A thin-layer metal-phase tungsten disulfide positive electrode material for high-rate zinc ion batteries, a preparation method and application thereof

Abstract

The application discloses a kind of thin layer metal phase tungsten disulfide anode material for high magnification zinc ion battery and electrode preparation method and application, it is related to zinc ion battery technical field.The method includes that alkali metal is mixed with tungsten disulfide uniformly after being in vacuum tube, and in 800~900 ℃, heating 10~15 h, obtain alkali metal intercalation's tungsten disulfide powder;Alkali metal intercalation's tungsten disulfide powder is uniformly dispersed in dilute potassium dichromate standard solution, obtain metal phase tungsten disulfide powder;Metal phase tungsten disulfide powder is dispersed into n-butyl lithium solution, and thin layer metal phase tungsten disulfide anode material is obtained.The thin layer metal phase tungsten disulfide prepared by the application has the characteristics of high magnification when being used as positive active material, with diaphragm, zinc ion aqueous electrolyte, zinc metal as negative electrode to form the aqueous neutral zinc ion battery system containing positive electrode-diaphragm-electrolyte-negative electrode, and has high specific capacity and cycle stability under high current.

Description

Technical Field

[0001] The present invention relates to the technical field of zinc ion batteries, and in particular to a thin-layer metal phase tungsten disulfide positive electrode material for high-rate zinc ion batteries, and an electrode preparation method and application. Background Art

[0002] With the rapid development of the global economy and the continuous growth of the population, natural resources are facing unprecedented depletion pressure. The overexploitation and use of fossil fuels has not only led to an energy crisis but also caused serious environmental pollution. Against this backdrop, the development of renewable energy and energy storage technologies is particularly urgent, becoming a key way to alleviate resource pressure and protect the environment. Renewable energy sources such as solar and wind power are clean and pollution-free, but their output is intermittent and unstable due to weather and geographical factors. Therefore, the development of energy storage technology is crucial for the efficient utilization of renewable energy. Lithium-ion batteries (LIBs), currently the mainstream energy storage technology, have been widely used in applications such as electric vehicles and smartphones. However, potential safety issues with their organic electrolytes, such as thermal runaway and short circuits, pose a serious threat to their safe use. Therefore, the search for safer and more reliable energy storage technologies has become a top priority.

[0003] In recent years, a range of aqueous batteries have been proposed and developed, including zinc-ion batteries (ZIBs), magnesium-ion batteries, and aluminum-ion batteries. Among these aqueous batteries, ZIBs have attracted considerable attention due to their large theoretical specific capacity (820 mAh g⁻¹ and 5855 mAh cm⁻³) and low redox potential (-0.762 V vs. standard hydrogen electrode). ZIBs not only possess high energy density and long cycle life, but also possess abundant and inexpensive zinc resources, offering broad application prospects. However, due to a lack of suitable cathode materials, their cycle life and rate performance are poor, and they are still in the early stages of development. Therefore, the development of high-performance cathode materials for ZIBs has become a current research priority.

[0004] The development of cathode materials for zinc-ion batteries has primarily focused on layered and tunnel-structured materials, including vanadium-based compounds, manganese-based oxides, and Prussian blue analogs. However, the performance of these mainstream zinc-ion battery cathode materials has been unsatisfactory. This is primarily due to the sluggish electrochemical kinetics caused by the cathode materials' poor conductivity, electrode degradation due to a lack of structural stability, and slow Zn²⁺ insertion / extraction kinetics resulting from strong electrostatic interactions between the cathode and the divalent Zn²⁺ carrier. These issues have severely hampered the development and application of high-rate zinc-ion batteries.

[0005] Compared with metal oxide cathodes, layered metal chalcogenides have high conductivity, good thermal stability and fast electrochemical kinetics, and therefore have attracted increasing attention as potential cathodes for high-rate zinc-ion batteries. Among layered metal chalcogenides, tungsten disulfide (WS2) is considered to be a very promising cathode material for zinc-ion batteries because its layers are connected by weak van der Waals interactions, providing a large lattice area that is conducive to the transport and storage of ions. It also has adjustable interlayer spacing and conductivity. However, due to the poor conductivity and limited interlayer spacing of traditional semiconductor phase tungsten disulfide, satisfactory rate performance cannot be achieved. Therefore, it is of great significance to develop thin-layer metal phase tungsten disulfide materials with high conductivity, large interlayer spacing and multiple reactive active sites for high-rate zinc-ion battery cathodes. Summary of the Invention

