Electrode material for low-temperature zinc ion battery and preparation method of electrode material

Abstract

The invention relates to an electrode material for a low-temperature zinc ion battery and a preparation method thereof, and belongs to the technical field of electrochemical energy storage, the material is prepared by an optimized one-step hydrothermal method: firstly, stirring and dispersing molybdenum trioxide powder in deionized water, then adding thioacetamide as a sulfur source, and fully stirring to form a uniform precursor mixed solution; then, the mixed solution is transferred into a hydrothermal reaction kettle, a product is separated through vacuum filtration after the hydrothermal reaction is completed, the Mo-S-O ternary compound with the low crystalline state characteristic is obtained after washing to remove impurities and drying, and the low-temperature electrochemical performance is effectively improved through rich active sites and rapid ion diffusion channels of the material. The preparation process is controllable in reaction condition, good in repeatability and easy for large-scale production, and a new material solution is provided for developing the low-temperature high-performance zinc ion battery.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of electrochemical energy storage, and particularly relates to an electrode material for a low-temperature zinc ion battery and a preparation method thereof. BACKGROUND

[0002] In the wave of global energy structure transformation, energy storage technology is facing unprecedented development opportunities. Large-scale grid connection of renewable energy sources puts higher requirements on the stability of power systems, and energy storage systems as key regulating units are becoming increasingly important.

[0003] Current mainstream energy storage battery technology is mainly designed for normal temperature environments, but in actual applications, it often faces more complex environmental challenges. Under extreme low temperature conditions, the performance of the battery system directly affects the reliability of the equipment. For example, the range decay and starting difficulty problems in cold weather of electric vehicles need to be solved, and the deployment of large-scale energy storage stations in high latitude areas is also restricted by low temperature environments. In special fields such as aerospace, energy storage equipment needs to adapt to extreme low temperature working environments. These application scenarios have strict requirements on the low temperature performance of the battery.

[0004] In recent years, new energy storage technologies have emerged, among which zinc ion batteries stand out due to their unique advantages; this battery system can use metal zinc as the negative electrode material, not only has a high theoretical specific capacity, but also has excellent safety performance. In addition, the high crust abundance of zinc element makes this technology have a significant advantage in cost control. From the perspective of market application, zinc ion batteries have significant advantages in energy storage safety and cost-sensitive fields (such as large-scale grid energy storage). However, the application of zinc ion batteries in low temperature environments still faces many technical bottlenecks, especially in working environments below zero degrees, the capacity retention rate and cycle life of the battery will decrease significantly. Solving this problem requires the coordinated optimization of electrode material selection and microstructure design.

[0005] The application proposes a low-crystalline Mo-S-O ternary compound electrode material with excellent low temperature performance, which shows excellent low temperature adaptability (-60℃ to 0℃) in zinc ion batteries. The preparation process of the material is simple and efficient, the reaction conditions are mild and controllable, the product consistency is excellent, and it has significant advantages in industrial scale production. SUMMARY

[0006] In view of the deficiencies of the prior art, the application provides an electrode material for a low-temperature zinc ion battery and a preparation method thereof, which is a Mo-S-O ternary compound with a special low-crystalline structure, which shows high specific capacity and excellent cycle stability under normal temperature and low temperature conditions.

[0007] In a first aspect, the present invention proposes a method for preparing electrode materials for low-temperature zinc-ion batteries, specifically including the following steps:

[0008] (1) Molybdenum trioxide was dispersed in deionized water, and then thioacetamide was added and stirred to form a precursor mixture;

[0009] (2) The precursor mixture is placed in a hydrothermal reactor for hydrothermal reaction. After separating the product, the impurities are washed away and dried in a low-temperature vacuum environment to obtain the electrode material.

[0010] in:

[0011] In step (1), the molar ratio of molybdenum trioxide to deionized water is 1:(200~2000).

[0012] In step (1), the molar ratio of molybdenum trioxide to thioacetamide is 1:(0.5~6).

[0013] In step (2), the hydrothermal reaction temperature is 160℃~220℃ and the reaction time is 6h~48h.

[0014] In step (2), the separation of products is specifically a vacuum filtration process, and the washing process uses deionized water and anhydrous ethanol alternately.

