Preparation method of zinc negative electrode material, zinc negative electrode material, zinc negative electrode and zinc ion battery

Abstract

The invention relates to the technical field of zinc ion batteries, in particular to a preparation method of a zinc negative electrode material, the zinc negative electrode material, a zinc negative electrode and a zinc ion battery. The preparation method of the zinc negative electrode material comprises the following steps that a precursor solution is obtained, and the precursor solution comprises at least one precursor raw material of Ta2O5, LiTaO3 and LiNbO3; carrying out microwave heat treatment on the precursor solution, and cooling to obtain a first system; and carrying out post-treatment on the first system to obtain the zinc negative electrode material. According to the preparation method of the zinc negative electrode material, the zinc negative electrode material with high dielectric constant and uniform size is prepared by adopting microwave heat treatment, has a nano-particle structure and a relatively large specific surface area, can be uniformly dispersed on the surface of a zinc negative electrode, and effectively shields an electric field, so that the electric field distribution on the surface of the zinc negative electrode is more uniform; therefore, excessive deposition of zinc ions in a local area is reduced, and formation of zinc dendrites is inhibited.

Description

Technical Field

[0001] The present invention relates to the technical field of zinc ion batteries, and in particular to a method for preparing a zinc negative electrode material, the zinc negative electrode material, a zinc negative electrode and a zinc ion battery. Background Art

[0002] Zinc-ion batteries are a new type of electrochemical energy storage device. Using zinc as the negative electrode, they utilize the intercalation and extraction of zinc ions between the positive and negative electrodes to achieve the mutual conversion of electrical energy and chemical energy. Zinc resources are abundant, low in cost, and have a high theoretical specific capacity, making them promising for application. Zinc-ion batteries are highly safe and environmentally friendly. They have broad application potential in the energy storage field, such as large-scale energy storage power stations and distributed energy storage. Currently, research on zinc-ion batteries is still in a stage of continuous development, and researchers are working to improve key indicators such as energy density, cycle life, and rate performance to promote their further development in practical applications.

[0003] As a key component of zinc-ion batteries, the zinc anode currently faces many challenges. First, the zinc anode is prone to side reactions with the electrolyte to produce by-products such as zinc salt precipitation, which not only consumes active materials but may also increase the internal impedance of the battery, affecting the battery's cycle stability and coulombic efficiency. Second, zinc ions are prone to uneven deposition during the deposition / dissolution process, forming zinc dendrites. These dendrites may penetrate the diaphragm, causing internal short circuits in the battery, posing a safety hazard, and also destroying the structural integrity of the zinc anode. In addition, the zinc anode expands significantly in volume during the charge and discharge process, which can lead to pulverization of the electrode material and shedding of the active material, further shortening the battery's service life. These problems limit the performance and practical application of zinc-ion batteries. Therefore, researchers have improved the performance of the zinc anode through methods such as electrolyte optimization and advanced structural design to promote the development of zinc-ion batteries.

[0004] Electrolyte additives can improve the electrolyte's conductivity, stability, and safety, and can be optimized as needed. For example, adding appropriate substances to ensure performance in low-temperature environments can ensure performance. However, there is a risk of incompatibility between additives or with electrolyte components, which may affect performance. Furthermore, high-quality additives are expensive, with limited room for improvement, and multiple additives often need to be used in synergy. Negative electrode structural design uses porous, nanostructured, and hollow structures to mitigate volume changes, shorten ion transport distances, and enhance conductivity. However, the preparation process is complex and costly, and the structural stability still needs to be enhanced, resulting in limited improvements for materials with poor conductivity.

[0005] In view of this, the present invention is proposed. Summary of the Invention

[0006] One object of the present invention is to provide a method for preparing a zinc negative electrode material. By combining the various steps, a zinc negative electrode material with a high dielectric constant, a high specific surface area, and uniform stability is obtained. The zinc negative electrode material can effectively shield the electric field, making the electric field distribution on the surface of the zinc negative electrode more uniform, thereby reducing the excessive deposition of zinc ions in local areas and inhibiting the formation of zinc dendrites.

[0007] Another object of the present invention is to provide a method for preparing a zinc negative electrode material.

[0008] Another object of the present invention is to provide a zinc negative electrode.

[0009] Another object of the present invention is to provide a zinc ion battery.

