A method for preparing a zinc-ion battery negative electrode

Abstract

The application belongs to the technical field of energy storage batteries, and discloses a preparation method of a zinc ion battery negative electrode. The steps include zinc sulfide foil, drying, setting a processing pattern, laser direct writing, heating and cooling. The negative electrode material prepared by the application is covered with a zinc sulfide layer and a zinc selenide layer, is highly stable in an aqueous electrolyte, and effectively avoids the occurrence of zinc negative electrode side reactions.

Description

Technical Field

[0001] This invention belongs to the field of energy storage battery technology, specifically relating to a method for preparing a zinc-ion battery negative electrode material. Background Technology

[0002] With the development of technology and the improvement of people's living standards, the demand for wearable electronic devices is constantly growing. Therefore, developing energy storage devices with higher energy density and better stability is becoming increasingly important for powering wearable electronic devices. Currently, lithium-ion batteries are widely used in commercial energy storage products due to their high energy density and long cycle life. However, the scarcity and high cost of lithium resources lead to high production costs for lithium batteries, and the electrolytes used are mostly toxic and flammable, posing safety hazards and limiting the further large-scale application of lithium batteries. Aqueous zinc-ion batteries have advantages such as good safety, low cost, and environmental friendliness, and are considered a promising energy storage technology that has attracted widespread attention. In addition, zinc metal has advantages such as high theoretical specific capacity and good cycle stability in aqueous solutions. Therefore, to meet the ever-growing energy storage demands of the future, zinc-ion batteries are considered an important choice for next-generation energy storage systems.

[0003] However, problems such as self-corrosion of the negative electrode, dendrite growth, and hydrogen evolution side reactions in aqueous zinc-ion batteries have not been effectively solved, seriously affecting battery life and limiting the industrial application of aqueous zinc-ion batteries.

[0004] However, zinc deposition and dissolution are the main processes during battery cycling. During the diffusion of zinc ions to the negative electrode, they preferentially adsorb at areas with strong electric fields, forming protrusions. As the number of cycles increases, a large number of zinc ions accumulate at these protrusions, further intensifying dendrite growth.

[0005] Therefore, developing a zinc-ion battery anode material that suppresses dendrite growth is of great practical significance. Summary of the Invention

[0006] To overcome the shortcomings of the prior art, the present invention provides a method for preparing a zinc-ion battery negative electrode material, which is stable in the electrolyte, increases the reversibility of zinc ions, and inhibits the formation of dendrites.

[0007] The above-mentioned objective of this invention is achieved through the following technical solution: a method for preparing a zinc-ion battery negative electrode material, comprising the following steps:

[0008] 1. Polish the zinc foil with sandpaper, rinse it with ultrapure water and anhydrous ethanol and dry it. Then, spread the dried zinc foil flat inside the quartz boat, spread sulfur powder evenly under the zinc foil, place the quartz boat in a tube furnace, pass N2 as a protective gas, heat the quartz boat with the tube furnace, and cool it to room temperature to obtain sulfurized zinc foil.

[0009] 2. Rinse the sulfided zinc foil described in step 1 with carbon disulfide to remove the sulfur powder that has not reacted with the zinc foil. After rinsing, dry the sulfided zinc foil.

[0010] 3. Use the control software EZCAD2.5.3 to control the scanning galvanometer to set the processing pattern, corresponding scanning speed and scanning spacing, and use the computer to set the laser parameters of the laser accordingly;

[0011] 4. Place the sulfurized zinc foil after step 2 at the bottom of the laser with the laser parameters set in step 3, calibrate using EZCAD2.5.3 control, move the zinc foil, select the laser area, and then start the laser using EZCAD2.5.3 control. Use the laser and scanning galvanometer to perform laser direct writing on the sulfurized zinc foil in the air to obtain a zinc foil with a uniform groove structure.

[0012] 5. Place the material obtained in step 4 into a quartz boat covered with selenium powder, heat it in a tube furnace, pass N2 as a protective gas, and then cool it to room temperature to obtain the zinc-ion battery anode material.

[0013] Furthermore, the zinc foil used in step 1 has a thickness of 80 μm and a size of 2 × 4 cm.

[0014] Furthermore, the sulfur powder used in step 1 is solid sulfur powder with a purity of 99.95% and a mass of 0.5-5g.