[0015] In step (2), the drying temperature is 30℃~35℃ and the time is 48h~168h.

[0016] Secondly, the present invention provides an electrode material for low-temperature zinc-ion batteries, which is prepared by the above method. Specifically, the electrode material is a Mo-SO ternary compound in which the three elements Mo, S and O are uniformly distributed and their crystal orientations are disordered.

[0017] Thirdly, this invention proposes the application of the above-mentioned electrode material in low-temperature zinc-ion batteries, with the specific steps as follows:

[0018] Electrode material, conductive agent and binder are mixed in mass ratio and placed in N-methylpyrrolidone solvent, and thoroughly mixed until uniformly dispersed to obtain slurry; then the slurry is uniformly coated on stainless steel current collector and dried under vacuum to form working electrode;

[0019] The conductive agent is acetylene black or Ketjen black, and the binder is polyvinylidene fluoride or polytetrafluoroethylene. The mass ratio of electrode material, conductive agent and binder is 5:4:1, 6:3:1, 7:2:1 or 8:1:1.

[0020] The working electrode can be used as a positive electrode to assemble a zinc-ion battery with a zinc foil negative electrode, or as a negative electrode to assemble a zinc-free zinc-ion battery with a manganese-based oxide positive electrode, a Prussian blue analog positive electrode, or a vanadium oxyphosphate positive electrode.

[0021] When the zinc-ion battery is used in an environment of 0℃~25℃, the electrolyte is selected from 0.5mol / L. -1 ~3mol L -1 Aqueous solution of Zn(CF3SO3)2, or 5 mol kg -1 ~15mol kg -1 ZnCl2 aqueous solution or 2 mol kg -1 ~5mol kg -1 Aqueous solution of Zn(BF4)2.

[0022] When the zinc-ion battery is used in an environment of -40℃ to -60℃, the electrolyte is 5 mol / kg. -1 ~15mol kg -1 ZnCl2 aqueous solution or 2 mol kg -1 ~5mol kg -1 Aqueous solution of Zn(BF4)2.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0024] 1. Excellent low-temperature performance: After the electrode materials of this invention are used to form a battery, they still maintain excellent electrochemical activity under extreme low-temperature conditions of -40℃ and -60℃, solving the key problem of conventional electrode materials failing in low-temperature environments.

[0025] 2. The low crystallinity structure of the electrode material prepared by this invention effectively alleviates volume strain during charging and discharging, endowing the material with ultra-high rate performance: at 30A g -1 It can maintain a high capacity even at ultra-high current density, far exceeding the performance limit of conventional electrode materials for existing zinc-ion batteries.

[0026] 3. Unique dual-function characteristics: The electrode material prepared by this invention can be used as both a positive electrode material and a negative electrode material, which greatly expands its application range in zinc-ion battery systems. Attached Figure Description

[0027] Figure 1 X-ray diffraction pattern of the electrode material prepared in Example 1 of this invention;

[0028] Figure 2 The full X-ray photoelectron spectrum of the electrode material prepared in Example 1 of this invention;

[0029] Figure 3An energy dispersive X-ray spectroscopy element mapping of the electrode material prepared in Embodiment 1 of the present application is shown in the following figure;

[0030] Figure 4 A charge-discharge curve of a battery formed by the electrode sheet prepared in Embodiment 1 of the present application and a zinc foil at 25℃ under different current densities is shown in the following figure;

[0031] Figure 5 A cycle performance of a battery formed by the electrode sheet prepared in Embodiment 1 of the present application and a zinc foil at 25℃ under a current density of 30A g -1

[0032] Figure 6 A charge-discharge curve of a battery formed by the electrode sheet prepared in Embodiment 1 of the present application and a zinc foil at 0℃ under a current density of 0.1A g -1

[0033] Figure 7 A charge-discharge curve of a battery formed by the electrode sheet prepared in Embodiment 1 of the present application and a zinc foil at -40℃ under a current density of 0.1A g -1

[0034] Figure 8 A charge-discharge curve of a battery formed by the electrode sheet prepared in Embodiment 1 of the present application and a zinc foil at -60℃ under a current density of 0.1A g -1