[0006] In view of the shortcomings of the above-mentioned background technology, the present invention mainly solves the problem that the existing semiconductor phase tungsten disulfide has poor conductivity and limited interlayer spacing, which makes it impossible to achieve satisfactory rate performance. The present invention provides a thin-layer metal phase tungsten disulfide positive electrode material for high-rate zinc ion batteries and an electrode preparation method and application. The thin-layer metal phase tungsten disulfide material of this method has a large interlayer spacing, high conductivity and multiple reaction active sites; when the thin-layer metal phase tungsten disulfide is used as the positive electrode active material, it is combined with a diaphragm, a zinc ion aqueous electrolyte, and zinc metal as the negative electrode to form an aqueous neutral zinc ion battery system comprising a positive electrode-diaphragm-electrolyte-negative electrode, which has the characteristics of high rate performance and still has a high specific capacity and cycle stability under large currents.

[0007] The first object of the present invention is to provide a method for preparing a thin layer of metallic phase tungsten disulfide positive electrode material for a high-rate zinc ion battery, comprising the following steps:

[0008] After the alkali metal and tungsten disulfide are evenly mixed, they are placed in a vacuum tube and heated at 800-900°C for 10-15 hours to obtain alkali metal intercalated tungsten disulfide powder;

[0009] The alkali metal intercalated tungsten disulfide powder is evenly dispersed in the diluted potassium dichromate standard solution, stirred and filtered to obtain the metal phase tungsten disulfide powder;

[0010] The metal phase tungsten disulfide powder is dispersed in n-butyl lithium solution, stirred and washed to obtain a thin layer of metal phase tungsten disulfide positive electrode material.

[0011] Preferably, the molar ratio of the alkali metal to tungsten disulfide is 0.75 to 1:1.

[0012] Preferably, the concentration of the diluted potassium dichromate standard solution is 0.0009 to 0.0018 mol / L; the mass ratio of the alkali metal intercalated tungsten disulfide powder to the diluted potassium dichromate standard solution is 2 to 4:1.

[0013] Preferably, the n-butyllithium solution is prepared by dissolving n-butyllithium in water solvent, and its concentration is 1.6 mol / L;

[0014] The molar ratio of the metallic phase tungsten disulfide powder to n-butyl lithium is 1 to 3:4.

[0015] Preferably, the alkali metal is sodium or potassium.

[0016] The second object of the present invention is to provide a thin layer of metal phase tungsten disulfide positive electrode material for high-rate zinc ion batteries.

[0017] The third object of the present invention is to provide a thin layer of metal phase tungsten disulfide positive electrode material for high-rate zinc ion batteries and its application in electrodes.

[0018] A fourth object of the present invention is to provide a thin-layer metallic phase tungsten disulfide electrode for a high-rate zinc ion battery, wherein the raw materials include, by mass fraction, 70-80% thin-layer metallic phase tungsten disulfide powder, 10-20% electronic conductive agent, 8-12% binder, and current collector, and the sum of the mass fractions of the components is 100%.

[0019] The electronic conductive agent includes one or more of carbon nanofibers, carbon nanotubes, conductive carbon black, and Ketjen black;

[0020] The binder includes polyvinylidene fluoride and N-methylpyrrolidone;

[0021] The current collector is a stainless steel sheet, a titanium sheet, a titanium mesh, a carbon cloth or a carbon paper.

[0022] A fifth object of the present invention is to provide a method for preparing a thin-layer metallic phase tungsten disulfide electrode for a high-rate zinc ion battery, comprising the following steps:

[0023] Weigh a thin layer of metallic tungsten disulfide cathode material, an electronic conductive agent, and a binder, add the binder to a reactor containing N-methylpyrrolidone at room temperature, and stir until completely dissolved to obtain a mixed solution;

[0024] The thin layer of metallic phase tungsten disulfide positive electrode material and the electronic conductive agent are mixed evenly, added into the mixed solution, and stirred to mix evenly to obtain an electrode slurry;

[0025] The electrode slurry is coated on the current collector and vacuum dried to obtain a thin-layer metal phase tungsten disulfide electrode for high-rate zinc ion batteries.

[0026] The sixth object of the present invention is to provide a thin-layer metal phase tungsten disulfide electrode for a high-rate zinc ion battery and its application in a zinc ion battery.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] The present invention provides a thin-layer metal phase tungsten disulfide positive electrode material for high-rate zinc ion batteries, an electrode preparation method and an application thereof. The thin-layer metal phase tungsten disulfide positive electrode material prepared by the present invention has a layered structure and good electrical conductivity. The electrical conductivity is increased by nearly 10% compared with commercial tungsten disulfide. 5 times; has a larger interlayer spacing of approximately 1.14 nm, a 90% increase compared to commercial tungsten disulfide (0.6 nm); and a thickness of approximately 10 to 20 nm, offering a higher specific surface area and more reactive sites. This cathode material, combined with zinc sheets, electrolyte, and separators, forms an aqueous zinc-ion battery system capable of high-rate performance, large capacity, and excellent cycling performance.

