped carbon nanofiber is 60 nm, the coating thickness is 5 nm, and the coverage is 20%. Nitrogen-doped carbon nanofibers are uniformly deposited on the MOF surface using chemical vapor deposition, and the deposition time is controlled to be 30 minutes.

[0057] Material 2: Nitrogen-doped carbon nanofibers with a diameter of 300 nm, a coating thickness of 50 nm, and a coverage of 60%. Nitrogen-doped carbon nanofibers were deposited using chemical vapor deposition (CVD) for 2 hours to ensure a thick coating layer and form a three-dimensional continuous network.

[0058] Material 3: Nitrogen-doped carbon nanofibers with a diameter of 180 nm, a coating thickness of 27.5 nm, and a coverage of 40%. Chemical vapor deposition was used, with a deposition time of 1 hour to ensure the formation of a uniform conductive coating.

[0059] 5. Battery Assembly and Performance Testing: The prepared MOF-based nano-cathode material, electrolyte, and symmetrical zinc electrode will be assembled into an aqueous zinc-ion battery. Battery capacity testing and cycle performance evaluation will be conducted under the same conditions.

[0060] Test conditions: 500 cycles at 1C. During the cycle test, the battery capacity retention rate was monitored.

[0061] Results Comparison: Material 1: After 500 cycles at 1C rate, the capacity retention is not less than 90%. Despite the smaller specific surface area, the battery still exhibits good stability.

[0062] Material 2: After 500 cycles at 1C, the capacity retention is still no less than 90%. The high specific surface area and larger nanowire size provide higher battery stability and better capacity retention.

[0063] Material 3: After 500 cycles at 1C rate, the capacity retention is not less than 90%, exhibiting balanced electrochemical performance, making it suitable for most conventional applications.

[0064] 6. Conclusion Based on the experimental results of different configurations, the following conclusions are drawn: Minimum configuration, Material 1: With a lower specific surface area and smaller size, the battery can still maintain more than 90% of its capacity, making it suitable for applications with low performance requirements.

[0065] Maximum configuration, Material 2: Nanowires with high specific surface area and large size improve battery performance and stability, making them suitable for high-performance battery applications.

[0066] Intermediate configuration, Material 3: This configuration exhibits good electrochemical performance, suitable for applications with moderate performance requirements, and provides good capacity retention and cycling stability.

[0067] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A MOF-based nano-cathode material, characterized in that, include: Bimetallic MOFs are formed by bimetallic cluster nodes composed of divalent manganese ions and trivalent vanadium ions. Organic ligand: a multidentate carboxylic acid ligand containing a rigid aromatic ring structure, wherein the organic ligand and the bimetallic cluster nodes are coordinated to form a three-dimensional framework structure, wherein the three-dimensional framework structure has hierarchical channels; conductive coating layer: the conductive coating layer is nitrogen-doped carbon nanofibers, wherein the nitrogen-doped carbon nanofibers are coated on the surface of the bimetallic MOF to form a three-dimensional continuous network on the surface of the bimetallic MOF.

2. The MOF-based nano-cathode material according to claim 1, characterized in that: The divalent manganese ions and the trivalent vanadium ions are connected by oxygen bridges to form the bimetallic cluster nodes, and the molar ratio of the divalent manganese ions to the trivalent vanadium ions in the bimetallic cluster nodes is 1:0.8-1:1.

2.

3. The MOF-based nano-cathode material according to claim 1, characterized in that: The bimetallic MOF has a microstructure of one-dimensional nanowires with a diameter of 20 nm-100 nm and a length of 1 μm-10 μm. The specific surface area of ​​the bimetallic MOF is 200 m². 2 / g-1200m 2 / g.

4. The MOF-based nano-cathode material according to claim 1, characterized in that: The hierarchical pore structure includes micropores, mesopores, and macropores. The pore size of the micropores is <2 nm, the pore size of the mesopores is 2 nm-50 nm, the pore size of the macropores is 50 nm-200 nm, and the loading of the organic ligand in the bimetallic MOF is 0.5 mmol / g-2.0 mmol / g.

5. The MOF-based nano-cathode material according to claim 1, characterized in that: The polydentate carboxylic acid ligand is 2,6-naphthalenedicarboxylic acid, and the angle between the aromatic ring plane of the polydentate carboxylic acid ligand and the plane of the bimetallic MOF layer is 70°-110°.

6. The MOF-based nano-cathode material according to claim 1, characterized in that: The nitrogen-doped carbon nanofibers have an average diameter of 60 nm to 300 nm, the conductive coating layer has a thickness of 5 nm to 50 nm, the mass ratio of the bimetallic MOF to the conductive coating layer is 10:1 to 1:1, and the nitrogen-doped carbon nanofibers and the bimetallic MOF form Mn-N coordination bonds and VN coordination bonds at the interface.

7. The MOF-based nano-cathode material according to claim 1, characterized in that: The three-dimensional continuous network has a coverage of 20%–60% on the surface of the bimetallic MOF, and the porosity of the three-dimensional continuous network is 10%–60%.

8. The application of a MOF-based nano-cathode material in an aqueous zinc-ion battery, as described in any one of claims 1-7, characterized in that... include: Application of MOF-based nano cathode materials in the preparation of aqueous zinc-ion battery cathodes with a capacity retention of no less than 90% after 500 cycles at 1C.

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