Zinc ion battery positive electrode material and preparation method and application thereof

Abstract

This invention discloses a zinc-ion battery cathode material, its preparation method, and its application, relating to the field of secondary battery technology. The zinc-ion battery cathode material disclosed in this invention has a perovskite structure, and its chemical formula is LaMn. x Mo y O3, where 0.85≤x≤0.95, 0.05≤y≤0.15, x+y=1. This invention, by selecting a perovskite structure for the zinc-ion battery cathode material and doping it with Mo, and controlling the amount of Mo doping, can significantly improve the cycle stability of the zinc-ion battery cathode material.

Description

Technical Field

[0001] This invention relates to the field of secondary battery technology, and more specifically, to a zinc-ion battery cathode material, its preparation method, and its application. Background Technology

[0002] With societal development, energy consumption is increasing, and the energy crisis and environmental pollution are becoming increasingly severe, making the demand for clean and renewable energy increasingly urgent. While renewable energy sources such as solar and wind power are generally readily available, energy storage and transportation remain challenging issues. Therefore, the development of stable and safe energy storage systems has attracted widespread attention. Batteries are currently one of the most commonly used energy storage systems and have become an indispensable part of daily life. Among them, lithium-ion batteries have been widely used due to their advantages such as low specific weight, high energy density, and long cycle life. However, lithium resources are limited, costs are high, and most commercial lithium-ion batteries use organic electrolytes, which are prone to safety accidents, greatly limiting their application. Aqueous zinc-ion batteries (AZIBs), on the other hand, are considered a promising electrochemical energy storage battery due to their low cost, high operational safety, and suitability for large-scale energy storage.

[0003] The positive electrode material of aqueous zinc-ion batteries serves as a storage medium for Zn. 2+ The host material is the main contributor to battery performance; however, most current zinc-ion battery cathode materials cannot meet the requirements of long lifespan, high energy density, and power density. Therefore, the design and development of high-performance cathode materials is currently a hot research topic in the field of aqueous zinc-ion batteries. Currently, commonly used cathode materials for aqueous zinc-ion batteries (AZIBs) include manganese-based oxides, which have high energy storage capacity and operating voltage, and are low in cost and environmentally friendly; however, manganese-based oxides have poor electronic conductivity, and Zn... 2+ Poor transport kinetics and the easy dissolution of manganese lead to structural collapse, resulting in severe capacity decay and poor cycle stability of the cathode material, seriously affecting its practical application potential. Therefore, there is an urgent need to provide a zinc-ion battery cathode material that combines good capacity and cycle stability. Summary of the Invention

[0004] The main objective of this invention is to provide a zinc-ion battery cathode material, its preparation method, and its application, in order to solve the problem of poor cycle stability of zinc-ion battery cathode materials.

[0005] To achieve the above objectives, according to a first aspect of the present invention, a zinc-ion battery cathode material is provided, which has a perovskite structure and has the chemical formula LaMn. x Mo y O3, where 0.85≤x≤0.95, 0.05≤y≤0.15, and x+y=1.

[0006] Perovskite-structured materials exhibit excellent electrochemical performance. LaMnO3, with its perovskite structure, boasts superior room-temperature conductivity, a small band gap, abundant A-site cation defects, and numerous oxygen anion vacancies, all of which contribute to improved electrochemical performance. By doping Mo into perovskite-structured LaMnO3 and controlling its dosage, the stability of zinc-ion battery cathode materials can be effectively enhanced, thereby increasing their application potential.

[0007] Furthermore, the positive electrode material of the zinc-ion battery has a popcorn-like structure.

[0008] Furthermore, the specific surface area of ​​the zinc-ion battery cathode material is 5m². 2 / g~10m 2 / g; and / or, the porosity of the zinc-ion battery cathode material is 15%–28%.

[0009] Controlling the specific surface area or porosity of zinc-ion battery cathode materials within the above-mentioned range is beneficial to improving the surface energy of zinc-ion battery cathode materials and enhancing their electrochemical activity; at the same time, their stability is relatively high.