[0029] The thin-layer metal phase tungsten disulfide aqueous zinc ion battery positive electrode prepared by the present invention has a high conductivity at 0.5 A g -1 The capacity is 365.89 mAh g at a current density of -1 Around; at 5 A g -1 The high current density capacity can still be maintained at 270 mAh g -1 About 10 A g -1 The ultra-high current density capacity can reach 107.22 mAh g -1 About 1000 charge and discharge cycles, the capacity retention rate reaches 71.02%. It has good rate performance, high specific capacity, long cycle period, stability and environmental friendliness. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the preparation process of the thin-layer metal phase tungsten disulfide positive electrode material obtained in Examples 1-3.

[0031] Figure 2 This is the laser Raman spectrum of the thin layer of metallic phase tungsten disulfide obtained in Example 1.

[0032] Figure 3 This is the X-ray diffraction pattern of the thin layer of metallic phase tungsten disulfide obtained in Example 1.

[0033] Figure 4 This is an atomic force microscope image of the thin layer of metallic phase tungsten disulfide obtained in Example 1.

[0034] Figure 5 This is a rate performance diagram of the thin-layer metallic phase tungsten disulfide aqueous zinc ion battery obtained in Example 1.

[0035] Figure 6 The thin-layer metallic phase tungsten disulfide aqueous zinc ion battery obtained in Example 1 has a current density of 0.5A g -1 , 1 A g -1 , 2 A g -1 , 5 A g -1 The charge and discharge curve under the following conditions; the horizontal axis is the specific capacity (SpecificCapacity), the unit is mAh g -1 ; The vertical axis is voltage (Voltage vs Zn 2+ / Zn), unit is V.

[0036] Figure 7 The thin-layer metallic phase tungsten disulfide aqueous zinc ion battery obtained in Example 1 was tested at a current density of 10 A g -1 Specific capacity-cycle diagram under different conditions; the horizontal axis is the cycle number (Cycle Number); the vertical axis is the capacity (Specific Capacity), the unit is mAh g -1 .

[0037] Figure 8 This is a scanning electron microscope image of the metallic phase tungsten disulfide obtained in Comparative Example 1.

[0038] Figure 9 This is a rate performance diagram of the metallic phase tungsten disulfide aqueous zinc ion battery obtained in Comparative Example 1.

[0039] Figure 10 The metallic phase tungsten disulfide aqueous zinc ion battery obtained in comparative example 1 was tested at a current density of 0.2 A g -1 Specific capacity-cycle diagram under different conditions; the horizontal axis is the cycle number (Cycle Number); the vertical axis is the capacity (Specific Capacity), the unit is mAh g -1 . DETAILED DESCRIPTION

[0040] In order to enable those skilled in the art to better understand and implement the technical solution of the present invention, the present invention is further described below with reference to specific embodiments and drawings, but the embodiments are not intended to limit the present invention.

[0041] The first aspect of the present invention provides a method for preparing a thin-layer metallic phase tungsten disulfide positive electrode material for a high-rate zinc ion battery, comprising the following steps:

[0042] After the alkali metal and tungsten disulfide are evenly mixed, they are placed in a vacuum tube and heated at 800-900°C for 10-15 hours to obtain alkali metal intercalated tungsten disulfide powder;

[0043] The alkali metal intercalated tungsten disulfide powder is evenly dispersed in the diluted potassium dichromate standard solution, stirred and filtered to obtain the metal phase tungsten disulfide powder;

[0044] The metal phase tungsten disulfide powder is dispersed in n-butyl lithium solution, stirred and washed to obtain a thin layer of metal phase tungsten disulfide positive electrode material.

[0045] The thin-layer metallic phase tungsten disulfide material prepared by the present invention has a large interlayer spacing, high conductivity and multiple reaction active sites. When the thin-layer metallic phase tungsten disulfide is used as the positive electrode active material, it is combined with a diaphragm, a zinc ion aqueous electrolyte and zinc metal as the negative electrode to form an aqueous neutral zinc ion battery system comprising a positive electrode-diaphragm-electrolyte-negative electrode. The system has the characteristics of high rate performance and still has high specific capacity and cycle stability under large current.