[0010] In order to achieve the above-mentioned purpose of the present invention, the following technical solutions are adopted: A method for preparing a zinc negative electrode material comprises the following steps: A precursor solution is obtained, wherein the precursor solution contains a precursor raw material of at least one of Ta2O5, LiTaO3 and LiNbO3.

[0011] The precursor solution is subjected to microwave heat treatment and cooled to obtain a first system.

[0012] The first system is post-processed to obtain a zinc negative electrode material.

[0013] In some embodiments, the Ta2O5 precursor comprises tantalum ethoxide.

[0014] In some embodiments, the precursor material of LiTaO3 includes lithium hydroxide and tantalum ethoxide.

[0015] In some embodiments, the precursor material of LiNbO 3 includes lithium hydroxide and niobium ethoxide.

[0016] In some embodiments, the concentration of the precursor solution is 300-900 mmol / L.

[0017] In some embodiments, the precursor solution further includes an organic solvent, and the organic solvent includes at least one of benzyl alcohol and 1,4-butanediol.

[0018] In some embodiments, the temperature of the microwave heat treatment is 180-220° C., and the time of the microwave heat treatment is 30-60 min.

[0019] In some embodiments, the post-treatment includes solid-liquid separation, washing, and drying.

[0020] In some embodiments, the post-treatment includes solid-liquid separation, washing and drying, the solid-liquid separation includes centrifugation, the rotation speed of the centrifugation is 1000-1500 rpm, and the time of the centrifugation is 5-10 min.

[0021] In some embodiments, the post-treatment includes solid-liquid separation, washing and drying, the drying temperature is 60-80° C., and the drying time is 10-15 hours.

[0022] A zinc negative electrode material is prepared by the method for preparing the zinc negative electrode material.

[0023] A zinc negative electrode comprises a zinc foil and a negative electrode layer located on the surface of the zinc foil, wherein the negative electrode layer comprises a zinc negative electrode material prepared by the method for preparing the zinc negative electrode material.

[0024] In some embodiments, the mass content of the zinc negative electrode material in the negative electrode layer is 5% to 15%.

[0025] In some embodiments, the negative electrode layer further includes a carbon-based conductive agent and a hydrophobic binder, and the mass content of the carbon-based conductive agent in the negative electrode layer is 5% to 15%.

[0026] In some embodiments, the negative electrode layer further comprises a carbon-based conductive agent and a hydrophobic binder, wherein the carbon-based conductive agent comprises at least one of single-walled carbon nanotubes and multi-walled carbon nanotubes; and the hydrophobic binder comprises at least one of polyvinylidene fluoride and polytetrafluoroethylene.

[0027] In some embodiments, the thickness of the negative electrode layer is 30-50 μm.

[0028] A zinc ion battery comprises the zinc negative electrode.

[0029] An electrical device comprises the zinc ion battery.

[0030] Compared with the prior art, the present invention has the following beneficial effects: (1) The preparation method of the zinc negative electrode material of the present invention adopts microwave heat treatment to prepare a zinc negative electrode material with high dielectric constant and uniform size, which has a nanoparticle structure and a large specific surface area. The zinc negative electrode material can be evenly dispersed on the surface of the zinc negative electrode, effectively shielding the electric field, making the electric field distribution on the surface of the zinc negative electrode more uniform, thereby reducing the excessive deposition of zinc ions in local areas and inhibiting the formation of zinc dendrites.

[0031] (2) The zinc negative electrode of the present invention has excellent structural stability and good cycle performance.

[0032] (3) The zinc ion battery of the present invention has excellent structural stability, good cycle performance and high safety performance. DETAILED DESCRIPTION

[0033] The embodiments of the present invention will be described in detail below with reference to the examples, but it will be understood by those skilled in the art that the following examples are merely illustrative of the present invention and should not be construed as limiting the scope of the invention. Where specific conditions are not specified in the examples, the methods were performed according to conventional conditions or the conditions recommended by the manufacturer. Where the manufacturers of the reagents or instruments are not specified, they are all commercially available conventional products.

[0034] According to one aspect of the present invention, the present invention relates to a method for preparing a zinc negative electrode material, comprising the following steps: Obtain a precursor solution, wherein the precursor solution contains at least one precursor raw material of Ta2O5 (tantalum pentoxide), LiTaO3 (lithium tantalate) and LiNbO3 (lithium niobate); perform microwave heat treatment on the precursor solution, and obtain a first system after cooling; and perform post-processing on the first system to obtain a zinc negative electrode material.