[0010] Furthermore, the zinc-ion battery cathode material is composed of primary particles stacked together, with an average particle size of 20nm to 35nm.

[0011] Controlling the average particle size of the primary particles in the zinc-ion battery cathode material within the above-mentioned range can shorten the ion diffusion path and improve the specific capacity of the zinc-ion battery cathode material.

[0012] According to a second aspect of the present invention, a method for preparing a zinc-ion battery cathode material according to the first aspect of the present invention is provided, comprising the following steps:

[0013] S1, La2O3 powder, MnO2 powder and MoO3 powder are mixed to obtain a first mixture;

[0014] S2, the first mixture is ball-milled to obtain a second mixture;

[0015] S3, calcining the second mixture to obtain the zinc-ion battery cathode material.

[0016] This invention uses a solid-state calcination method to prepare zinc-ion battery cathode materials. This preparation method is simple, has few steps, and can be industrialized for large-scale production.

[0017] Further, in S1, the La2O3 powder, the MnO2 powder, and the MoO3 powder are mixed by grinding.

[0018] Grinding is a highly efficient and low-cost mixing method. By using this method to mix raw materials, the resulting zinc-ion battery cathode material can have good uniformity.

[0019] Furthermore, in S2, the ball milling method is as follows:

[0020] The grinding balls are mixed with the material at a ball-to-material ratio of (15-20):1, and then ethanol is added. The mixture is then ball-milled at 500-700 rpm for 2-4 hours. The grinding balls include large, medium, and small balls. The diameter of the large balls is 15-18 mm, the diameter of the medium balls is 10-12 mm, and the diameter of the small balls is 5-8 mm. The weight ratio of the large, medium, and small balls is (15-25):(25-35):(45-55).

[0021] The conditions of ball milling have a significant impact on the physicochemical properties of zinc-ion battery cathode materials. By controlling the ball milling conditions, the specific surface area, porosity, and average particle size of the prepared zinc-ion battery cathode materials are more moderate, which is beneficial to enable the zinc-ion battery cathode materials to have both high specific capacity and cycle stability, thereby expanding their application range.

[0022] Furthermore, in S3, the calcination temperature is 700℃~900℃ and the time is 8h~12h.

[0023] Calcination conditions have a significant impact on the structure of zinc-ion battery cathode materials. By controlling the calcination conditions, zinc-ion battery cathode materials can achieve higher crystallinity and a stable perovskite structure, which is less prone to collapse during cycling.

[0024] Furthermore, after calcination, the calcined product is ground and filtered through a sieve to obtain the zinc-ion battery cathode material.

[0025] According to a third aspect of the present invention, the application of a zinc-ion battery cathode material prepared by the preparation method of the zinc-ion battery cathode material of the first aspect of the present invention or the zinc-ion battery cathode material of the second aspect of the present invention in the field of zinc-ion batteries, especially aqueous zinc-ion batteries.

[0026] By applying the technical solution of this invention and selecting the type of positive electrode material for zinc-ion batteries, the energy storage capacity of the positive electrode material can be improved on the one hand, and its cycle stability can be significantly improved on the other hand, which helps to expand the application range of zinc-ion batteries. Attached Figure Description

[0027] Figure 1 The XRD patterns of the zinc-ion battery cathode materials in Examples 1-3 and Comparative Examples 1-2 are shown.

[0028] Figure 2 The images show the energy dispersive spectroscopy (EDS) spectrum and scanning electron microscope (SEM) image of the zinc-ion battery cathode material in Example 1.

[0029] Figure 3 This is a transmission electron microscope (TEM) image of the primary particles of the zinc-ion battery cathode material in Example 1.

