Zinc ion battery positive electrode material with vanadium oxide oxygen vacancies backfilled by heteroatoms and application of zinc ion battery positive electrode material

Abstract

The invention belongs to the technical field of zinc ion batteries, and discloses a zinc ion battery positive electrode material with vanadium oxide oxygen vacancies backfilled by heteroatoms and application of the zinc ion battery positive electrode material. The invention provides a preparation method of the positive electrode material, which comprises the following steps: (1) synthesizing an oxygen-rich defect V6O13-Vo precursor by using a vanadium source and an acid source as raw materials through a hydrothermal method; and (2) heating the V6O13-Vo precursor and a heteroatom raw material in a protective atmosphere to obtain the zinc ion battery positive electrode material with the heteroatoms backfilled with the vanadium oxide oxygen vacancies. The vanadium oxide material prepared by the method disclosed by the invention has remarkably improved performance, the electrochemical performance of the zinc ion battery is remarkably improved when the vanadium oxide material is used as a positive electrode material of the zinc ion battery to be assembled into the zinc ion battery, and the vanadium oxide material has the excellent characteristics of high specific capacity and long-acting cycle stability; and the capacity retention ratio reaches 90.3% after 10000 times of circulation under the high current density of 10A. G <-1 >.

Description

Technical Field

[0001] This invention belongs to the field of zinc-ion battery technology, and specifically relates to a zinc-ion battery cathode material with heteroatoms backfilling oxygen vacancies in vanadium oxide and its application. Background Technology

[0002] In recent years, with the rapid increase in market demand for smart portable devices and energy storage systems, zinc-ion batteries (ZIBs) have been widely regarded as a promising next-generation energy storage solution due to their low cost, high safety, and excellent ion transport efficiency. As a key component of ZIBs, the cathode is fundamentally related to electrochemical performance. V6O 13 With its single / double layer VO x The alternating arrangement of structures, the mixed valence state of vanadium (V 5+ / V 4+ Zn has attracted much attention due to its high theoretical specific capacity. However, due to the fact that Zn... 2+ In V6O 13 The high charge density of cathode materials leads to sluggish diffusion kinetics within the crystal lattice, a bottleneck that hinders their large-scale application. Research has found that introducing oxygen vacancies can effectively modulate the diffusion barrier of zinc ions, significantly improving ion migration efficiency. Oxygen vacancies disrupt the periodic arrangement of the crystal lattice, forming defect sites that reconstruct more open ion transport channels and release local lattice stress, directly lowering the ion migration barrier and promoting rapid zinc ion migration. Simultaneously, oxygen vacancies, acting as positively charged defect centers, induce local charge redistribution, forming a positive charge on Zn. 2+ The electrostatic traction effect enables the adsorption / desorption process to transition from a physical process to a chemical process; furthermore, defect sites can guide Zn... 2+ Prioritizing reversible embedding and maintaining structural stability by accommodating volume expansion, the system ultimately achieves a breakthrough in the practical application bottleneck of zinc-ion batteries through multi-dimensional synergistic effects from diffusion dynamics to interfacial reactions, realizing a dual improvement in efficient ion transport and long-term cycle durability.

[0003] In aqueous electrolyte systems, the dynamic filling effect of oxygen is the core mechanism leading to the disappearance of oxygen vacancies on the electrode material surface. Because water and dissolved oxygen molecules are rich in reactive oxygen species, these oxygen elements actively interact with oxygen vacancies in the cathode material through surface adsorption, lattice diffusion, or electrochemical reactions, gradually filling vacancy defects and restoring lattice integrity. This process not only directly weakens the ability of oxygen vacancies to regulate zinc ion transport, but also leads to surface structural degradation and increased ion diffusion barriers due to vacancy disappearance, ultimately causing battery capacity decay and shortened cycle life. Stabilizing oxygen vacancies in the cathode is crucial for ensuring the long-term cycle performance and durability of zinc-ion batteries. However, existing research focuses primarily on methods for constructing oxygen vacancies, often neglecting their structural stability during long-term battery cycling. Therefore, how to stabilize vanadium oxide oxygen vacancies to further improve the cycle stability of zinc-ion batteries, while simultaneously developing low-cost, simple, and reliable preparation processes, is a pressing technical problem that needs to be solved. Summary of the Invention

[0004] In order to overcome the shortcomings and deficiencies of the prior art, the primary objective of this invention is to provide a method for preparing a zinc-ion battery cathode material with heteroatoms backfilling oxygen vacancies in vanadium oxide.

