Zinc electrode surface modification method based on 1H-tetrazole and application of zinc electrode surface modification method in aqueous zinc battery

Abstract

The invention discloses a zinc electrode surface modification method based on 1H-tetrazole and application of the zinc electrode surface modification method in an aqueous zinc battery. The modification method comprises the step of immersing the zinc electrode into a 1H-tetrazole aqueous solution (NIM) for chemical corrosion treatment. The corrosion process utilizes the mild acidity and coordination ability of-NH-groups in 1H-tetrazole molecules to realize preferential etching of a convex region on the zinc surface, so that the surface roughness is effectively reduced, and a uniform deposition substrate is formed. When the modified zinc negative electrode is applied to an aqueous zinc battery, the growth of zinc dendrites can be remarkably inhibited, side reactions are reduced, stable circulation of more than 4000 hours is realized under the conditions of 0.5 mA / cm < 2 > and 0.5 mAh / cm < 2 >, and the cycle life is prolonged by more than 40 times compared with that of an untreated zinc negative electrode. The method disclosed by the invention is simple and convenient in process, mild in condition and environment-friendly, and provides an effective solution for the negative electrode design of the high-performance and long-service-life aqueous zinc battery.

Description

Technical Field

[0001] This invention belongs to the field of new energy materials technology, specifically relating to a method for modifying the surface of a zinc electrode based on 1H-tetrazole and its application in aqueous zinc batteries. Background Technology

[0002] With the accelerated global energy structure shift towards cleaner and lower-carbon energy, the large-scale grid connection of renewable energy and the booming development of the electric vehicle industry have created an unprecedented and urgent demand for efficient, safe, and low-cost electrochemical energy storage technologies. Currently, while lithium-ion batteries dominate the market, their widespread application in large-scale energy storage is limited by the flammability of their organic electrolytes, their dependence on scarce metal resources, and cost pressures. Against this backdrop, aqueous zinc batteries, with their inherent safety, abundant resources, low cost, and theoretical capacity of up to 820 mAh / g for the zinc anode, have become one of the most promising alternative energy storage systems. However, the commercialization of this technology is severely hampered by the zinc anode interface problem.

[0003] One of the core challenges facing zinc anodes in practical applications is their inherent surface roughness and inhomogeneity. Microscopic protrusions, scratches, or defects on the initial surface can become "hot spots" during electrochemical cycling, inducing preferential zinc ion deposition and exacerbating the uncontrolled growth of zinc dendrites. These dendrites not only accelerate the loss of active materials and trigger side reactions, but can also puncture the separator, leading to internal short circuits and severely compromising the battery's cycle life and safety performance. Therefore, achieving precise control over the surface morphology of the zinc anode to create a uniform deposition substrate from the source is crucial for suppressing dendrites and improving battery performance.

[0004] Among numerous zinc anode modification strategies, controlled chemical treatment of the electrode surface using etchants is a direct, efficient, and uniquely advantageous method for interface smoothing. Unlike traditional physical polishing or complex coating processes, chemical etching, by selecting appropriate etchants (such as mild acids, coordination etchants, or oxidants), can selectively etch the zinc surface at the molecular or micrometer scale. Its mechanism lies in the fact that the etchant preferentially reacts with the highly reactive protrusions on the zinc surface, reducing surface roughness through "peak smoothing and valley filling," and even constructing a smoothed interface with specific textures or nanoporous structures. This modified surface effectively homogenizes the local current density distribution, providing numerous uniform zinc nucleation sites, thereby guiding zinc to grow in a planar epitaxial or dense layered manner during subsequent deposition, fundamentally inhibiting dendrite germination and growth.

[0005] Compared to other modification methods, the "etcher" strategy has potential advantages such as ease of operation, scalability, and good compatibility with existing processes. By precisely controlling the type, concentration, treatment time, and environment of the etchant, the final surface morphology and structure can be designed and controlled, providing high flexibility for zinc anode interface engineering. Combining this surface pretreatment with strategies such as electrolyte optimization and three-dimensional structure design is expected to create a synergistic effect, jointly driving breakthroughs in cycle stability, rate performance, and safety of aqueous zinc batteries. Therefore, in-depth exploration and development of efficient and controllable etchant systems are of significant scientific and engineering value for deepening the fundamental theoretical research on zinc deposition and promoting the practical application of high-performance aqueous zinc batteries. Summary of the Invention

[0006] The purpose of this invention is to address the problems existing in the prior art by providing a method for modifying the surface of a zinc electrode based on 1H-tetrazole and its application in aqueous zinc batteries. This invention's method is simple, operates under mild conditions, and is environmentally friendly, providing an effective solution for the design of negative electrodes in high-performance, long-life aqueous zinc batteries.