[0030] Figure 4 This is a nitrogen adsorption-desorption curve of the zinc-ion battery cathode material in Example 1;

[0031] Figure 5 This is a pore size distribution diagram of the zinc-ion battery cathode material in Example 1;

[0032] Figure 6 The batteries assembled from the zinc-ion battery cathode materials in Examples 1-3 and Comparative Examples 1-2 are tested at 1 A·g -1 Electrochemical performance test graphs obtained under the specified conditions;

[0033] Figure 7 The batteries assembled from the zinc-ion battery cathode materials in Example 1 and Comparative Example 1 were tested at 0.5 A·g. -1 Electrochemical performance test graphs obtained under the specified conditions;

[0034] Figure 8 The battery assembled from the zinc-ion battery cathode material in Example 1 is at 2 A·g -1 Electrochemical performance test graphs obtained under the specified conditions;

[0035] Figure 9 The graph shows the rate performance test results of the battery assembled from the zinc-ion battery cathode material in Example 1 at different current densities. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0037] As described in the background section of this invention, existing technologies suffer from poor cycle stability of zinc-ion battery cathode materials. To address this technical problem, in a typical embodiment of this invention, a zinc-ion battery cathode material is provided. This zinc-ion battery cathode material has a perovskite structure and the chemical formula of the zinc-ion battery cathode material is LaMn. x Mo y O3, where 0.85≤x≤0.95, 0.05≤y≤0.15, x+y=1; specifically, it can be LaMn 0.85 Mo0.15 O3, LaMn 0.9 Mo 0.1 O3, LaMn 0.95 Mo 0.05 O3, etc., can also be other materials within this range.

[0038] LaMn with perovskite structure x Mo y O3 possesses excellent electrical conductivity, a small band gap, abundant A-site cation defects, and numerous oxygen anion vacancies, which are beneficial for improving electrochemical performance. This invention suppresses the dissolution of manganese by doping Mo into LaMnO3. By controlling the amount of Mo doping, zinc-ion battery cathode materials can achieve both high capacity and high cycle stability, thus expanding the application range of zinc-ion battery cathode materials.

[0039] In some embodiments, the zinc-ion battery cathode material has a popcorn-like structure.

[0040] The popcorn-like structure helps to increase the specific capacity and specific energy density of the cathode material, storing more energy, and it can provide a higher electron transport rate.

[0041] In some implementations, 0.88≤x≤0.92, 0.05≤y≤0.12.

[0042] By further optimizing x and y, the specific capacity and stability of zinc-ion battery cathode materials can be further improved.

[0043] In some embodiments, the specific surface area of ​​the zinc-ion battery cathode material is 5 m². 2 / g~10m 2 / g, specifically 5m 2 / g、6m 2 / g、7m 2 / g、8m 2 / g、9m 2 / g, 10m 2 / g, etc., can also be other values ​​within this range, which are not limited here; and / or, the porosity of the zinc-ion battery cathode material is 15% to 28%.

[0044] Controlling the specific surface area and porosity of zinc-ion battery cathode materials helps to further improve the specific capacity of the cathode materials, increase their energy density, and improve their cycle stability.

[0045] In some embodiments, the zinc-ion battery cathode material is formed by stacking primary particles with an average particle size of 20nm to 35nm, specifically 20nm, 24nm, 26nm, 29nm, 31nm, 33nm, 35nm, etc., or other values ​​within this range, which are not limited here.

[0046] Controlling the average particle size of primary particles in zinc-ion battery cathode materials can shorten ion transport distance and increase electron transport rate, which is beneficial to improving the electrochemical activity of zinc-ion battery cathode materials.

[0047] In a typical embodiment of the present invention, a method for preparing a zinc-ion battery cathode material is provided, comprising the following steps:

[0048] S1, La2O3 powder, MnO2 powder and MoO3 powder are mixed to obtain a first mixture;

[0049] S2, the first mixture is ball-milled to obtain the second mixture;

[0050] S3, the second mixture is calcined to obtain a zinc-ion battery cathode material.

[0051] This invention prepares zinc-ion battery cathode materials by solid-state calcination. The preparation process is simple, requires no special equipment or conditions, and is suitable for industrial production.

[0052] In some embodiments, in S1, La2O3 powder, MnO2 powder and MoO3 powder are mixed by grinding.