[0005] The method of this invention first prepares oxygen-rich defective V6O via a hydrothermal method. 13 -V o A zinc-ion battery cathode material with heteroatom-filled oxygen vacancies in vanadium oxide was prepared by heat treatment of a precursor and heteroatom-containing materials. Oxygen-rich defect V6O was achieved by utilizing a combined acid source. 13 -V o The oxygen vacancy of the precursor is directionally regulated; vanadium oxide materials with reconstructed surface structures are obtained by backfilling heteroatoms, thereby improving the structural stability of vanadium oxide cathode materials.

[0006] Another objective of this invention is to provide a zinc-ion battery cathode material with heteroatom-backfilled vanadium oxide oxygen vacancies prepared by the above method.

[0007] Another object of the present invention is to provide the application of the above-mentioned zinc-ion battery cathode material in zinc-ion batteries. The vanadium oxide material of the present invention has excellent properties. When used as a cathode material in a zinc-ion battery assembly, it can significantly improve the electrochemical performance of the zinc-ion battery, exhibiting excellent characteristics such as high specific capacity and long-term cycle stability.

[0008] The objective of this invention is achieved through the following solution: A method for preparing a zinc-ion battery cathode material with heteroatoms backfilling oxygen vacancies in vanadium oxide includes the following steps: (1) Using vanadium source and acid source as raw materials, oxygen-rich defect V6O was synthesized by hydrothermal method.13 -V o Precursor; (2) V6O 13 -V o The precursor and heteroatom raw materials are heated in a protective atmosphere to obtain a zinc-ion battery cathode material with heteroatom backfilling of oxygen vacancies in vanadium oxide.

[0009] In step (1), the acid source is a combination of ascorbic acid and organic acid.

[0010] Furthermore, the molar ratio of ascorbic acid to organic acid can be 2.6:1-10:1.

[0011] Furthermore, the organic acid may be selected from at least one of oxalic acid, citric acid, and acetic acid.

[0012] In step (1), the molar ratio of the vanadium source and the acid source is 1:1-1:2.

[0013] In step (1), the vanadium source can be any vanadium source commonly used in the art, such as at least one of vanadium pentoxide, ammonium metavanadate, etc.

[0014] In step (1), the temperature of the hydrothermal reaction can be 120-180℃; the reaction time can be 6-24h. The hydrothermal reaction can be carried out in a hydrothermal reactor. In this invention, the reaction is carried out in water, specifically by adding the vanadium source and acid source to water and placing them in a hydrothermal reactor for heating and reaction.

[0015] In step (1), the acid source is a combination of ascorbic acid and organic acid. During the crystallization process, ascorbic acid breaks the periodic arrangement of the crystal lattice through reduction, and simultaneously introduces oxygen vacancy defects to obtain oxygen-defect-rich V6O. 13 -V o Precursor.

[0016] In step (2), the V6O 13 -V o The mass ratio of precursor to heteroatom raw material can be 1:1 to 1:5.

[0017] In step (2), the temperature of the heating treatment can be 300-500℃; the heating rate of the heating treatment can be 2-10℃ / min; and the heating time can be 2-6h.

[0018] In step (2), the heat treatment can be carried out in a tube furnace. For example, the heteroatom raw material can be placed on the upstream side of the tube furnace, V6O 13 -V o The precursor is placed on the downstream side, and the reaction is heated.

[0019] In step (2), the heteroatom raw material may include at least one of nitrogen source and phosphorus source, such as at least one of melamine, ammonium bicarbonate, sodium dihydrogen phosphate, ammonium dihydrogen phosphate, etc.

[0020] In step (2), the protective atmosphere can be selected from at least one of inert gases such as nitrogen and argon.

[0021] In step (2), the active heteroatoms generated by the decomposition of heteroatomic raw materials under high temperature conditions fill the oxygen vacancy defects through solid-state diffusion mechanism, forming a cathode material in which heteroatoms backfill the oxygen vacancy of vanadium oxide.

