Preparation method of zinc composite electrode and application of zinc composite electrode in aqueous zinc ion battery
By hot rolling the zinc foil to expose its (002) crystal surface, the dendrite and corrosion problems of the zinc anode in aqueous zinc-ion batteries are solved, thereby improving the utilization rate of the zinc anode and the cycle stability of the battery.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-26
- Publication Date
- 2026-03-27
AI Technical Summary
In existing aqueous zinc-ion batteries, the zinc anode exhibits poor electrochemical reversibility and chemical stability, leading to dendrite growth and byproduct accumulation, which affects the battery's cycle life.
By hot rolling the zinc foil to expose its (002) crystal plane, the strength ratio of the (002) crystal plane to the (101) crystal plane is increased, thus preparing a zinc composite electrode with high strength.
It significantly improves the utilization rate of zinc anode and the cycle performance of battery, especially maintaining excellent cycle performance at high depth of discharge.
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Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the technical field of aqueous zinc ion batteries, and particularly relates to a zinc composite electrode with (002) crystal face exposure and a preparation method thereof and application thereof in aqueous zinc ion batteries. BACKGROUND
[0002] Energy storage is crucial for ensuring the reliability of power grid systems and renewable energy. Aqueous zinc ion batteries (AZIBs) have attracted much attention due to their high abundance, low toxicity, low reduction potential, high hydrogen evolution overpotential, high theoretical capacity (mass capacity of 820 mAhg -1 , volume capacity of 5855 mAh cm -3 ), low redox potential and high inherent safety provided by aqueous electrolyte, and are a promising battery candidate. However, the development of AZIBs is still limited by the poor electrochemical reversibility and chemical stability of metallic Zn in aqueous electrolyte. These problems, including the hydrogen evolution reaction (HER), dendrite growth and byproduct accumulation, easily lead to the reduction of the cycle life of the battery. Therefore, it is crucial to explore simple and effective methods to realize a zinc anode with high reversibility / stability for AZIBs. It has been reported that the problems can be solved by designing a hierarchical structure of Zn, constructing a passivation layer on Zn, regulating the exposed crystal face and electrolyte formula. In these strategies, controlling the crystallographic orientation of the Zn anode to Zn (002) is an effective means to inhibit Zn dendrites. Since Zn (002) is conducive to the uniform deposition of zinc, it reduces the chemical activity with the aqueous electrolyte, thereby improving the electrochemical performance of the zinc anode. However, the currently reported methods for regulating the Zn (002) crystal face are too cumbersome and are not conducive to large-scale preparation and application. SUMMARY
[0003] In order to facilitate subsequent large-scale application and practicality, the application discloses a zinc composite electrode with (002) crystal face exposure and a preparation method thereof and application thereof in aqueous zinc ion batteries. The zinc composite electrode is obtained by heating and rolling a zinc foil on a current collector by a rolling machine. The heat rolling treatment of the zinc sheet in the application promotes the exposure of the (002) crystal face of the zinc foil, and the intensity ratio of the (002) crystal face to the (101) crystal face is as high as 4.28. The super-high (002) crystal face overcomes the defects of zinc anode dendrites, passivation and corrosion in aqueous zinc ion batteries, and significantly improves the utilization rate of the zinc anode. Even at a high discharge depth of 50%, the zinc anode still has excellent cycle performance.
[0004] The purpose of the application is achieved by the following technical solutions: The application provides a preparation method of a zinc composite electrode with (002) crystal face exposure, comprising: rolling a zinc foil on a current collector by a high-temperature rolling machine to prepare a zinc composite electrode with (002) crystal face exposure.
[0005] In the technical solution, further, the thickness of the zinc foil is 10 µm~50 µm.
[0006] In the technical solution, further, the temperature of the rolling is 100℃~300℃.
[0007] In the technical solution, further, the temperature of the rolling is 140℃~150℃.
[0008] In the technical solution, further, under a certain roller speed, the zinc foil is tightly attached to the surface of the current collector, and is rolled out from the roller gap as the speed increases, which is regarded as rolling once. Under the same conditions, the rolling is repeated for 15~20 times in one direction. The roller speed is 3-10 r / min, preferably 4-6 r / min.
[0009] In the technical solution, further, the current collector comprises one of a titanium mesh, a stainless steel mesh, and a copper mesh.
[0010] The application further provides a zinc composite electrode prepared by any of the above preparation methods.
[0011] In the technical solution, further, the intensity ratio of the (002) crystal face to the (101) crystal face of the zinc composite electrode is 2~5.