[0053] Grinding can increase the contact area between materials, promote the reaction, and improve the reaction rate and efficiency; it can also change the morphology and structure of materials. In addition, grinding is a fast and low-cost method of mixing, making it suitable for large-scale applications.

[0054] In some embodiments, in S2, the ball milling method is as follows: the ball milling beads and the material are mixed at a ball-to-material ratio of (15-20):1, and ethanol is added at a material-to-liquid ratio of 1g:(0.75-2)mL. The mixture is then ball milled at a speed of 500rpm-700rpm for 2-4 hours. The ball milling beads include large beads, medium beads, and small beads. The diameter of the large beads is 15mm-18mm, the diameter of the medium beads is 10mm-12mm, and the diameter of the small beads is 5mm-8mm. The weight ratio of the large beads, the medium beads, and the small beads is (15-25):(25-35):(45-55).

[0055] Controlling various parameters during the ball milling process is essential for preparing zinc-ion battery cathode materials of the required size, ensuring they exhibit good electrochemical activity and cycle stability.

[0056] In some embodiments, the grinding beads can be made of zirconium oxide, which has high hardness and wear resistance, and can effectively grind various materials; in addition, zirconium oxide has good corrosion resistance, can be used stably for a long time in humid environments, and has good thermal stability, is non-polluting, and has a long service life.

[0057] In some implementations, the ball milling process is carried out in a planetary ball mill, a drum ball mill, or a vibratory ball mill.

[0058] In some embodiments, in S3, the calcination temperature is 700℃~900℃, specifically 700℃, 750℃, 800℃, 850℃, 900℃, etc., or other values ​​within this range, which are not limited here; the calcination time is 8h~12h, specifically 8h, 8.5h, 9h, 10h, 11h, 12h, etc., or other values ​​within this range, which are not limited here.

[0059] Controlling the calcination conditions is to obtain zinc-ion battery cathode materials with complete structures, so as to give them good stability and improve their cycle performance.

[0060] In some embodiments, the heating rate during calcination is 2℃ / min to 5℃ / min, specifically 2℃ / min, 3℃ / min, 4℃ / min, 5℃ / min, etc., or other values ​​within this range, which are not limited here.

[0061] Controlling the heating rate is to ensure that the material is heated evenly, thus producing zinc-ion battery cathode material with uniform composition.

[0062] In some embodiments, after calcination, the calcined product is ground and filtered through a sieve to obtain the zinc-ion battery cathode material. Filtration removes large particles with uneven sizes. Specifically, a 100-mesh sieve can be used for filtration.

[0063] In another typical embodiment of the present invention, an application is provided in the field of aqueous zinc-ion batteries using the zinc-ion battery cathode material of the above embodiments of the present invention or the zinc-ion battery cathode material prepared by the above preparation method.

[0064] The present application will be further described in detail below with reference to specific embodiments, which should not be construed as limiting the scope of protection claimed in the present application.

[0065] Zinc-ion battery cathode materials

[0066] Example 1

[0067] An embodiment of the zinc-ion battery cathode material of the present invention includes the following steps in its preparation method:

[0068] S1, 1.629g La2O3 powder, 0.782g MnO2 powder and 0.144g MoO3 powder are added to a quartz mortar and ground and mixed thoroughly to obtain the first mixture;

[0069] S2, add the first mixture into a ball mill jar, then add 50g of zirconia grinding beads (the weight ratio of large beads with a diameter of 15mm, medium beads with a diameter of 10mm, and small beads with a diameter of 8mm is 20:30:50), then add 5mL of ethanol, put the ball mill jar into a planetary ball mill, and ball mill at 600rpm for 3h, then dry to obtain the second mixture;

[0070] S3. The second mixture was placed in a crucible and compacted. After covering the crucible, it was placed in a muffle furnace and heated at a rate of 2℃ / min. Calcination was carried out at 900℃ for 10 hours. After natural cooling, the calcined product was transferred to a quartz mortar and ground thoroughly. The unevenly sized powder was filtered through a 100-mesh sieve to obtain LaMn. 0.9 Mo 0.1 2.126 g of O3 powder was produced, with a yield of 83.21%.

