Preparation method of aqueous zinc ion battery with zinc metal interface modification layer and aqueous zinc ion battery

Abstract

The invention belongs to the related field of zinc metal negative electrodes, and relates to preparation and application of an aqueous zinc ion battery with a zinc metal interface modification layer. The method comprises the following steps: treating commercial zinc foil, carrying out hydrothermal treatment on the zinc foil, and cleaning and drying the obtained material. After the reaction, a substance with a nano rod-shaped structure can be generated on the surface of the zinc foil, and the rod-shaped substance can induce zinc to realize preferential growth of a zinc (101) crystal face during electro-deposition, so that the zinc is densely deposited on an electrode, and dendritic crystal growth of the zinc is inhibited. Meanwhile, generation of by-products can be reduced in the circulation process. The method is an economical and efficient method for improving the performance of the zinc electrode in the zinc ion battery.

Description

Technical Field

[0001] The present invention relates to the technical field related to zinc metal negative electrodes, and more specifically, to the preparation and application of a zinc metal interface modification layer in an aqueous zinc ion battery. Background Art

[0002] As the global demand for large-scale energy storage increases, batteries have attracted much attention as an efficient energy storage device. At present, the application of lithium-ion batteries in energy storage, power energy, 3C electronic products and other fields has been commercialized on a large scale, but it has safety hazards due to its own risk of spontaneous combustion. With the rapid development of life, the scientific community has developed a variety of new energy storage batteries. Among them, aqueous zinc-ion batteries are now a new type of energy storage battery with great development potential due to their advantages such as safety, reliability, abundant resources, environmental friendliness, low cost and low risk of spontaneous combustion of electrolytes. However, during use, zinc electrodes have problems such as dendrite growth, self-corrosion, passivation, and severe hydrogen evolution reaction. Among them, dendrite growth may cause the battery diaphragm to pierce and cause a short circuit, and form zinc that cannot continue to circulate, reducing capacity and reducing the effective area of ​​the electrode.

[0003] The hydrothermal solvothermal synthesis method is a wet chemical synthesis method that completes chemical reactions in a closed container. It is one of the most commonly used wet chemical synthesis methods in the laboratory. Among them, the hydrothermal method is commonly used to heat water in a closed container to a metastable state of high temperature and high pressure, so as to increase its chemical activity and promote the reaction. When preparing crystals by the hydrothermal method, compared with other preparation methods, the crystals obtained by the hydrothermal method have the characteristics of complete grains, small particle size, and less agglomeration. The solvothermal method expands the solvent from water to other solvents, with a higher upper limit of reaction temperature and a wider range of applications. The combination of the two is the hydrothermal solvothermal synthesis method. The high temperature and high pressure formed can change the reaction properties of the reactants and increase their activity, so some materials that cannot be synthesized at room temperature can be synthesized.

[0004] Based on the above background, in order to obtain aqueous zinc-ion batteries with better performance, the hydrothermal solvothermal method can be used to treat zinc metal to improve the problems of dendrite growth existing in zinc metal itself. Summary of the invention

[0005] In view of this, the present invention provides a zinc metal interface modification layer in an aqueous zinc ion battery. The zinc metal electrode modified by the interface layer of the present invention can induce zinc to grow preferentially along the (101) crystal plane during deposition after charge and discharge cycles, thereby significantly reducing the growth of dendrites and the appearance of by-products.

[0006] In order to achieve the above-mentioned invention object, the present invention provides the following technical solutions: The present invention provides a method for preparing a zinc metal interface modification layer in an aqueous zinc ion battery, comprising the following steps: (1) Cutting and cleaning the zinc foil, adding a solvent and performing a solvothermal reaction; (2) After the solvent thermal reaction, the mixture is cooled to room temperature, cleaned, and dried to obtain an aqueous zinc ion battery having a zinc metal interface modification layer.

[0007] In some embodiments, the zinc foil is cut into suitable sizes and its surface is cleaned with ethanol and deionized water, and then added into a high-pressure reactor, which is then placed in a constant-temperature forced air drying oven for heating to perform a solvent thermal reaction.

[0008] In step (1), the volume concentration of the solvent is 5-15%. In some preferred cases, the solvent is preferably one of a 1-tridecanol aqueous solution with a volume concentration of 5-13%, a 1-tetradecanol aqueous solution with a volume concentration of 5-11%, and a 2-hexyl-1-decanol aqueous solution with a volume concentration of 5-10%.

[0009] In step (1), the volume of the solution is 75-80% of the volume of the high-pressure reactor.