[0022] This invention utilizes ascorbic acid and organic acids as acid sources, which react with a vanadium source via a hydrothermal reaction. The redox reaction of ascorbic acid desorbs oxygen atoms from the vanadium oxide lattice, forming positively charged oxygen vacancies, thus achieving directional control of these vacancies. These oxygen vacancies increase the electron density at the vanadium centers, enhancing pseudocapacitive surface adsorption and providing additional active sites for zinc ion adsorption and storage, synergistically improving specific capacity. Simultaneously, the oxygen vacancies disrupt the symmetry of the VO polyhedron, causing a decrease in the 3d electron orbital energy level of V, thereby improving the material's conductivity. During subsequent heat treatment, nitrogen / phosphorus atoms and other heteroatoms generated from the decomposition of heteroatomic raw materials diffuse into the oxygen vacancies via solid-state diffusion, forming a VN / VP bond structure. This anchors the oxygen vacancies around the heteroatoms, resulting in a vanadium oxide material with a reconstructed surface structure, thereby improving the structural stability of the vanadium oxide cathode material.

[0023] This invention also provides a zinc-ion battery cathode material with heteroatom-filled vanadium oxide oxygen vacancies, prepared by the above method. The material prepared by the method of this invention exhibits significantly improved performance. Using this material as a zinc-ion battery cathode material in a zinc-ion battery assembly not only reduces the zinc-ion diffusion barrier and improves migration efficiency through surface structure reconstruction, but also stabilizes the defect structure through the high electronegativity of heteroatoms, suppressing lattice collapse during cycling. This achieves dual optimization of ion transport and structural stability, resulting in a significant improvement in the electrochemical performance of the zinc-ion battery. It possesses excellent characteristics such as high specific capacity and long-term cycle stability, achieving a performance of 10 A·g -1 After 10,000 cycles at high current density, the capacity retention rate reached 90.3%, demonstrating excellent long-term cycling stability.

[0024] This invention also provides the application of the zinc-ion battery cathode material with heteroatoms backfilling oxygen vacancies in vanadium oxide in zinc-ion batteries.

[0025] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0026] (1) This invention provides a method for preparing a zinc-ion battery cathode material with heteroatoms backfilling oxygen vacancies in vanadium oxide. The method first prepares oxygen-rich defective V6O by a hydrothermal method. 13 -V o The precursor process is mild and controllable, which can reduce damage to the material structure, ensure the stability of the overall material performance, and precisely control the generation location and quantity of oxygen vacancies, thus achieving directional regulation of oxygen vacancies. Then, it is heated with heteroatom materials, and the decomposed heteroatoms are used to fill oxygen vacancies. This can reduce the formation energy of the material and oxygen vacancies, anchor the oxygen vacancies around the heteroatoms, and prevent the oxygen vacancies from disappearing due to filling or migration, thereby further improving the stability of oxygen vacancies and structure of the material. This process yields a high-performance zinc-ion battery cathode material with heteroatom-filled vanadium oxide oxygen vacancies.

[0027] (2) The zinc-ion battery cathode material with heteroatom-backfilled vanadium oxide oxygen vacancies prepared by the method of the present invention has excellent performance. When used as a zinc-ion battery cathode material to assemble zinc-ion batteries, it significantly improves the electrochemical performance of zinc-ion batteries, exhibiting high specific capacity and long cycle life (at 10 A·g). -1 After 10,000 cycles at high current density, the capacity retention rate reaches 90.3%.

[0028] (3) The preparation method provided by the present invention is simple to operate, has high efficiency, wide applicability, low production cost, and is suitable for large-scale industrial production and promotion. Attached Figure Description

[0029] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 The image shows the X-ray diffraction (XRD) pattern of the zinc-ion battery cathode material obtained in Example 1.

[0031] Figure 2 The image shows the electron paramagnetic resonance (EPR) spectrum of the zinc-ion battery cathode material obtained in Example 1.

[0032] Figure 3 The zinc-ion battery cathode material obtained in Example 1 was subjected to a reaction at 10 A·g -1 The following is a graph showing the cyclic performance.

[0033] Figure 4 The zinc-ion battery cathode material obtained in Example 3 was tested at 10 A·g. -1The following is a graph showing the cyclic performance.