[0071] Example 2

[0072] An embodiment of the zinc-ion battery cathode material of the present invention includes the following steps in its preparation method:

[0073] S1, 1.629g La2O3 powder, 0.826g MnO2 powder and 0.072g MoO3 powder are added to a quartz mortar and ground and mixed thoroughly to obtain the first mixture;

[0074] S2, add the first mixture into a ball mill jar, then add 50g of zirconia grinding beads (the weight ratio of large beads with a diameter of 15mm, medium beads with a diameter of 10mm, and small beads with a diameter of 8mm is 20:30:50), then add 5mL of ethanol, put the ball mill jar into a planetary ball mill, and ball mill at 600rpm for 3h, then dry to obtain the second mixture;

[0075] S3. The second mixture was placed in a crucible and compacted. After covering the crucible, it was placed in a muffle furnace and heated at a rate of 2℃ / min. Calcination was carried out at 900℃ for 10 hours. After natural cooling, the calcined product was transferred to a quartz mortar and ground thoroughly. The unevenly sized powder was filtered through a 100-mesh sieve to obtain LaMn. 0.95 Mo 0.052.095 g of O3 powder was produced, with a yield of 82.90%.

[0076] Example 3

[0077] An embodiment of the zinc-ion battery cathode material of the present invention includes the following steps in its preparation method:

[0078] S1, 1.629g La2O3 powder, 0.739g MnO2 powder and 0.216g MoO3 powder are added to a quartz mortar and ground and mixed thoroughly to obtain the first mixture;

[0079] S2, add the first mixture into a ball mill jar, then add 50g of zirconia grinding beads (the weight ratio of large beads with a diameter of 15mm, medium beads with a diameter of 10mm, and small beads with a diameter of 8mm is 20:30:50), then add 5mL of ethanol, put the ball mill jar into a planetary ball mill, and ball mill at 600rpm for 3h, then dry to obtain the second mixture;

[0080] S3. The second mixture was placed in a crucible and compacted. After covering the crucible, it was placed in a muffle furnace and heated at a rate of 2℃ / min. Calcination was carried out at 900℃ for 10 hours. After natural cooling, the calcined product was transferred to a quartz mortar and ground thoroughly. The unevenly sized powder was filtered through a 100-mesh sieve to obtain LaMn. 0.85 Mo 0.15 2.276 g of O3 powder was produced, with a yield of 88.08%.

[0081] Example 4

[0082] An embodiment of the zinc-ion battery cathode material of the present invention includes the following steps in its preparation method:

[0083] S1, 1.629g La2O3 powder, 0.782g MnO2 powder and 0.144g MoO3 powder are added to a quartz mortar and ground and mixed thoroughly to obtain the first mixture;

[0084] S2, add the first mixture into a ball mill jar, then add 50g of zirconia grinding beads (the weight ratio of large beads with a diameter of 15mm, medium beads with a diameter of 10mm, and small beads with a diameter of 8mm is 30:50:20), then add 5mL of ethanol, put the ball mill jar into a planetary ball mill, and ball mill at 600rpm for 3h, then dry to obtain the second mixture;

[0085] S3. The second mixture was placed in a crucible and compacted. After covering the crucible, it was placed in a muffle furnace and heated at a rate of 2℃ / min. Calcination was carried out at 900℃ for 10 hours. After natural cooling, the calcined product was transferred to a quartz mortar and ground thoroughly. The unevenly sized powder was filtered through a 100-mesh sieve to obtain LaMn. 0.9 Mo 0.1 2.331 g of O3 powder was obtained, with a yield of 91.23%.