[0046] Wherein, the molar ratio of the alkali metal to tungsten disulfide is 0.75 to 1:1.

[0047] The concentration of the diluted potassium dichromate standard solution is 0.0009 to 0.0018 mol / L; the mass ratio of the alkali metal intercalated tungsten disulfide powder to the diluted potassium dichromate standard solution is 2 to 4:1.

[0048] The n-butyl lithium solution is prepared by dissolving n-butyl lithium in water solvent, and its concentration is 1.6 mol / L; the molar ratio of the metallic phase tungsten disulfide powder to n-butyl lithium is 1 to 3:4.

[0049] The alkali metal is sodium or potassium.

[0050] Exemplarily, a method for preparing a thin-layer metallic phase tungsten disulfide positive electrode material for a high-rate zinc ion battery comprises the following steps:

[0051] Step 1: Mix the alkali metal and tungsten disulfide evenly and seal them in a vacuum glass tube.

[0052] Step 2: Place the glass tube described in step 1 in a muffle furnace and heat it; after natural cooling, obtain alkali metal-intercalated tungsten disulfide powder. The heating temperature in step 2 is 800°C to 900°C, the heating time is 10 to 15 hours, and the heating rate is 12.5°C to 14°C / min.

[0053] Step 3: Disperse the powder in step 2 into a diluted potassium dichromate standard solution, stir, filter, and dry to obtain metallic phase tungsten disulfide powder.

[0054] Step 4: Disperse the powder in step 3 into n-butyl lithium solution and stir, add ultrapure water after drying, perform ultrasonication, centrifuge and dry; obtain a thin layer of metal phase tungsten disulfide positive electrode material.

[0055] The stirring speed in step 3 and step 4 is 600 ~ 1000 r / min, wherein the stirring time in step 3 is 2 ~ 4 h, and the stirring time in step 4 is 20 ~ 24 h.

[0056] A second aspect of the present invention provides a thin-layer metal phase tungsten disulfide positive electrode material for a high-rate zinc ion battery.

[0057] A third aspect of the present invention provides an application of a thin-layer metal phase tungsten disulfide positive electrode material in an electrode for a high-rate zinc ion battery.

[0058] A fourth aspect of the present invention provides a thin-layer metallic phase tungsten disulfide electrode for a high-rate zinc ion battery, wherein the raw materials include, by mass fraction, 70-80% thin-layer metallic phase tungsten disulfide powder, 10-20% electronic conductive agent, 8-12% binder, and current collector, and the sum of the mass fractions of the components is 100%.

[0059] The electronic conductive agent includes one or more of carbon nanofibers, carbon nanotubes, conductive carbon black, and Ketjen black;

[0060] The binder includes polyvinylidene fluoride and N-methylpyrrolidone;

[0061] The current collector is a stainless steel sheet, a titanium sheet, a titanium mesh, a carbon cloth or a carbon paper.

[0062] The mass fraction of the thin layer metal phase tungsten disulfide powder can be 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79% or 80%, etc., the mass fraction of the electronic conductive agent can be 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19% or 20%, etc., and the mass fraction of the binder can be 8%, 9%, 10%, 11% or 12%, etc., but are not limited to the listed values, and other values ​​not listed within the above numerical ranges are also applicable.

[0063] The binder of the present invention comprises, by mass, 28-33% polyvinylidene fluoride and 67-72% N-methylpyrrolidone. The mass fraction of the polyvinylidene fluoride can be 28%, 29%, 30%, 31%, 32%, or 33%, and the mass fraction of the N-methylpyrrolidone can be 67%, 68%, 69%, 70%, 71%, or 72%, but is not limited to the values ​​listed above. Other values ​​not listed within the above numerical ranges are also applicable.

[0064] A fifth aspect of the present invention provides a method for preparing a thin-layer metallic phase tungsten disulfide electrode for a high-rate zinc ion battery, comprising the following steps:

[0065] Weigh a thin layer of metallic tungsten disulfide cathode material, an electronic conductive agent, and a binder, add the binder to a reactor containing N-methylpyrrolidone at room temperature, and stir until completely dissolved to obtain a mixed solution;

[0066] The thin layer of metallic phase tungsten disulfide positive electrode material and the electronic conductive agent are mixed evenly, added into the mixed solution, and stirred to mix evenly to obtain an electrode slurry;

[0067] The electrode slurry is coated on the current collector and vacuum dried to obtain a thin-layer metal phase tungsten disulfide electrode for high-rate zinc ion batteries.