[0035] The method for preparing the zinc negative electrode material of the present invention adopts microwave heat treatment to prepare a zinc negative electrode material with a high dielectric constant and uniform size. The zinc negative electrode material has a nanoparticle structure and a large specific surface area. The zinc negative electrode material can be uniformly dispersed on the surface of the zinc negative electrode, effectively shielding the electric field, making the electric field distribution on the surface of the zinc negative electrode more uniform, thereby reducing excessive deposition of zinc ions in local areas and inhibiting the formation of zinc dendrites.

[0036] The present invention adopts microwave heat treatment to synthesize zinc negative electrode material, which is efficient and energy-saving, can greatly shorten the reaction time and reduce energy consumption; microwave heat treatment is conducive to uniform nucleation of the precursor, and obtains zinc negative electrode material with high specific surface area.

[0037] In some embodiments, the Ta2O5 precursor comprises tantalum ethoxide.

[0038] In some embodiments, the precursor material of LiTaO3 includes lithium hydroxide and tantalum ethoxide.

[0039] In some embodiments, the precursor material of LiNbO 3 includes lithium hydroxide and niobium ethoxide.

[0040] The present invention adopts the above-mentioned precursor raw materials to ensure the stability of the obtained zinc negative electrode material.

[0041] In some embodiments, the concentration of the precursor solution is 300-900 mmol / L, for example, 300 mmol / L, 400 mmol / L, 500 mmol / L, 600 mmol / L, 700 mmol / L, 800 mmol / L, 900 mmol / L, etc. The present invention employs an appropriate precursor solution concentration to optimize the reaction yield and the performance of the zinc anode material. If the concentration is too low, the yield is low; if the concentration is too high, uneven microwave heat transfer can occur, affecting crystallization and weakening the performance of the zinc anode material.

[0042] In some embodiments, the precursor solution further comprises an organic solvent, wherein the organic solvent comprises at least one of benzyl alcohol and 1,4-butanediol. The present invention uses a suitable solvent to facilitate microwave heat treatment and ensure the physical and chemical properties of the obtained zinc negative electrode material.

[0043] In some embodiments, the temperature of the microwave heat treatment is 180-220°C, for example, 180°C, 185°C, 190°C, 195°C, 200°C, 205°C, 210°C, 215°C or 220°C. The time of the microwave heat treatment is 30-60 min, for example, 30 min, 35 min, 40 min, 45 min, 50 min, 55 min or 60 min. The present invention adopts an appropriate microwave heat treatment temperature and time to ensure complete reaction, and can increase the specific surface area of ​​the zinc negative electrode material and improve the electrical conductivity. If the temperature of the microwave heat treatment is too low, the reaction is incomplete. If the temperature of the microwave heat treatment is too high, the grains will grow excessively, reducing the electrochemical performance of the zinc negative electrode material.

[0044] In some embodiments, the post-treatment includes solid-liquid separation, washing, and drying. In some embodiments, the solid-liquid separation includes centrifugation, wherein the centrifugation speed is 1000-1500 rpm, such as 1000 rpm, 1100 rpm, 100 rpm, 1300 rpm, 1400 rpm, 1500 rpm, etc.; and the centrifugation time is 5-10 minutes, such as 5 minutes, 6 minutes, 7 minutes, 8 minutes, 9 minutes, or 10 minutes. The present invention uses appropriate centrifugation conditions to ensure efficient separation while maintaining the structural integrity of the material.

[0045] In some embodiments, the drying temperature is 60-80° C., for example, 60° C., 70° C., 80° C., etc. The drying time is 10-15 hours, for example, 10 hours, 12 hours, 15 hours, etc. Appropriate drying conditions are conducive to ensuring the structural stability and electrochemical performance of the zinc negative electrode material.

[0046] According to another aspect of the present invention, the present invention also relates to a zinc negative electrode material prepared by the above-described method for preparing a zinc negative electrode material. The zinc negative electrode material of the present invention has a high dielectric constant and surface area, can effectively shield the electric field, make the electric field distribution on the surface of the zinc negative electrode more uniform, reduce excessive deposition of zinc ions in local areas, and inhibit the formation of zinc dendrites.

[0047] According to another aspect of the present invention, a zinc negative electrode is provided, comprising a zinc foil and a negative electrode layer located on the surface of the zinc foil, wherein the negative electrode layer comprises a zinc negative electrode material prepared by the method for preparing a zinc negative electrode material. The zinc negative electrode has excellent structural stability and good cycle performance.