[0035] Figure 9 A charge-discharge curve of a battery formed by the electrode sheet prepared in Embodiment 1 of the present application and a manganese-based oxide positive electrode under a current density of 0.2A g -1

[0036] Figure 10 A cycle performance of a battery formed by the electrode sheet prepared in Embodiment 1 of the present application and a manganese-based oxide positive electrode under a current density of 0.2A g -1

[0037] Figure 11 A scanning electron microscope image of the electrode material prepared in Embodiment 2 of the present application is shown in the following figure;

[0038] Figure 12 A scanning electron microscope image of the electrode material prepared in Embodiment 3 of the present application is shown in the following figure. DETAILED DESCRIPTION

[0039] The specific embodiments of the present application will be further described in detail below with reference to the accompanying drawings and examples.

[0040] A preparation method of an electrode material for a low-temperature zinc ion battery, specifically comprising the following steps:

[0041] ​​​​​​(1) dispersing molybdenum trioxide in deionized water, the molar ratio of molybdenum trioxide to deionized water being 1: (200-2000), then adding thioacetamide, the molar ratio of molybdenum trioxide to thioacetamide being 1: (0.5-6), and stirring to form a precursor mixture;

[0042] (2) placing the precursor mixture in a hydrothermal reaction kettle for hydrothermal reaction, the reaction temperature being 160-220 DEG C, and the reaction time being 6-48 hours; after separating the product by vacuum filtration, washing with deionized water and anhydrous ethanol alternately to remove impurities, drying in a low-temperature vacuum environment, the drying temperature being 30-35 DEG C, and the time being 48-168 hours, an electrode material is obtained.

[0043] An electrode material for a low-temperature zinc ion battery, prepared by the above method, specifically a low-crystalline Mo-S-O ternary compound, the three elements Mo, S and O being uniformly distributed in the compound, the crystal structure anisotropy being weak, and the crystal face orientation being disordered.

[0044] Application of the above electrode material in a low-temperature zinc ion battery, the specific steps being as follows:

[0045] After the electrode material, a conductive agent and a binder are proportioned by mass ratio, they are placed in an N-methylpyrrolidone solvent, mixed thoroughly to a uniformly dispersed state, and a slurry is prepared; then the slurry is uniformly coated on a stainless steel current collector, and a working electrode is prepared by vacuum drying; the conductive agent is acetylene black or ketjen black, the binder is polyvinylidene fluoride or polytetrafluoroethylene, and the mass ratio of the electrode material, the conductive agent and the binder is 5:4:1 or 6:3:1 or 7:2:1 or 8:1:1.

[0046] The working electrode can be assembled into a zinc ion battery as a positive electrode with a zinc foil negative electrode, or assembled into a zinc-free zinc ion battery as a negative electrode with a manganese-based oxide positive electrode, a Prussian blue analogue positive electrode or a vanadium phosphate oxide positive electrode.

[0047] In the embodiment of the application, when the zinc ion battery prepared is used in an environment of 0 DEG C-25 DEG C, the electrolyte is selected from 0.5 mol / L -1 ~3 mol / L -1 Zn(CF3SO3)2 aqueous solution, or 5 mol / kg -1 ~15 mol / kg -1 ZnCl2 aqueous solution or 2 mol / kg -1 ~5 mol / kg -1 Zn(BF4)2 aqueous solution.

[0048] In the embodiment of the application, when the zinc ion battery prepared is used in an environment of -40 DEG C--60 DEG C, the electrolyte is 5 mol / kg -1 ~15 mol / kg-1 ZnCl2 aqueous solution or 2 mol kg -1 ~5 mol kg -1 Zn(BF4)2 aqueous solution.

[0049] Example 1

[0050] A preparation method of an electrode material for a low-temperature zinc ion battery, specifically comprising the following steps:

[0051] (1) 0.43 g of molybdenum trioxide is dispersed in 30 mL of deionized water, and after stirring for 10 min, 0.51 g of thioacetamide is added to form a precursor mixed solution.