[0068] Exemplarily, a method for preparing a thin-layer metallic phase tungsten disulfide electrode for high-rate zinc ions comprises the following steps:

[0069] Step S1: weigh a thin layer of metallic phase tungsten disulfide positive electrode material, a conductive agent, and a binder, add the binder into a reactor containing N-methylpyrrolidone at room temperature, and stir until completely dissolved to obtain a mixed solution.

[0070] Step S2, mixing the thin layer of metallic phase tungsten disulfide positive electrode material and the conductive agent uniformly, adding the mixture to the mixed solution described in step S1, and stirring to make the mixture uniform, to obtain an electrode slurry;

[0071] Step S3: coating the electrode slurry on carbon paper, and vacuum drying to obtain a thin-layer metal phase tungsten disulfide electrode for high-rate zinc-ion batteries.

[0072] A sixth aspect of the present invention provides an application of a thin-layer metal phase tungsten disulfide electrode for a high-rate zinc ion battery in a zinc ion battery.

[0073] It should be noted that the experimental methods used in the present invention are all conventional methods unless otherwise specified; the reagents and materials used are all commercially available unless otherwise specified.

[0074] Example 1

[0075] This embodiment provides a preparation method and application of a thin-layer metallic phase tungsten disulfide cathode material and electrode for high-rate zinc ion batteries. Figure 1 As shown, the following steps are included:

[0076] (1) Preparation of thin-layer metallic phase tungsten disulfide positive electrode material: 0.2 g of metallic potassium and 1.057 g of tungsten disulfide were weighed in a glove box, mixed evenly, and sealed in a quartz glass tube. The glass tube was placed in a muffle furnace and heated at 850 ° C for 15 h; it was naturally cooled to room temperature to obtain metallic potassium intercalated tungsten disulfide powder. The powder obtained above was dispersed in 100 mL of 0.0009 mol / L potassium dichromate solvent, stirred continuously for 3 h, filtered and washed with ultrapure water, and freeze-dried for 24 h to obtain metallic phase tungsten disulfide. In a glove box, the metallic phase tungsten disulfide powder obtained above was dispersed in 2 mL of 1.6 mol / L n-butyl lithium solution, stirred continuously for 20 h, dried, added 20 mL of ultrapure water, and ultrasonicated in an ice water bath for 1 h. The obtained solution was centrifuged at 10,000 rpm for 30 min, and the black liquid was collected and freeze-dried to obtain a thin-layer metallic phase tungsten disulfide powder.

[0077] (2) Preparation of thin-layer metallic tungsten disulfide electrode: 30 wt% of polyvinylidene fluoride powder and 70 wt% of N-methylpyrrolidone solution were stirred until the powder was completely dissolved to obtain a binder; 80 wt% of thin-layer metallic tungsten disulfide powder, 10 wt% of carbon nanofiber powder and 10 wt% of binder were stirred evenly to obtain electrode ink; the electrode ink was coated on titanium foil and dried in a vacuum oven at 60 °C for 10 h to obtain a thin-layer metallic tungsten disulfide electrode for high-rate zinc-ion batteries.

[0078] (3) Application of thin-layer metallic tungsten disulfide electrode: The positive electrode of zinc ion secondary battery is prepared by using the above-mentioned thin-layer metallic tungsten disulfide electrode. The negative electrode material is a zinc negative electrode made of metal zinc sheet. The electrolyte is 2 mol / L zinc sulfate as solute and water as solvent. The diaphragm is a glass fiber diaphragm and the stainless steel shell is used as the outer shell to assemble into a CR2025 button battery.

[0079] The intermediate samples and final samples prepared in Example 1 were subjected to actual testing.

[0080] Figure 2 This is the laser Raman spectrum of the prepared thin-layer metallic phase tungsten disulfide. According to the position of the Raman peak, it can be concluded that the prepared thin-layer metallic phase tungsten disulfide is a pure metallic phase and does not contain other phases (such as semiconductor phase). This can ensure that it has excellent electrical conductivity. High electrical conductivity is conducive to the rapid migration of zinc ions.

[0081] Figure 3 The X-ray diffraction pattern of the prepared thin-layer metallic phase tungsten disulfide shows that the prepared thin-layer metallic phase tungsten disulfide has good crystallinity, and according to the Bragg equation for the 002 crystal plane, its interlayer spacing is calculated to be approximately 1.14 nm. The larger interlayer spacing is conducive to the deintercalation of a large number of zinc ions.

