High-utilization high-stability zinc electrode, preparation method and application

Abstract

The application relates to the technical field of aqueous zinc ion batteries, and discloses a high-utilization high-stability zinc electrode, a preparation method and application thereof. The zinc electrode comprises a substrate and a functional coating attached to the surface of the substrate, the functional coating is formed by coating slurry formed by zinc powder, a binder and a functional additive onto the surface of the substrate and drying. The zinc electrode obtained by the application can significantly improve the zinc ion diffusion under high DOD conditions, inhibit the parasitic side reactions induced by free water, and solve the stress cracking problem caused by the volume effect, thereby prolonging the long cycle stability under the condition of high zinc metal utilization (15-96%), and showing a good application prospect in low N / P zinc-based devices.

Description

Technical Field

[0001] This invention relates to the field of zinc metal electrode technology for aqueous zinc-ion batteries, and more specifically, to a high-utilization, high-stability zinc electrode, its preparation method, and its application. Background Technology

[0002] With the rapid development of new energy sources such as wind and solar power, electrochemical energy storage technology is playing an increasingly crucial role. Electrochemical energy storage can efficiently regulate the storage and transmission of electrical energy, ensuring its safe and stable delivery. It not only has broad application prospects in large-scale power grid systems but is also gradually penetrating into green transportation, residential, and industrial sectors. Among various electrochemical energy storage technologies, aqueous zinc-ion batteries are highly competitive in large-scale energy storage and high-safety applications such as residential use due to their inherent high safety, abundant zinc resources, and low cost.

[0003] Achieving stable cycling performance of zinc metal electrodes under high depth of discharge (DOD) conditions remains a significant challenge, severely limiting the commercialization of zinc-based batteries. Currently, zinc foil and zinc powder are the most widely used materials for zinc metal electrodes. However, zinc foil produced in industrial applications is often too thick, typically between 100 and 300 μm, resulting in an excessively high zinc mass loading in the electrode. This leads to low zinc metal utilization in the battery device, negatively impacting the overall energy density of the battery. In recent years, zinc powder has been considered a promising zinc metal anode material. Zinc powder shares similar low-cost advantages with zinc foil, while also offering convenient availability, which is beneficial for improving zinc metal utilization. However, the cycle life of zinc powder electrodes remains limited at high DOD, typically lasting less than 400 hours when DOD exceeds 15% (EnergyStorage Materials, 2025, 74, 103934). At high DOD, zinc powder electrodes exhibit significant polarization. This is because under high DOD conditions, zinc ion transfer kinetics, corrosion reactions, and stress issues associated with zinc powder electrodes become more severe. To achieve long-cycle performance under high DOD, novel electrode structure designs are needed to comprehensively regulate the electrochemical-mechanical properties of zinc powder.

[0004] Therefore, it is necessary to provide a zinc electrode with high utilization and high stability, its preparation method and application, in order to regulate the electrochemical and mechanical properties of zinc powder and alleviate the problem of electrode stress cracking caused by the volume stress of zinc electrode. Summary of the Invention

[0005] The purpose of this invention is to provide a high-utilization, high-stability zinc electrode, its preparation method, and its applications. This invention achieves rapid zinc ion migration, locks in free water molecules, and alleviates stress concentration by rationally adjusting the composition and structure of the zinc powder composite, thereby enhancing the long cycle life of the zinc powder anode in zinc-based energy storage devices under high DOD. This enables the construction of zinc-based batteries with high-utilization, high-stability zinc metal anodes and low anode / cathode capacity ratio (N / P ratio), promoting the practical development of zinc-based energy storage.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows:

[0007] On the one hand, the present invention provides a high-utilization and high-stability zinc electrode, comprising a substrate and a functional coating attached to the surface of the substrate.

[0008] Furthermore, the thickness of the substrate and the coating is 1: (0.1~0.5).

[0009] Furthermore, the substrate is carbon paper, carbon cloth, copper mesh, or copper foil.

[0010] Furthermore, the functional coating includes zinc powder, binder, and functional additives.

[0011] Furthermore, the adhesive is a polymer molecule with a room temperature viscosity of less than 1000 Pa·s. In this invention, the room temperature is 10~40°C, preferably 15~35°C.

[0012] Furthermore, the adhesive is at least one of random polyether, polyether polyol or polyethylene glycol.

[0013] Furthermore, the adhesive is selected from at least one of glycerol random polyether, elastomeric polyether polyol, or polyethylene glycol.