[0086] Example 5

[0087] An embodiment of the zinc-ion battery cathode material of the present invention includes the following steps in its preparation method:

[0088] S1, 1.629g La2O3 powder, 0.782g MnO2 powder and 0.144g MoO3 powder are added to a quartz mortar and ground and mixed thoroughly to obtain the first mixture;

[0089] S2, add the first mixture into a ball mill jar, then add 50g of zirconia grinding beads (the weight ratio of large beads with a diameter of 15mm, medium beads with a diameter of 10mm, and small beads with a diameter of 8mm is 15:20:65), then add 5mL of ethanol, put the ball mill jar into a planetary ball mill, and ball mill at 600rpm for 3h, then dry to obtain the second mixture;

[0090] S3. The second mixture was placed in a crucible and compacted. After covering the crucible, it was placed in a muffle furnace and heated at a rate of 2℃ / min. Calcination was carried out at 900℃ for 10 hours. After natural cooling, the calcined product was transferred to a quartz mortar and ground thoroughly. The unevenly sized powder was filtered through a 100-mesh sieve to obtain LaMn. 0.9 Mo 0.1 2.111 g of O3 powder was obtained, with a yield of 82.62%.

[0091] Comparative Example 1

[0092] A zinc-ion battery cathode material, the preparation method of which includes the following steps:

[0093] S1, 1.63g of La2O3 powder and 0.87g of MnO2 powder are added to a quartz mortar and ground and mixed thoroughly to obtain the first mixture;

[0094] S2, add the first mixture into a ball mill jar, then add 50g of zirconia grinding beads (the weight ratio of large beads with a diameter of 15mm, medium beads with a diameter of 10mm, and small beads with a diameter of 8mm is 20:20:60), then add 5mL of ethanol, put the ball mill jar into a planetary ball mill, and ball mill at 600rpm for 3h, then dry to obtain the second mixture;

[0095] S3. The second mixture was placed in a crucible and compacted. After covering the crucible, it was placed in a muffle furnace and heated at a rate of 2℃ / min. It was calcined at 900℃ for 10 hours. After the calcination was completed and the mixture was allowed to cool naturally, the calcined product was transferred to a quartz mortar and ground thoroughly. The unevenly sized powder was then filtered through a 100-mesh sieve to obtain 2.25g of LaMnO3 powder, with a yield of 90%.

[0096] Comparative Example 2

[0097] A zinc-ion battery cathode material, the preparation method of which includes the following steps:

[0098] An embodiment of the zinc-ion battery cathode material of the present invention includes the following steps in its preparation method:

[0099] S1, 1.629g La2O3 powder, 0.696g MnO2 powder and 0.288g MoO3 powder are added to a quartz mortar and ground and mixed thoroughly to obtain the first mixture;

[0100] S2, add the first mixture into a ball mill jar, then add 50g of zirconia grinding beads (the weight ratio of large beads with a diameter of 15mm, medium beads with a diameter of 10mm, and small beads with a diameter of 8mm is 20:20:60), then add 5mL of ethanol, put the ball mill jar into a planetary ball mill, and ball mill at 600rpm for 3h, then dry to obtain the second mixture;

[0101] S3. The second mixture was placed in a crucible and compacted. After covering the crucible, it was placed in a muffle furnace and heated at a rate of 2℃ / min. Calcination was carried out at 900℃ for 10 hours. After natural cooling, the calcined product was transferred to a quartz mortar and ground thoroughly. The unevenly sized powder was filtered through a 100-mesh sieve to obtain LaMn. 0.8 Mo 0.2 2.307 g of O3 powder was produced, with a yield of 88.29%.

[0102] Zinc-ion batteries

[0103] The zinc-ion battery cathode materials from Examples 1-5 and Comparative Examples 1-2 were assembled into coin cells, and the preparation method is as follows:

[0104] Zinc-ion battery positive electrode material, carbon black, and PVDF were added to an N-methylpyrrolidone solution at a mass ratio of 7:2:1 and stirred for 24 hours to form a slurry. This slurry was then coated onto a 0.01 mm titanium foil current collector and vacuum dried for 12 hours before being cut into 12 mm diameter discs. A 0.1 mm thick zinc foil was cut into 17 mm diameter discs, and a glass fiber separator was cut into 19 mm diameter discs. Using a 304 stainless steel CR2025 battery casing, the battery was assembled in the following order: positive electrode casing - positive electrode - 100 μL electrolyte - separator - 100 μL electrolyte - negative electrode - gasket - corrugated spring sheet - negative electrode casing. Finally, the battery was packaged using a tablet press to obtain an aqueous zinc-ion battery. The electrolyte was an aqueous solution with a ZnSO4 concentration of 2 mol / L and a MnSO4 concentration of 0.2 mol / L.

