Zinc battery positive electrode material, preparation method and application thereof

Abstract

The invention discloses a zinc battery positive electrode material, a preparation method and application thereof, and the preparation method comprises the following steps: dissolving vanadium pentoxide, oxalic acid hydrate, lanthanum nitrate hydrate and hydrogen peroxide in a solvent to obtain a mixed solution, transferring the mixed solution to a hydrothermal kettle for heating reaction, separating and washing a solid product to obtain the zinc battery positive electrode material. A one-pot hydrothermal synthesis preparation process is adopted, the process conditions are mild and controllable, raw materials are easy to obtain, the cost is controllable, complex and precise instruments are not needed, the equipment investment is low, the process steps are simple, and continuous large-scale production is easy to achieve.

Description

Technical Field

[0001] This application relates to the field of electrochemical energy storage technology, specifically to a zinc battery cathode material, its preparation method, and its application. Background Technology

[0002] Faced with the dual challenges of continuously growing global energy demand and dwindling fossil fuel reserves, vigorously developing renewable energy has become a crucial and urgent path forward. Against this backdrop, electrochemical energy storage technology has attracted significant attention due to its ability to efficiently store and utilize renewable energy, driving the continuous research and application of various battery systems.

[0003] Currently, lithium-ion batteries have achieved large-scale commercialization, but they still face safety issues such as flammability, limiting their application in scenarios with high safety requirements. Meanwhile, novel battery systems such as sodium-ion, potassium-ion, and zinc-ion batteries have attracted widespread research attention due to their abundant resources, lower costs, or higher safety. Among them, aqueous zinc-ion batteries, with their high safety, high volumetric capacity, and relatively low redox potential, have shown significant application potential in large-scale energy storage, low-speed electric vehicles, and emergency power supplies, becoming an important complementary direction to lithium-ion batteries.

[0004] In aqueous zinc-ion batteries, the performance of the cathode material directly determines the battery's capacity, cycle stability, and rate capability. Among numerous cathode materials, vanadium-based materials such as vanadium dioxide and vanadium pentoxide, due to their rich crystal structures, can provide channels for zinc ion insertion / extraction, making them one of the research hotspots in this field.

[0005] However, existing vanadium-based cathode materials still face two major challenges in practical applications. First, due to the relatively closed crystal structure of traditional vanadium-based materials, the exposed active sites are limited, resulting in actual specific capacity far lower than theoretical values, and the reaction rate is also restricted. Second, during charge-discharge cycles, vanadium oxides easily dissolve in aqueous electrolytes, leading to continuous loss of active material. Repeated zinc ion insertion / extraction causes lattice expansion and contraction, which can easily lead to structural collapse after long-term cycling. These issues severely restrict the performance improvement and commercialization of zinc batteries. Summary of the Invention

[0006] The purpose of this application is to solve the problems of low actual specific capacity, poor cycle stability and long activation cycle of existing vanadium-based cathode materials.

[0007] To achieve the above objectives, the technical solution adopted in this application is as follows: to provide a zinc battery cathode material, the raw materials for which preparation includes vanadium oxide, lanthanum salt, reducing agent and solvent.

[0008] As a preferred embodiment, the vanadium oxide is vanadium pentoxide, and the lanthanum salt is lanthanum nitrate.

[0009] This application also provides a method for preparing a zinc battery cathode material, wherein vanadium pentoxide, oxalic acid hydrate, lanthanum nitrate hydrate and hydrogen peroxide are dissolved in a solvent to obtain a mixed solution, the mixed solution is transferred to a hydrothermal reactor for heating and reaction, and the solid product is separated and washed to obtain the zinc battery cathode material.

[0010] As another preferred option, the lanthanum nitrate hydrate is lanthanum nitrate hexahydrate.

[0011] As another preferred option, the concentration of the lanthanum nitrate hexahydrate is 1.5-2 g / L.

[0012] As another preferred embodiment, the concentration of vanadium pentoxide is 15-20 g / L.

