Modification Method of Anode Material for Zinc Sulfide Ion Battery

Abstract

The invention belongs to the technical field of zinc ion battery modification, and discloses a method for modifying the negative electrode material of a zinc sulfide ion battery. The steps include sulfurization, purification, setting and laser direct writing of zinc foil. The zinc foil after sulfurization is laser engraved so that the surface of the zinc sulfide layer regularly exposes zinc metal grooves, and the zinc metal has a strong affinity to Zn. 2+ Stronger affinity, can regulate Zn 2+ The deposition / dissolution process of Zn 2+ It preferentially deposits in the exposed Zn metal grooves, inhibiting the formation of Zn dendrites.

Description

Technical Field

[0001] The present invention belongs to the technical field of modification of zinc-ion batteries, and particularly relates to a method for modifying the anode material of a zinc sulfide ion battery. Background Art

[0002] With the development of science and technology in today's society, energy and environmental issues have attracted more and more attention. However, the most widely used fossil energy at present is non-renewable and is accompanied by serious environmental pollution. As a general trend, technologies for widely applying renewable energy such as wind energy and solar energy need to be solved urgently. In order to ensure that these natural energies can be continuously and stably converted into available energy, electrochemical energy storage has become the development direction of current large-capacity energy storage technologies due to its advantages such as short response time, large energy density, and low maintenance cost. Lithium-ion batteries are widely used in current commercial energy storage devices due to their high energy density and long cycle life. However, the high cost, shortage of resources, and poor safety of lithium metal limit the large-scale application of lithium-ion batteries. Aqueous zinc-ion batteries (ZIBs) have very high safety, and because metallic zinc has abundant reserves in nature, low cost, low toxicity, and high theoretical specific capacity (820 mAh·g -1 ), low redox potential (-0.76 V compared to the standard hydrogen electrode), etc. It shows great potential in large-scale high-efficiency energy storage technologies.

[0003] The main problems existing in zinc-ion batteries are that when Zn2+ deposits / dissolves between the positive and negative electrodes unevenly, a large number of zinc dendrites will be formed on the surface of the zinc foil, which will exacerbate the growth of dendrites during the charge and discharge process of the battery. The too-long dendrites will pierce the diaphragm and cause the battery to short-circuit, affecting the battery life. In addition, hydrogen evolution side reactions and self-corrosion passivation on the surface of the zinc negative electrode will also occur in the aqueous electrolyte, all of which will make the deposition / dissolution of zinc ions more uneven and further shorten the battery life. Therefore, solving the dendrite problem is of crucial significance for the practical application of future zinc-based energy storage devices. Summary of the Invention

[0004] In order to overcome the deficiencies of the prior art, the present invention provides a method for modifying the anode material of a zinc sulfide ion battery. Sulfuration will form a dense zinc sulfide layer on the surface of the zinc foil. The zinc sulfide layer is highly stable in the aqueous electrolyte, which helps to avoid the occurrence of side reactions and enhance the reversibility of the zinc negative electrode. Laser engraving is performed on the sulfided zinc foil to regularly expose zinc metal grooves on the surface of the zinc sulfide layer. Zinc metal has a stronger affinity for Zn 2+ and can regulate the deposition / dissolution process of Zn 2+ , so that Zn 2+ is preferentially deposited in the exposed zinc metal grooves, inhibiting the formation of zinc dendrites.

[0005] The above object of the present invention is achieved by the following technical solutions: A method for modifying a negative electrode material of a zinc sulfide ion battery, comprising the following steps:

[0006] 1. Polish the zinc foil smoothly with sandpaper, rinse it clean with ultrapure water and anhydrous ethanol and dry it. Then lay the dried zinc foil flat inside a quartz boat, evenly spread sulfur powder on the zinc foil, place the quartz boat in a tube furnace, pass N2 as a protective gas, heat it using the tube furnace, and then cool it to room temperature to obtain sulfided zinc foil.

[0007] 2. Rinse the sulfided zinc foil described in step 1 with carbon disulfide to wash away the sulfur powder that has not reacted with the zinc foil. After rinsing, dry the sulfided zinc foil.