[0007] To achieve the above-mentioned objectives, the specific technical solution adopted by this invention is as follows:

[0008] One of the objectives of this invention is to provide the application of 1H-tetrazole (aqueous) solution in the surface modification of zinc electrodes.

[0009] Furthermore, in the aforementioned applications, the concentration of the 1H-tetrazole solution is 0.2~1.5 mol / L (specifically, it can be 0.2 mol / L, 0.3 mol / L, 0.4 mol / L, 0.5 mol / L, 0.6 mol / L, 0.7 mol / L, 0.8 mol / L, 0.9 mol / L, 1.0 mol / L, 1.1 mol / L, 1.2 mol / L, 1.3 mol / L, 1.4 mol / L, 1.5 mol / L, etc.).

[0010] The second objective of this invention is to provide a method for modifying the surface of a zinc electrode, the method comprising the following steps: immersing the zinc electrode in a 1H-tetrazole (water) solution for chemical etching treatment.

[0011] Furthermore, in the zinc electrode surface modification method described above, the concentration of the 1H-tetrazole solution is 0.2~1.5 mol / L; more preferably, the optimal concentration is 1 mol / L.

[0012] Furthermore, in the zinc electrode surface modification method, the corrosion treatment time is 5 to 60 minutes (specifically, it can be 5 minutes, 10 minutes, 15 minutes, 20 minutes, 25 minutes, 30 minutes, 35 minutes, 40 minutes, 45 minutes, 50 minutes, 55 minutes, 60 minutes, etc.); more preferably, the optimal corrosion time is 5 minutes.

[0013] Furthermore, in the zinc electrode surface modification method, the corrosion treatment temperature is room temperature, more preferably 25 °C.

[0014] This invention also protects modified zinc electrodes (with a porous ordered array structure on the surface) obtained by the modification method described above. This etching process utilizes the mild acidity and coordination ability of the -NH- group in the 1H-tetrazole molecule to preferentially etch the raised areas of the zinc surface, thereby effectively reducing surface roughness and forming a homogeneous deposition substrate.

[0015] This invention also protects the application of the modified zinc electrode in aqueous zinc batteries.

[0016] The present invention also protects an aqueous zinc battery comprising a modified zinc electrode as described above.

[0017] This invention also protects a method for preparing an aqueous zinc battery, which includes the following steps: Cut the zinc sheet into 20 mm × 20 mm × 0.2 mm sizes, and polish it with a silver polishing stick to remove the surface oxide layer and scratches until the zinc sheet surface has a uniform and bright metallic luster, thus obtaining the polished zinc sheet. Place the polished zinc sheet into an ultrasonic cleaner and ultrasonically clean it for 15 minutes each with acetone, anhydrous ethanol, and deionized water to remove residual polishing debris and oil stains from the surface and let it air dry naturally. The pretreated zinc sheet was immersed in a 1 mol / L 1H-tetrazole aqueous solution and placed in a 25 ℃ constant temperature incubator for 5 min. Then, the surface was rinsed with deionized water to remove the residual corrosion solution and surface moisture, and then air-dried. Battery assembly: Place the negative electrode shell at the bottom of the mold, then add the modified zinc electrode, separator, electrolyte, and positive electrode material as described above in sequence. Next, add the gasket and spring sheet, and finally place the positive electrode shell and seal it.

[0018] Furthermore, in the preparation method described above, the electrolyte is a 2 mol / L zinc sulfate aqueous solution.

[0019] This invention also protects aqueous zinc batteries prepared using the methods described above.

[0020] In this application, the modified zinc anode is used in aqueous zinc batteries, which can significantly suppress the growth of zinc dendrites and reduce side reactions.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) In this invention, 1H-tetrazole is selected as the etchant. Its molecule has a cyclic conjugated structure and active hydrogen sites, which can achieve precise control of the zinc electrode surface through the synergistic effect of "adsorption-coordination-selective etching".

[0022] (2) Unlike traditional strong corrosion methods, the acidic site (-NH-) of 1H-tetrazole slowly releases H+. + The etching process involves localized etching of the coordination region, ultimately forming a "porous ordered array" structure. This structure not only increases the effective surface area of ​​the electrode and provides more zinc deposition sites, but also facilitates ion transport, inhibits zinc dendrite growth, and reduces side reactions. Experimental results show that the zinc electrode treated with 1H-tetrazole etching for 5 minutes exhibits improved performance at 0.5 mA / cm². 2 0.5 mAh / cm 2 Under stable cycling conditions, it can cycle for more than 4,000 hours, which is more than 40 times longer than the untreated zinc electrode (90 hours of cycling).