[0105] [Performance Testing]

[0106] 1. Zinc-ion battery cathode material

[0107] 1) Structure: Tested using an X-ray diffractometer;

[0108] 2) Morphology: Observed using scanning electron microscopy and transmission electron microscopy;

[0109] 3) Specific surface area, porosity, and average particle size: These were measured using a specific surface area and porosity analyzer.

[0110] 2. Zinc-ion batteries

[0111] 1) Discharge specific capacity and cycle performance: at 0.5 A·g -1 Cycle 200 times under the condition, at 1A·g -1 Cycle 500 times under the condition of 2A·g -1 Under certain conditions, the battery was cycled 1000 times and tested using a battery testing system.

[0112] 2) Rate performance: at 0.3 A·g -1 0.5A·g -1 1A·g -1 3A·g -1 5A·g -1 10A·g -1 The battery was tested using a battery testing system under the specified conditions.

[0113] The performance test results of the zinc-ion battery cathode material and the zinc-ion battery are recorded in Table 1.

[0114] Table 1

[0115]

[0116] As shown in Table 1, the batteries made from the zinc-ion battery cathode materials in the examples exhibit high discharge specific capacity and good cycle stability. Furthermore, the test results from Examples 1-5 show that the specific surface area of ​​the zinc-ion battery cathode material is 5 m². 2 / g~10m 2 When the porosity of the zinc-ion battery cathode material is 15%–28%, and / or the average particle size of the primary particles of the zinc-ion battery cathode material is 20 nm–35 nm, the electrochemical performance of the zinc-ion battery cathode material is better, and it also has excellent discharge specific capacity and cycle stability.

[0117] Figure 1 The figures show the XRD patterns of the zinc-ion battery cathode materials in Examples 1-3 and Comparative Examples 1-2. As can be seen from the figures, the zinc-ion battery cathode materials in the examples all have a good perovskite structure. Among them, when 0.9≤x≤0.95, the structure of the zinc-ion battery cathode material is almost exactly the same as that of LaMnO3, but when x≤0.85, obvious peaks of La2MnMoO6 appear in the XRD pattern.

[0118] Figure 2 The figures show the energy dispersive spectroscopy (EDS) spectrum and scanning electron microscope (SEM) image of the zinc-ion battery cathode material in Example 1. As can be seen from the figures, the zinc-ion battery cathode material has a popcorn-like structure, and its EDS spectrum shows that the elements are uniformly distributed in the cathode material.

[0119] Figure 3 The image shows a transmission electron microscope (TEM) image of the primary particles of the zinc-ion battery cathode material in Example 1. As can be seen from the image, the zinc-ion battery cathode material prepared by this invention has fine and uniform particles, which is beneficial to improving the stability of the cathode material.

[0120] Figure 4 The figure shows the nitrogen adsorption-desorption curve of the zinc-ion battery cathode material in Example 1. As can be seen from the figure, the prepared zinc-ion battery cathode material has a large specific surface area and a large active area, which is beneficial to improving the electrochemical performance of the cathode material.

[0121] Figure 5 The figure shows the pore size distribution of the zinc-ion battery cathode material in Example 1. As can be seen from the figure, the prepared zinc-ion battery cathode material has a small particle size and many active sites, which is beneficial to improving the electrochemical performance of the cathode material.

[0122] Figure 6 The batteries assembled from the zinc-ion battery cathode materials in Examples 1-3 and Comparative Examples 1-2 are tested at 1 A·g -1 The electrochemical performance test graph under the specified conditions shows that after 500 cycles, the discharge specific capacity of Examples 1-3 changed very little. This result indicates that the zinc-ion battery prepared with the zinc-ion battery cathode material disclosed in this invention has both good discharge specific capacity and cycle stability.