[0008] 3. Use the control software EZCAD2.5.3 to control the scanning galvanometer to set the processing pattern, the corresponding scanning speed and scanning spacing, and use a computer to set the laser parameters of the laser.

[0009] 4. Place the sulfided zinc foil processed in step 2 at the bottom of the laser with the laser parameters set in step 3, use EZCAD2.5.3 to control for calibration, move the zinc foil, select the laser area, and then use EZCAD2.5.3 to control to start the laser. Use the laser and the scanning galvanometer to perform laser direct writing on the sulfided zinc foil in the air to obtain a negative electrode material for an aqueous zinc ion battery with a heterostructure.

[0010] Further, the thickness of the zinc foil used in step 1 is 80 μm, and the size is 2×4 cm.

[0011] Further, the sulfur powder used in step 1 is solid sulfur powder with a purity of 99.95%, and the mass is 0.5 - 5 g.

[0012] Further, the tube furnace heating step in step 1 is as follows: a. The heating-up time is 10 min, and the temperature is raised to 150°C; b. Keep the temperature at 150°C for 5 min; c. The heating-up rate is 20°C / min, and the temperature is raised to the required sulfidation temperature of 350 - 500°C; d. Keep the temperature at the sulfidation temperature for 1 hour; e. Stop heating.

[0013] Further, in the laser direct writing in step 4, the angle between the laser and the surface of the sulfided zinc foil is 90°.

[0014] Further, the laser direct writing parameters in step 4 are: the spot diameter is 1 - 1000 μm, the laser frequency is 1 - 20 kHz, the laser wavelength is 1064 nm, the pulse width is 50 ns, the scanning speed is 0.001 - 1000 mm / s, and the spacing of the linear filling is 5 - 30 μm.

[0015] The beneficial effects of the present invention compared with the prior art are:

[0016] (1) The present invention provides a method for preparing a modified negative electrode of an aqueous zinc-ion battery. The surface of a zinc foil is sulfided using a tube furnace, and then the sulfided zinc foil is subjected to patterned laser direct writing using a laser. Sulfidation forms a zinc sulfide layer on the surface of the zinc foil, and the zinc sulfide layer is highly stable in an aqueous electrolyte, which helps to avoid side reactions of the zinc negative electrode;

[0017] (2) By performing laser direct writing on the surface of the sulfided zinc foil, a regular groove structure is formed on the surface of the zinc foil. Laser treatment increases the surface roughness of the zinc foil, increases the contact area between the electrolyte and the negative electrode material, reduces the contact angle between the electrolyte and the negative electrode material, and reduces the resistance interface impedance;

[0018] (3) By performing laser direct writing on the surface of the sulfided zinc foil, a heterostructure is formed on the zinc surface, which effectively regulates the deposition of zinc ions on the zinc electrode, avoids the pulverization of the zinc negative electrode and the generation of zinc dendrites, reduces the occurrence of side reactions of the zinc negative electrode, thereby increasing the cycle life of the symmetric zinc-ion battery and improving the capacity retention rate and cycle life of the aqueous zinc-ion battery;

[0019] (4) The present invention provides a method for preparing a modified negative electrode of an aqueous zinc-ion battery. The surface of the zinc foil is sulfided using a tube furnace, and then the sulfided zinc foil is directly subjected to laser direct writing in air, overcoming the disadvantages of requiring a large amount of chemical reagents and complex processes in the traditional modification process of the negative electrode of an aqueous zinc-ion battery, and realizing the preparation of a modified negative electrode of an aqueous zinc-ion battery by sulfidation + laser; the preparation process of this method is simple, efficient, low in preparation cost and environmentally friendly, and is easy to realize large-scale production. Specific Embodiments

[0020] The present invention will be described in detail below through specific embodiments, but the protection scope of the present invention is not limited. 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 from commercial channels.