[0023] (3) The method of the present invention is simple, mild and environmentally friendly, and provides an effective solution for the design of negative electrodes for high-performance, long-life aqueous zinc batteries. Attached Figure Description

[0024] Figure 1 The surface morphology of zinc after 1H-tetrazole corrosion treatment for 60 min; Figure 2 The surface morphology of zinc after 1H-tetrazole corrosion treatment for 5 min; Figure 3 The graph shows the cycle performance of an unmodified zinc-zinc symmetric battery. Figure 4 The graph shows the cycle performance of a zinc-zinc symmetric cell after 5 min of 1H-tetrazole corrosion treatment. Figure 5 The graph shows the cycle performance of a zinc-zinc symmetric cell after 60 min of 1H-tetrazole corrosion treatment. Detailed Implementation

[0025] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the examples in the specification.

[0026] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0027] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0028] Unless otherwise specified, all materials used in the embodiments of this invention are commercially available.

[0029] Battery testing method of this invention embodiment: The charge-discharge curve and long-cycle performance test of the battery are completed by the Blue Battery Tester (CT3001A).

[0030] Example 1 This embodiment provides a method for modifying the surface of a zinc electrode based on 1H-tetrazole, including the following steps: (1) Preparation of 1H-tetrazole corrosion solution: Weigh a certain mass of 1H-tetrazole at a concentration of 1 mol / L and dissolve it in deionized water and stir until homogeneous.

[0031] (2) Zinc electrode pretreatment: Cut the zinc sheet into 20 mm × 20 mm × 0.2 mm sizes, polish it with a silver polishing stick to remove the surface oxide layer and scratches until the zinc sheet surface has a uniform and bright metallic luster; put the polished zinc sheet into an ultrasonic cleaner and ultrasonically clean it for 15 min each with acetone, anhydrous ethanol and deionized water to remove the residual polishing debris and oil stains on the surface; let it air dry naturally.

[0032] (3) Chemical corrosion treatment: The pretreated zinc sheet is immersed in 1 mol / L 1H-tetrazole solution and corroded at a constant temperature of 25 ℃ for 5 minutes. After the preset corrosion time is reached, the zinc sheet is removed, the surface is rinsed with deionized water to remove the residual corrosion solution, and then air-dried to obtain the modified zinc electrode.

[0033] Example 2 This embodiment provides a method for preparing an aqueous zinc battery, including the following steps: (1) Electrode preparation: A modified zinc electrode was prepared by corrosion for 5 minutes according to the method of Example 1.

[0034] (2) Electrolyte preparation: Prepare zinc sulfate electrolyte at a concentration of 2 mol / L.

[0035] (3) Battery assembly: CR2025 button cell mold is used. The specific assembly sequence is as follows: First, place the negative electrode shell at the bottom of the mold, then put in the modified zinc electrode, glass fiber separator, electrolyte, and another zinc electrode (as counter electrode) in sequence, then add the gasket and spring sheet, and finally put in the positive electrode shell and seal it to obtain a Zn||Zn symmetric cell, i.e., an aqueous zinc battery.

[0036] Example 3 The preparation method of the modified zinc electrode in this embodiment is the same as that in Example 1, except that the corrosion time in step (3) is replaced with 60 minutes to obtain the modified zinc electrode.

[0037] Example 4 The preparation method of the aqueous zinc battery in this embodiment is the same as that in Example 2, except that the modified zinc electrode in step (1) is replaced with the modified zinc electrode in Example 3. The remaining steps are the same as in Example 2, and a Zn||Zn symmetric battery is obtained.

[0038] Comparative Example 1 In this comparative example, the zinc electrode is not chemically etched; the pretreated original zinc sheet is used directly as the electrode, and further assembly yields a Zn||Zn symmetric cell.

[0039] The performance of the zinc electrodes and aqueous zinc batteries prepared in Examples 1-4 and Comparative Example 1 was tested, specifically including the following steps: (1) Characterization of zinc electrode surface morphology: The surface morphology of the zinc electrode after different corrosion times was observed by scanning electron microscopy (SEM). See details below. Figure 1 , Figure 2 .

[0040] The results showed that after corrosion in 1 mol / L 1H-tetrazole for 60 min, the zinc surface was corroded by the strong acidity of tetrazolium, forming holes and the zinc sheet was severely consumed; while the zinc sheet that was corroded for only 5 min had a very regular surface, forming a uniform "porous ordered array" structure.

[0041] (2) Charge-discharge performance test: Assemble a Zn||Zn symmetric battery with 2 M ZnSO4 electrolyte and set the current density to 0.5 mA / cm². 2 The charge / discharge time was 1 hour; the battery's cycle stability was recorded. See the detailed results below. Figures 3-5 The results showed that the uncorroded zinc sheet could be stably cycled for 90 hours, the zinc sheet corroded for 60 minutes could not be stably cycled, while the zinc sheet corroded for 5 minutes could be stably cycled at 0.5 mA / cm. 2 0.5 mAh / cm2 It can withstand stable cycling for more than 4,000 hours, which is 40 times better than the original zinc sheet.