[0014] Furthermore, the random polyether is selected from at least one of isotridecyl alcohol random polyether, propylene glycol random polyether, glycerol random polyether, glycerol random polyether, butylene glycol random polyether, lauric acid random polyether, and dodecyl alcohol random polyether.

[0015] Furthermore, the glycerol random polyether can be glycerol random polyether 3000.

[0016] Furthermore, the polyethylene glycol may be polyethylene glycol 200, polyethylene glycol 400, or polyethylene glycol 600.

[0017] Furthermore, the functional additive is preferably a spherical carbon material.

[0018] Furthermore, the functional additive is selected from at least one of nano carbon black, fullerene, activated carbon, and carbon microspheres.

[0019] Furthermore, the mass ratio of the zinc powder, binder and functional additive is (0.5~2):(0.3~0.8):(0.5~2), preferably 1:0.6:1.

[0020] On one hand, the present invention provides a method for preparing a zinc electrode, comprising the following specific steps:

[0021] S1: Zinc powder, binder, and functional additives are mixed with solvent to form a slurry;

[0022] S2: Apply the slurry to the substrate surface of the current collector and dry it to form a functional coating;

[0023] S3: After drying, cut into electrode sheets to obtain zinc electrodes.

[0024] Furthermore, the solvent is selected from at least one of ethanol, methanol, and water.

[0025] Furthermore, the mixing can be carried out by uniform mixing in a mixer or by ultrasonic dispersion or other methods.

[0026] Furthermore, the mixing is carried out in a mixer with a rotation speed of 5-20 rpm and a mixing time of 2-10 hours.

[0027] Furthermore, the mixing is performed using ultrasonic dispersion, with an ultrasonic power of 50-100 W and an ultrasonic duration of 5-40 min.

[0028] Furthermore, the substrate of the current collector is carbon paper, carbon cloth, copper mesh, copper foil, etc.

[0029] Furthermore, the drying temperature is 60~100℃, and the time is 1~10h.

[0030] On one hand, the present invention provides a zinc-containing battery or zinc-based energy storage device, comprising the zinc electrode described in the present invention. Further, the zinc-containing battery or zinc-based energy storage device is a low N / P zinc-based battery.

[0031] On the other hand, the present invention provides an application of the zinc electrode described herein in the preparation of zinc-containing batteries or zinc-based energy storage devices.

[0032] Compared with the prior art, the beneficial technical effects of the present invention are as follows:

[0033] 1. This invention provides a high-utilization, high-stability zinc electrode; this zinc electrode has excellent zinc ion conductivity, can efficiently suppress free water-induced zinc metal corrosion, and can alleviate the electrode stress cracking problem caused by the zinc electrode volume effect. Figure 1 It can be seen that there are no cracks; Figure 2It can be seen that the components are highly uniform, and it can be used as a zinc metal electrode for various zinc-based energy storage devices.

[0034] 2. This invention provides a method for preparing a high-utilization, high-stability zinc electrode. This method involves mixing zinc powder, a low-viscosity oxygen-containing polymer binder, and functional carbon material additives in a simple solvent, then coating the mixture onto a current collector. After drying, the electrode is cut and shaped to obtain a high-utilization, high-stability zinc electrode. This method overcomes the shortcomings of existing technologies and can achieve stable cycling performance of the zinc electrode under high utilization (Example 1). Figure 3 The display shows a cycle life of 600~1000h, which makes the practical application of zinc-based energy storage devices possible in the future.

[0035] 3. Unlike previous composite technologies for zinc electrodes, this invention uses a low-viscosity oxygen-containing polymer as a binder, combined with spherical carbon material additives to enhance ion migration kinetics during the electrochemical cycling process of the zinc electrode (e.g., Figure 3 , Figure 4 and Figure 7 As shown), suppressing parasitic side reactions and mitigating stress concentration (such as...) Figure 5 and 6 As shown in the figure, this comprehensively improves the electrochemical and mechanical properties of the zinc electrode.

[0036] 4. The high-utilization and high-stability zinc electrode prepared by this invention has the advantages of simple preparation method, the use of commercially available materials, and the safety, non-toxic or low-toxicity of the materials used, resulting in minimal environmental pollution and significant low cost and environmental protection advantages. In addition, the loading of the high-utilization and high-stability zinc electrode of this invention can be easily controlled, which is beneficial for matching the positive electrode to assemble a low N / P zinc battery system and improving the overall energy density of the zinc battery.