[0123] Figure 7 The batteries assembled from the zinc-ion battery cathode materials in Example 1 and Comparative Example 1 were tested at 0.5 A·g. -1 The electrochemical performance test results obtained under the specified conditions show that the zinc-ion battery cathode material is gradually activated with increasing cycle number. After 200 cycles, the discharge specific capacity of the battery assembled from the zinc-ion battery cathode material in Example 1 reaches 445 mAh·g. -1 This is superior to Comparative Example 1, and the results show that the zinc-ion battery prepared with the zinc-ion battery cathode material disclosed in this invention has excellent discharge specific capacity.

[0124] Figure 8 The battery assembled from the zinc-ion battery cathode material in Example 1 is at 2 A·g -1 The electrochemical performance test graph obtained under the conditions shows that the zinc-ion battery made with the zinc-ion battery cathode material disclosed in this invention also has good electrochemical performance under high rate conditions.

[0125] Figure 9 The graph shows the rate performance test results of the zinc-ion battery assembled from the positive electrode material in Example 1 at different current densities. As can be seen from the graph, the discharge specific capacity of the zinc-ion battery decreases approximately linearly with the increase of current density. When the current density decreases, the discharge specific capacity of the zinc-ion battery can recover to the initial value, showing good stability.

[0126] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A zinc-ion battery cathode material, characterized in that, The zinc-ion battery cathode material has a perovskite structure, and the chemical formula of the zinc-ion battery cathode material is LaMn. x Mo y O3, where 0.85≤x≤0.95, 0.05≤y≤0.15, and x+y=1.

2. The zinc-ion battery cathode material according to claim 1, characterized in that, The zinc-ion battery cathode material has a popcorn-like structure.

3. The zinc-ion battery cathode material according to claim 1, characterized in that, The specific surface area of ​​the zinc-ion battery cathode material is 5m². 2 / g~10m 2 / g; and / or, the porosity of the zinc-ion battery cathode material is 15% to 28%.

4. The zinc-ion battery cathode material according to claim 1, characterized in that, The zinc-ion battery cathode material is formed by the stacking of primary particles, and the average particle size of the primary particles is 20nm to 35nm.

5. A method for preparing a zinc-ion battery cathode material according to any one of claims 1 to 4, characterized in that, Includes the following steps: S1, La2O3 powder, MnO2 powder and MoO3 powder are mixed to obtain a first mixture; S2, the first mixture is ball-milled to obtain a second mixture; S3, calcining the second mixture to obtain the zinc-ion battery cathode material.

6. The method for preparing the zinc-ion battery cathode material according to claim 5, characterized in that, In step S1, the La2O3 powder, the MnO2 powder, and the MoO3 powder are mixed by grinding.

7. The method for preparing the zinc-ion battery cathode material according to claim 5, characterized in that, The ball milling method is as follows: The grinding balls are mixed with the material at a ball-to-material ratio of (15-20):1, and then ethanol is added. The mixture is then ball-milled at 500-700 rpm for 2-4 hours. The grinding balls include large, medium, and small balls. The diameter of the large balls is 15-18 mm, the diameter of the medium balls is 10-12 mm, and the diameter of the small balls is 5-8 mm. The weight ratio of the large, medium, and small balls is (15-25):(25-35):(45-55).

8. The method for preparing the zinc-ion battery cathode material according to claim 5, characterized in that, The calcination temperature is 700℃~900℃ and the time is 8h~12h.

9. The method for preparing the zinc-ion battery cathode material according to claim 5, characterized in that, After calcination, the calcined product is ground and filtered through a sieve to obtain the zinc-ion battery cathode material.

10. The application of a zinc-ion battery cathode material according to any one of claims 1 to 4 or a zinc-ion battery cathode material prepared by any one of claims 5 to 9 in the field of zinc-ion batteries.

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