[0048] The present invention adopts the above-mentioned negative electrode layer, which has the following advantages compared to electrolyte additives and negative electrode structure design: the negative electrode layer of the present invention directly forms a protective layer on the surface of the zinc negative electrode, which can effectively isolate the direct contact between the zinc negative electrode and the electrolyte, thereby significantly reducing the occurrence of side reactions, and is more targeted than the indirect regulation of electrolyte additives and the negative electrode structure design based on the material itself. The negative electrode layer can also guide the deposition / dissolution process of zinc ions, promote its uniformity, and effectively inhibit the growth of zinc dendrites, while the effect of electrolyte additives in this regard is relatively limited, and the negative electrode structure design mainly focuses on alleviating volume changes and enhancing conductivity. In addition, the negative electrode layer of the present invention can adapt to different electrolyte systems and negative electrode material structures, and has good versatility and flexibility. In contrast, electrolyte additives need to be selected and matched according to the specific system, and the negative electrode structure design is limited by the preparation process and cost of the material.

[0049] In some embodiments, the weight content of the zinc negative electrode material in the negative electrode layer is 5% to 15%, for example, 5%, 7%, 8%, 9%, 10%, 11%, 12%, 15%, etc. The present invention uses an appropriate ratio of zinc negative electrode material to improve the uniformity of zinc deposition, inhibit dendrites, and ensure the structural stability and electrochemical performance of the negative electrode layer.

[0050] In some embodiments, the negative electrode layer further includes a carbon-based conductive agent and a hydrophobic binder, with the mass content of the carbon-based conductive agent in the negative electrode layer ranging from 5% to 15%, for example, 5%, 7%, 8%, 9%, 10%, 11%, 12%, 15%, etc. The flexibility of the binder buffers volume changes, while the rigidity of the zinc negative electrode material resists mechanical deformation. The combination of the two forms a stable interface similar to reinforced concrete. This "rigid and flexible" composite structure extends the service life of the zinc negative electrode. Simultaneously, the introduction of an appropriate proportion of the conductive agent enhances the charge transfer capability of the overall coating and reduces interfacial impedance.

[0051] In some embodiments, the carbon-based conductive agent includes at least one of single-walled carbon nanotubes and multi-walled carbon nanotubes. Single-walled carbon nanotubes are formed by curling a single layer of graphene sheets, while multi-walled carbon nanotubes are formed by coaxially curling multiple layers of graphene sheets. Both have excellent electrical conductivity and mechanical properties.

[0052] In some embodiments, the hydrophobic binder includes at least one of polyvinylidene fluoride and polytetrafluoroethylene. The hydrophobic binder of the present invention has strong hydrophobicity and adhesion, can be stably adsorbed on the surface of the zinc negative electrode, prevents active water molecules from contacting the zinc, and can evenly disperse the metal oxide to prevent agglomeration.

[0053] In some embodiments, the thickness of the negative electrode layer is 30-50 μm, for example, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, etc. An appropriate thickness of the negative electrode layer ensures structural stability and electrochemical performance. If the negative electrode layer is too thin, the protective effect is insufficient and the structural stability is poor. If the negative electrode layer is too thick, ion transport is hindered, and the internal resistance of the battery increases.

[0054] In some embodiments, the method for preparing a zinc negative electrode comprises the following steps: At least one of tantalum pentoxide, lithium niobate, and lithium tantalate is mixed with a conductive agent and a binder in a certain mass ratio in an organic solvent (such as N-methyl-2-pyrrolidone) to form a uniform slurry; the slurry is coated on the surface of a zinc foil by a doctor blade method; and the zinc negative electrode is obtained by drying in a vacuum environment.

[0055] In some embodiments, the coating thickness of the blade coating method is 30-50 μm, for example, 30 μm, 40 μm, 50 μm, etc.

[0056] In some embodiments, the drying time is 10-15 hours, and the drying temperature is 50-80° C. Appropriate drying conditions can ensure the structural stability and electrochemical performance of the negative electrode layer.

[0057] According to another aspect of the present invention, the present invention also relates to a zinc ion battery comprising the zinc negative electrode.

[0058] The zinc ion battery of the present invention has excellent structural stability, good cycle performance and high safety performance.

[0059] In some embodiments, the electrolyte used in the zinc ion battery is an aqueous electrolyte. The zinc salt used in the electrolyte is one or more of zinc sulfate, zinc acetate, and zinc trifluoromethanesulfonate; and the zinc salt concentration is 1.5 to 3 mol / L.