[0013] As another preferred embodiment, the oxalic acid hydrate is oxalic acid dihydrate, and the concentration of the oxalic acid dihydrate is 35-40 g / L.

[0014] As another preferred embodiment, the mixed solution is heated in a hydrothermal reactor at a temperature of 140-180 °C for 1-2 days.

[0015] This application also provides a zinc battery, including a positive electrode, a negative electrode, a separator, a positive electrode electrolyte, and a negative electrode electrolyte, wherein the positive electrode is made of the above-described zinc battery positive electrode material, or the positive electrode is made of the zinc battery positive electrode material prepared by the above-described preparation method.

[0016] Further preferred, the zinc battery positive electrode material is mixed and ground with a conductive material to obtain a mixture, a binder is added and stirred evenly, then coated onto carbon paper and dried to form the positive electrode.

[0017] Compared with the prior art, the beneficial effects of this application are as follows: (1) This application introduces lanthanum ions into the positive electrode material of zinc battery. The open nanoflower morphology induced by lanthanum ions increases the specific surface area of ​​the material, allowing the electrode to contact the electrolyte more fully, while providing more zinc ion intercalation active sites, which greatly improves the capacity performance and activation speed of zinc battery. (2) The zinc battery cathode material of this application solves the problems of structural collapse and rapid capacity decay of traditional vanadium-based cathode materials. Through the design of the zinc battery cathode material, it can still maintain excellent stability under high rate conditions and effectively extend the service life of the battery. (3) This application adopts a one-pot hydrothermal synthesis preparation process. The process conditions are mild and controllable, the raw materials are easy to obtain and the cost is controllable. It does not require complex and precision instruments, the equipment investment is low, the process steps are simple, and it is easy to realize continuous large-scale production. Attached Figure Description

[0018] Figure 1X-ray diffraction analysis of the zinc battery cathode materials prepared in Example 1 and Comparative Example 1.

[0019] Figure 2 These are scanning electron microscope images of the zinc battery cathode materials prepared in Example 1 and Comparative Example 1.

[0020] Figure 3 The image shows the elemental distribution of the zinc battery cathode material prepared in Example 1.

[0021] Figure 4 The image shows the elemental distribution of V, O, and La in the zinc battery cathode material prepared in Example 1.

[0022] Figure 5 The graphs show the rate charge-discharge cycle test results of the full cells prepared in Example 1 and Comparative Example 1.

[0023] Figure 6 The diagram shows the high-rate charge-discharge cycle test results of the full cells prepared in Example 1 and Comparative Example 1.

[0024] Figure 7 The images show the electrochemical impedance spectroscopy of the full cells prepared in Example 1 and Comparative Example 1.

[0025] Figure 8 The cyclic voltammograms are for the full cells prepared in Example 1 and Comparative Example 1. Detailed Implementation

[0026] The present application will be further described below with reference to specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0027] The terms “comprising” and “having”, and any variations thereof, in the specification and claims of this application are intended to cover non-exclusive inclusion, for example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product, or device.

[0028] This application provides a zinc battery cathode material, the raw materials for which include vanadium oxide, lanthanum salt, reducing agent and solvent.

[0029] Preferably, the raw materials for preparing the zinc battery cathode material include vanadium pentoxide, oxalic acid dihydrate, lanthanum salt, hydrogen peroxide, and a solvent, wherein the lanthanum salt is suitable for dissolving in the solvent and providing lanthanum ions.

[0030] This application introduces lanthanum ions into the cathode material of zinc batteries. The unique f-orbital electronic structure of lanthanum ions helps improve the conductivity of vanadium dioxide and achieve high-rate capacity. The positively charged lanthanum ions can reduce the electrostatic interaction between vanadium dioxide layers and promote the diffusion of zinc ions. Lanthanum ions can stabilize the vanadium dioxide structure and prevent the vanadium dioxide structure from collapsing, so that the vanadium dioxide cathode can cycle stably during charge and discharge, thereby improving battery capacity, capacity retention and electrochemical kinetics.

[0031] In some embodiments, the lanthanum salt is dissolved in a solvent such that the concentration of lanthanum ions in the solvent is 3-5 mmol / L.