[0034] Figure 5 The zinc-ion battery cathode material obtained in Comparative Example 2 was tested at 10 A·g -1 The following is a graph showing the cyclic performance. Detailed Implementation

[0035] The present invention will be further described in detail below with reference to embodiments, but the implementation of the present invention is not limited thereto. Unless otherwise specified, all materials involved in the following embodiments are commercially available. Unless otherwise specified, all methods described are conventional methods. The amounts of each component are expressed in parts by mass and parts by volume, in g and mL.

[0036] One embodiment of the method for preparing a zinc-ion battery cathode material with heteroatoms backfilling oxygen vacancies in vanadium oxide includes the following steps: (1) Using vanadium source and acid source as raw materials, oxygen-rich defect V6O was synthesized by hydrothermal method. 13 -V o Precursor; (2) V6O 13 -V o The precursor is mixed with heteroatom raw materials and heated in a protective atmosphere to obtain a zinc-ion battery cathode material with heteroatoms backfilled into oxygen vacancies in vanadium oxide.

[0037] Furthermore, in step (1), the acid source is a combination of ascorbic acid and organic acid.

[0038] Furthermore, the molar ratio of ascorbic acid to organic acid can be 2.6:1-10:1. As can be seen from specific embodiments of the present invention, under the dosage ratios of the present invention, the acid source can achieve oxygen-rich defect V6O. 13 -V o Preparation of the precursor. In one embodiment, the molar ratio of ascorbic acid to organic acid is 2.6:1; in another embodiment, the molar ratio of ascorbic acid to organic acid is 10:1; and in yet another embodiment, the molar ratio of ascorbic acid to organic acid is 5:1.

[0039] Furthermore, the organic acid may be selected from at least one of oxalic acid, citric acid, and acetic acid. In one embodiment, the organic acid is oxalic acid; in another embodiment, the organic acid is citric acid; and in yet another embodiment, the organic acid is acetic acid.

[0040] Furthermore, in step (1), the molar ratio of the vanadium source and the acid source is 1:1 to 1:2. As can be seen from a specific embodiment of the present invention, under the dosage ratio of the present invention, both can react and generate the target product, oxygen-rich defect V6O. 13 -V oPrecursor. In one embodiment, the ratio of vanadium source to acid source is 1:1; in another embodiment, the ratio of vanadium source to acid source is 1:2.

[0041] Furthermore, in step (1), the vanadium source can be any vanadium source conventionally used in the art, such as at least one selected from vanadium pentoxide, ammonium metavanadate, etc. In one embodiment, the vanadium source is vanadium pentoxide; in another embodiment, the vanadium source is ammonium metavanadate.

[0042] Furthermore, in step (1), the temperature of the hydrothermal reaction can be 120-180℃; in one embodiment, the temperature is 120℃, in another embodiment, the temperature is 150℃, and in yet another embodiment, the temperature is 180℃. The reaction time can be 6-24h; in one embodiment, the reaction time is 6h, in another embodiment, the reaction time is 10h, and in yet another embodiment, the reaction time is 24h. The reaction of the present invention can be carried out in a hydrothermal reactor. The reaction of the present invention is carried out in water, specifically by adding the vanadium source and the acid source to water and placing them in a hydrothermal reactor for heating and reaction.

[0043] The acid source in this invention is a combination of ascorbic acid and organic acid. During crystallization, ascorbic acid breaks the periodic arrangement of the crystal lattice through reduction, simultaneously introducing oxygen vacancy defects to obtain oxygen-defect-rich V6O. 13 -V o Precursor.

[0044] Furthermore, in step (2), the V6O 13 -V o The mass ratio of precursor to heteroatom raw material can be 1:1 to 1:5. According to specific embodiments of the present invention, under the dosage ratio of the present invention, the heteroatoms can effectively fill the oxygen vacancies in vanadium oxides. In one embodiment, the V6O... 13 -V o The mass ratio of precursor to heteroatom raw material is 1:5; in another embodiment, the V6O 13 -V o The mass ratio of the precursor to the heteroatom raw material is 1:1.5; in another embodiment, the V6O 13 -V o The mass ratio of precursor to heteroatom raw material is 1:1.