[0037] 5. The preparation method of this invention is green and safe, low in energy consumption, low in cost, highly scalable, and has excellent controllability. The obtained zinc electrode can significantly improve the zinc ion diffusion under high DOD conditions. Figure 4 As shown in the figure, it suppresses parasitic side reactions induced by free water and stress cracking caused by volume effect, and prolongs the long cycle stability under high zinc metal utilization (15-96%) conditions, showing good application prospects in low N / P zinc-based devices. Attached Figure Description

[0038] Figure 1 A photograph of the high-utilization, high-stability zinc electrode prepared in Example 1 of this invention.

[0039] Figure 2 The surface morphology of the high-utilization and high-stability zinc electrode prepared in Example 1 is shown in the scanning electron microscope.

[0040] Figure 3The figure shows the cycle performance of a symmetric cell assembled based on the zinc electrode prepared in Example 1 at a high utilization rate (15%). In the figure, GPE-CB-ZnP represents the high-utilization, high-stability zinc electrode, while the control group is a zinc electrode composited with conventional PVDF binder. PVDF is a high-viscosity polymer.

[0041] Figure 4 Cyclic performance of a symmetric cell assembled based on the zinc electrode prepared in Example 1 at ultra-high utilization (96%).

[0042] Figure 5 The morphology of GPE-CB-ZnP and conventional PVDF binder zinc anodes after cycling at high utilization rates.

[0043] Figure 6 The zinc electrode prepared based on Example 1 and Zn 0.25 The cycling performance of the full cell assembled with V2O5 cathode matching under low N / P conditions was tested. The test conditions were: after the battery was assembled, it was allowed to stand for 6 hours before charge-discharge cycling was started, and the current density was 0.1 A g. -1 .

[0044] Figure 7 Impedance and ion mobility number of zinc anodes with GPE-CB-ZnP and conventional PVDF binders Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. The specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention in any way. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concepts of this disclosure. Such structures and techniques have also been described in many publications.

[0046] All reagents used in this invention can be purchased commercially or prepared by the methods described in this invention.

[0047] The technical solution of the present invention will be illustrated below with examples. The scope of protection sought by the present invention includes, but is not limited to, the following embodiments.

[0048] Example 1

[0049] (1) Weigh 1 g of zinc powder, 0.6 g of carbon black, 1 g of glycerol random polyether, add 1 mL of ethanol, and grind evenly;

[0050] (2) The mixture obtained in step (1) is subjected to ultrasound (ultrasound power of 80 W) for 30 min to ensure that the components are fully mixed.

[0051] (3) Coat the slurry obtained in step (2) onto the carbon paper current collector and dry it in a 60-degree oven for 2 hours.

[0052] Figure 1 A photograph of the high-utilization, high-stability zinc electrode prepared in Example 1; from Figure 1 It can be seen that the surface of the obtained zinc electrode is uniform and there is no cracking. Figure 2 The scanning electron microscope surface morphology of the high-utilization, high-stability zinc electrode prepared in Example 1; from Figure 2 It can be seen that the zinc powder and other components of the obtained zinc electrode are highly uniformly combined.

[0053] Figure 3 The cycling performance of a Zn||Zn symmetric cell based on the zinc electrode prepared in Example 1 is shown. Figure 3 As can be seen, the Zn‖Zn symmetric cell based on a high-utilization, high-stability zinc electrode exhibits excellent long-cycle performance (600-1000 h) under high utilization. In contrast, the high-viscosity PVDF composite zinc electrode system can only cycle for 50 h.

[0054] Figure 4 The Zn‖Zn symmetric cell based on the zinc electrode prepared in Example 1 exhibits ultra-high cycle performance (96%). From... Figure 4 As can be seen from this, the Zn‖Zn symmetric cell based on a high-utilization and high-stability zinc electrode can still cycle stably for 400 h even when it is close to 100% fully utilized.

[0055] Figure 5 The morphology of GPE-CB-ZnP and conventional PVDF binder zinc anodes after cycling at high utilization rates. Figure 5 It can be seen that the morphology after GPE-CB-ZnP cycling has good integrity, while the PVDF binder zinc anode shows electrode cracking after cycling.

[0056] Figure 6 The zinc electrode prepared based on Example 1 and Zn 0.25 The cycling performance of the full cell assembled with a V2O5 cathode under low N / P conditions. Figure 5 As can be seen, under low N / P conditions, the full cell can cycle stably for 200 hours and maintain an extremely high capacity retention rate (over 90%).