[0052] (2) The precursor mixed solution is placed in a 50 mL hydrothermal reactor for hydrothermal reaction, the reaction temperature is 180℃, and the reaction time is 24 h. After the reaction is completed, the product is separated by vacuum filtration and washed with deionized water and anhydrous ethanol alternately for multiple times to remove impurities, and dried in a vacuum oven for 168 h at a drying temperature of 32℃ to obtain a low-crystalline Mo-S-O ternary compound, which is the electrode material.

[0053] The X-ray diffraction pattern of the electrode material prepared in Example 1 is shown in Figure 1 , and the results show that the crystallinity of the material is weak, there is no obvious characteristic peak, the crystal structure anisotropy is weak, and the crystal face orientation is disordered; a diffraction broad peak is exhibited at ~ 38°, and another broadened diffraction peak is exhibited at ~ 64.5°, and there is no standard PDF card that can be matched, indicating that it is a new low-crystalline material. The X-ray photoelectron spectroscopy full spectrum of the electrode material is shown in Figure 2 , and the energy dispersive X-ray spectroscopy element mapping is shown in Figure 3 , which confirms that Mo, S, and O elements coexist in the Mo-S-O ternary compound, and the Mo, S, and O elements exhibit a uniform distribution state.

[0054] The application of the electrode material prepared in Example 1 in a low-temperature zinc ion battery, specifically comprising the following steps:

[0055] The Mo-S-O ternary compound, acetylene black, and polyvinylidene fluoride are mixed and ground in a mass ratio of 7:2:1, and then placed in an N-methyl pyrrolidone solvent, and fully mixed to a uniform dispersion state to prepare a slurry; then the slurry is uniformly coated on a stainless steel current collector, and vacuum dried to prepare a Mo-S-O ternary compound-based electrode sheet.

[0056] The Mo-S-O ternary compound-based electrode sheet prepared in Example 1 is used as a positive electrode, and a zinc ion battery composed of the Mo-S-O ternary compound-based electrode sheet and a zinc foil negative electrode is tested at 25℃ under different current densities (0.5A g -1 , 1A g-1 2A g -1 5A g -1 10A g -1 15A g -1 20Ag -1 30A g -1 Typical charge-discharge curves are shown below. Figure 4 As shown, the battery is at 0.5A g -1 The specific charging capacity at the current density is 112.0 mAh g. -1 , at 30A g -1 The charging specific capacity at the current density is 54.2 mAh g. -1 .

[0057] A zinc-ion battery consisting of a Mo-SO ternary compound-based electrode sheet as the positive electrode and a zinc foil negative electrode was tested at 25°C and 30 A g. -1 Cyclic performance at current density is shown in the figure. Figure 5 As shown, the specific capacity during the first charge cycle is 78.3 mAh g. -1 After 1000 cycles, the battery still exhibits a capacity of 59.2 mAh g. -1 The charging capacity.

[0058] A zinc-ion battery consisting of a Mo-SO ternary compound-based electrode sheet as the positive electrode and a zinc foil negative electrode was tested at 0°C and 0.1 A g. -1 The charge-discharge curves at current density are shown below. Figure 6 As shown, the specific capacity reached 121.8 mAh g during the first charge cycle. -1 After 40 charge cycles, the specific capacity is 89.2 mAh g. -1 .

[0059] A zinc-ion battery consisting of a Mo-SO ternary compound-based electrode sheet as the positive electrode and a zinc foil negative electrode is tested at -40℃ and 0.1 A g. -1 The charge-discharge curves at current density are shown below. Figure 7 As shown, the specific capacity during the first charge cycle is 68.6 mAh g. -1 After 170 charge cycles, the specific capacity is 73.3 mAh g. -1 .

[0060] A zinc-ion battery consisting of a Mo-SO ternary compound-based electrode sheet as the positive electrode and a zinc foil negative electrode is tested at -60℃ and 0.1 A g. -1 The charge-discharge curves at current density are shown below. Figure 8 As shown, the specific capacity during the first charge cycle is 64.8 mAh g. -1 After 230 charge cycles, the specific capacity is 46.1 mAh g.-1 .

[0061] In summary, the zinc ion battery assembled by Mo-S-O ternary compound and zinc foil exhibits high capacity and cycle performance at different current densities and temperatures, which is suitable as a positive electrode material of zinc ion battery.