[0032] This application also provides a method for preparing a zinc battery cathode material, comprising the following steps: dissolving vanadium pentoxide, oxalic acid dihydrate, lanthanum nitrate hydrate and hydrogen peroxide in a solvent to obtain a mixed solution; heating the mixed solution in a hydrothermal reactor to react; separating and washing the solid product to obtain the zinc battery cathode material of this application.

[0033] In some embodiments, the concentration of lanthanum nitrate hydrate is 1.5-2 g / L. Lanthanum nitrate hydrate is preferably lanthanum nitrate hexahydrate.

[0034] In some embodiments, the mixed solution is heated in a hydrothermal reactor at 140-180 °C for 1-2 days.

[0035] In a preferred embodiment, the concentration of vanadium pentoxide is 15-20 g / L, and the concentration of oxalic acid dihydrate is 35-40 g / L.

[0036] Preferably, vanadium pentoxide, oxalic acid dihydrate, and lanthanum nitrate hexahydrate can be obtained by purchasing, and the above raw materials are selected as commercial raw materials with a purity of not less than 99%.

[0037] In some embodiments, vanadium pentoxide, oxalic acid dihydrate, and lanthanum nitrate hexahydrate are dissolved, and then an aqueous solution of hydrogen peroxide is added while stirring continues to obtain a mixed solution. Adding the aqueous solution of hydrogen peroxide can reduce the vanadium content by 6%. 5+ Restore to V 4+ Furthermore, the reduction process is mild and controllable, avoiding excessive reduction of vanadium valence due to strong reducing agents and ensuring that the product is mainly VO2 phase. The liquid reduction system of hydrogen peroxide allows the reaction to proceed at room temperature, reducing energy consumption while avoiding particle agglomeration caused by high temperature, which is highly compatible with the low energy consumption and easy scalability characteristics of this application.

[0038] Hydrogen peroxide can also form vanadium peroxide complexes with vanadium sources. These complexes have a specific spatial configuration and can serve as structural guiding units for subsequent hydrothermal crystallization, directing the growth of VO2 crystals along a specific direction. When the system enters the hydrothermal stage, H2O2 slowly decomposes to produce trace amounts of O2, preventing the growing VO2 crystals from packing together tightly. This provides the spatial conditions for lanthanum ions to induce the formation of open nanoflower structures, ultimately increasing the specific surface area of ​​the material.

[0039] In some embodiments, the hydrogen peroxide aqueous solution contains 30 wt.% hydrogen peroxide. This application also provides a specific method for preparing a zinc battery cathode material, comprising: adding vanadium pentoxide and oxalic acid dihydrate to deionized water; starting a stirrer and setting the magnetic stirring speed to 600-800 rpm, the stirring temperature to 20-85 ℃, and the stirring time to 90-120 minutes; then adding lanthanum nitrate hexahydrate and continuing stirring, setting the magnetic stirring speed to 400-800 rpm, the stirring temperature to 20-35 ℃, and the stirring time to 10-30 minutes; adding an aqueous solution of hydrogen peroxide to the solution and continuing stirring, setting the magnetic stirring speed to 400-600 rpm, the stirring temperature to 30-35 ℃, and the stirring time to 20-30 minutes, to obtain a mixed solution.

[0040] The mixed solution was transferred to a hydrothermal reactor and heated to 140-180 °C for 1-2 days. The solid product was then separated, washed repeatedly with deionized water, and dried in a vacuum oven for 10-48 hours at 50-70 °C to obtain the zinc battery cathode material of this application.

[0041] This application employs a one-pot method to prepare zinc battery cathode materials, enhancing battery capacity and electrochemical kinetics by introducing lanthanum ions. The preparation method utilizes a mild and controllable reduction system, ensuring product purity. Stirring and hydrothermal synthesis are well-suited for structural control. Raw materials are readily available and cost-effective, and the process requires no special equipment, making it suitable for large-scale production.