[0012] The application further provides an application of the above zinc composite electrode to a negative electrode of a water-based zinc ion battery.
[0013] Compared with the prior art, the application has the following beneficial effects: The method is low in cost, simple in operation, and environmentally friendly, and is suitable for large-scale production.
[0014] The application promotes the exposure of the (002) crystal face of the zinc foil by hot rolling, and the intensity ratio of the (002) crystal face to the (101) crystal face is as high as 4.28. The super-high (002) crystal face overcomes the defects of dendrite, passivation, and corrosion of the zinc negative electrode in the water-based zinc ion battery, and significantly improves the utilization rate of the zinc negative electrode. Even under a high discharge depth of 50%, the zinc negative electrode still has excellent cycle performance. BRIEF DESCRIPTION OF DRAWINGS
[0015] Figure 1 XRD curves of the zinc composite electrode of Example 1 and the zinc negative electrode of Comparative Example 1 after the zinc foil is hot-rolled 20 times at 150℃; Figure 2 Battery cycle performance of a zinc-zinc symmetric battery assembled by the zinc composite electrode of Example 1 and the zinc negative electrode of Comparative Example 1 at a discharge depth of 50%; Figure 3The zinc-iodine full cell assembled with the zinc composite electrode of Example 1 and the zinc negative electrode of Comparative Example 1 has a positive electrode loading of 20 mg / cm³. -2 The full-cell cycle performance with a current density of 1 C and a negative electrode capacity / positive electrode capacity (N / P) ratio of 3 / 1; Figure 4 The XRD curves of Example 2 and Comparative Example 1 are shown below after zinc foil has been hot-rolled 15 times at 150°C. Figure 5 The cycling performance of the zinc-zinc symmetrical battery assembled with the zinc composite electrode of Example 2 and the zinc negative electrode of Comparative Example 1 at a current density of 50% and a discharge depth of 50% is shown. Figure 6 The zinc-iodine full cell assembled with the zinc composite electrode of Example 2 and the zinc negative electrode of Comparative Example 1 has a positive electrode loading of 20 mg / cm³. -2 The full-cell cycle performance with a current density of 5 C and a negative electrode capacity / positive electrode capacity (N / P) ratio of 3 / 1; Figure 7 The XRD curves of the zinc composite electrode of Example 3 and the zinc negative electrode of Comparative Example 1 after zinc foil has been hot-rolled 25 times at 150°C are shown. Figure 8 The XRD curves of the zinc composite electrodes of Comparative Example 2, Example 4 and Example 5 and the zinc negative electrode of Comparative Example 1 after zinc foil has been hot rolled 20 times at 80℃, 100℃ and 200℃ are shown. Detailed Implementation
[0016] The following detailed description, in conjunction with specific embodiments, provides further insight into the invention. It should be understood that these embodiments are illustrative and not intended to limit the scope of the invention. The implementation conditions used in the embodiments may be further adjusted based on specific construction conditions; implementation conditions not explicitly stated are typically those used in routine experiments.
[0017] Example 1 A method for preparing a zinc composite electrode with (002) crystal plane exposure includes: rolling a 20 µm Zn foil onto a titanium mesh using a roller press at a temperature of 150°C for 20 times; the rolling process is performed by pressing the zinc foil tightly onto the titanium mesh at a roller speed of 5 r / min, and rolling it out from the roller gap as the speed increases, which is considered as one rolling operation. The rolling is repeated 20 times in one direction under the same conditions to finally obtain a zinc negative electrode with (002) crystal plane exposure.
[0018] Comparative Example 1: Commercially purchased 20 µm zinc foil without any treatment.
[0019] XRD characterization: The crystal structure of the zinc anode surface was characterized by X-ray diffraction. Figure 1 As shown, it can be seen that the intensity ratio of the (002) crystal plane to the (101) crystal plane of the zinc composite electrode of Example 1 after treatment increased from 0.29 to 4.28.
[0020] Zn||Zn symmetric cell assembly method: the cell was assembled in the following order: positive electrode shell, 12 mm diameter zinc negative electrode, 19 mm diameter GF / D glass fiber separator, 130 μL of 2 M ZnS04electrolyte, 12 mm diameter zinc negative electrode, gasket, spring, negative electrode shell, and packaged under a pressure of 1.0 T.