[0062] The electrode sheet of Mo-S-O prepared in Example 1 can also be assembled into a zinc ion battery as a negative electrode with a typical positive electrode sheet, and the corresponding battery exhibits good performance. The battery composed of Mo-S-O ternary compound as a negative electrode and a manganese-based oxide positive electrode exhibits stable curves at a current density of 0.2 A g -1 . Figure 9 The charge-discharge curves of the battery at a current density of 0.2 A g -1 .

[0063] The zinc ion battery composed of Mo-S-O ternary compound as a negative electrode and a manganese-based oxide positive electrode exhibits stable curves at a current density of 0.2 A g -1 . Figure 10 The charge-discharge curves of the battery at a current density of 0.2 A g -1 .

[0064] Example 2

[0065] A preparation method of an electrode material for a low-temperature zinc ion battery, specifically comprising the following steps:

[0066] (1) Disperse 0.86 g of molybdenum trioxide in 30 mL of deionized water, and after stirring for 10 min, add 2.04 g of thioacetamide to form a precursor mixed solution.

[0067] (2) Put the precursor mixed solution into a 50 mL hydrothermal reactor for hydrothermal reaction, the reaction temperature is 160℃, and the reaction time is 48 h. After the reaction is completed, the product is separated by vacuum filtration and washed with deionized water and anhydrous ethanol alternately for multiple times to remove impurities, and dried in a vacuum oven for 56 h at a drying temperature of 30℃ to obtain a low-crystalline Mo-S-O ternary compound, which is the electrode material, and the scanning electron microscope image thereof is shown in Figure 11 .

[0068] The application of the electrode material prepared in Example 2 in a low-temperature zinc ion battery, specifically comprising the following steps:

[0069] The Mo-S-O ternary compound, acetylene black and polyvinylidene fluoride are mixed in a mass ratio of 6:3:1, ground and then placed in an N-methylpyrrolidone solvent, mixed thoroughly to a uniformly dispersed state to prepare a slurry; then the slurry is uniformly coated on a stainless steel current collector and vacuum dried to prepare a Mo-S-O ternary compound-based electrode sheet.

[0070] The zinc ion battery composed of the Mo-S-O ternary compound-based electrode sheet prepared in Example 2 as a positive electrode and a zinc foil negative electrode exhibits excellent electrochemical performance. The zinc ion battery composed of the Mo-S-O ternary compound as a negative electrode and a Prussian blue analog positive electrode exhibits good electrochemical performance.

[0071] Example 3

[0072] A preparation method of an electrode material for a low-temperature zinc ion battery, specifically comprising the following steps:

[0073] (1) 1.72 g of molybdenum trioxide is dispersed in 60 mL of deionized water, 1.02 g of thioacetamide is added after stirring for 10 min, and a precursor mixed solution is formed by stirring.

[0074] (2) The precursor mixed solution is placed in a 100 mL hydrothermal reactor for hydrothermal reaction, the reaction temperature is 220°C, and the reaction time is 6 h. After the reaction is completed, the product is separated by vacuum filtration and washed with deionized water and anhydrous ethanol alternately for multiple times to remove impurities, dried in a vacuum oven for 56 h, and the drying temperature is 35°C, to obtain a low-crystalline Mo-S-O ternary compound, which is an electrode material, and a scanning electron microscope image thereof is shown in Figure 12 .

[0075] Application of the electrode material prepared in Example 3 in a low-temperature zinc ion battery, specifically comprising the following steps:

[0076] The Mo-S-O ternary compound, acetylene black and polyvinylidene fluoride are mixed in a mass ratio of 6:3:1, ground and then placed in an N-methylpyrrolidone solvent, mixed thoroughly to a uniformly dispersed state to prepare a slurry; then the slurry is uniformly coated on a stainless steel current collector and vacuum dried to prepare a Mo-S-O ternary compound-based electrode sheet.

[0077] The zinc ion battery composed of the Mo-S-O ternary compound-based electrode sheet prepared in Example 3 as a positive electrode and a zinc foil negative electrode exhibits excellent electrochemical performance. The zinc ion battery composed of the Mo-S-O ternary compound as a negative electrode and a vanadyl phosphate positive electrode exhibits good electrochemical performance.