[0042] This application also provides a zinc battery, including a positive electrode, a negative electrode, a separator, a positive electrode electrolyte, and a negative electrode electrolyte, wherein the positive electrode is prepared from the zinc battery positive electrode material of this application.

[0043] This application also provides a method for preparing a zinc battery positive electrode sheet, wherein the zinc battery positive electrode material of this application is mixed with conductive carbon and ground to obtain a mixture, a binder is added and stirred evenly, and then coated on carbon paper and dried to obtain a zinc battery positive electrode sheet.

[0044] Zinc batteries using the zinc battery cathode sheet of this application can promote zinc ion diffusion, accelerate electrochemical kinetics, suppress battery capacity decay, shorten activation cycle, and improve production efficiency. This effectively increases battery capacity while also increasing battery capacity retention, thus promoting the commercial application of zinc battery cathodes.

[0045] Example 1 Preparation of a zinc battery cathode material: Weigh 1.4 g of vanadium pentoxide powder and 2.5 g of oxalic acid dihydrate powder, place them in a 100 mL beaker, add 70 mL of deionized water to the beaker, add a magnetic stir bar and set the stirring speed to 800 rpm, and stir the solution for 120 minutes; add 0.2 g of lanthanum nitrate hexahydrate and continue stirring for 15 minutes; add 6 mL of 30% hydrogen peroxide aqueous solution to the beaker, set the stirring speed to 600 rpm, and stir for 30 minutes to obtain a mixed solution; The mixed solution was transferred to a hydrothermal reactor with a 100 mL polytetrafluoroethylene liner and placed in an oven for constant heating at 160°C for 1 day. The product in the hydrothermal reactor was filtered to separate the solid product, washed three times with deionized water, and dried in a vacuum drying oven at 60°C for 24 hours to obtain the zinc battery cathode material of this application.

[0046] A zinc battery positive electrode is prepared by mixing the prepared zinc battery positive electrode material with conductive carbon at a mass ratio of 7:2 and grinding them to obtain a mixture. Then, 1 / 9 of the mass of polyvinylidene fluoride binder (dissolved in N-methylpyrrolidone) is added to prepare a positive electrode slurry. After stirring for 24 hours, the slurry is coated onto carbon paper and dried overnight to obtain a zinc battery positive electrode sheet.

[0047] Battery assembly: Whatman fiber membrane is used as the separator, 2 mol / L Zn(CF3SO3)2 solution is used as the electrolyte, zinc foil electrode is used as the negative electrode, and lanthanum ion-doped vanadium dioxide electrode or undoped vanadium dioxide electrode is used as the positive electrode. The surface area of ​​each electrode is 1 cm². 2 Stainless steel sheet is used as negative electrode pad, and a full cell is obtained by assembling Example 1.

[0048] Example 2 Preparation of a zinc battery cathode material: Weigh 1.4 g of vanadium pentoxide powder and 2.5 g of oxalic acid dihydrate powder, place them in a 100 mL beaker, add 70 mL of deionized water to the beaker, add a magnetic stir bar and set the stirring speed to 800 rpm, and stir the solution for 120 minutes; add 0.4 g of lanthanum nitrate hexahydrate and continue stirring for 15 minutes; add 6 mL of 30% hydrogen peroxide aqueous solution to the beaker, set the stirring speed to 600 rpm, and stir for 30 minutes to obtain a mixed solution; The mixed solution was transferred to a hydrothermal reactor with a 100 mL polytetrafluoroethylene liner and placed in an oven for constant heating at 160 °C for 1 day. The product in the hydrothermal reactor was filtered to separate the solid product, washed three times with deionized water, and dried in a vacuum drying oven at 60 °C for 24 hours to obtain the zinc battery cathode material of this application.

[0049] A zinc battery positive electrode is prepared by mixing the prepared zinc battery positive electrode material with conductive carbon at a mass ratio of 7:2 and grinding them to obtain a mixture. Then, 1 / 9 of the mass of polyvinylidene fluoride binder (dissolved in N-methylpyrrolidone) is added to prepare a positive electrode slurry. After stirring for 24 hours, the slurry is coated onto carbon paper and dried overnight to obtain a zinc battery positive electrode sheet.