[0057] Figure 7 Impedance and ion transference number of zinc anodes with GPE-CB-ZnP and conventional PVDF binders. From Figure 7 The impedances of GPE-CB-ZnP and conventional PVDF binder zinc anodes can be observed. Based on the impedance, the corresponding ion transference number of GPE-CB-ZnP is higher.

[0058] Example 2

[0059] (1) Weigh 1 g of zinc powder, 0.6 g of carbon black, 1 g of polyethylene glycol 400, add 1 mL of ethanol, and grind evenly;

[0060] (2) The mixture obtained in step (1) is subjected to ultrasound (ultrasound power of 100 W) for 40 min to ensure that the components are fully mixed.

[0061] (3) The slurry obtained in step (2) is coated onto the copper mesh current collector and dried in an 80-degree oven for 1 h.

[0062] Example 3

[0063] (1) Weigh 1 g of zinc powder, 0.6 g of carbon black, 1 g of glycerol random polyether, add 1 mL of ultrapure water, and grind evenly;

[0064] (2) The mixture obtained in step (1) is subjected to ultrasound (ultrasound power of 100 W) for 30 min to ensure that the components are fully mixed.

[0065] (3) Coat the slurry obtained in step (2) onto the carbon paper current collector and dry it in a 100-degree oven for 1 h.

[0066] Example 4

[0067] (1) Weigh 1 g of zinc powder, 0.6 g of carbon black, 1 g of glycerol random polyether, add 1 mL of ultrapure water, and grind evenly;

[0068] (2) Mix the mixture obtained in step (1) evenly in a mixer with a speed of 15 rpm and a stirring time of 3 h to ensure that the components are fully mixed.

[0069] (3) Coat the slurry obtained in step (2) onto the carbon paper current collector and dry it in a 100-degree oven for 1 h.

[0070] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A high utilization and high stability zinc electrode, characterized by, The zinc electrode comprises a substrate and a functional coating attached to the surface of the substrate, wherein the functional coating comprises zinc powder, a binder and a functional additive; The binder is a polymer molecule with a viscosity less than 1000 Pa·S at room temperature; The binder is a random polyether, the functional additive is a spherical carbon material, and the random polyether is at least one selected from isomeric tridecanol random polyether, propylene glycol random polyether, glycerol random polyether, butanetriol random polyether, lauric acid random polyether, and dodecanol random polyether; the glycerol random polyether is glycerol random polyether 3000; The mass ratio of the zinc powder, the binder and the functional additive is (0.5-2):(0.3-0.8):(0.5-2).

2. The high-utilization high-stability zinc electrode according to claim 1, wherein the functional additive is at least one selected from nano-carbon black, fullerene, activated carbon, and carbon microspheres. The method comprises the following specific steps:

3. A method of producing the zinc electrode of claim 1, characterized in that, S1: mixing zinc powder, a binder and a functional additive with a solvent to form a slurry; S2: coating the slurry onto the surface of a substrate of a current collector and drying to form a functional coating; S3: cutting the dried functional coating into an electrode sheet to obtain a zinc electrode. The solvent is at least one selected from ethanol, methanol and water; 4. The production method according to claim 3, characterized by, The mixing is uniform mixing in a mixer or ultrasonic dispersion; The substrate of the current collector is carbon paper, carbon cloth, copper mesh or copper foil. The mixing is performed in a mixer, the rotation speed of the mixer is 5-20 rpm, and the stirring time is 2-10 h; 5. The preparation method according to claim 3, characterized in that, The mixing is performed by ultrasonic dispersion, the power of the ultrasonic is 50-100 W, and the ultrasonic time is 5-40 min; The drying temperature is 60-100℃, and the time is 1-10 h.

6. A zinc-containing battery or zinc-based energy storage device comprising the zinc electrode of any one of claims 1-2 or the zinc electrode prepared by the method of any one of claims 3-5. The zinc-containing battery or zinc-based energy storage device is a low N / P zinc-based battery.

7. The zinc-containing battery or zinc-based energy storage device of claim 6, wherein, 8. Use of the zinc electrode of any one of claims 1-2 or the zinc electrode prepared by the method of any one of claims 3-5 in the preparation of a zinc-containing battery or zinc-based energy storage device. The zinc-containing battery or zinc-based energy storage device is a low N / P zinc-based battery.

9. Use according to claim 8, characterized in that, ​

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