[0021] Example 1

[0022] The synthesis of a modified negative electrode material of an aqueous zinc-ion battery specifically includes the following steps:

[0023] 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 of size 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 3 g of sulfur powder on the zinc foil, place the quartz boat in the tube furnace, introduce N2 as the protective gas, and set the heating program of the tube furnace as follows: a. The heating-up time is 10 min, and the temperature is raised to 150 °C; b. Keep the temperature at 150 °C for 5 min; c. The heating rate is 20 °C / min, and the temperature is raised to the required sulfidation temperature of 500 °C; d. Keep the temperature at the sulfidation temperature for 1 hour; e. Stop heating, let the sample cool to room temperature with the tube furnace, and then take out the sample to obtain the sulfided zinc foil.

[0024] Step 2: Rinse the sulfided zinc foil with carbon disulfide to wash off the sulfur powder that did not react with the zinc foil. Thoroughly clean, dry and flatten the zinc foil with mechanical external force. Among them, the purchased zinc foil is pure zinc.

[0025] 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 50 μm, the laser frequency is 16 - 20 kHz, the laser wavelength is 1064 nm, the scanning speed is 200 - 400 mm / s, and the spacing of the linear filling is 1 - 50 μm.

[0026] Step 4: Use a nanosecond pulsed laser for laser patterning treatment. The specific process is as follows: Use a spherical lens (with a focal length of 170 mm) to focus the laser beam into a dot shape, and perform the patterning process in a computer-controlled two-axis (x and y) array lens system. Obtain the negative electrode material for the aqueous zinc-ion battery with a heterogeneous structure, and the directly written pattern is stripe-shaped.

[0027] Assemble the prepared zinc negative electrode into a zinc-ion battery, where the positive electrode material of the battery is V2O5 material; the membrane material of the separator is a glass fiber membrane; the electrolyte is 2 mol d·L -1 zinc sulfate solution. Conduct various electrochemical tests.

[0028] The test method is as follows: The charge-discharge test conditions for the symmetric battery are a current density of 1 mA·cm -2 , and the capacity cut-off is 1 mA h·cm -2 , and perform charge-discharge cycle tests; the test conditions for the zinc-ion full battery are a current density of 0.5 A·g -1 , and the voltage cut-off range is 0.2 - 1.6 V.

[0029] Example 2

[0030] Synthesis of a modified aqueous zinc-ion battery anode material, specifically including the following steps:

[0031] Step 1: Select commercially available zinc foil (with a thickness of 80 μm) as the anode material of the aqueous zinc-ion battery. Cut the zinc foil into a size of 2×4 cm. Polish the zinc foil smooth with sandpaper, and then cut another zinc foil of size 2×4 cm. Rinse it thoroughly with ultrapure water and absolute ethanol and dry it. Then lay the dried zinc foil flat inside the quartz boat. Evenly spread 2 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 10 min, and heat up to 150 °C; b. Keep it at 150 °C for 5 min; c. The heating rate is 20 °C / min, and heat up to the required sulfidation temperature of 450 °C; d. Keep it at the sulfidation temperature for 1 hour; e. 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.

[0032] 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 and flatten the zinc foil with ethanol. Among them, the purchased zinc foil is pure zinc.

[0033] 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 anode 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 50 μm, the laser frequency is 12 - 16 kHz, the laser wavelength is 1064 nm, the scanning speed is 400 - 800 mm / s, and the spacing of the linear filling is 0.01 - 1 μm.

[0034] Step 4: Use a nanosecond pulsed laser for laser patterning treatment. The specific process is as follows: Use a spherical lens (with a focal length of 170 mm) to focus the laser beam into a dot, and perform the patterning process in a computer-controlled two-axis (x and y) array lens system. Obtain an anode material of the aqueous zinc-ion battery with a heterogeneous structure, and the directly written pattern is stripe-shaped.

[0035] Assemble the prepared zinc anode into a zinc-ion battery, where the battery cathode material is V2O5 material; the membrane material of the separator is a glass fiber membrane; the electrolyte is 2 mol·L -1 zinc sulfate solution. Conduct various electrochemical tests.