[0082] Figure 4 From the atomic force micrograph of the prepared thin layer of metallic phase tungsten disulfide, it can be seen that the thickness of the prepared thin layer of metallic phase tungsten disulfide is about 15.96 nm. Thinner nanosheets are beneficial in exposing more reactive sites and adsorbing more zinc ions to participate in the reaction.

[0083] Figure 5 The obtained thin-layer metallic phase tungsten disulfide aqueous zinc ion battery is at 0.5 A g -1 , 1 A g -1 , 2 A g -1 , 5 A g -1 Four rate performance diagrams at different densities. It can be found that at 0.5 A g -1 At a low current density, the battery's discharge capacity is as high as 365.89 mAh g -1 , and at 5 A g -1 Even at a high current density of 270 mAh g -1 High capacity. This shows that the thin-layer metal phase tungsten disulfide electrode not only has high capacity, but also has high rate performance.

[0084] Figure 6 The obtained thin-layer metallic phase tungsten disulfide aqueous zinc ion battery has a high conductivity at 0.5 A g -1 , 1 A g -1 , 2 A g -1 , 5 A g -1 The charge and discharge curves at four different densities show that when the current density is from 0.5 A g −1 Increased 10-fold to 5 A g −1 The charge-discharge curves always maintain similar shapes when the charge is high. This indicates that the thin-layer metallic phase tungsten disulfide electrode has good redox reaction reversibility and fast charge storage kinetics.

[0085] Figure 7 The obtained thin-layer metallic phase tungsten disulfide aqueous zinc ion battery has a current density of 10 A g -1 The specific capacity-cycle diagram under the conditions shows that at 10 A g -1 Even at an ultra-high current density, its capacity can still reach 107.22 mAh g -1 , and after 1000 charge and discharge cycles, the capacity retention rate reached 71.02%, indicating that the thin-layer metal phase tungsten disulfide electrode has good cycle performance.

[0086] The above data show that the thin-layer metallic phase tungsten disulfide electrode prepared by the present invention has high capacity and high rate performance when used as the positive electrode of zinc ion battery, and also has good cycle stability.

[0087] Example 2

[0088] This embodiment provides a preparation method and application of a thin-layer metallic phase tungsten disulfide cathode material and electrode for high-rate zinc ion batteries. Figure 1 As shown, the following steps are included:

[0089] (1) Preparation of thin-layer metallic phase tungsten disulfide positive electrode material: 0.4 g of metallic potassium and 2.114 g of tungsten disulfide were weighed in a glove box, mixed evenly, and sealed in a quartz glass tube. The glass tube was placed in a muffle furnace and heated at 800 °C for 12 h; cooled naturally to room temperature to obtain metallic potassium intercalated tungsten disulfide powder. The powder obtained above was dispersed in 100 mL of 0.0012 mol / L potassium dichromate solvent, stirred continuously for 4 h, filtered and washed with ultrapure water, and freeze-dried for 24 h to obtain metallic phase tungsten disulfide. In a glove box, the metallic phase tungsten disulfide powder obtained above was dispersed in 3 mL of 1.6 mol / L n-butyl lithium solution, stirred continuously for 24 h, dried, added 20 mL of ultrapure water, and ultrasonicated in an ice-water bath for 1 h. The obtained solution was centrifuged at 10,000 rpm for 30 min, and the black liquid was collected and freeze-dried to obtain a thin-layer metallic phase tungsten disulfide powder.

[0090] (2) Preparation of thin-layer metallic tungsten disulfide electrode: 28 wt% of polyvinylidene fluoride powder and 72 wt% of N-methylpyrrolidone solution were stirred until the powder was completely dissolved to obtain a binder; 70 wt% of thin-layer metallic tungsten disulfide powder, 20 wt% of carbon nanofiber powder and 10 wt% of binder were stirred evenly to obtain electrode ink; the electrode ink was coated on carbon paper and dried in a vacuum oven at 60 °C for 10 h to obtain a thin-layer metallic tungsten disulfide electrode for high-rate zinc-ion batteries.

[0091] (3) Application of thin-layer metallic tungsten disulfide electrode: The positive electrode of zinc ion secondary battery is prepared by using the above-mentioned thin-layer metallic tungsten disulfide electrode. The negative electrode material is a zinc negative electrode made of metal zinc sheet. The electrolyte is 2 mol / L zinc sulfate as solute and water as solvent. The diaphragm is a glass fiber diaphragm and the stainless steel shell is used as the outer shell to assemble into a CR2025 button battery.