[0045] Furthermore, in step (2), the temperature of the heat treatment can be 300-500℃. In one embodiment, the temperature is 300℃; in another embodiment, the temperature is 400℃; and in yet another embodiment, the temperature is 500℃. The heating rate of the heat treatment can be 2-10℃ / min. The heat treatment time can be 2-6 hours. In one embodiment, the reaction time is 2 hours; in another embodiment, the reaction time is 4 hours; and in yet another embodiment, the reaction time is 6 hours.

[0046] Furthermore, in step (2), the heat treatment can be carried out in a tube furnace. For example, the heteroatom raw material can be placed on the upstream side of the tube furnace, V6O 13 -V o The precursor is placed on the downstream side, and the reaction is heated.

[0047] Furthermore, in step (2), the heteroatom raw material may include at least one of a nitrogen source and a phosphorus source, such as at least one of melamine, ammonium bicarbonate, sodium dihydrogen phosphate, and ammonium dihydrogen phosphate. In one embodiment, the heteroatom raw material is melamine; in another embodiment, the heteroatom raw material is ammonium bicarbonate; in yet another embodiment, the heteroatom raw material is sodium dihydrogen phosphate; and in still another embodiment, the heteroatom raw material is ammonium dihydrogen phosphate.

[0048] Furthermore, in step (2), the protective atmosphere can be selected from at least one of conventionally used inert gases such as nitrogen and argon; in one embodiment, the protective atmosphere is nitrogen, and in another embodiment, the protective atmosphere is argon. Example 1

[0049] A V6O with heteroatoms filling oxygen vacancies 13 -V o -N cathode material, prepared by a method including the following steps: (1) Dissolve 12 parts by mass of vanadium pentoxide (V2O5) with 5 parts by mass of H2C2O4•2H2O and 1.76 parts by mass of ascorbic acid (C6H8O6) in 700 parts by volume of deionized water, stir for 30 min, transfer to a polytetrafluoroethylene-lined autoclave, and keep in an oven at 180°C for 10 h. After naturally cooling to room temperature, wash the product with deionized water and ethanol, and then dry in a vacuum oven at 60°C for 12 h to obtain V6O 13 -V o； (2) In an argon gas flow, 5 parts by weight of melamine (C3H6N6) powder are placed on the upstream side of a tube furnace, and 1 part by weight of V6O 13 -V o The tube furnace was placed downstream. The temperature was increased to 500°C at a rate of 5°C / min and maintained at that temperature for 2 hours to obtain V6O. 13 -Vo -N cathode material. Example 2

[0050] A V6O with heteroatoms filling oxygen vacancies 13 -V o -N cathode material, prepared by a method including the following steps: (1) Dissolve 7 parts by mass of ammonium metavanadate, 7.56 parts by mass of H2C2O4•2H2O, and 6.04 parts by mass of ascorbic acid (C6H8O6) in 700 parts by volume of deionized water, stir for 30 min, transfer to a polytetrafluoroethylene-lined autoclave, and keep in an oven at 160℃ for 12 h. After naturally cooling to room temperature, wash the product with deionized water and ethanol, and then dry it in a vacuum oven at 60℃ for 12 h to obtain V6O. 13 -V o； (2) In an argon gas flow, place 5 parts by mass of ammonium bicarbonate powder on the upstream side of a tube furnace, and 1 part by mass of V6O 13 -V o The tube furnace was placed downstream. The temperature was increased to 450°C at a rate of 5°C / min and maintained at that temperature for 3 hours to obtain V6O. 13 -V o -N cathode material. Example 3

[0051] A V6O with phosphorus atoms filling oxygen vacancies 13 -V o -P cathode material, prepared by a method including the following steps: (1) V6O 13 -V o The preparation is the same as step (1) in Example 1; (2) In an argon gas flow, place 1 part by mass of sodium dihydrogen phosphate (NaH2PO4) powder on the upstream side of a tube furnace, and 1 part by mass of V6O 13 -V o The tube furnace was placed downstream. The temperature was increased to 500°C at a rate of 5°C / min and maintained at that temperature for 2 hours to obtain V6O. 13 -V o -P cathode material. Example 4