[0060] In some embodiments, the positive electrode used in the zinc ion battery includes commercial vanadium pentoxide.

[0061] According to another aspect of the present invention, the present invention also relates to an electric device comprising the zinc ion battery. The electric device of the present invention includes electric cars, laptop computers, power tools, etc.

[0062] The following is further explained with reference to specific embodiments and comparative examples.

[0063] Example 1 A method for preparing a zinc negative electrode material comprises the following steps: (a) 6 mmol of tantalum ethoxide was weighed and dissolved in 10 mL of benzyl alcohol to form a uniform mixture. The mixture in the microwave tube was heated at 205°C for 40 minutes. After completion of the reaction, the first system was obtained.

[0064] (b) Cooling the first system using an air compressor. Centrifuging the precipitate at 1200 rpm for 8 minutes is then performed. The precipitate is washed with ether and dried under vacuum at 60°C for 12 hours to obtain tantalum pentoxide.

[0065] A method for preparing a zinc negative electrode comprises the following steps: The zinc negative electrode material, multi-walled carbon nanotubes and polyvinylidene fluoride were mixed in N-methyl-2-pyrrolidone (NMP) in a mass ratio of 10:10:80 to form a uniform slurry. The slurry was coated on the surface of the zinc foil by a doctor blade method (the coating thickness was about 40 μm). The zinc foil was dried under a vacuum environment at 60°C for 12 hours to obtain a zinc negative electrode.

[0066] Example 2 A method for preparing a zinc negative electrode material comprises the following steps: (a) 3 mmol of tantalum ethoxide and 3 mmol of lithium hydroxide were weighed and dissolved in 10 mL of 1,4-butanediol to form a uniform mixture. The mixture was heated in a microwave reactor at 195°C for 30 minutes to obtain the first system.

[0067] (b) Cooling the first system using an air compressor. Centrifuging the precipitate at 1200 rpm for 8 minutes, washing the precipitate with ether, and drying it under vacuum at 60°C for 12 hours to obtain lithium tantalate.

[0068] A method for preparing a zinc negative electrode, except that the zinc negative electrode material in this embodiment is used, other conditions are the same as those in Example 1.

[0069] Example 3 A method for preparing a zinc negative electrode material comprises the following steps: (a) Weigh 3 mmol of niobium ethoxide and 3 mmol of lithium hydroxide and dissolve them in 10 mL of 1,4-butanediol to form a uniform mixture. Heat the mixture in a microwave tube at 195°C for 30 minutes. After completion of the reaction, the first system is obtained.

[0070] (b) Cooling the first system using an air compressor. Centrifuging the precipitate at 1200 rpm for 8 minutes was performed. The precipitate was washed with ether and dried under vacuum at 60°C for 12 hours to obtain lithium niobate.

[0071] A method for preparing a zinc negative electrode, except that the zinc negative electrode material in this embodiment is used, other conditions are the same as those in Example 1.

[0072] Example 4 A method for preparing a zinc negative electrode, which differs from Example 1 in that: Replace multi-walled carbon nanotubes with single-walled carbon nanotubes.

[0073] Example 5 A method for preparing a zinc negative electrode, which differs from Example 1 in that: Replace polyvinylidene fluoride with polytetrafluoroethylene.

[0074] Example 6 A method for preparing a zinc negative electrode comprises the following steps: Tantalum pentoxide was obtained according to the method of Example 1, lithium tantalate was obtained according to the method of Example 2, and lithium niobate was obtained according to the method of Example 3. A mixture of tantalum pentoxide, lithium tantalate, and lithium niobate was used as the zinc negative electrode material, with the mass ratio of tantalum pentoxide, lithium tantalate, and lithium niobate being 2:2:1.

[0075] The zinc negative electrode material, multi-walled carbon nanotubes and polyvinylidene fluoride were mixed in N-methyl-2-pyrrolidone (NMP) in a mass ratio of 10:10:80 to form a uniform slurry. The slurry was coated on the surface of the zinc foil by a doctor blade method (the coating thickness was about 40 μm). The zinc foil was dried under a vacuum environment at 60°C for 12 hours to obtain a zinc negative electrode.