[0050] Battery assembly: Whatman fiber membrane is used as the separator, 2 mol / L Zn(CF3SO3)2 solution is used as the electrolyte, zinc foil electrode is used as the negative electrode, and lanthanum ion-doped vanadium dioxide electrode or undoped vanadium dioxide electrode is used as the positive electrode. The surface area of ​​each electrode is 1 cm². 2 Stainless steel sheet is used as negative electrode pad, and the full cell of Example 2 is obtained by assembly.

[0051] Example 3 Weigh 1.4 g of vanadium pentoxide powder and 2.5 g of oxalic acid dihydrate powder, place them in a 100 mL beaker, add 70 mL of deionized water to the beaker, add a magnetic stir bar and set the stirring speed to 600 rpm, and stir the solution for 120 minutes; add 0.6 g of lanthanum nitrate hexahydrate and continue stirring for 15 minutes; add 6 mL of 30% hydrogen peroxide aqueous solution to the beaker, set the stirring speed to 400 rpm, and stir for 30 minutes to obtain a mixed solution; The mixed solution was transferred to a hydrothermal reactor with a 100 mL polytetrafluoroethylene liner and placed in an oven for constant heating at 160 °C for 1 day. The product in the hydrothermal reactor was filtered to separate the solid product, washed three times with deionized water, and dried in a vacuum drying oven at 60 °C for 24 hours to obtain the zinc battery cathode material of this application.

[0052] A zinc battery positive electrode is prepared by mixing the prepared zinc battery positive electrode material with conductive carbon at a mass ratio of 7:2 and grinding them to obtain a mixture. Then, 1 / 9 of the mass of polyvinylidene fluoride binder (dissolved in N-methylpyrrolidone) is added to prepare a positive electrode slurry. After stirring for 24 hours, the slurry is coated onto carbon paper and dried overnight to obtain a zinc battery positive electrode sheet.

[0053] Battery assembly: Whatman fiber membrane is used as the separator, 2 mol / L Zn(CF3SO3)2 solution is used as the electrolyte, zinc foil electrode is used as the negative electrode, and lanthanum ion-doped vanadium dioxide electrode or undoped vanadium dioxide electrode is used as the positive electrode. The surface area of ​​each electrode is 1 cm². 2 Stainless steel sheet is used as negative electrode pad, and the full cell of Example 3 is obtained by assembly.

[0054] Comparative Example 1 Lanthanum nitrate hexahydrate was not added during the preparation of the cathode material, and the other preparation steps were consistent with those in Example 1.

[0055] Performance testing X-ray diffraction analysis was performed on the zinc battery cathode materials prepared in Example 1 and Comparative Example 1, and the results were compared with the standard diffraction pattern of VO2. Figure 1 As shown, the zinc battery cathode material prepared in this application has a C2 / m space group structure, and the doping of lanthanum with vanadium dioxide causes the characteristic peaks to shift and broaden, proving the successful introduction of lanthanum ions.

[0056] The zinc battery cathode materials prepared in Example 1 and Comparative Example 1 were subjected to morphological characterization and analysis. For example... Figure 2 As shown, Figure 2 a and Figure 2 b is a scanning electron microscope image of the zinc ion cathode material prepared in Comparative Example 1. Figure 2 c and Figure 2 Image d shows a scanning electron microscope (SEM) image of the zinc ion cathode material prepared in Example 1. Analysis of the image reveals that the zinc ion cathode material prepared in Comparative Example 1 exhibits an aggregated nanoribbon morphology, while the zinc ion cathode material prepared in Example 1 shows an open nanoflower morphology. This results in a larger specific surface area, which facilitates more thorough contact between the electrode and the electrolyte after preparing the zinc battery cathode, thus benefiting the electrochemical reaction process.