[0010] In step (1), the heating temperature is 90 to 180° C. and the heating time is 2 to 8 h.

[0011] In step (1), the heating temperature is 140-150° C. and the heating time is 4-6 h.

[0012] The present invention also provides a negative electrode material for a zinc ion battery, including a negative electrode material prepared by the method described above. The present invention provides a zinc metal interface modification layer prepared by the method described above.

[0013] The invention also provides an aqueous zinc ion battery, comprising a positive electrode material, a battery electrolyte, and a negative electrode material of the zinc ion battery.

[0014] The positive electrode material includes one of activated carbon, V2O5, MnO2, polyaniline, polypyrrole and polythiophene.

[0015] The solute in the battery electrolyte is ZnX a , where X = SO4 2- or CF3SO 3- , a=1~2, the molar concentration is 1~3M, and the solvent is deionized water.

[0016] The present invention provides an application of a zinc metal interface modification layer prepared by the method in an aqueous zinc ion battery. By modifying the surface of a zinc electrode sheet in a battery system, the interface layer on the zinc negative electrode side in the zinc ion battery induces zinc deposition, so that zinc preferentially grows along the (101) crystal plane. The (101) crystal plane of zinc has a denser surface atomic arrangement, which can provide a good interface for nucleation, inhibit the occurrence of zinc dendrites and side reactions, and greatly improve reversibility; this method also effectively inhibits side reactions such as hydrogen evolution and corrosion caused by reaction with an aqueous electrolyte, thereby showing excellent zinc deposition and dissolution reversibility.

[0017] Compared with the prior art, the present invention has the following advantages: 1. The method is hydrothermal solvent thermal method, which is simple to operate, easy to apply and has low time cost; 2. The formed interface modification layer is a nanostructure, and the zinc electrode has almost no volume change before and after treatment; 3. The raw materials are easily available, and the reactants mainly come from the zinc metal itself, so there is no need to add too many other substances. The products are easily obtained and have good repeatability.

[0018] 4. It can induce zinc to deposit on the (101) crystal plane, improving the problems of easy growth of dendrites, easy side reactions, and severe hydrogen evolution reaction caused by the original polycrystalline deposition in the form of hexagonal flakes. This allows zinc to be deposited in a more compact form in subsequent cyclic deposition.

[0019] 5. The formed interface modification layer has good chemical stability, which can make the zinc electrode less susceptible to corrosion in the electrolyte and has better chemical stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 : The microstructure of the zinc interface modification layer after modification in Example 1.

[0021] Figure 2 : Voltage-time curves of different current density cycle tests in Example 1 and Comparative Example 1.

[0022] Figure 3 : Voltage-time curves of different current density cycle tests in Example 2 and Comparative Example 2.

[0023] Figure 4 : 1 A g in Example 3 and Comparative Example 3 -1 Specific capacity-cycle number and coulombic efficiency-cycle number curves of zinc||activated carbon battery cycle test.

[0024] Figure 5 : The zinc electrode without the interface modification layer in Example 2 and Comparative Example 2 and the zinc electrode with the interface modification layer of the present invention at 1 mA cm -2Scanning electron microscope image after 20 h of cycling at a current density of .

[0025] Figure 6 : The zinc electrode without the interface modification layer in Example 2 and Comparative Example 2 and the zinc electrode with the interface modification layer of the present invention at 1 mA cm -2 XRD comparison images after 20 h of cycling at a current density of . DETAILED DESCRIPTION The present invention provides a method for preparing a zinc metal interface modification layer in an aqueous zinc ion battery, and the preparation method comprises the following steps: (1) Cut the zinc foil into appropriate size and clean the surface with ethanol and deionized water, pour an appropriate amount of solvent into a high-pressure reactor and then put the cleaned zinc foil into it, and then put the reactor into a constant temperature forced air drying oven for heating; (2) After the reactor is cooled to room temperature, the zinc after the reaction is taken out, washed with deionized water, and dried to obtain an improved zinc ion battery negative electrode material.

[0026] (3) Assembling the negative electrode material into a battery for use.

[0027] In the present invention, unless otherwise specified, the raw materials used are commercially available products well known in the art.

[0028] In the present invention, the solvent is preferably one of a 1-tridecanol aqueous solution with a volume concentration of 5-13%, a 1-tetradecanol aqueous solution with a volume concentration of 5-11%, and a 2-hexyl-1-decanol aqueous solution with a volume concentration of 5-10%, and more preferably a 2-hexyl-1-decanol aqueous solution with a volume concentration of 8%, which serves to provide a place, medium and raw materials for the reaction; In the present invention, the volume of the solution accounts for 75% of the volume of the high-pressure reactor, and its function is to provide appropriate pressure for the reaction; In the present invention, the heating temperature is preferably 90-180° C., and the heating time is 2-8 h, more preferably 140° C., 6 h, which serves to provide appropriate temperature and time for the reaction.