[0076] Example 7 A method for preparing a zinc negative electrode differs from Example 6 in that: Tantalum pentoxide was obtained according to the method of Example 1, and lithium tantalate was obtained according to the method of Example 2. A mixture of tantalum pentoxide and lithium tantalate was used as the zinc negative electrode material, with a mass ratio of tantalum pentoxide to lithium tantalate of 2:3.

[0077] Example 8 A method for preparing a zinc negative electrode material comprises the following steps: (a) 6 mmol of tantalum ethoxide was weighed and dissolved in 10 mL of benzyl alcohol to form a uniform mixture. The mixture in the microwave tube was heated at 180°C for 60 minutes. After completion of the reaction, the first system was obtained.

[0078] (b) Cooling the first system using an air compressor. Centrifuging the system to obtain a precipitate at 1000 rpm for 10 minutes. Washing the precipitate with ether and drying it under vacuum at 80°C for 15 hours yields tantalum pentoxide.

[0079] A method for preparing a zinc negative electrode comprises the following steps: The zinc negative electrode material, multi-walled carbon nanotubes and polyvinylidene fluoride were mixed in N-methyl-2-pyrrolidone in a mass ratio of 5:5:90 to form a uniform slurry. The slurry was coated on the surface of the zinc foil by a doctor blade method (the coating thickness was about 40 μm). The zinc foil was dried under a vacuum environment at 60°C for 12 hours to obtain a zinc negative electrode.

[0080] Example 9 A method for preparing a zinc negative electrode material comprises the following steps: (a) 6 mmol of tantalum ethoxide was weighed and dissolved in 10 mL of benzyl alcohol to form a uniform mixture. The mixture in the microwave tube was heated at 220°C for 30 minutes. After completion of the reaction, the first system was obtained.

[0081] (b) Cooling the first system using an air compressor. Centrifuging the precipitate at 1000 rpm for 5 minutes is then performed. The precipitate is washed with ether and dried under vacuum at 80°C for 15 hours to obtain tantalum pentoxide.

[0082] A method for preparing a zinc negative electrode comprises the following steps: The zinc negative electrode material, multi-walled carbon nanotubes and polyvinylidene fluoride were mixed in N-methyl-2-pyrrolidone (NMP) at a mass ratio of 15:15:70 to form a uniform slurry. The slurry was coated on the surface of a zinc foil by a doctor blade method (the coating thickness was about 40 μm). The zinc foil was dried at 60°C in a vacuum environment for 12 hours to obtain a zinc negative electrode.

[0083] Comparative Example 1 A method for preparing a zinc negative electrode, which differs from Example 1 in that: Without adding carbon-based conductive agent, the mass ratio of tantalum pentoxide to polytetrafluoroethylene is 10:90.

[0084] Comparative Example 2 A method for preparing a zinc negative electrode, which differs from Example 1 in that: No zinc negative electrode material is added, and the mass ratio of multi-walled carbon nanotubes to polytetrafluoroethylene is 10:90.

[0085] Comparative Example 3 A method for preparing a zinc negative electrode, which differs from Example 1 in that: The coating thickness was adjusted to 15 μm.

[0086] Comparative Example 4 A method for preparing a zinc negative electrode, which differs from Example 1 in that: The coating thickness was adjusted to 65 μm.

[0087] Comparative Example 5 A zinc negative electrode material, which differs from Example 1 in that: The reaction temperature in step (a) was set to 150°C. A method for preparing a zinc negative electrode, except that the zinc negative electrode material of this comparative example is used, other conditions are the same as those in Example 1.

[0088] Comparative Example 6 A zinc negative electrode material, which differs from Example 1 in that: The reaction temperature in step (a) was set to 240°C. A method for preparing a zinc negative electrode, except that the zinc negative electrode material of this comparative example is used, other conditions are the same as those in Example 1.

[0089] Experimental example Zinc ion batteries were prepared using the zinc negative electrodes of the various examples and comparative examples.

[0090] Positive electrode preparation: V2O5 powder, conductive carbon black powder, and PVDF powder were mixed in NMP at a mass ratio of 7:2:1 to form a positive electrode slurry. The slurry with appropriate viscosity was evenly coated on commercial Ti foil (thickness 20μm), vacuum dried, and then punched into battery positive electrode sheets (diameter 12mm). The active material loading was 2mg / cm 2 .

[0091] Battery assembly: Assemble the zinc ion battery in the order of zinc negative electrode, separator, electrolyte, positive electrode, gasket, and shrapnel (the separator is glass fiber separator (GF / D), the electrolyte is 2 mol / L zinc sulfate solution, and the battery shell model is CR2032.