[0092] Example 3

[0093] This embodiment provides a preparation method and application of a thin-layer metallic phase tungsten disulfide cathode material and electrode for high-rate zinc ion batteries. Figure 1 As shown, the following steps are included:

[0094] (1) Preparation of thin-layer metallic phase tungsten disulfide positive electrode material: 0.2 g of metallic sodium and 1.057 g of tungsten disulfide were weighed in a glove box, mixed evenly, and sealed in a quartz glass tube. The glass tube was placed in a muffle furnace and heated at 900 °C for 12 h; cooled naturally to room temperature to obtain metallic sodium intercalated tungsten disulfide powder. The powder obtained above was dispersed in 100 mL of 0.0018 mol / L potassium dichromate solvent, stirred continuously for 2 h, filtered and washed with ultrapure water, and freeze-dried for 24 h to obtain metallic phase tungsten disulfide. In a glove box, the metallic phase tungsten disulfide powder obtained above was dispersed in 2 mL of 1.6 mol / L n-butyl lithium solution, stirred continuously for 24 h, dried, added 20 mL of ultrapure water, and ultrasonicated in an ice-water bath for 1 h. The obtained solution was centrifuged at 10,000 rpm for 30 min, and the black liquid was collected and freeze-dried to obtain a thin-layer metallic phase tungsten disulfide powder.

[0095] (2) Preparation of thin-layer metallic tungsten disulfide electrode: 32 wt% of polyvinylidene fluoride powder and 68 wt% of N-methylpyrrolidone solution were stirred until the powder was completely dissolved to obtain a binder; 70 wt% of thin-layer metallic tungsten disulfide powder, 10 wt% of carbon nanofiber powder, 10 wt% of conductive carbon black powder and 10 wt% of binder were stirred evenly to obtain electrode ink; the electrode ink was coated on titanium foil and dried in a vacuum oven at 60 °C for 10 h to obtain a thin-layer metallic tungsten disulfide electrode for high-rate zinc-ion batteries.

[0096] (3) Application of thin-layer metallic tungsten disulfide electrode: The positive electrode of zinc ion secondary battery is prepared by using the above-mentioned thin-layer metallic tungsten disulfide electrode. The negative electrode material is a zinc negative electrode made of metal zinc sheet. The electrolyte is 2 mol / L zinc sulfate as solute and water as solvent. The diaphragm is a glass fiber diaphragm and the stainless steel shell is used as the outer shell to assemble into a CR2025 button battery.

[0097] Comparative Example 1

[0098] Compared with Example 1, the metal phase tungsten disulfide was not treated with n-butyl lithium solution;

[0099] (1) Preparation of metallic tungsten disulfide cathode material: 0.2 g of potassium metal and 1.057 g of tungsten disulfide were weighed in a glove box, mixed evenly, and sealed in a quartz glass tube. The glass tube was placed in a muffle furnace and heated at 850°C for 15 h; it was naturally cooled to room temperature to obtain tungsten disulfide powder intercalated with potassium metal. The obtained powder was dispersed in 100 mL of 0.0009 mol / L potassium dichromate solvent and stirred for 3 h. The mixture was filtered and washed with ultrapure water and freeze-dried for 24 h to obtain metallic tungsten disulfide.

[0100] (2) Preparation of metallic tungsten disulfide electrode: 30 wt% of polyvinylidene fluoride powder and 70 wt% of N-methylpyrrolidone solution were stirred until the powder was completely dissolved to obtain a binder; 80 wt% of metallic tungsten disulfide powder, 10 wt% of carbon nanofiber powder and 10 wt% of binder were stirred evenly to obtain electrode ink; the electrode ink was coated on titanium foil and dried in a vacuum oven at 60 °C for 10 h to obtain a metallic tungsten disulfide electrode for zinc ion battery.

[0101] (3) Application of metallic tungsten disulfide electrode: The positive electrode of zinc ion secondary battery is prepared by using the metallic tungsten disulfide electrode. The negative electrode material is a zinc negative electrode made of metal zinc sheet. The electrolyte is 2 mol / L zinc sulfate as solute and water as solvent. The diaphragm is a glass fiber diaphragm and the stainless steel shell is used as the outer shell to assemble into a CR2025 button battery.

[0102] The following is actual testing of the intermediate samples and final samples prepared in Example 1.

[0103] Figure 8 From the scanning electron microscope image of the prepared metal phase tungsten disulfide, it can be seen that the prepared metal phase tungsten disulfide is blocky and cannot expose more reactive sites for zinc ions to participate in the reaction.