[0021] The assembled aqueous zinc-ion symmetric cell was tested for cycle stability under 50% depth of discharge conditions as shown in Figure 2 Figure 2. The (002) plane exposed zinc composite electrode of Example 1 corresponding Zn||Zn symmetric cell can be stably cycled for 105 h under 50% depth of discharge conditions. But the Zn||Zn symmetric cell of Comparative Example 1 zinc negative electrode cycled for 45 h, the cycle life is lower than the (002) plane exposed zinc negative electrode. It shows that the (002) plane of the zinc composite electrode of the present application helps to improve the cycle stability of the cell.
[0022] Positive electrode material preparation method: 500 mg of iodine and 500 mg of Ketjenblack were weighed according to a weight ratio of 5:5, ground in a mortar for 30 min, transferred to a glass bottle and then put into a hydrothermal reactor, heated at 90°C for 6 h, and the iodine was immersed into the Ketjenblack by sublimation, called I2@C. Then 700 mg of I2@C, 200 mg of Ketjenblack and 100 mg of PTFE emulsion were weighed according to a ratio of 7:2:1, ground in a mortar for 30 min, and then a glass rod and a cutting knife were used to roll the iodine positive electrode into a 12 mm diameter disc. The iodine positive electrode was then dried and pressed onto a titanium mesh current collector using a tablet press, with a loading of about 20 mg cm -2 .
[0023] Full cell assembly method: the iodine positive electrode with a diameter of 12 mm was used as the positive electrode material, the (002) plane exposed zinc composite electrode of Example 1 with a diameter of 12 mm and a thickness of 20 μm and the commercial zinc foil were used as the negative electrode material respectively, the separator was a GF / D glass fiber separator with a diameter of 19 mm, and the electrolyte was 130 μL of 2 M ZnS04, and the cell was packaged under a pressure of 1.0 T.
[0024] The assembled aqueous zinc-iodine full cell was tested for cycle stability under 1 C conditions as shown in Figure 3 Figure 4. The zinc-iodine full cell corresponding to the (002) plane exposed zinc composite electrode of Example 1 can be stably cycled for nearly 1300 cycles under 1 C conditions, with a specific capacity maintained at 220 mAh g -1 . But the zinc-iodine full cell of Comparative Example 1 has poor stability and a cycle life lower than the (002) plane exposed zinc composite electrode. It shows that the (002) plane of the zinc composite electrode of the present application helps to improve the cycle stability of the cell.
[0025] Example 2 The preparation method of Example 1 was followed, with the exception that the rolling was performed 15 times, and a (002) plane exposed Example 2 zinc anode was finally obtained.
[0026] XRD characterization: The crystal structure of the surface of the zinc anode was characterized by an X-ray diffractometer as shown in Figure 4 It can be seen that the intensity ratio of the (002) plane to the (101) plane of the treated Example 2 zinc composite electrode was increased from 0.29 to 3.99.
[0027] Zn||Zn symmetric battery assembly method: The battery was assembled in the following order: positive electrode shell, 12 mm diameter zinc anode, 19 mm diameter GF / D glass fiber separator, 130 μL of 2 M ZnS04electrolyte, 12 mm diameter zinc anode, gasket, spring, negative electrode shell, and packaged under a pressure of 1.0 T.
[0028] The assembled aqueous zinc ion symmetric battery was tested for cycle stability under a discharge depth of 50% as shown in Figure 5 Under a 50% DOD condition, the (002) plane exposed Example 2 zinc composite electrode corresponding to the Zn||Zn symmetric battery can be stably cycled for 90 h. However, the Zn||Zn symmetric battery of Comparative Example 1 was cycled for 45 h, and the service life was lower than that of the (002) plane exposed zinc anode. This indicates that the (002) plane helps to improve the cycle stability of the battery.
[0029] Positive electrode material preparation method: 500 mg of iodine and 500 mg of Ketjen black were weighed according to a weight ratio of 5:5 using a balance, ground in a mortar for 30 min, transferred to a glass bottle and then placed into a hydrothermal reaction kettle, heated at 90°C for 6 h, and the iodine was immersed into the Ketjen black by sublimation, which is called I2@C. Then 700 mg of I2@C, 200 mg of Ketjen black and 100 mg of PTFE emulsion were weighed according to a ratio of 7:2:1, ground in a mortar for 30 min and then a glass rod and a cutting knife were used to roll the iodine positive electrode into a 12 mm diameter iodine positive electrode disc. Then the iodine positive electrode was dried and pressed onto a titanium mesh current collector using a tablet press, with a loading of about 20 mg cm -2 .