[0078] Example 4

[0079] A preparation method of an electrode material for a low-temperature zinc ion battery, specifically comprising the following steps:

[0080] (1) 2.40 g of molybdenum trioxide was dispersed in 60 mL of deionized water, and 0.63 g of thioacetamide was added after stirring for 10 min to form a precursor mixture.

[0081] (2) The precursor mixture was placed in a 100 mL hydrothermal reactor for hydrothermal reaction, the reaction temperature was 200℃, and the reaction time was 24 h. After the reaction was completed, the product was separated by vacuum filtration and washed with deionized water and anhydrous ethanol alternately for multiple times to remove impurities, and dried in a vacuum oven for 150 h at a drying temperature of 33℃ to obtain a low-crystalline Mo-S-O ternary compound, which was the electrode material.

[0082] The application of the electrode material prepared in Example 4 in a low-temperature zinc ion battery, the specific steps are as follows:

[0083] The Mo-S-O ternary compound, acetylene black and polyvinylidene fluoride were mixed and ground in a mass ratio of 5:4:1, and then placed in an N-methyl pyrrolidone solvent, and fully mixed to a uniformly dispersed state to prepare a slurry; then the slurry was uniformly coated on a stainless steel current collector, and vacuum dried to prepare a Mo-S-O ternary compound-based electrode sheet.

[0084] The zinc ion battery composed of the Mo-S-O ternary compound-based electrode sheet prepared in Example 4 as a positive electrode and a zinc foil negative electrode showed excellent electrochemical performance. The zinc ion battery composed of the Mo-S-O ternary compound as a negative electrode and a manganese-based oxide positive electrode showed good electrochemical performance.

[0085] Example 5

[0086] A preparation method of an electrode material for a low-temperature zinc ion battery, specifically comprising the following steps:

[0087] (1) 0.24 g of molybdenum trioxide was dispersed in 60 mL of deionized water, and 0.75 g of thioacetamide was added after stirring for 10 min to form a precursor mixture.

[0088] (2) The precursor mixture was placed in a 100 mL hydrothermal reactor for hydrothermal reaction, the reaction temperature was 220℃, and the reaction time was 40 h. After the reaction was completed, the product was separated by vacuum filtration and washed with deionized water and anhydrous ethanol alternately for multiple times to remove impurities, and dried in a vacuum oven for 72 h at a drying temperature of 33℃ to obtain a low-crystalline Mo-S-O ternary compound, which was the electrode material.

[0089] The application of the electrode material prepared in Example 5 in a low-temperature zinc ion battery, the specific steps are as follows:

[0090] The Mo-S-O ternary compound, acetylene black and polyvinylidene fluoride are mixed in a mass ratio of 7:2:1 and ground, then placed in an N-methylpyrrolidone solvent, and mixed thoroughly to a uniformly dispersed state to prepare a slurry; then the slurry is uniformly coated on a stainless steel current collector, and vacuum dried to prepare a Mo-S-O ternary compound-based electrode sheet.

[0091] The zinc ion battery composed of the Mo-S-O ternary compound-based electrode sheet prepared in Example 5 as a positive electrode and a zinc foil negative electrode exhibits excellent electrochemical performance. The zinc ion battery composed of the Mo-S-O ternary compound as a negative electrode and a manganese-based oxide positive electrode exhibits good electrochemical performance.

[0092] Example 6

[0093] A preparation method of an electrode material for a low-temperature zinc ion battery, specifically comprising the following steps:

[0094] (1) 0.24 g of molybdenum trioxide is dispersed in 60 mL of deionized water, and after stirring for 10 min, 0.063 g of thioacetamide is added to form a precursor mixture.

[0095] (2) The precursor mixture is placed in a 100 mL hydrothermal reactor for hydrothermal reaction, the reaction temperature is 220°C, and the reaction time is 24 h. After the reaction is completed, the product is separated by vacuum filtration and washed with deionized water and anhydrous ethanol alternately for multiple times to remove impurities, and dried in a vacuum oven for 48 h at a drying temperature of 35°C to obtain a low-crystalline Mo-S-O ternary compound, which is the electrode material.