[0052] A V6O with phosphorus atoms filling oxygen vacancies 13 -V o -P cathode material, prepared by a method including the following steps: (1) V6O 13 -V o The preparation is the same as step (1) in Example 1; (2) In an argon gas flow, 1.5 parts by mass of ammonium dihydrogen phosphate powder are placed on the upstream side of a tube furnace, and 1 part by mass of V6O 13 -V o The tube furnace was placed downstream. The temperature was increased to 400°C at a rate of 5°C / min and held at that temperature for 2 hours to obtain V6O. 13 -V o -P cathode material. Comparative Example 1

[0053] A V6O 13 The positive electrode material was prepared by the following steps: 12 parts by mass of vanadium pentoxide (V₂O₅) and 7 parts by mass of oxalic acid hydrate (H₂C₂O₄•2H₂O) were dissolved in 700 parts by volume of deionized water, stirred for 30 min, transferred to a polytetrafluoroethylene-lined autoclave, and kept in an oven at 180°C for 10 h. After naturally cooling to room temperature, the product was washed with deionized water and ethanol, and then dried in a vacuum oven at 60°C for 12 h to obtain V₆O₅. 13 Positive electrode material. Comparative Example 2

[0054] A nitrogen-doped V6O 13 The preparation method of the cathode material includes the following steps: (1) V6O 13 The preparation of the material was the same as in Comparative Example 1; (2) In an argon gas flow, 5 parts by weight of melamine (C3H6N6) powder are placed on the upstream side of a tube furnace, and 1 part by weight of V6O 13 The tube furnace was placed downstream. The temperature was increased to 500°C at a rate of 5°C / min and maintained at that temperature for 2 hours to obtain V6O. 13 -N cathode material. Performance testing

[0055] (1) The structures of the materials prepared in Examples 1-4 and the comparative examples were determined by X-ray diffraction (XRD). The results are shown in the figure. Figure 1 .

[0056] (2) The materials prepared in Examples 1-4 and the comparative examples were tested using electron paramagnetic resonance. The results are shown in the figure. Figure 2 .

[0057] (3) The material prepared in the example was used as the positive electrode material. It was mixed with a conductive agent (Super P) and polyvinylidene fluoride (PVDF) in a mass ratio of 7:2:1 in an appropriate amount of N-methylpyrrolidone (NMP) solvent, and stirred continuously to obtain a uniform slurry. The prepared slurry was coated onto a stainless steel mesh and dried in a vacuum oven at 60°C for 12 hours to obtain the positive electrode. The mass loading of the active material was approximately 2.0 mg·cm³. -2Commercial zinc foil, glass fiber, and a 2M aqueous solution of zinc trifluoromethanesulfonate (Zn(CF3SO3)2) were used as the negative electrode, separator, and electrolyte, respectively, to assemble 2032 button batteries. Electrical performance tests were conducted, and the results are shown below. Figures 3-5 .

[0058] Figure 1 The V6O prepared in Example 1 and Comparative Example 1 are shown. 13 -V o V6O 13 -V o -N and V6O 13 The diffraction patterns of the three are shown in the figure. As can be seen, the diffraction patterns of the three are highly similar and all match the standard card, indicating that the introduction of oxygen vacancies and nitrogen backfilling in this invention did not induce a phase transition. V6O 13 -V o The (110) characteristic peak compared to V6O 13 The shift from 25.5° to a lower angle (25.1°) can be attributed to the increased interplanar spacing caused by the formation of oxygen vacancies during reduction. Conversely, V6O 13 -V o The (110) peak of -N relative to V6O 13 -V o The shift to a higher angle (25.3°) is likely due to smaller nitrogen atoms partially filling oxygen vacancies. Results in other embodiments are similar and will not be described in detail.

[0059] Figure 2 The V6O prepared in Example 1 and Comparative Example 1 are shown. 13 -V o V6O 13 -V o -N and V6O 13 The EPR spectrum is shown in the figure. A strong signal peak appears at a g value of 1.96, corresponding to tetravalent vanadium ions. Therefore, changes in EPR signal intensity can reflect changes in oxygen vacancy concentration. This invention, by adding ascorbic acid, [achieves a certain effect on V6O]. 13 -V o The signal strength reaches its maximum, indicating that the process is V6O. 13 -V o It introduces abundant oxygen vacancies; and after heteroatom backfilling, V6O 13 -V o The peak intensity of -N is significantly weaker than that of V6O. 13 -V o This indicates that nitrogen atoms were effectively filled into oxygen vacancies, verifying the feasibility of the method of the present invention using heteroatoms to fill oxygen vacancies. Results from other embodiments are similar and will not be described in detail.