[0104] Figure 9 The obtained metallic phase tungsten disulfide aqueous zinc ion battery is at 0.2 A g -1 , 0.5 A g -1 , 1 A g -1 、2A g -1 , 5 A g -1 The rate performance diagrams at five different densities show that at 0.2 A g -1 At a low current density, the battery's discharge capacity is only 109.7 mAh g -1 , and when the current density increases to 5 A g -1 When the discharge capacity drops to 78.2 mAh g -1 This shows that the capacity and rate performance of the metallic phase tungsten disulfide electrode are relatively weak.

[0105] Figure 10 The obtained metallic phase tungsten disulfide aqueous zinc ion battery has a current density of 0.2 A g -1 The specific capacity-cycle diagram under the conditions shows that at 0.2 A g -1 After 200 charge-discharge cycles at a current density of 1.5 GHz, the capacity retention rate was only 63.1%, indicating relatively weak cycling performance.

[0106] In summary, compared with the examples, the metal phase tungsten disulfide that has not been treated with n-butyl has problems such as thick material thickness that cannot provide sufficient active sites for electrochemical energy storage reactions and insufficient interlayer spacing, which leads to relatively weak battery capacity and cycle stability.

[0107] The present invention describes preferred embodiments and their effects. However, those skilled in the art, once informed of the basic inventive concept, may make additional changes and modifications to these embodiments. Therefore, it is intended that the appended claims be interpreted to include the preferred embodiments as well as all changes and modifications that fall within the scope of the invention.

[0108] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a thin-layer metallic phase tungsten disulfide cathode material for a high-rate zinc ion battery, characterized in that: The following steps are involved: After the alkali metal and tungsten disulfide are evenly mixed, they are placed in a vacuum tube and heated at 800-900°C for 10-15 hours to obtain alkali metal intercalated tungsten disulfide powder; The alkali metal intercalated tungsten disulfide powder is evenly dispersed in the diluted potassium dichromate standard solution, stirred and filtered to obtain the metal phase tungsten disulfide powder; The metal phase tungsten disulfide powder is dispersed in n-butyl lithium solution, stirred and washed to obtain a thin layer of metal phase tungsten disulfide positive electrode material; The molar ratio of the alkali metal to tungsten disulfide is 0.75 to 1:1; The concentration of the diluted potassium dichromate standard solution is 0.0009 to 0.0018 mol / L; the mass ratio of the alkali metal intercalated tungsten disulfide powder to the diluted potassium dichromate standard solution is 2 to 4:1; The n-butyl lithium solution is prepared by dissolving n-butyl lithium in water solvent, and its concentration is 1.6 mol / L; The molar ratio of the metallic phase tungsten disulfide powder to n-butyl lithium is 1 to 3:

4.

2. The method for preparing a thin-layer metal phase tungsten disulfide cathode material for a high-rate zinc ion battery according to claim 1, wherein The alkali metal is sodium or potassium.

3. A thin-layer metal phase tungsten disulfide positive electrode material for a high-rate zinc ion battery prepared by the method according to claim 1 or 2.

4. Use of the thin-layer metallic phase tungsten disulfide positive electrode material for high-rate zinc ion batteries according to claim 3 in an electrode.

5. A thin-layer metallic phase tungsten disulfide electrode for a high-rate zinc ion battery, characterized in that: The raw materials include, by mass fraction, 70-80% of the thin-layer metallic phase tungsten disulfide positive electrode material according to claim 3, 10-20% of an electronic conductive agent, 8-12% of a binder, and a current collector, and the sum of the mass fractions of the components is 100%; The electronic conductive agent includes one or more of carbon nanofibers, carbon nanotubes, and conductive carbon black; The binder includes polyvinylidene fluoride and N-methylpyrrolidone; The current collector is a stainless steel sheet, a titanium sheet, a titanium mesh, a carbon cloth or a carbon paper.

6. A method for preparing a thin-layer metallic phase tungsten disulfide electrode for a high-rate zinc ion battery according to claim 5, characterized in that: The following steps are involved: Weigh a thin layer of metallic tungsten disulfide cathode material, an electronic conductive agent, and a binder, add the binder to a reactor containing N-methylpyrrolidone at room temperature, and stir until completely dissolved to obtain a mixed solution; The thin layer of metallic phase tungsten disulfide positive electrode material and the electronic conductive agent are mixed evenly, added into the mixed solution, and stirred to mix evenly to obtain an electrode slurry; The electrode slurry is coated on the current collector and vacuum dried to obtain a thin-layer metal phase tungsten disulfide electrode for high-rate zinc ion batteries.

7. Use of the thin-layer metallic phase tungsten disulfide electrode for high-rate zinc ion batteries according to claim 5 in zinc ion batteries.

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