[0029] In order to make the purpose and technical advantages of the present invention more clearly understood, the present invention is further described below in conjunction with the accompanying drawings, embodiments and comparative examples, but they should not be construed as limiting the scope of protection of the present invention.

[0030] Embodiment 1: (1) Mix 6 mL of 2-hexyl-1-decanol and 69 mL of deionized water to prepare a solution.

[0031] (2) Cut the zinc foil into 2*8 cm size, clean the surface stains with anhydrous ethanol and deionized water, put it into a 100 mL reaction kettle and add the solution of step (1), and then put it into a constant temperature forced air drying oven at 140°C and heat it for 6 h; (3) After the reactor is cooled to room temperature, the reacted zinc is taken out, washed with deionized water and dried; (4) A 2 M ZnSO4 aqueous solution was prepared as the electrolyte, the material obtained in step (2) was cut into 14 mm discs as the positive and negative electrode materials, a glass fiber membrane was used as the separator, and the CR2032 button battery was directly assembled in the air. After the battery is assembled, it is connected to the CT3001 battery test system and tested at 1 mA cm -2 The constant current charge and discharge test is carried out at a current density of Figure 2 As shown, at 1 mA cm -2 At a current density of , the zinc electrode with the interface modification layer of the present invention can be cycled for more than 1000 h and remain stable, and has excellent cycle stability.

[0032] Embodiment 2: The material obtained in step (3) of Example 1 was cut into discs with a diameter of 8 mm as positive and negative electrode materials, a glass fiber membrane was used as a separator, and 2M ZnSO4 was used as an electrolyte. After assembling the battery in air, it was connected to a CT3001 battery test system and tested at 10 mA cm -2 The constant current charge and discharge test is carried out at a current density of Figure 3 As shown, at 10 mA cm -2 At a current density of , the zinc electrode with the interface modification layer of the present invention can be cycled for more than 600 h and remain stable.

[0033] Example 3 The material obtained in step (3) of Example 1 was cut into sheets with a diameter of 8 mm as the negative electrode material, activated carbon as the positive electrode material, glass fiber membrane as the separator, 2M ZnSO4 as the electrolyte, assembled into CR2032 button batteries in air and connected to the CT3001 battery testing system. Figure 4 As shown, at 1A g -1 At a current density of , the zinc electrode with the interface modification layer of the present invention can be cycled more than 12,000 times and maintain a stable high coulombic efficiency.

[0034] Example 4 The method of Example 1 was used to prepare and assemble the battery, except that the solvent was replaced with 1-tetradecanol. After the battery was assembled, it was connected to the CT3001 battery test system and tested at 1 mA cm -2The constant current charge and discharge test was carried out at a current density of , and the battery was damaged after 450h of cycling.

[0035] Example 5 The method of Example 1 was used to prepare and assemble the battery, except that the solvent was replaced with lauryl alcohol. After the battery was assembled, it was connected to the CT3001 battery test system and tested at 1 mA cm -2 The constant current charge and discharge test was carried out at a current density of , and the battery was damaged after 330 h of cycling.

[0036] Comparative Example 1: Commercial zinc foil was cleaned with ethanol and deionized water, and directly cut into discs with a diameter of 14 mm as positive and negative electrode materials without solvent thermal treatment. 2 M ZnSO4 aqueous solution was used as the electrolyte, and a glass fiber membrane was used as the separator. CR2032 button batteries were directly assembled in air.

[0037] After the battery is assembled, it is connected to the CT3001 battery test system and tested at a current density of 1 mA cm -2 The constant current charge and discharge test is carried out under the condition of Figure 2 As shown, the battery in which the zinc electrode without the interface modification layer is located is damaged after less than 300 hours, indicating that the interface modification layer in the present invention can improve the reversibility of the zinc electrode at low current density.