[0042] After 5 minutes of etching in 1H-tetrazole, a uniform porous structure was formed on the zinc surface. This structure is attributed to the slow release of H+ from the acidic sites (-NH-) in the 1H-tetrazole molecule. + By selectively etching only the coordination regions, precise control of the surface morphology is achieved. This porous, ordered array structure significantly increases the active surface area of ​​the electrode, provides more zinc deposition / dissolution sites, and facilitates electrolyte penetration and ion transport, thereby significantly improving the cycling stability of the zinc electrode.

[0043] Comparative Example 2 The preparation method of the modified zinc electrode in this comparative example is the same as that in Example 1, except that the concentration of the 1H-tetrazole aqueous solution in step (1) is replaced with 0.2 mol / L. The preparation method of the aqueous zinc battery is the same as that in Example 2, and finally the modified zinc electrode and the Zn||Zn symmetric cell are obtained.

[0044] Comparative Example 3 The preparation method of the modified zinc electrode in this comparative example is the same as that in Example 1, except that the concentration of the 1H-tetrazole aqueous solution in step (1) is replaced with 1.5 mol / L. The preparation method of the aqueous zinc battery is the same as that in Example 2, and finally the modified zinc electrode and the Zn||Zn symmetric cell are obtained.

[0045] The modified zinc electrodes and aqueous zinc batteries prepared in Example 1 and Comparative Examples 1-3 were subjected to performance testing, as shown in Table 1 below. Too low a concentration of 1H-tetrazole makes it difficult to reduce the surface roughness of the zinc electrode, easily leading to the formation of zinc dendrites and causing a short circuit in the battery. Too high a concentration of 1H-tetrazole easily corrodes the zinc negative electrode, creating pores and preventing the battery from cycling properly.

[0046] Table 1. Effect of different 1H-tetrazole concentrations on zinc battery performance

[0047] Comparative Example 4 The preparation method of the modified zinc electrode in this comparative example is the same as that in Example 1, except that 1H-tetrazole is replaced with a citric acid solution of equal concentration. All other steps are the same as in Example 1 to obtain the modified zinc electrode. The results showed that the citric acid corrosion was too severe, resulting in the formation of a disordered and rough porous structure on the zinc surface, and the corrosion depth was difficult to control, which actually reduced the cycle stability of the electrode.

[0048] This invention uses 1H-tetrazole as a mild and controllable etchant. By precisely controlling the etching time, a porous ordered array structure is constructed on the surface of the zinc electrode, which significantly improves the cycle stability and reaction reversibility of the zinc electrode, providing a new approach to solving the anode problem of aqueous zinc batteries.

[0049] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the present invention.

Claims

1. 1 Application of H-tetrazole solution in the surface modification of zinc electrodes.

2. The application as described in claim 1, characterized in that: The concentration of the 1H-tetrazole solution is 0.2~1.5 mol / L.

3. A method for modifying the surface of a zinc electrode, characterized in that: This includes immersing the zinc electrode in a 1H-tetrazole solution for chemical etching.

4. The zinc electrode surface modification method as described in claim 3, characterized in that: The concentration of the 1H-tetrazole solution is 0.2~1.5 mol / L; the corrosion treatment time is 5~60 minutes.

5. The modified zinc electrode obtained by the modification method according to any one of claims 3-4.

6. The application of the modified zinc electrode as described in claim 5 in an aqueous zinc battery.

7. An aqueous zinc battery, characterized in that: The modified zinc electrode as described in claim 5 was used.

8. A method for preparing an aqueous zinc battery, characterized in that... Includes the following steps: Cut the zinc sheet into 20 mm × 20 mm × 0.2 mm sizes, and polish it with a silver polishing stick to remove the surface oxide layer and scratches until the zinc sheet surface has a uniform and bright metallic luster, thus obtaining the polished zinc sheet. Place the polished zinc sheet into an ultrasonic cleaner and ultrasonically clean it for 15 minutes each with acetone, anhydrous ethanol, and deionized water to remove residual polishing debris and oil stains from the surface and let it air dry naturally. The pretreated zinc sheet was immersed in a 1 mol / L 1H-tetrazole aqueous solution and placed in a 25 ℃ constant temperature incubator for 5 min. Then, the surface was rinsed with deionized water to remove the residual corrosion solution and surface moisture, and then air-dried. Assemble the battery: Place the negative electrode shell at the bottom of the mold, then sequentially add the modified zinc electrode, separator, electrolyte, and positive electrode material as described in claim 5, followed by the addition of a gasket and a spring sheet, and finally place the positive electrode shell in and seal it.

9. The preparation method according to claim 8, characterized in that: The electrolyte is a 2 mol / L zinc sulfate aqueous solution.

10. An aqueous zinc battery prepared by the method described in claim 8 or 9.

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