[0030] Full battery assembly method: A 12 mm diameter iodine positive electrode was used as the positive electrode material, a (002) plane exposed zinc composite electrode with a diameter of 12 mm and a thickness of 20 μm and a commercial zinc foil were used as the negative electrode material, a 19 mm diameter GF / D glass fiber was used as the separator, and 130 μL of 2 M ZnS04was used as the electrolyte, and the battery was packaged under a pressure of 1.0 T.
[0031] The assembled aqueous zinc-iodine full cell was tested for cycle stability at 5 C as shown in Figure 6 The zinc-iodine full cell corresponding to the zinc composite electrode of Example 2 with (002) plane exposure can be stably cycled for 2500 cycles with a specific capacity maintained at 156 mAh g -1 However, the zinc-iodine full cell assembled with the zinc negative electrode of Comparative Example 1 was cycled for only 600 cycles, with a lower cycle life than the zinc composite electrode with (002) plane exposure. This shows that the (002) plane of the zinc composite electrode of the application helps to improve the cycle stability of the battery.
[0032] Example 3 The preparation method of Example 1 was followed, except that the rolling was performed 25 times, and finally a zinc negative electrode of Example 3 with (002) plane exposure was obtained.
[0033] XRD characterization: The crystal structure of the surface of the zinc negative electrode was characterized by X-ray diffractometer as shown in Figure 7 It can be seen that the intensity ratio of the (002) plane to the (101) plane of the treated zinc composite electrode of Example 3 is 4.1. Compared with the 20 times of rolling of Example 1, increasing the number of rolling times on the basis of 20 times did not significantly improve the exposure intensity of the (002) plane.
[0034] Comparative Example 2 The preparation method of Example 1 was followed, except that the rolling temperature of the rolling machine was 80°C, and finally a zinc negative electrode of Comparative Example 2 with (002) plane exposure was obtained.
[0035] XRD characterization: The crystal structure of the surface of the zinc negative electrode was characterized by X-ray diffractometer as shown in Figure 8 It can be seen that the intensity ratio of the (002) plane to the (101) plane of the treated zinc composite electrode of Example 4 is 0.32. It can be seen that when the temperature is not satisfied, the (002) plane cannot be exposed in large quantities.
[0036] Example 4 The preparation method of Example 1 was followed, except that the rolling temperature of the rolling machine was 100°C, and finally a zinc negative electrode of Example 5 with (002) plane exposure was obtained.
[0037] XRD characterization: The crystal structure of the surface of the zinc negative electrode was characterized by X-ray diffractometer as shown in Figure 8 It can be seen that the intensity ratio of the (002) plane to the (101) plane of the treated zinc composite electrode of Example 4 is 3.39.
[0038] Example 5 The preparation method of Example 1 was followed, except that the rolling temperature of the rolling machine was 200°C, and finally a zinc negative electrode of Example 5 with (002) plane exposure was obtained.
[0039] XRD characterization: The crystal structure of the surface of the zinc anode was characterized by X-ray diffractometer as shown in FIG. 6. It can be seen that the intensity ratio of (002) crystal plane to (101) crystal plane of the treated Example 5 zinc composite electrode is 4.2. When the roll pressing temperature is increased to 200°C, the exposure intensity of (002) crystal plane is not significantly increased. Figure 8
[0040] The above is a further detailed description of the application in combination with specific examples, and the specific implementation of the application cannot be limited to these descriptions. For those skilled in the art of the technical field described in the application, any obvious simple deduction or replacement without departing from the concept of the application is within the protection scope of the application.
Claims
1. A method of producing a zinc composite electrode having (002) plane exposure, characterized by, The application relates to a zinc composite electrode with exposed (002) crystal faces. The zinc foil is rolled on the current collector by high temperature to prepare the zinc composite electrode with exposed (002) crystal faces.
2. The production method according to claim 1, characterized by, The thickness of the zinc foil is 10-50 microns.
3. The production method according to claim 1, characterized by, The temperature of the rolling is 100-300 DEG C.
4. The production method according to claim 3, characterized by, The temperature of the rolling is 140-150 DEG C.
5. The preparation method according to claim 1, characterized in that, The rolling times of the rolling are 15-20 times.
6. The method of claim 1, wherein, The current collector comprises one of a titanium mesh, a stainless steel mesh and a copper mesh.
7. A zinc composite electrode characterized in that, The zinc composite electrode is prepared by any one of the preparation methods in claims 1-6.
8. The zinc composite electrode according to claim 7, characterized in that, The intensity ratio of the (002) crystal face to the (101) crystal face of the zinc composite electrode is 2-5.
9. The zinc composite electrode in claims 7 or 8 is applied to a water-based zinc ion battery negative electrode.