[0038] like Figure 5 As shown in the figure, after 20 h of cycling, the zinc electrode without the interface modification layer undergoes electrochemical reaction and the zinc grown thereon is in the form of dispersed hexagonal flakes, which is in sharp contrast to the surface morphology of the material obtained in Example 1 after 20 h of charge and discharge. The deposition of the latter is more compact and uniform, indicating that the interface modification layer in the present invention can make the zinc grown thereon after the electrochemical reaction deposit more compactly. Figure 6 It was found that after 20 h of cycling, the peak of the impurity phase Zn4SO4(OH)6•xH2O appeared in the XRD spectrum of the zinc electrode without the interface modification layer, while it did not appear in the zinc electrode with the interface modification layer of the present invention, indicating that the interface modification layer of the present invention can reduce the occurrence of by-products; and the (101) crystal plane in the zinc electrode with the interface modification layer of the present invention is significantly increased, and the interface modification layer of the present invention can induce zinc to deposit on the (101) crystal plane.

[0039] Comparative Example 2: Commercial zinc foil was cleaned with ethanol and deionized water, and directly cut into 8 mm diameter discs as positive and negative electrode materials without solvent thermal treatment. 2 M ZnSO4 aqueous solution was used as the electrolyte, and a glass fiber membrane was used as the separator. CR2032 button batteries were directly assembled in the air.

[0040] After the battery is assembled, it is connected to the CT3001 battery test system and tested at a current density of 10 mA cm -2 The constant current charge and discharge test is carried out under the condition of Figure 3 As shown, the battery in which the zinc electrode without the interface modification layer is located is damaged in less than 100 h, indicating that the interface modification layer of the present invention can improve the reversibility of the zinc electrode at high current density.

[0041] Comparative Example 3: Commercial zinc foil was cleaned with ethanol and deionized water, and was directly cut into 14 mm diameter discs as negative electrode materials without solvent thermal treatment. Activated carbon was used as positive electrode material, 2 M ZnSO4 aqueous solution was used as electrolyte, and glass fiber membrane was used as separator. CR2032 button batteries were directly assembled in air. Figure 4 As shown, the battery in which the zinc electrode without the interface modification layer is located is damaged in less than 1500 cycles, indicating that the interface modification layer of the present invention can improve the reversibility of the zinc electrode.

[0042] The results of the above embodiments and comparative examples show that the interface modification layer provided by the present invention can induce zinc to deposit on the (101) crystal plane, thereby improving the problems of easy growth of dendrites, easy occurrence of side reactions, and severe hydrogen evolution reaction caused by the original deposition along the (002) and dispersion in various places in the form of hexagonal flakes, so that zinc is deposited in a more compact form during subsequent cyclic deposition, greatly improving the reversibility of the zinc electrode.

[0043] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing an aqueous zinc ion battery with a zinc metal interface modification layer, characterized in that: The preparation process is as follows: (1) Cutting and cleaning the zinc foil, adding a solvent and performing a solvothermal reaction; (2) After the solvent thermal reaction, the mixture is cooled to room temperature, cleaned, and dried to obtain an aqueous zinc ion battery having a zinc metal interface modification layer.

2. according to the preparation method of the aqueous zinc ion battery of claim 1 zinc metal interface modification layer, it is characterized in that, In step (1), the solvent is a combination of one or more of 1-tridecanol, 1-tetradecanol or 2-hexyl-1-decanol.

3. according to the preparation method of the aqueous zinc ion battery of claim 1 zinc metal interface modification layer, it is characterized in that, The volume concentration of the solvent is 5-15%.

4. according to the preparation method of the aqueous zinc ion battery of claim 1 zinc metal interface modification layer, it is characterized in that, In step (1), the volume of the solution is 75-80% of the volume of the high-pressure reactor.

5. according to the preparation method of the aqueous zinc ion battery of claim 1 zinc metal interface modification layer, it is characterized in that, In step (1), the heating temperature is 90 to 180° C. and the heating time is 2 to 8 h.

6. according to the preparation method of the aqueous zinc ion battery of claim 5 zinc metal interface modification layer, it is characterized in that, In step (1), the heating temperature is 140-150° C. and the heating time is 4-6 h.

7. A negative electrode material for a zinc ion battery, characterized in that: The method comprises preparing the product by the method described in any one of claims 1 to 6.

8. An aqueous zinc ion battery, characterized in that: It comprises a positive electrode material, a battery electrolyte, and the negative electrode material of the zinc ion battery according to claim 5.

9. The aqueous zinc ion battery according to claim 8, characterized in that: The positive electrode material includes any one of activated carbon, V2O5, MnO2, polyaniline, polypyrrole, and polythiophene.

10. The aqueous zinc ion battery according to claim 8, characterized in that: The solute in the battery electrolyte is ZnX a , where X = SO4 2- or CF3SO 3- , a=1~2, the molar concentration is 1~3M, and the solvent is deionized water.

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