[0096] Application of the electrode material prepared in Example 6 in a low-temperature zinc ion battery, specifically comprising the following steps:

[0097] The Mo-S-O ternary compound, acetylene black and polyvinylidene fluoride are mixed in a mass ratio of 7:2:1 and ground, then placed in an N-methylpyrrolidone solvent, and mixed thoroughly to a uniformly dispersed state to prepare a slurry; then the slurry is uniformly coated on a stainless steel current collector, and vacuum dried to prepare a Mo-S-O ternary compound-based electrode sheet.

[0098] The zinc ion battery composed of the Mo-S-O ternary compound-based electrode sheet prepared in Example 6 as a positive electrode and a zinc foil negative electrode exhibits excellent electrochemical performance. The zinc ion battery composed of the Mo-S-O ternary compound as a negative electrode and a manganese-based oxide positive electrode exhibits good electrochemical performance.

[0099] Example 7

[0100] A preparation method of an electrode material for a low-temperature zinc ion battery, specifically comprising the following steps:

[0101] (1) 11.98 g of molybdenum trioxide was dispersed in 300 mL of deionized water, and after stirring for 10 min, 37.50 g of thioacetamide was added to form a precursor mixture solution.

[0102] (2) The precursor mixture solution was placed in a 500 mL hydrothermal reactor for hydrothermal reaction, the reaction temperature was 200°C, and the reaction time was 48 h. After the reaction was completed, the product was separated by vacuum filtration and washed with deionized water and anhydrous ethanol alternately for multiple times to remove impurities, and dried in a vacuum oven for 168 h at a drying temperature of 35°C to obtain a low-crystalline Mo-S-O ternary compound, which was the electrode material.

[0103] The application of the electrode material prepared in Example 7 in a low-temperature zinc ion battery is as follows:

[0104] The Mo-S-O ternary compound, acetylene black and polyvinylidene fluoride were mixed and ground in a mass ratio of 7:2:1, and then placed in an N-methylpyrrolidone solvent to form a slurry after being fully mixed and uniformly dispersed. The slurry was uniformly coated on a stainless steel current collector, and a Mo-S-O ternary compound-based electrode sheet was prepared after vacuum drying.

[0105] The zinc ion battery composed of the Mo-S-O ternary compound-based electrode sheet prepared in Example 7 as a positive electrode and a zinc foil negative electrode showed excellent electrochemical performance. The zinc ion battery composed of the Mo-S-O ternary compound as a negative electrode and a manganese-based oxide positive electrode showed good electrochemical performance.

[0106] Example 8

[0107] A preparation method of an electrode material for a low-temperature zinc ion battery, specifically comprising the following steps:

[0108] (1) 11.98 g of molybdenum trioxide was dispersed in 300 mL of deionized water, and after stirring for 10 min, 37.50 g of thioacetamide was added to form a precursor mixture solution.

[0109] (2) The precursor mixture solution was placed in a 500 mL hydrothermal reactor for hydrothermal reaction, the reaction temperature was 200°C, and the reaction time was 48 h. After the reaction was completed, the product was separated by vacuum filtration and washed with deionized water and anhydrous ethanol alternately for multiple times to remove impurities, and dried in a vacuum oven for 168 h at a drying temperature of 35°C to obtain a low-crystalline Mo-S-O ternary compound, which was the electrode material.

[0110] The application of the electrode material prepared in Example 8 in a low-temperature zinc ion battery is as follows:

[0111] The Mo-S-O ternary compound, acetylene black and polyvinylidene fluoride are mixed in a mass ratio of 7:2:1, ground and then placed in an N-methylpyrrolidone solvent, mixed thoroughly to a uniformly dispersed state to prepare a slurry; then the slurry is uniformly coated on a stainless steel current collector and vacuum dried to prepare a Mo-S-O ternary compound-based electrode sheet.

[0112] The zinc ion battery composed of the Mo-S-O ternary compound-based electrode sheet prepared in Example 8 as a positive electrode and a zinc foil negative electrode exhibits excellent electrochemical performance. The zinc ion battery composed of the Mo-S-O ternary compound as a negative electrode and a manganese-based oxide positive electrode exhibits good electrochemical performance.