[0036] The test method is as follows: The charge and discharge test conditions of the symmetric battery are a current density of 1 mA·cm -2 , and the capacity cut-off is 1 mA h·cm -2, perform charge-discharge cycle tests; the test conditions for the zinc-ion full battery are a current density of 0.5 A·g -1 , and the voltage cut-off range is 0.2 - 1.6 V.

[0037] Example 3

[0038] Synthesis of a modified aqueous zinc-ion battery anode material, specifically including the following steps:

[0039] Step 1: Select commercially available zinc foil (with a thickness of 80 μm) as the anode 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 of size 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 10 min, and heat up to 150 °C; b. Keep the temperature at 150 °C for 5 min; c. The heating rate is 20 °C / min, and heat up to the required sulfidation temperature of 400 °C; d. Keep the temperature at the sulfidation temperature for 1 hour; e. 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.

[0040] Step 2: Rinse the sulfided zinc foil with carbon disulfide to wash off the sulfur powder that did not react with the zinc foil. Thoroughly clean, dry and flatten the zinc foil with ethanol. Among them, the purchased zinc foil is pure zinc.

[0041] 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 on the surface of the anode material. In this example, 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 50 μm, the laser frequency is 8 - 12 kHz, the laser wavelength is 1064 nm, the scanning speed is 800 - 1000 mm / s, and the spacing of the linear filling is 0.005 - 0.01 μm.

[0042] Step 4: Use a nanosecond pulse laser for laser patterning. The specific process is as follows: Use a spherical lens (with a focal length of 170 mm) to focus the laser beam into a dot shape, and perform the patterning process in a computer-controlled two-axis (x and y) array lens system. Obtain an aqueous zinc-ion battery anode material with a heterogeneous structure, and the directly written pattern is stripe-shaped.

[0043] The above-described embodiments are only the preferred embodiments of the present invention, rather than all the feasible embodiments of the present invention. For those of ordinary skill in the art, any obvious changes made 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 modifying the negative electrode material of a zinc sulfide ion battery, characterized in that the steps Including: S1. Polish the zinc foil with sandpaper until it is smooth, rinse it thoroughly with ultrapure water and absolute ethanol, and then dry it. Then, lay the dried zinc foil flat inside a quartz boat, evenly spread sulfur powder on the zinc foil, place the quartz boat in a tube furnace, introduce N2 as a protective gas, heat it using the tube furnace, and then cool it to room temperature to obtain a sulfided zinc foil. S2. Rinse the sulfided zinc foil obtained in step S1 with carbon disulfide to wash away the sulfur powder that did not react 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, the corresponding scanning speed, and the scanning pitch, and use a computer to set the laser parameters of the laser. S4. Place the sulfided zinc foil treated in step S2 at the bottom of the laser with the laser parameters set in step S3. Use EZCAD2.5.3 to control for calibration, move the zinc foil, select the laser area, and then use EZCAD2.5.3 to control to start the laser. Perform laser direct writing on the sulfided zinc foil in the air using the laser and the scanning galvanometer to obtain a negative electrode material for an aqueous zinc-ion battery with a heterostructure.

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

3. The modification method of the negative electrode material of the zinc sulfide ion battery 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 the mass is 0.5 - 5 g.

4. The modification method of the negative electrode material of the zinc sulfide ion battery according to claim 1, characterized in that, The tube furnace heating step in step S1 is as follows: a. The heating-up time is 10 min, and the temperature is raised to 150 °C; b. Keep the temperature at 150 °C for 5 min; c. The heating rate is 20 °C / min, and the temperature is raised to the required sulfidation temperature of 350 - 500 °C; d. Keep the temperature at the sulfidation temperature for 1 hour; e. Stop heating.

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

6. The modification method of the anode material of the zinc sulfide ion battery according to claim 1, wherein For the laser direct writing in step S4, the parameters are: the spot diameter is 1 - 1000 μm, the laser frequency is 1 - 20 kHz, the laser wavelength is 1064 nm, the pulse width is 50 ns, the scanning speed is 0.001 - 1000 mm / s, and the spacing of the linear filling is 5 - 30 μm.