[0015] Furthermore, the tubular furnace heating step in step 1 is as follows: a) heating time 60 min, heating to 350℃; b) holding at 350℃ for 120 min; c) stopping heating.

[0016] Furthermore, in step 4, laser direct writing, the angle between the laser and the surface of the sulfurized zinc foil is 90°.

[0017] Furthermore, the laser direct writing parameters in step 4 are: spot diameter 1-100μm, laser frequency 1-100kHz, laser wavelength 1064nm, pulse width 50ns, scanning speed 1-1000mm / s, and straight line filling spacing 1-200μm.

[0018] Furthermore, the selenium powder used in step 5 is a solid selenium powder with a purity of 99.99% and a mass of 0.5-3g.

[0019] Furthermore, the tubular furnace heating step in step 5 is as follows: a) heating time 60 min, heating to 300℃; b) holding at 300℃ for 120 min; c) stopping heating.

[0020] The advantages of this invention compared to the prior art are:

[0021] (1) The negative electrode material prepared by the present invention is covered with a zinc sulfide layer and a zinc selenide layer, which are highly stable in aqueous electrolytes and effectively avoid the occurrence of zinc negative electrode side reactions.

[0022] (2) The present invention utilizes laser etching technology to form a regular groove structure on the surface of zinc foil. This groove structure enhances the wettability of the material, increases the contact area between the electrolyte and the zinc foil, and reduces the contact angle between the electrolyte and the negative electrode material, thereby reducing the charge transfer resistance.

[0023] (3) This invention provides a method for preparing a zinc-ion battery anode material with a heterogeneous structure. This uneven surface generates a regular electric field and associated current density fluctuations, suppressing the tip growth of pre-existing protrusions in the planar foil. These characteristics ensure uniform zinc electrodeposition / stripping over a wide range of current densities and cycle counts, avoiding dendrite growth.

[0024] (4) The present invention uses sulfidation, laser etching and selenization to prepare a zinc-ion battery anode material. The preparation process is simple, low cost and easy to achieve large-scale production. Detailed Implementation

[0025] The present invention is described in detail below through specific embodiments, but this does not limit the scope of protection of the present invention. Unless otherwise specified, the experimental methods used in the present invention are all conventional methods, and the experimental equipment, materials, reagents, etc. used can all be obtained commercially.

[0026] Example 1

[0027] A method for preparing a zinc-ion battery negative electrode, the specific steps of which are as follows:

[0028] Step 1: Select commercially available zinc foil (80μm thick) as the negative electrode material for aqueous zinc-ion batteries. Cut the zinc foil to a size of 2×4cm. Smooth the zinc foil with sandpaper, then cut it to a size of 2×4cm. Rinse it with ultrapure water and anhydrous ethanol and dry it. Then lay it flat inside a quartz boat. Spread 1g of sulfur powder evenly under the zinc foil. Place the quartz boat in a tube furnace and purge with N2 as a protective gas. Set the heating program of the tube furnace to: a) Heating time 60min, heating to 350℃; b) Holding at 350℃ for 120min; c) Stop heating and let the sample cool to room temperature with the tube furnace. Then take out the sample to obtain sulfurized zinc foil.

[0029] Step 2: Rinse the sulfurized zinc foil with carbon disulfide to remove any unreacted sulfur powder. Thoroughly clean the zinc foil with ethanol, dry it, and flatten it with mechanical rollers. The purchased zinc foil is pure zinc.

[0030] Step 3. Set the pattern to be processed and the corresponding laser parameters in the control software EZCAD2.5.3 supporting the scanning galvanometer, and use the laser to perform pattern engraving on the surface of the negative electrode material. In this embodiment, the pattern on the zinc foil surface consists of uniformly spaced rows controlled by the laser. In the experiment, the fixed output pulse width is set to 50 ns, the spot diameter is 20 μm, the laser frequency is 60 - 80 kHz, the laser wavelength is 1064 nm, the scanning speed is 200 - 400 mm / s, and the spacing of the linear filling is 200 μm.

[0031] Step 4. Perform laser patterning using a nanosecond pulsed laser. The specific process is as follows: Use a spherical lens (focal length of 117 mm) to focus the laser beam into a dot, and perform the composition process in a computer-controlled two-axis (x and y) array lens system to laser-etch the sulfided zinc foil, and the pattern is stripe-shaped.