[0113] As can be seen from the above, the electrode material prepared in the embodiments of the present application can still maintain a relatively high capacity under an ultra-high current density of 30 A g -1 , far exceeding the performance limit of conventional electrode materials of existing zinc ion batteries. (Carbon Neutralization 2023, 2, 186-212.; Chin. Chem. Lett. 2023, 34, 108307).

[0114] It is easy for those skilled in the art to understand that the above is only a preferred embodiment of the present application and is not used to limit the present application. Any modification, equivalent replacement and modification within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for preparing electrode material for low-temperature zinc-ion batteries, characterized in that, Specifically, the following steps are included: (1) Molybdenum trioxide was dispersed in deionized water, and then thioacetamide was added and stirred to form a precursor mixture; (2) The precursor mixture is placed in a hydrothermal reactor for hydrothermal reaction. After separating the product, the impurities are washed away and dried in a low-temperature vacuum environment to obtain the electrode material.

2. The method for preparing an electrode material for a low-temperature zinc-ion battery according to claim 1, characterized in that, In step (1), the molar ratio of molybdenum trioxide to deionized water is 1:(200~2000).

3. The method for preparing an electrode material for a low-temperature zinc-ion battery according to claim 1, characterized in that, In step (1), the molar ratio of molybdenum trioxide to thioacetamide is 1:(0.5~6).

4. The method for preparing an electrode material for a low-temperature zinc-ion battery according to claim 1, characterized in that, In step (2), the hydrothermal reaction temperature is 160℃~220℃ and the reaction time is 6h~48h.

5. The method for preparing an electrode material for a low-temperature zinc-ion battery according to claim 1, characterized in that, In step (2), the separation of products is specifically a vacuum filtration process, and the washing process uses deionized water and anhydrous ethanol alternately.

6. The method for preparing an electrode material for a low-temperature zinc-ion battery according to claim 1, characterized in that, In step (2), the drying temperature is 30℃~35℃ and the time is 48h~168h.

7. An electrode material for low-temperature zinc-ion batteries, prepared by the method according to any one of claims 1-6, characterized in that, The electrode material is specifically a Mo-SO ternary compound, in which the three elements Mo, S, and O are uniformly distributed and their crystal orientations are disordered.

8. The application of the electrode material for low-temperature zinc-ion batteries as described in claim 7, characterized in that, The specific steps are as follows: Electrode material, conductive agent and binder are mixed in mass ratio and placed in N-methylpyrrolidone solvent, and thoroughly mixed until uniformly dispersed to obtain slurry; then the slurry is uniformly coated on stainless steel current collector and dried under vacuum to form working electrode; The conductive agent is acetylene black or Ketjen black, and the binder is polyvinylidene fluoride or polytetrafluoroethylene. The mass ratio of electrode material, conductive agent and binder is 5:4:1, 6:3:1, 7:2:1 or 8:1:

1.

9. The application of the electrode material for low-temperature zinc-ion batteries according to claim 8, characterized in that, The working electrode can be used as a positive electrode to assemble a zinc-ion battery with a zinc foil negative electrode, or as a negative electrode to assemble a zinc-free zinc-ion battery with a manganese-based oxide positive electrode, a Prussian blue analog positive electrode, or a vanadium oxyphosphate positive electrode.

10. The application of the electrode material for low-temperature zinc-ion batteries according to claim 9, characterized in that, When the zinc-ion battery is used in an environment of 0℃~25℃, the electrolyte is selected from 0.5mol / L. -1 ~3mol L -1 Aqueous solution of Zn(CF3SO3)2, or 5 mol kg -1 ~15mol kg -1 ZnCl2 aqueous solution or 2 mol kg -1 ~5mol kg -1 Zn(BF4)2 aqueous solution; When the zinc-ion battery is used in an environment of -40℃ to -60℃, the electrolyte is 5 mol / kg. -1 ~15mol kg -1 ZnCl2 aqueous solution or 2 mol kg -1 ~5mol kg -1 Aqueous solution of Zn(BF4)2.

Images