[0057] The zinc ion cathode material prepared in Example 1 was characterized and analyzed for its composition. Figure 3 This is a panoramic view of the elemental distribution of the zinc battery cathode material in Example 1. It shows the overall distribution trend of all major elements in lanthanum-doped vanadium dioxide. It can be clearly observed in the figure that the signals of V, O and La elements completely overlap in the material region, with no obvious blank or missing areas. This directly proves that lanthanum has been successfully introduced into the vanadium dioxide material, and there is no phenomenon of undoped region or pure vanadium dioxide phase separation. This achieves uniform dispersion of lanthanum ions in the vanadium dioxide precursor solution, thereby ensuring the macroscopic uniformity of doped elements in the zinc battery cathode material.

[0058] Figure 4The elemental signal of the zinc battery cathode material in Example 1 was decomposed into three independent single-element distribution sub-maps for V, O, and La. In the La sub-map, the signal is uniformly distributed throughout the entire material region in a diffuse manner, and the position of each La element signal corresponds exactly to the position of the V and O element signals, without any point-like enrichment or linear aggregation. This distribution characteristic of single elements being completely synchronized with the matrix elements proves that lanthanum ions do not exist in the form of surface adsorption or independent La2O3 impurity phases, but are truly embedded in the lattice interstices of vanadium dioxide or replace part of V. 4+ The lattice sites of ions enable uniform doping at the lattice level.

[0059] The aqueous zinc-ion full cells assembled in Example 1 and Comparative Example 1 were subjected to cycle performance tests under conditions of 2 A / g and 20 A / g. Figure 5 The discharge specific capacity-cycle number curves of the full cells prepared in Example 1 and Comparative Example 1 at a current density of 2 A / g are shown. In the initial discharge, the discharge specific capacity of the zinc battery in Comparative Example 1 was only 325 mAh / g, while the discharge specific capacity of the zinc battery in Example 1 was as high as 450 mAh / g, indicating that the open nanostructure can provide more intercalation sites for zinc ions.

[0060] The full cell in Comparative Example 1 exhibited an activation process (electrochemical oxidation-induced phase transition, leading to capacity increase) in the early stages of charge-discharge cycling, requiring nearly 25 cycles for activation. In contrast, the full cell in Example 1 only required 10 cycles for activation, indicating that lanthanum ion intercalation accelerates the activation process. Under test conditions of 20 A / g current density, such as... Figure 6 As shown, the aqueous zinc-ion full cell prepared in Example 1 can retain 70% of its capacity after 10,500 cycles, while the full cell in Comparative Example 1 decays to 0. This demonstrates the superior high-rate performance of the zinc battery cathode material of this application.

[0061] Electrochemical impedance spectroscopy (EIS) was performed to analyze the conductivity of the cathode material. The EIS spectra of the zinc battery cathodes of Example 1 and Comparative Example 1 are shown below. Figure 7 As shown, the zinc battery positive electrode prepared in Example 1 of this application has a smaller charge transfer resistance (Rct), which proves that its conductivity is better.

[0062] Cyclic voltammetry tests were performed at 0.4 mV / s. The cyclic voltammetry curves of the full cells prepared in Example 1 and Comparative Example 1 are shown below. Figure 8As shown. The oxidation and reduction peak currents of the zinc battery cathode in Comparative Example 1 are low, indicating that there is high resistance to the zinc ion insertion / extraction process and the reaction rate is slow. It is speculated that this is because the pure VO2 lattice has poor conductivity and narrow interlayer channels, which restricts the rapid transfer of ions and charges. The oxidation and reduction peak currents of the zinc battery cathode prepared in Example 1 are significantly higher than those in Comparative Example 1: on the one hand, the f-orbital electronic structure of lanthanum ions optimizes the electronic band structure of VO2, improves the bulk conductivity of the material, and accelerates charge transfer; on the other hand, La 3+ By increasing the interlayer distance of VO2 and widening the zinc ion diffusion channels, the nanoflower structure provides more ion transport paths, which together reduce kinetic resistance and significantly enhance the peak current.