[0032] Step 5. Rinse and dry the material obtained in Step 4 with ultrapure water and ethanol, then lay it flat inside the quartz boat. There is 1 g of selenium powder evenly spread under the zinc foil. Place the quartz boat in a tube furnace, pass N2 as the protective gas, and set the heating program of the tube furnace as follows: a. The heating time is 60 min, and the temperature is raised to 300 °C; b. Keep the temperature at 300 °C for 120 min; c. Stop heating, and the sample cools to room temperature with the tube furnace, then take out the sample to obtain the negative electrode material ZnS / ZnSe@Zn of the aqueous zinc-ion battery with a heterostructure.

[0033] Step 6. Use two pieces of ZnS / ZnSe@Zn as the positive and negative electrodes of the battery respectively, a glass fiber filter membrane as the separator, and a 2.0 M ZnSO4 solution as the electrolyte to assemble a 2032-type symmetric battery, and perform cyclic performance testing at a constant temperature. At a current density of 1 mA / cm

[0037] , , ,

[0036] ,

[0035] and a capacity of 1 mA·h / cm 2 for cycling.

[0034] Step 7: Use ZnS / ZnSe@Zn as the negative electrode of the battery, V2O5 as the positive electrode of the battery, a glass fiber filter membrane as the separator, and a 2.0 M ZnSO4 solution as the electrolyte to assemble a 2032-type full battery, and perform full battery cyclic performance testing at a constant temperature. The current density is 1 A / g, and the voltage cut-off range is 0.2 - 1.6 V.

[0035] Example 2

[0036] A preparation method of a negative electrode of a zinc-ion battery, the specific steps are as follows:

[0037] Step 1. Select commercially available zinc foil (with a thickness of 80 μm) as the negative electrode material for the aqueous zinc-ion battery. Cut the zinc foil into a size of 2×4 cm, polish the zinc foil smooth with sandpaper, then cut another zinc foil with a size of 2×4 cm, rinse it thoroughly with ultrapure water and anhydrous ethanol and dry it. Then lay the dried zinc foil flat inside the quartz boat, evenly spread 1 g of sulfur powder on the zinc foil, place the quartz boat in a tube furnace, and pass N2 as the protective gas. Set the heating program of the tube furnace as follows: a. The heating time is 60 min, and the temperature is raised to 350 °C; b. Keep the temperature at 350 °C for 120 min; c. Stop heating, and let the sample cool to room temperature with the tube furnace, then take out the sample to obtain the sulfided zinc foil.

[0038] Step 2. Rinse the sulfided zinc foil with carbon disulfide to wash off the sulfur powder that has not reacted with the zinc foil. Thoroughly clean, dry the zinc foil with ethanol and flatten it with mechanical external force. Among them, the purchased zinc foil is pure zinc.

[0039] Step 3. Set the pattern to be processed and the corresponding laser parameters in the control software supporting the scanning galvanometer, and use the laser to perform pattern engraving treatment on the surface of the negative electrode material. In this embodiment, the pattern on the zinc foil surface consists of evenly spaced rows controlled by the laser. In the experiment, the fixed output pulse width is set to 50 ns, the spot diameter is 20 μm, the laser frequency is 40 - 60 kHz, the laser wavelength is 1064 nm, the scanning speed is 400 - 800 mm / s, and the spacing of the linear filling is 100 μm.

[0040] Step 4. Perform laser patterning using a nanosecond pulsed laser. The specific process is as follows: Use a spherical lens (with a focal length of 117 mm) to focus the laser beam into a dot, and perform the composition process in a computer-controlled two-axis (x and y) array lens system, and laser-etch the sulfided zinc foil. The pattern is stripe-shaped.

[0041] Step 5. Rinse and dry the material obtained in Step 4 with ultrapure water and ethanol, then lay it flat inside the quartz boat, and evenly spread 0.5 g of selenium powder under the zinc foil. Place the quartz boat in a tube furnace, pass N2 as the protective gas, and set the heating program of the tube furnace as follows: a. The heating time is 60 min, and the temperature is raised to 300 °C; b. Keep the temperature at 300 °C for 120 min; c. Stop heating, and let the sample cool to room temperature with the tube furnace, then take out the sample to obtain the negative electrode material ZnS / ZnSe@Zn with a heterostructure for the aqueous zinc-ion battery.