[0092] At room temperature, the cycle performance of the zinc ion battery was tested at a current density of 3A / g, with the upper and lower voltage limits being 0.2V and 1.6V respectively.

[0093] The test results of the zinc ion battery are shown in Table 1.

[0094] Table 1 Test results of zinc ion battery

[0095] From the above, it can be seen that the zinc ion battery prepared by the zinc negative electrode material of the present invention has excellent structural stability and good cycle performance, and the capacity retention rate of the battery after 2500 cycles is above 75%.

[0096] The capacity retention rates of the zinc ion batteries of Comparative Examples 1 and 2 were significantly reduced.

[0097] The coating of the zinc ion battery in Comparative Example 3 is too thin, resulting in insufficient protection and poor structural stability; the coating of the zinc ion battery in Comparative Example 4 is too thick, ion transmission is hindered, and the internal resistance of the battery increases; Comparative Examples 3 and 4 are all not conducive to the performance of the battery.

[0098] The reaction temperature in step (a) of Comparative Example 5 is too low, and the reaction temperature in step (a) of Comparative Example 6 is too high, both of which are not conducive to the performance of the zinc negative electrode material, and the capacity retention rate of the obtained battery is reduced.

[0099] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a zinc negative electrode material, characterized in that: The following steps are involved: Obtaining a precursor solution, wherein the precursor solution contains a precursor raw material of at least one of Ta2O5, LiTaO3 and LiNbO3; The precursor solution is subjected to microwave heat treatment, and a first system is obtained after cooling; The first system is post-processed to obtain a zinc negative electrode material.

2. The method for preparing the zinc negative electrode material according to claim 1, wherein: Contains at least one of the following features (1) to (3): (1) The Ta2O5 precursor material includes tantalum ethoxide; (2) The precursor raw materials of LiTaO3 include lithium hydroxide and tantalum ethoxide; (3) The precursor materials of LiNbO3 include lithium hydroxide and niobium ethoxide.

3. The method for preparing the zinc negative electrode material according to claim 1, wherein: Contains at least one of the following features (1) to (2): (1) The concentration of the precursor solution is 300-900 mmol / L; (2) The precursor solution further includes an organic solvent, and the organic solvent includes at least one of benzyl alcohol and 1,4-butanediol.

4. The method for preparing the zinc negative electrode material according to claim 1, wherein: The temperature of the microwave heat treatment is 180-220° C., and the time of the microwave heat treatment is 30-60 min.

5. The method for preparing the zinc negative electrode material according to claim 1, wherein: Contains at least one of the following features (1) to (3): (1) The post-treatment includes solid-liquid separation, washing and drying; (2) The post-treatment includes solid-liquid separation, washing and drying, the solid-liquid separation includes centrifugal treatment, the rotation speed of the centrifugal treatment is 1000~1500rpm, and the time of the centrifugal treatment is 5~10min; (3) The post-treatment includes solid-liquid separation, washing and drying. The drying temperature is 60-80°C and the drying time is 10-15 hours.

6. A zinc negative electrode material, characterized in that The zinc negative electrode material is prepared by the preparation method of any one of claims 1 to 5.

7. A zinc negative electrode, characterized in that The invention comprises a zinc foil and a negative electrode layer located on the surface of the zinc foil, wherein the negative electrode layer comprises a zinc negative electrode material prepared by the method for preparing the zinc negative electrode material according to any one of claims 1 to 5.

8. The zinc negative electrode according to claim 7, characterized in that Contains at least one of the following features (1) to (4): (1) The mass content of the zinc negative electrode material in the negative electrode layer is 5% to 15%; (2) The negative electrode layer further includes a carbon-based conductive agent and a hydrophobic binder, and the mass content of the carbon-based conductive agent in the negative electrode layer is 5% to 15%; (3) The negative electrode layer further comprises a carbon-based conductive agent and a hydrophobic binder, wherein the carbon-based conductive agent comprises at least one of single-walled carbon nanotubes and multi-walled carbon nanotubes; and the hydrophobic binder comprises at least one of polyvinylidene fluoride and polytetrafluoroethylene; (4) The thickness of the negative electrode layer is 30-50 μm.

9. A zinc ion battery, characterized in that: Comprising the zinc negative electrode according to claim 7 or 8.

10. An electrical device, characterized in that: Including the zinc ion battery according to claim 9.

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