[0060] Depend on Figures 3-5As can be seen from the cycle performance graph, the individual V6O 13 The material exhibits rapid capacity decay during 5000 zinc ion insertion / extraction cycles, which is due to structural collapse caused by vanadium dissolution after cycling.

[0061] V6O without heteroatom backfilling 13 -V o Although oxygen-rich vacancies provide abundant active sites and improve zinc storage capacity, the stability of oxygen vacancies is difficult to maintain during long-term cycling, and the capacity retention rate is less than 90%.

[0062] V6O directly doped with nitrogen atoms 13 -N material at 10 A·g -1 Under high current density, it can only be charged and discharged 5000 times, with a retention rate of only 74.9%, indicating poor cycle stability.

[0063] The V6O of this invention 13 -V o -N、V6O 13 -V o Materials such as -P achieve oxygen vacancy anchoring and structural reinforcement by backfilling oxygen vacancies with heteroatoms, thereby obtaining optimal zinc storage performance and cycling characteristics. Among them, V6O... 13 -V o -N after 10,000 cycles, V6O 13 -V o -N remains at 184.1 mAh·g -1 High reversible specific capacity, with a capacity retention of 90.3%, at 10 A·g -1 It exhibits excellent long-term cycling performance at high current densities; V6O 13 -V o -P at 10 A·g -1 After 5000 cycles at high current density, the capacity did not show significant decay and still provided 169.9 mAh·g. -1 The high discharge specific capacity is V6O 13 and V6O 13 -V o The 6.45-fold and 1.31-fold increase in specific capacity provided under the same conditions demonstrate the synergistic effect of phosphorus atoms on the number of active sites and the stability of oxygen vacancies.

[0064] As can be seen from the above, this invention first prepares oxygen-rich vacancy V6O 13 -V o By using precursor materials and then filling oxygen vacancies with heteroatoms such as N and P, a cathode material with high specific capacity and significantly improved long-term stability can be prepared. Moreover, heteroatom backfilling is crucial for stabilizing oxygen vacancies and thus improving material performance.

[0065] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A method for preparing a zinc-ion battery cathode material with heteroatoms backfilling oxygen vacancies in vanadium oxide, characterized in that... The steps include: (1) using vanadium source and acid source as raw materials, oxygen-rich defect V6O is synthesized by hydrothermal method. 13 -V o Precursor; (2) V6O 13 -V o The precursor and heteroatom raw materials are heated in a protective atmosphere to obtain a zinc-ion battery cathode material with heteroatom backfilling of oxygen vacancies in vanadium oxide.

2. The preparation method according to claim 1, characterized in that: In step (1), the acid source is a combination of ascorbic acid and organic acid; the molar ratio of ascorbic acid and organic acid is 2.6:1-10:

1.

3. The preparation method according to claim 2, characterized in that: The organic acid mentioned includes at least one of oxalic acid, citric acid, and acetic acid.

4. The preparation method according to claim 1, characterized in that: In step (1), the molar ratio of the vanadium source and the acid source is 1:1-1:

2.

5. The preparation method according to claim 1, characterized in that: In step (1), the temperature of the hydrothermal reaction is 120-180℃; the reaction time is 6-24h.

6. The preparation method according to claim 1, characterized in that: In step (2), the V6O 13 -V o The mass ratio of precursor to heteroatom raw material is 1:1 to 1:

5.

7. The preparation method according to claim 1, characterized in that: In step (2), the temperature of the heating treatment is 300-500℃; the heating rate of the heating treatment is 2-10℃ / min; and the heating time is 2-6h.

8. The preparation method according to claim 1, characterized in that: In step (2), the heteroatom raw material includes at least one of nitrogen source and phosphorus source.

9. A zinc-ion battery cathode material with heteroatom-backfilled vanadium oxide oxygen vacancies obtained by the preparation method according to any one of claims 1-8.

10. The application of the zinc-ion battery cathode material with heteroatom backfilling vanadium oxide oxygen vacancies as described in claim 9 in zinc-ion batteries.

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