[0042] Step 6. Use two pieces of ZnS / ZnSe@Zn as the positive and negative electrodes of the battery respectively, a glass fiber filter membrane as the separator, and a 2.0 M ZnSO4 solution as the electrolyte to assemble a 2032-type symmetric battery, and perform cyclic performance testing at a constant temperature. At 1 mA / cm 2Current density, 1 mA·h / cm 2 The capacity is used for looping.

[0043] Step 7: Using ZnS / ZnSe@Zn as the negative electrode, V2O5 as the positive electrode, glass fiber filter membrane as the separator, and 2.0M ZnSO4 solution as the electrolyte, assemble a 2032 model full cell and conduct full cell cycle performance tests at constant temperature with a current density of 1A / g and a voltage cutoff range of 0.2-1.6V.

[0044] The embodiments described above are merely preferred embodiments of the present invention, and not all feasible embodiments of the present invention. Any obvious modifications made by those skilled in the art without departing from the principles and spirit of the present invention should be considered to be included within the scope of protection of the claims of the present invention.

Claims

1. A method for preparing a zinc-ion battery negative electrode material, characterized in that, Includes the following steps: S1. Smooth the zinc foil with sandpaper, rinse it with ultrapure water and anhydrous ethanol and dry it. Then, spread the dried zinc foil flat inside the quartz boat, spread sulfur powder evenly under the zinc foil, place the quartz boat in a tube furnace, pass N2 as a protective gas, heat the quartz boat using the tube furnace, cool it to room temperature, and obtain sulfided zinc foil. S2. Rinse the sulfided zinc foil described in step S1 with carbon disulfide to remove the sulfur powder that has not reacted with the zinc foil. After rinsing, dry the sulfided zinc foil. S3. Use the control software EZCAD2.5.3 to control the scanning galvanometer to set the processing pattern, corresponding scanning speed and scanning spacing, and use the computer to set the laser parameters of the laser accordingly; S4. Place the sulfurized zinc foil after step S2 at the bottom of the laser with the laser parameters set in step 3, calibrate using EZCAD2.5.3 control, move the zinc foil, select the laser area, and then start the laser using EZCAD2.5.3 control. Use the laser and scanning galvanometer to perform laser direct writing on the sulfurized zinc foil in the air to obtain a zinc foil with a uniform groove structure. S5. Place the material obtained in step S4 into a quartz boat covered with selenium powder, heat it in a tube furnace, pass N2 as a protective gas, and then cool it to room temperature to obtain the zinc-ion battery anode material.

2. The method for preparing the zinc-ion battery negative electrode material according to claim 1, characterized in that, The zinc foil used in step S1 has a thickness of 80 μm and a size of 2 × 4 cm.

3. The method for preparing the zinc-ion battery negative electrode material according to claim 1, characterized in that, The sulfur powder used in step S1 is solid sulfur powder with a purity of 99.95% and a mass of 0.5-5g.

4. The method for preparing the zinc-ion battery negative electrode material according to claim 1, characterized in that, The heating steps of the tubular furnace in step S1 are as follows: a) Heating time is 60 minutes, heating to 350℃; b) Holding at 350℃ for 120 minutes; c) Stop heating.

5. The method for preparing the zinc-ion battery negative electrode material according to claim 1, characterized in that, In step S4, laser direct writing, the angle between the laser and the surface of the sulfurized zinc foil is 90°.

6. The method for preparing the zinc-ion battery negative electrode material according to claim 1, characterized in that, The laser direct writing parameters for step S4 are: spot diameter 1-100μm, laser frequency 1-100kHz, laser wavelength 1064nm, pulse width 50ns, scanning speed 1-1000mm / s, and straight line filling spacing 1-200μm.

7. The method for preparing the zinc-ion battery negative electrode material according to claim 1, characterized in that, The selenium powder used in step S5 is a solid selenium powder with a purity of 99.99% and a mass of 0.5-3g.

8. The method for preparing the zinc-ion battery negative electrode material according to claim 1, characterized in that, The heating steps of the tubular furnace in step S5 are as follows: A. Heating time is 60 minutes, and the temperature is raised to 300℃; B. The temperature is maintained at 300℃ for 120 minutes; C. Heating is stopped.