[0063] The CV curve of the zinc battery cathode in Comparative Example 1 has a smaller enclosed area, corresponding to its lower actual capacity. This is presumably due to the limited number of active sites exposed by the agglomerated nanoribbons of pure VO2, and the fact that some sites cannot fully participate in the reaction due to kinetic limitations. In contrast, the CV curve of the zinc battery cathode in Example 1 has a much larger enclosed area than that in Comparative Example 1. The core reason is La... 3+ The induced nanoflower structures have a larger specific surface area, exposing more zinc ion intercalation sites; simultaneously, La 3+ Uniform doping avoids local waste of active sites, allowing more sites to participate in redox reactions, directly supporting its high initial discharge specific capacity of 450 mAh / g.

[0064] The oxidation and reduction peak potential difference of the zinc battery cathode in Comparative Example 1 is relatively large, reflecting poor reversibility of its redox reaction. Lattice distortion is prone to occur during charge and discharge, making it difficult for the reaction to proceed stably and reversibly. In contrast, the peak potential difference of the zinc battery cathode in Example 1 is smaller. Lanthanum ions, as lattice pillars, can stabilize the layered structure of VO2, reduce lattice collapse and reconstruction during charge and discharge, and make it easier for the zinc ion insertion / extraction reaction to return to the initial state, thus improving the reversibility of the reaction.

[0065] This application uses vanadium pentoxide, lanthanum nitrate, and other raw materials to prepare cathode materials using a one-pot hydrothermal process. By introducing lanthanum ions to induce the formation of open nanoflower morphology and achieve lattice-level uniform doping, the specific surface area and conductivity of the material are improved, and the electrochemical performance of the battery is optimized. At the same time, the process is mild and controllable, the raw materials are readily available, and no complex equipment is required, making it easy to scale up production. The resulting cathode material can be used to assemble zinc batteries, promoting their application in large-scale energy storage and other scenarios, and filling the gap in lithium-ion battery technology.

[0066] The basic principles, main features, and advantages of this application have been described above. Those skilled in the art should understand that this application is not limited to the above embodiments. The embodiments and descriptions in the specification are merely the principles of this application. Various changes and modifications can be made to this application without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claims. The scope of protection claimed by this application is defined by the appended claims and their equivalents.

Claims

1. A zinc battery cathode material, characterized in that, The raw materials for preparation include vanadium oxide, lanthanum salt, reducing agent, and solvent.

2. The zinc battery cathode material as described in claim 1, characterized in that, The vanadium oxide is vanadium pentoxide, and the lanthanum salt is lanthanum nitrate.

3. A method for preparing a zinc battery cathode material, characterized in that, Vanadium pentoxide, oxalic acid hydrate, lanthanum nitrate hydrate, and hydrogen peroxide are dissolved in a solvent to obtain a mixed solution. The mixed solution is then transferred to a hydrothermal reactor for heating and reaction. The solid products are separated and washed to obtain the zinc battery cathode material.

4. The preparation method according to claim 3, characterized in that, The lanthanum nitrate hydrate is lanthanum nitrate hexahydrate.

5. The preparation method according to claim 4, characterized in that, The concentration of lanthanum nitrate hexahydrate is 1.5-2 g / L.

6. The preparation method according to claim 3, characterized in that, The concentration of vanadium pentoxide is 15-20 g / L.

7. The preparation method according to claim 3, characterized in that, The oxalic acid hydrate is oxalic acid dihydrate, and the concentration of oxalic acid dihydrate is 35-40 g / L.

8. The preparation method according to claim 3, characterized in that, The mixed solution is heated in a hydrothermal reactor at a temperature of 140-180 °C for 1-2 days.

9. A zinc battery, characterized in that, It includes a positive electrode, a negative electrode, a separator, a positive electrode electrolyte, and a negative electrode electrolyte. The positive electrode is made of any of the zinc battery positive electrode materials described in claims 1 to 2, or the positive electrode is made of the zinc battery positive electrode material prepared by any of the preparation methods described in claims 3 to 8.

10. The zinc battery as described in claim 9, wherein the zinc battery positive electrode material is mixed and ground with a conductive material to obtain a mixture, a binder is added and stirred evenly, then coated onto carbon paper and dried to form the positive electrode.

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